a study of ruthenium 106 as a beta source in radiation ... ·...
TRANSCRIPT
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A STUDY OFRUTHENIUM 106 AS A BETA SOURCE IN
RADIATION THERAPY
Russell B. Buchanan, Jr.Captain, U. S. ArmyRadiological Defense Engineering Prog
1951
a stmt or smmm 106 as a bra
III 8ADIATI0* THEflAFI
A Thoo-U
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By
WB31U. mnerr wxxm*, jr., b. 1. s.
Hid Ohio 3t**t Univ«rtit*
Approved fejr»
William a. kyar#, Advisor
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IaoA4anUl JSqalpaant. * .
Bata Say Paa»iratie» Pattawsin Watar Ffcantoi . , .
Biological Iffartt i . i
Fraparatio* of a TharapautJLc Applicator
Bat* Bar Paaetratloft Patternin {uiw rnswi « « • <» * • •
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k STUM 'UiliM 106 AS A B«TA SOT
XX sADXATXOS THEfcAPT
irogagcnQg
It is the purpose of this paper to present a study of
the properties of the radiation* emitted by Ruthenium 106 and
its daughters as applied to the therapy of the external lesions
of cancer, various varta and moles* and such ether surface dis-
turbances of the body as nay be responsive to irradiation.
The generally accepted current medical practice is to
treat these abnormal conditions by surgery (excision or cauterisa-
tion) , by the use of various shemotherapeutie agents (very limited
in caster and scope ) t or by irradiation of the affected area when
other methods are not considered practicable. Surgery and, to n
lesser degree # chemotherapy are frequently considered impractica-
ble* ' for a number of reasons!
1* The position of the growth r*adi9TB surgical
approach difficult without high mortality or crippling
Nats
2. The growth may be too extensive*
3* Metastases may be present.
4* The poor irsneral health of the patient due
to cardlo-vaaeulnr or renal disease , obesity, or
debility from old age.
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5* The patient asy, for his ana reasons, refuse
surgical treatment*
According to statistic* compiled by the Swedish Cancer
Association, only one-third of ell cancerous eendltieae cowing
under medieal supervision arc suitable for surgery f and, of those
who undergo surgery, only one-third (1/9 of the total) show other
than temporary, short-lived relief* One must also consider all
of the noncancerous conditions, many of which are not suitable
for surgery. It is, therefore* frequently neoessery to employ one
or Bore of the various methods for radiation therapy* Currently*
the most commonly employed radiation sources are X-ray machines
and radium for gamma and/or beta-ray treatments* Any of these
methods involve essentially the same hacards an are found in the
deep Irradiation therapy of malignant growths which cannot be
reached by the short-range beta particles. This is true even of
the radiun beta ray applicators since the beta-emitting daughters
of rediun are oaintained in equilibrium with those emitting gamma
rays, and thus produce a dean irradiation field whleh is unnecessary
la the treatment of surface lesions, and is undesirably detrimental
to the normal tissues of the patient and to the health of the attend-
ing physician. The euoeei* fa treatment of any malignant or disfig-
uring erowth by Irradiation depends upon the administration of s
quantity of radiation suffielent to produce nermannnt arrest of the
growth without causing extensive damage to the underlying normal
tissue which is essential to proper repair* Where usable, surface
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Irradiation baa the distinct added advantage la that no surgical
or anaesthetic risks mao be taken*
Fortunately* daring the treatment of a surface lesion, the
X-ray or gamma ray dose received by both the patient and the radiol-
ogist is not normally sufficient to induce either the acute or the
chronic tyre of radiation sickness* the patient, having received
his treatment, leavts the radiation field and, therefore, discontin-
ues his exposure. This is not true of the attending physlolem*
however, for he must also expose himself during the preliminary
preparations for a treatment and again afterward in returning the
source used to its place of safe storage (when sources other than
X-ray machines are need). In addition, it most fee considered that
a busy radiologist will expose himself In this *«me manner many
times during a single day, and that this daily exposure Is continued
throughout the year. The proof that many of these doctors do receive
an Injurious dose leading to chronic radiation injuries may he soon
in the lares numhor of radiologist* And dentists who have been com-
pelled to underfo amputation of finders, and even of hands, in the
malformed fingernail structure of others* and in the frequently
observed pigjmmtation changes, loukemias, aplastic anemias, and
high incidence of carcinoma observed in pioneer radiologists(4)
,
Zt has definitely heen shown that chronic exposure to nuclear
radiations, even at low dose levels, is carcinogenic'*'.
It is, therefore, essential to develop some new source
or sources of mildly penetrating radiation for treatment of these
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surface lesione, vbiob vill not Include tfa© serious gamma-ray
haaard incidental to the use of radium sources for beta particles*
Another advantage of employing beta ray sources other than radium
derivatives la the elimination of the gas-leek hasard, union ia ao
dangeroua ia radius work* For this purpose, many inveetlgatore nave
been examining the table of isotopes, particularTyr those fiaaion
products available in relatively large quantities fro* nuclear
reactors, In an effort to find beta-emitting materiale with a
suitable penetrating power and half-life, with a ainimue of elec-
tromagnetic radiation, Of the various isotopes investigated to
date, the current favorite ia the strontium 9®-yttriu» 90 family,
of which the effective beta particle has a amxiuBuw energy of B*l
Mev. However, with appropriate filtering to eliminate the low
energy 0*63 Mev particle emitted by Br 90, the intensity of the
radiation field falls to 50$ of the surface dose in 0.3 milli-
neters of tiesmt' 3*', as shown ia Figure 7. Since the effective
penetrating depth ia aoft tissue of this bete particle la fairly
low, and, therefore, only very superficial leaions will be reached
by it, it ia desirable to find sane other bete source which pea-
ses, es a greater penetrating power, thereby requiring a lower
total surface exposure to the lesion to achieve the some thera-
peutic reeult. Thia would provide an appreciable reduction ia
tissue necrosis and the resultant ulceration and secondary Infection,
as well as a better cosmetic effect, aa the lesion heals*
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Slate high-energy *eta particles? i:*ipinflag on the
meta] lie portions of the »rrllc*tor holdom currently Id we
produce a rather high Bremsstrahlung flux, it Id oleo desirable
to develop holders whleh will minimise thin effect. In addition,
the «t r-licRtore should be designed in such a manner ss to provide
for eaey mounting on the patient without requiring the physician
to bold them in place at la the eaee with the current St 90 appli-
cators.
It la with theae faetora in mind that N is study, designed
to explore the advantageous physical properties of Ku 106 with a
view to the advantageous utill at! on of then in radiation therapy,
was initiated* Included herein are data showing the intensity
distribution of the beta field surrounding varl©us En 106 sourest
in tissue equivalent phantoms, information concerning the relative
X-ray and gamma ray output when the emitter is electroplated on
various plating bases, sons Information on the physiological effects,
at well at aethods for measuring the penetration of beta particles
la tissut phantomt.
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hu 106 waa selected as a possible radiation source
for this work due to the conveniently high energy of the beta
particle from the daughter element Rh 106, the eomperetivcly
constant output incidental to Ita ona year half-life, the
extremely low g*mme~ray output relative to a radius aouree of
the earn? beta intensity, and due to the absence of any gee-leek-
age problem. In addition, ruthenium, unlike strontium(^), does
not deposit la the skeletal structure when aocldenteily ingested;*
The decay scheme of the Ru 106 family is^3)|
n 1 1 i« n l>i iJTtBw i 1 11 ^» 11 Vmf*iwmmmmmmmmammmJmStMmm i 1 1—«——<m—»U heta Q.oa Kev 45 beta)\
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The beta particle from Ku 10© la of very low energy. That portion
which Is not eliminated by self absorption within the source
proper can be readily screened out of the effective radiation
field by a thin plastic film which will not appreciably attenuate
the dealred beta field. This nay be readily seen by comparison
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of thir ranre of the two particles* The 3*55-Mcv particle has a
rang* of 1.924 g»/eq em, while the 9*0£UM*r particle has a range
of lea* than 0*004 gn/eq em*
At part of the general aim of thia project, an effort waa
»ade to determine the relative levels of Bremsstrahlung emission
from the various plating bases* For eleotron energies In the neigh-
borhood of 100 Key, the efficiency of conversion of electron eaergy
to X»ray energy la directly proportional to the atomic number*
That thia la not directly applicable to electrons of higher energy
la substantiated by experimentel work now in pr*gr**9 at the labora-
tories of the General Hoctrio Company* However, Indications are
that the final relationship, whan developed, will ahow that the
conversion efficiency for those higher energy eleotrone will bo
eoae function of the atonic nwaber of the target material, such
that the use of a target of low atomic number will produce less
X-ray output than will targets of high atonic number* Gold, copper,
and beryllium were selected for study in this aspect.
The specific Hu 106 aources employed in this study wore
furnished from the Isotopes Division, Oak Ridge national Laboratory*
Since QH1IL does not specify the exact quantity of material provided
in any shipment of this nature, the amounts specified herein are
only within the accuracy of the information provided on the shipping
papers from 0RKL.
floaraa li 7. nC Ru 106 electroplated on a gold disc 0.01
inch thick and 1 inch in diamter. Sxperiaoatal evidence encountered
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la tbette tent* thawed that the Ru 106 was sot uniformly plated
thereon (Figure 1)» Data vat not taken from this disc due to
the unsatisfactory nature of the emitting surface*
faurme 2 . 3 uC Ru 106 electroplated on a got per disc
0.01 Inch thick and 1 inch In diameter. Again, experimental
evidence showed a lack of uniforaity in pitting the sample oa
the dlec (Figure 2), although thie aausf le was efficiently sat-
iefactory to permit the taking of data therefrom* It la believed
that both sample* were probably plated oa material which had net
received adequate preparation and, possibly, at too high a deposi-
tion rate*
Fig, !• Source 1*Autoradlograpb of source laapplicator holder* Motethe uneven plating of thefia 106.
Fig. 2. Source 2*
Autoradiograpb of source laapplicator holder* Hots thatthe Ru 106 is more evenlyplated hare*
Sourea 1 i This source has not yet been delivered from
ORKL* It has been requested that 3 mC Ru 106 be plated oa s
beryllium disc 1 aa thick and 1 inch la diameter* Although
beryllium is s difficult sad haaardous material with which to work'2*',
it was selected as the material with the lowest atonic number with
which to carry out these tssts satisfactorily* The range of the
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3*55 Mev beta particle in beryllium Is U.l mm* Sine* thia
beryllium diss should be covered with about I w of U to i
convenient handling case, essentially all the beta rays frmm
this sours* will be completely stopped within the source proper*
This will eliminate any beta hasard from back radiation to the
radiologist who nay be called upon to manipulate it, and will
also sake the applicator a convenient else and weight to bo
fastened directly to the area to be irradiated* The light-
weight feature is highly desirable in that* although surface
growths of the type to be tr»at»d with this applicator are *:ot
normally supplied with neural fibers • pressure on the lesion
transferred to the surrounding tissue can sense the patient
considerable iasomfort*
Blag Ironic Circuital
The electronic circuit employed la this study is cms
(31)designed by A* 0* Jfier ' for use in a mass spectrograph, and
modified for use as s d.c. amplifier with miniature ionization
chambers by D* T* Sggsn* who also did the initial construction
work on the instrument. Or* Eggen's modification merely con*
slsted of employing one channel of Dr, Xlsr*s circuit and modi-
fying the filament supply of the amplifier to provide the propw
current for half as many tubes in series*
Since th« equipment had been in deed storage for some
time prior to the beginning of this prelect and had been rather
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badly mishandled during that period, it wat aeceeeary to rebuild
« large portion of the ayatem before it could be placed la oper-
ation* In apr lying this instrument to the work with ruthenium, it
wa« neceaaary to introduce ea additional 100,000 ohm realstor
into the feedback aad watering circuit la order to desensitise
the system to the point where it could properly handle the signal
strength obtained.
For the assistance of others who may employ this system,
operating voltagea are shown on the circuit la Figure 3* Caution
must be used to insure that the high voltages are uot applied to
the preamplifier until its cathode has had at least thirty seconds
to warm* It Is also advisable to permit the entire electronic
system to warm for several minutes to establish the stability
required for this work* Shielding is necessary on the cable from
the preamplifier to subsequent stages as there is enough cable
pickup to make the unshielded system unstable* It is also neces-
sary to establish aa electrical connection between the mercury-
water system (see discussion of phantom) and the amplifier, sines
the ohanging electric field and static eharge developed while the
mercury is flowing will otherwise drive the meter off scale,
requiring several seconds for the system to discharge • For this
purnose 9 it Is recommended that the connection be made to the
outer electrode of the chamber for the additional reasons discussed
under ion chamber windows*
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The ionization chamber und as a means of studying
the intenaity distribution ©f th«* bets ray field is shown la
Figure 4. Xt la supported from a plastic disc in the; preempllftar
housing, and la dir«etly corrected Into the preamplifier* Tha
chamber has a volume Qt 0.008 ml* Since X r/see la the equivalent
of 2M x 10 Ion paire/eec/iBl, or one atatcouloab/eec/«l, 1 r
for this chamber volume la 7*416 a lCT1* amperes. Thla would
glv« a signal Input to tha grid of tha preamplifier of 7.416
av/r/aee, and If oaa vara to uaa a aouroa of 100 r/see, tbe ^rid
awing of 0.7 volts wo ild atill be within that allowable for tha
VX-*U~A used.
Various window materials vara triad with this chamber,
and tha ohaabar was also triad as an open-ended ohaabar* This
latter proved to be unsatisfactory since water vapor from the
surface of the phantom aborted tha chamber* The moat satisfactory
window material used waa 0*002 inch Zepoa* Plaatloa each as
Zapoa are so close to the stopping power of water and are so
thla that they need not be taken into account in computing the
reduction in bean intensity by passage through the water phantom*
aluminum windows were tried and found to be unsatisfactory.
Electrolytic ectlon In the phantom teak rapidly produced pin-
bolea in tha window, which resulted In the short-circuiting of
the chamber* Thla affect waa partially eliminated by placing
the entire bath at the aame potential aa tha window , but-15-
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aluesinuw continued to enter Into solution, although
slowly, to produce punctures In the foil.
sr; Heater Md«»
The applicator holder used la these test* (Figure 5)
van designed to take advantage of the low atomic number of elusd-
nun in the production of -radiation* The actual structural
design was as shown to pormit easy and rapid changes from one
source to another, as well as to permit the taking of data on
one type of beam collimator (the scarce may be placed in position
at either end of the retaining cylinder)*
The beryllium* «se source may also be used in this
holder for comparison purposes • although such a massive construe*
tion would not be used in therapy*
7o determine the penetration pattern of the hh 106 bets
particles in tissue, It vws necessary to devise some met. od of
simulating tbe stopping power of soft tissue, since the use of
tissue itself is not practicable* Water is commonly used for
that purpose^,16,30,36), mn(j ^%a m9& b#re*
In ti is system, thero also had to be included provisions
for accurately varying the position relationship between the
emitting surface and the measuring device (ion chamber), provision
for measuring these variations, and safety measures for protecting
~17-
m» Of frfv;
.»:.. Mr1
-
*•! tow tU*<*-;^jt «,,*!*
.-**> 1 1NT BTIftttlC *Jw I
APPLICATOR MOLDCR
All pa.rts a^rt AlummwrA except
i **&
O.OOZ. Ration
O.I2^" \
O. /^J"
J| kvi m rod
i" r^
O .0\ Source Pi$c
Coaled uJitb Ku
due ^
/="/? 5"
-£-
the operator fro* the high bote flux involved*
The aye tea ee stowa la Figure 6 was finelly evolved
after trial of several variations thereof. Sinee mechanical
systems are vulnerable to the corrosive effects of water and
electrolytes, frequently develop leaks, and contain inherent
backlash and other neeheudeal difficulties, it wee decided to
employ a hydraulic system to drive the .oving parte of tv ie
acehanisr.. The t«ck need was e rises cylinder, 9. 56 on Inside
dle&etrvr, and ID em long* this was mounted on a half-inch
Plaglglas sheet drilled as shown, and fitted vith glass nipples
for attachment of the mercury reservoir and a bottoa drain for
removing mercury without reaoving water or otherwise disturbing
the system. A F^exlglas stage was used upon which the applicator
was aountod This whole assembly plus the phantoai water • vat then
floated on the mercury surface* The seal* on the side of the tank
is divided Into millimeters, and can, therefore, be read to the
nearest 0*1 mm with the aid of a suitable Magnifying lens. Thus,
by adding or substreeting oercury from the system and reading the
position of the Flexiglas stage* it Is possible to da terai* • the
position of the scarce relative to the lea chamber* Xf greater
accuracy or acre finely spaaed readinga are desirable, it is mere-
ly necessary to eonputs froa the physical dimensions of the teal
the voltasa of aeroury which Bust be added or taken away to provide
the desired variation in source-chamber spaaing* When employing
the volumetrio addition of mercury* constant temperature must
•19»
' «av 4 * mm x**is>\,* mdX
?*«..*».*. j. *wm V> I hit:- i-iU
4 MK
o* -*. * .. *.-•* .•* , i• *.* *: *•;: Himrn iu4IM &.* fttl >**
• rto
Ml * M fcv
I O04V INMKF MIT /:;• if» fCltTT f^ 1 .nfcts^a *H#
I ^ItfMMM f>torfv. ,' b v*8.MOC MV
*» >« aC \*.<% iwvum mdi am bmimml\
Orf* »&':&«•* I-JI . I»J _^ ;!Ai y.-U r«tt v* ;*lMft r !
"
^*** •rft 4# — art o#i«*a«» o# fin—mm yj.
<oi/>
•*1l/t
tf
rf <J->
u \(A Q_ _ T-,<r-^
„ \
\ \CO
\Jriiiiniiiiiiiiiii -
3-5\ \
o \ \iz<
-*""*
Id
r\ \a- -91 Os^Cautf
v -
uiOCO \ \D
to
\ \h g
<*>
1
\
\\
\
\
i
^j (j/ V-
/«1
<4
y»
5L6
he naintftined to prevent expaselos errors* For accuracy require*
aente within tbt lii&its of th* tank scale, acrenry la introduced
fron a separatory funnel aa a convenient reservoir. Whore greater
accuracy requirements oaoaaaltata the voluaetric addition of
aereury, a burette la substituted for the funnel. Peraca* who
nay employ this ayr.tea ara cautioned that tho burette *ast have a
long stopcock, alnea a abort l ?*ock will he 't by the
pressure of tba mercury column |a tha burette. It la »lao aug~
gaatad that all hoaa connections be clamped and la«c\arad to
prevent aplllinp ctarcury. A traversing doviec for tha ion chamber
wan alao provided to facilitate reproducible readings at all
points of the arplica tor surface. A alphon arrangement (not
ahown) waa alao provided for convenience In removing water from
the tank during operation without exposing tha operator to tha
radiation field, k light waa mounted behind the tank to improve
visibility. To add contrast between the Plexiglaa stnf© and the
water* a blue dye waa added to the water. This greatly facilitated
aeaaurenent and reduced eyeatrain.
Other equipment used for gaaemv-ray readings » autoradio-
graphs, and the adjustment of the electronic aycten ware of the
variety standard in any pkysics laboratory and nerit no special
mention or description here.
<4sV
iwasb* m» wis
oiw toot vui,^ it ttwnMb *xutt *«mi •JJsnsrf «-v tmd* bmavltomm mxn 3** •<-<(» aid* fi^t fM
, ^*?w? erf* oi —In i \wm« «s* *» •wmviq
ci fcvcorpMi lot t iiyi i l » «r iiihiI»iii—u —*d Urn tadi ft**t«§
mi. m4i
—
t
l«i *l*tmb*vm% *tatMiami mi bmbiroiq mmlm ut#•*) tmmmmwn* mrndqlm A •mmmtan *• »*tlwi md* *5© aisicq
*am a* •ttftfeMWtt* vtl trtlt^n 09JU turn (aworft
•If •# v
****** ** **** *U bm> -m mv M^ll A ,bl»n .^ilclbtt
•Af boa a»a#a ulabnis; w<# naaWarf *M*t«o9 {** oT .x#«l./10v
«a\t»a*aiM ,ionib^/i \ bM>
•*** '•' a*av a**anft • ad> 1o Jnmnfwibm wU bum % <
imlmmmm mm IJNa* ho* ., •oiartod
-a
^.ttra in, Wittr, ftantaH
The equipment for thia portion of the study vu arranged
• described* The actual measurement procedure, occasionally
modified slightly for special variations* was aa follows*
a. Preparation!
1. Balance and aero-act the awtorlog ay* tern. This was
ofaookod periodically daring all runs to insure continued satin-
factory operation*
2* Introduce auffielent mercury Into the tank to raise
the source to a convenient level for the test to be performed,
lowers* the ion chamber until contact is made with the surface
of the applicator*
b* Keasuiumanti
1* With the chamber In contact uith the applicator ,
record the meter reeding* This Initial reading is normally node
st the center of the ej plicator and is used as the "100$ of Surface
Dose" reference* Record, also, the position of the stage.
2* Move the ion chamber to other points on the surface
of the applicator end record the meter reeding and ^ceition date
et each point. These lateral potato et wv Ich readings are node
ere selected to provide date which will permit accurate determin-
ation of the penetration pattern.
•22-
"-. ,..--. .
MM
,a»fMft lidtottB *&.? $
|MmM^|| Hi* :'•' lft#M " n"
' ttttMft ^gy gfift „
;
i tAlMnec «! awfi—« f»t#J*t •**? »*!*• n i*?«kt ***
I * *0Q£" •** fii t>«ftv ai to* it&tati *««• «**# tn
•ftftflfft •*'? 1» ".':f'i «oq ftft> jtftUt^HMdl •ftftftyxoferi "ftafttf
fctt tffttftMV *ftftft «€M Jw«rr
oftM in ftfftMftftt rt» *ft«4f »*ifte« 4ftft* .r*
3. drain nercury fr<r* ih*- tank until th* deeired
aouroe-ehajRber apselug is obtained. Record the new stage portion
and the «eter reading* at each of the lateral positions selected
In Step 2*
4* Repeat Step 3 at aa a*ny positions aa nay ^* neceeeary
to obtain sufficient data to plot a curve of intensity versus dis-
tance for e«ah point on tha applicator arorfsea, The s^urco-chamber
spacing" la dsteraiwad aa tha difference betveen tha oontaet position
of tha atago and tha pooitloft at any given reeding. Dietsnee
intervals of 0*2 or 9 J an vara need up to ranges where tha intenaity
becaae less than 70% of tha surfacq intensity and where pattarn
fringe* were baing examined* Thi» was dona It locate tha femes of
tha curve accurately (Figure 7)* Greater intervals ara permiaaibls
thereafter*
5* For each readlnf obtained in Stops 3-4» compute tha
percentage of tha contact reading , using aa reference tha reading
obtained In Step 1. From tbaee data, plot isodose pattern* for
each source cfsploy^d (i.e., Figure 0)*
Autoradiographf! ware introduced into thic study to
provide the reader with visual conformation of some of tha informa-
tion determined during tha penetration »*a*ure»eote in tha tleaue
phantom*
-23-
Mt> *i•
• liftt' **
Ml
As was mentioned previously, the nonuniform!ty of source
plating la demonstrate 1 by Figures 1 and 2. Additional autoradio-
graphy vara prepared to eubstantlat* the iaodoaa patterns ©twined
by electronic messurement. Theee are included In the data auction,
along with photodensitoaeter readings obtained therefrom. These
vara prepared by stacking film to a depth equivalent to tha maximum
range of the beta partielaa and allying tha aourea to tha top of
that atack for tha Indicated period, or by mounting the* film
vertically between paraffin blooka and applying the aourea to tha
edge of the film. Each film layer with emulaton was measured to
have an average thiekneae of 0.223 n» and a density of 1.41 g»/ce.
Thua, each 0*71 mm of film has an equivalent stopping pewey of 1
an of tissue or water. Figure 7 demonstrates tha correlation be-
tween the deasitometric data and th* electronic data along tha axis
of tha ar plicator. Sines film enuliions undergo a saturation
affect st high intensitiesU0) f proper correlation at close ranges
is difficult to accomplish.
Exposures are indicated with each autoradlograph. Enfant
Type 508 It-ray film was used, sad was developed according to the
manufacturer's specifications U minute* in Du Font X-ray Developer}
10 minutes in Kodak X-ray Fixer) 69 degress F.).
Ths information obtained in the brief biological test
dons in conjunction vitb this study osnnet be considered adequate.
«snV
4*m*Mb« fmhi Iff>j| * bu i • *s-M - ifmtmtfm il v-^'-K
attvs'SJ HP "V- I.*/.*»'-' ; f - f ' *J «
a«tf e# fMm *f# *
•»•%) X mdb * hem tm
t» w**q »/il<pr.t» tjtt*/av!- r-.» an •* lr 'ami ? a*rf7
aer^WM'f a#GM> #j> b*» fa #•>
fa*** J br
wit OS aolb^»OM tiaocrwftf' «M» te ,k« «*v oil 1
* X»*«I IP? a^I
<*»C -/at-5. #«o* tA «1 ••ftml* >) a >aqa a'lvwtotffcKaai
!•*•*• WW an.' Mi na*la#ifo ooi^aenricJ' ttff
Tbt test was aerely perfonaed to obtain an Indication of the nature
of the biological reaction to a Ru 106 eource.
Source 2 was taped to the shaved back of a ronle rabbit
for a period of 15 hours and -CO nlnutes* for a total surface dose
of 23,930 rep* The rabbit was then observed periodically to deter-
in* any biological effects*
Stoli sad Sfflrartatfana
tAfftt of i
To prepare a therapeutic an Ileator vhieb will proviso
s dose rate suitable for clinical use* the physician's require-
seats Bust be considered* JBaob tuntor typo possesses its own
Minimum lctVT dose which must be applied to nsure
growth (6*17*2. \
eor*dition of the w^,.m
periods of treatment* In addition* evidence has been presented
whioh purports to show a relstlonsblp between the effectiveness of
the total doss and the rate at which it is applied*6 ). It is the
function of the physician to correlate thase factors and select
the optiausj total dose and optima* doss rats for a particular
pathological condition* This paper does not attempt to do this
for hla*
Included herein are the calculations to be used to
dotontine the activity for a specific treatment based upon
-25-
tint j *m^.-
.:« 0|J
Yofl'CiJxP-j II tod - .;.-1 tttaUlf» *&*
the desired total dose and the rate at which it is to he
administered.
Rh 106 has two decay paths for each of which separate
calculation must he nade to determine the actual energy trans-
ferred to an Irradiated area*
Assuming no Breasstrahlung to be present (introduced
later)* the rate at which energy is emitted from any beta source
1st
energy/sec • (number of beta particles emitted/sec)(average energy per particle).
gg 1 ergs/sec • W&M where K * number of mC present
1 number of particles emittedjmr mC
- 3.7 x 10?
k * conversion factor from Hevto ergs
• 1.6 x 1CT* ergs/Mev
I average energy per particle(Mev)
To obtain the dose rate in any medium in rep/sec 9 one
must use the rep as defined t 1 rep • 95 ergs absorbed per gram
of absorbent tissue* The mass of absorbent in any material 1st
ftp 2 gms « da£ where d • density
A • area of surface irradiated
& « range of partiole of average energy
Division of Eq 1 by Eq 2 then gives the dose rate of the
source material est
«JeV»
Mf ft* si #* *#*« v-s h/tr. e
. ••'•?. Mfci
ftJsts^fta d»M» t* rfftSS (•*•& Mrf SM* 'H?£ 48
-e tartf <*f*«S -;-*.*t>r Mb *lijrs*J«B •# staff s*l ^t
iirtvl us ft* bftv
Immmmni) #mmjmi *t 9$ vmHattomm • ?> pflwmi
MW»i *#•«* V* i«7 h«#*2s» ei ^pftse rfftlrfv #• olll •*# ,(?«*•£
Ml
s?tdv m I
••* ^ '* to mum MfT • M/oaiJ Jn*4?oHc?« to
s • • «tdv Ub 9 mm £ c4
S*1S • A
• i> *>o 1 n MJi Mjfl as-.' MM : 01 I .'.'". H NfcjMI
t«S Itttf1 1MS
Sg ? rep/*ee/ga of tissue • 1eMKMq/<UA where q oonvanlon factorfroi8 org* to r9p«s defined above
• 1/95
"king the density of tIssue at unity and assuning, tenpo-
rarily, 10051 geometry, substitution of the appropriate conversion
factors into Eq 3 gives
i
rep/see » ( 3*7 x 107 )(1.6 x ICT6).^95 i
• 0.623 mJojL ab
Application of Eq A to a Sr 90 applicator produced and
calibrated by Tracerlab, Inc., gives values comparable to those
obtained by the calibration naasurenents, within a ailtable geo-
metric correction* This applicator contains ap roxlaately 25 nC
of Sr 90, maximum beta energy of 1*1 Mev, and was Measured by the
manufacturer to provide 28.1 rep/see at the surface.
The following equation*27 ' permits calculation of the
average energy per beta particle
t
la-i « - H^L- - 0.33(1 - _Z1/2
) (1 »JLJ/2
)
where a * the ratio of the average beta particle energyto the aaxiaus beta particle energy.
Tor Sr 90, the average energy Is therefore
i
I - n Bj, .(2.2)(0.33)(1 - J«l/2
)(1 - 2*^*)A3 I
• 0.853 Mev
Aaploying this average energy in £q A» the Sr 90 appli-
cator in question having a diameter of 7.7 an, the dose ratio 1st
•27-
9Dil
>*'4
'&i KWi
•
3-.1v t* Uwim IMf bstrf ,»*.• t*ww ,-^W AkhIxsk ,09 ** *•
aai *•: • #s nfm\^»i £«tfi i
aai ||
•j I PMffcl
IWC^rNdJ si tyraft
ial attar *«< a lafaa&IA k
rep/eec » O.ftgJ (p,W)(2«-)0.330 (U 7.72 )
86.5 rep/sec7.7* )
4
To obtain the calibrated value of 28.1 rep/sec, an
adjuatment factor of 32. 5,i moat be applied to account, for loaaea
due to applicator geometry and to account for conversion of beta
particle energy to Rraawatrahlung. Thla correction would aeeai
to be of the proper magnitude baaed on the limited available in-
formation on the Internal construction of thla Sr 90 applicator
,
and allowing for the approximation error in the 25 mC value.
Similar ealeulationa for kh 106 enow the average enarglea
of the two beta particles to bet
1 • 1.45 Mev for a* • 3.55 *fev
1 - OM Mev for It, « 2.30 Mev
Application of theae average energiee to 5q 4, with
proper allowance for the 824-135 relationehlp between the two
decay paths, and uaing unit area for the source, shows*
rep/aec » 2^2J Cgl) * £*&3 (*I> for 1 mCA (R )x A (R )2
where eubeerlpt 1 portaina to the 822 decay path, and
2 pertain* to the 18:4 decay path
g • fraction of transition* by the
aelected path
The range (cm of tissue) for the 1.45 Mev particle la
0.6^5 cm, and for the 0,88 Mev particle la 0.344 cm.
Substitution of the given values of g, I, and R, and
assuming unit area for convenience, gives!
mmrnVBa)
am 'S ?r- aetBV t»t
* '••'•' " Btfmm " :
.'\, p J - .*»-:- ' - '• QfHH re-.-
-•I •Id*! f^pytq .».ij 1e «,! |
na «•> jnlvoII-6 feo*
Ml*i«tt* *»;..:»•:©* wdt vol taXte
owi «dt cmw*W <ftrfar. *mmmLI» *•
& i tc^ (&) £&£*& * (la, m*\»»*
•1 «fai*i*i *
fcflfl ,« fcim * -inn I,* 0» „
0.645 0.344
- 1.429 for 1 mC Kh 106 on 1 «q cm of surface
The test applicator employed herein hat a geometry
factor of approximately 50% whan reflection froa the plating baaa
aad radiative losses arc taken into acount, Thugs, for each nC'em*
exposed in this system, 0,715 rap/see enter the area to be irradi-
ated* This is not true in the present practice, since the nonuni-
form!ty of the plated surface has already bean demonstrated, end
the inaccuracies of the ORML shipping data have bean mentioned,
ASsustt 3 mC to be plated uniformly on a Cu disc 1 inch in diameter.
Since a 1/8 inch lip covers a portion of the emitting surface, only
36,3£ of the emitter is exposed, leaving 1,69 aG effective in
creating the beta field. Applying the geometric corrections, this
applicator has 0,593 aC/oa*, and therefore, supplies (0,593) (0.715
5
• 0,424 rep/seo/cn? to the Irradiated surface,
Xa the preparation of a practical therapeutic applicator,
it la desirable that a minima of the active emitter be masked
sy the supporting structure. This can be aceoapllshed by reduction
of the width of the supporting lip and/or h> masking the ar^a, which
Is to be covered by the supporting structure, such that no active
deposit is made in this region during electroplating,
la the preceding discussion, the production of Breme-
strahlung was omitted la order not to detract from the discussion
at that time. Since this process accounts for an appreciable
-29-
(i *
4 I OC -I •
"•OBVf & **9* «i*T«! i TWITS'.* *0*<
MMf
No I BMtoX (
•
f4T« »fo «f .n+mnrtfb a«9d \b**nl» Mri •erihara hw*lq •& to f*J«rol
.ittmutl a no wmItrn « b novo. X * toalc
at *rt*99y\* dm 7&»L %nlr*9l t fri>o<pf «£ T»^.fhw «tt *> *€«<*£
taa nM»\a «»rf *ot*&McNB
ftlttVt'U' L-« !ft£I.(GKS9ii 0< 049 *>.<>n*
wr oft on » yg toi«v»» *tt •# at
<
portion of the electromagnetic radiation in a problem of this
sort, and, therefore, it a major contribution to the radiation
baiard of high energy beta ray sources, it must be taken into
consideration.
In the introductory remarks, it was noted that the
true efficiency of conversion of electron energy to X-radiation
ia probably not an exact linear function of the atonic number*
However, since such a true relationship is not yet available,
the direct proportionality approach will be employed for the pur-
poses of this discussion. The following equation' 2*" ^m ^
Jg_& n M ZA600 ac2 where
i
a • the portion of the energy convertedto Bremsetrahlung
bE m the average energy for a given betaray spectrum
me2 • the rest mass of the electron• 0.00055 »u • 0.512 Mev
Consider only the active disc without any arrlicator
holder, such that the Bremestrahlung emission is due almost en-
tirely to electrons impinging on the plating base. Over ail of
the beta energies from Rh 106, the average is 1.35 Mev§ therefor*,
this ease, n » 1.65 a 10-32. Values of n for the materials
in this project are included in the tables
•30-
floral V- **$ ftg mateticih**-,™ «sfM - R » •—**—»•* k-i nm miipiRiOT W^JM • ©I ..?•JOINTSa; ,»fl* a « tot
f i«iU b«#oii bcv *1 ( aaK«ierx
-•
istttiv *m GO*A* W • * 6 n|
*«*f»v»»» Wat* «*d to .icUioff aft » a
TABUt 1
*l*tlat &AB&IliT' UYi SB * %5?
Gold 0,130Copper 0.048AlCBRintJB 0.021Beryllium 0.006
0.31 aa 0.990.67 as 2.15?.21 m 7.133.29«i 11.10
From the ebove Talust of n, it la readily seen that
beryllium is by far the beat plating base for use in attempting
to reduce the X-radistion field around a beta applicator. It la
unfortunate that the sources did not arrive fro» ORSIL in sufficient
tine , or with sufficient accompanying informs tion, to permit verifi-
cation of this statement with adequate experimental evidence.
This syateta contains a gamma"ray source. Allowances must,
therefore, be made for this electromagnetic radiation as well as
for Bremastrshlung. As pointed out in the introductory material,
the patient undergoing treatment is exposed only for the period
of the treatment, and need not be considered in the long-term
radiation-exposure picture. Therefore, In computing the gamma-ray
intensity about one of these sources, dose rates will be figured
as pertaining to the physician, who, in general, will be in close
proximity to the patient only while actually fastening am applica-
tor to the patient 1 a person. Since he will be some distance away
(at least arm's length) for the remainder of the treatment, the
-31-
mitff'-<-
. ..
4. .-: , tlJLJBkJk
urn
am I*. ffter-.i '.
fc* ft•!
ttort ti #1 ,« *• MffJtar **e«i* •&- r
|Bl#fMJ##» sa •«! MH Mrf *£#*. ? «f# *rt x* •! a»
ImteHlM .:£ -- tm4 'I
' Ml N>r b.i:
* ?J '• '• ;•'" r •-.?• •.
-,-< -••• ;
-_,
• ' ' !' " . ' i ' *
ii.: ' " -r
. ttp.-ctf .i f& ••
%Jwr* MKtfusvo;!* tMjMJMl •te*r-«ato^ «. Ml4#«M flM>Mg| ftMl
«a H«v m «©2>*lb«i »iS«a»MK»x*»*ia -: ..t t*l m>«* «f ,orelink
t ££lT«*M f«#«rftt#il mU «i #m» fcMhtJMq ml iMrftfirrftMMiff M?t
NMMM, >H^ «H JMM MMMpt Ji* hMMtcut* r.'civ"* f n s mmIIm] ttfl
tW-mmI »-;. at tm^luN Mf Jo* 6mm mm t#ftM*Mvf* «C# fe
fcfr^&t? Mf II Iw uWm met ,aun-t:oe »MMtl ^o mm *UO0>
•Mle ci *.< 111% ,I*tM?n ei t*** Ju.iolwigrfo; #* ; *0l*t*to»q «i
\MA Mlfl ti MM • Ml M» C«T©*j J»**T*tf*| *U * *•#
Ml# ,J<IM*M«J •* M tMte **i iMwi ,.,„. i%ml ,#)
applicator may bo oooaldcrod to ftawtloa a* & point soaro*«
Oompmtaticnc may, tharcfora« be made toy tho aao of tho tmilmriat
equation'**'!
^^(tr/lon pat?) (lorn pair/*yoc)(Ulr*)
OPMPpf^HtViAaaQ^ W^P VPWfewm* e» wkww Pn OF OraOmP VHP PJP^PP) A• ^pmn- Oft M^B^^MMPl
ana moat take late aceoamt tho three dlfftreat giwi raj
lordied. Iq 7 thea tapamaPl
• 0.127 x iflrJ
where, gA • fraction of traasltl&ae by a fitem path
% • energy of the emitted phetea by the five* path
«A* »*V *rt * oaT * °*51 • 0al7 * °*73 • 0#01 * *•**
tSnffrii iiMif in ijnKMUUtiMijfi ii^iiinBri TffiBffffii nffliB*
Xba data oMaiitod by meaeoring depth doee oo o femet&aa
of ottrfaoo deem am preeeated la Figaroe 1$ 8» and o#
Figaro 7 lojloiop too axial dapth-floae date afrbaUerf
from Somree 2 (in the ai holder) by ion ahoahar meaeorweittt, a
cunra for a 3r 90 applicator'**' for pcmparlecn pureeeca , ami
photodonaitomatrio readlnge from tha avtoradicerapbe (Figaro 11).
It may bo soon that tho Sr oo applicator field falia to $0* of
ito enrfaee intenaity at 0*6 am penetration into a water phantom*
at which distance tho intenaity of tho M 106 applicator field
la excess of 100$* Theoretical eeneepte iadioato that a
ft*
'•'" ~ -
4*•* itftfl w*>*
^*#
*$4tm m • X
MK -:- .-.;,..' .,-' -';^ i
"-/:.-i.:-.,c'... :...'
* •• m* **** ^vmm f* AftoUtt* «« aft MR1
• ,ftjlMlllllli <utfft** Aeg. tf («Mte iA «ti wreyi: mft
tIWi tmmmUmM oar *t •w.t •< ttlaaUvl «tf# i—itiiti ^u» 4*
<:
(00
\
to
So
7o\
Co
SO
^
40
3o
to
—
\
10
\®
S (2/
i
Vd
r~/c y :
i 3 * S (, 7
/Penetration Death ~ mm.Depth Dose Curvms m Wa.fer Phantom
41
10
G)\£) Ph«to <len(it<"ncfnc
T~e.ff- Aw/ccater (lo« CHAMStP)0<aa-la. or> k PP I* t.o.'tc
l
PJ"
-33-
similar plateau should appear for the Sr 90 applicator, However,
1b medical practice, It is necessary to filter the 0*63 Hot
parttela emitted by the Sr 90 since It will produce an undesirable
necrotic condition at tha tissue aurfaca while the therapeutically
effective 2*2 Mev particle froa I 90 la delivering the desired
depth doea. Tbie condition doaa ot exist in the Ru-Rh system,
since the Ru 106 particle is of such lew energy* It is also
notable that at a depth of 5 mm* the Sr 90 dose rate Is leas than
2% of the surface dose while that froa Hu 106~Rh 106 sourcee is
still 261 of the surface rate* Thus, it nay be seen that the use
of Sr 90 applicators entails thirteen tinea the total surface dose
of « Hu 106»Rh 106 applicator to produce the saae dose at 5 am
depth, with a proportionately aore amff surface necrosis*
The faaily of curves in Figure 8 represents the gradation
of depth dose as aeosureaents are node laterally across the face of
the test applicator* The axial contact reading Is used as the 100$
reference* The beta ray beaa appears to be quite well colligated
by the 0,7-mm aluminum lip of the container structure, since the
Intensity beyond the limits ot the exposed emitting surface does
not exceed a small fraction of the intensity of that portion of the
field to be used in therapy* However, for long exposures, addition-
al oolliaation amy be desirable as evidenced by the autoradiegrapfae
shown in Figure 12* This requirement would, of course, be adjusted
to the typo of tumor growth or other leaion to be irradiated, since
-34*
tfrfMlMM* « mv*m
i.-» -: |M MM BMMMXM kl H 1 BWfl * ;.; foM MM '-«•
oet* «i /I ,^4'iofl* wol oMi 1» «* « »**•
m*£ si tin mm Of M • -
•2 MM»« <*U «*-*>! «K mm **** •&*** «** M«**tf» * W to tt
'4H «rf *m #1 «m*T ***** mlw «i» 1« *te UUn
mM m**w« ir.^ oAt mm# mMvM* %UU*M 9n*4>
am * 3* mm mm •*> m«mm, o.- w««l^j. *>I «M6X M • M
•MMVMB tMtWf WWW MM KltfW irww * *>** ,rf*qM
MtMftMJ • •- pJMMMJM I MMW *J HM li |BMfl Hi
* M** ««# HNM \XiM«#«i ft**u MB WIW1IIH 1« MM MM* 1*
*C0I «di «a MM M )«i'bm #B**M8 f*bc« wP ,»^aM^# *•*# Mf
|gH | M N IMM *J *J MJM - MM Ml INtf *J tMMMI
M» mbIb #MMll MBit *ft«e *«* %» «li mbJmAi m>**0 «f» *jf
MM Ms-hui Mi##lM Um« ofiar * *ti*if Mi No** **£*m#iil
ttl "l» Mi#M« #M# 10 M1m*JbJ M# %» Ml * MMM MS
•MU#Mto ,WMfil M*I Mt v«WM0l
Mj|*l*jlfctMlBB M# «tf llMMl** M BltfttlMft M" MS MMMtXiM in
M#MtM M %MMM to tllMV JMMlhIBM •!« »fiX MC^n «i M<l
MBit ,M#*i»«Ttl M M MiMX MtfM M <>Mf| ml 'to MM M* M
3rSL:lob
Isodose Curves around Ru ' /Applicator Immersed in
Water
£
l,
5f|
--
0)
o
?7o( _^
»0%
stor.
N
1 o owr*<- £-
3 l
Durante Lt i"h€. 5ot/fc e F"*» c_ C — rr* *»i
/*"/<? *? = Isodose Pattern at tbe E. al a e ol Source 2 l*nr>-> erj e dl m Wat«»C
Perce^tooes ore oi the A/iaX*"i»tQ.ct r-«aal/n<>
may require a r ther high total Job* at all the fringe*
and on into the surrounding skin. In measuring these lsodose
patterns, readings were taken along a single radius line in
order to present the conditions wMch would prevail If the source
bed been properly plated* The curves shown are for a completely
Immersed source* Tissue nay not fill tho recess in the applicator
face in actual practice* The lsodose pattern could then be applied
frost the tissue surface rather then the emitting surface, and would,
therefore, give a better collimeting effect* Due to the physical
dimensions of the ion chamber and a plicator (Figures A and 5),
It was not possible to complete a closed traverse of the 100.* and
M lsodose curves In the regie of the retaining lip Qt the a pli-
oator. Ho intensity in excess of 25£ of the surface dose rate was
noted on the surface of the applicator at a radius of 13 mm from
the center, and no beta intensity was nessureahle at the edge, back,
or side of the container. Combined gamma ray and Dremsstrahlung
readings, using a Geirer-ttueller counter, (no beta) for Source 2
•honed 14 mr/hr after penetration of A cm of tissue equivalent
plastic*
Figure 9 is an lsodose plot of data obtained using the
lorn chamber and a* roaching the edge of the unshielded Source 2
(no container) immersed in water* It is indicative of the rela-
tively small amount of eollimating material necessary to oonfine
the beta particle beam to the desired limits* Ewn as the lorn
(a
I
«l mil ZLihai *£$al« fl «**•* **«* WJ«*to»l ««fl«*#*l
tMJPPt art. U I **'H : - i-o. w MMjtlUT«Mli » *>** «« .rw- -- MTV* «tf •&* >W?«'l °*** ****
tojt&w «f «wU M««>» *«•**«r Motocl «tf 'ue#*» «1 •***
tllc«f to* ,»«**»?« yalfttm *U r.ttif X9di»t •*•*•*• mnmXi *i* **!
tolwpM **<* tt» ft » !•##* « m** %wf\m**$
i , ' M^Wi k
***** **&*» » " ** *ttfe/'>f| A*1* •«*••• ***
yvUKlMMBTtfl EMC Ca-S MtBC.
£ t*WOc i»l («#ftd >*) ,i^r*a film* a yrttff tlflfi—
t
v
«i# yiittf MMl2*#(fo "•':, *W«1 ITU 3l t? tWftftY
«*sk£ tofcltlrfaw «(# 1o **£«• *&s yiwa • tea ti<—it» «t
•*:•? mH V a #1 .a**** *1 &•* «r! (wrlfctiipp o«)
•Gi'ittu© «# yu>M»n lata*m v«1*««UI©« •*• favaat Haasa T£«vft#
eel 94* t» *«*fl ««mU tartlet* erf* o! twd ml*U%»% «>«f wtf
hanber approached so close to the edpe of the disc that appreelabia
radiation could enter directly from either face of the dice, the
intensity did not exceed 20* of the axial reading. Since the
geeaetry was so unsatisf .ctory in tfc<» measurements involved hare,
it is safe to say that the trot gradient and maximum value is
much more favorable than indicated*
iusQrttdlaimrhji
The autorediogrepbe ahovn in Figures 10, 11, and 12
were prepared in confirmstlo of the information obtained by
electronic measurement*
Figure 10 war obtained by laying the applicator holder,
with So roe 2 in place, on its side on a atrip of X-ray film.
It serves to demonstrate that no particulate enissioa is observed
from the sides of the container. The apparent curvature of the
edf© Is due to the geometry of a circular source standing on edge
on a flat plate* The apparent fringing in also due to this
itrical distortion*
Figure 10, Applicator placed en ltesside on Way film todenonet.rete sharp cutoff ofsradlation field *t appli-cator surfaoe* Exposure * 5 sen. Source 2*
-37-
•if*. Z".'"-*";. Q ', H
«f* ra
rf « •
•**»!
Xrf rfe «©
,l«rf
•Cf' rtf*-
4t r roto* «fT
raft
• <*«<lata* «rf* ^ Vftfiit #tfj _*^
-
•
>lMhN 'ccv7»r.
« This la * portion of a aarisa of autoradlopTapha ob-tained by stacking X-ray fil« in frait of tha appli-cator. It demonstrates tha variation in depth doaeiEapoeure • X sec. Sourea 2.
a* Contact b. 5 layers of fila0.15© ga/eq ca
c* 10 layers of fila0.312 ga/eq ea
d. 15 layers of fila0.468 ga/sq aa
**fl*
Ml
'
Figure U. (continued)
e. 30 layers of flla f # 25 layers ©f fii»0.624 gV«q eat 0.780 gs/aq on
ft* 30 layera of fila0.936 m/*t ob
~39_
•V*r W«tlt
m
w
.?F~
12* Edto of JHngr fil* oxpoood to beta-ny fiold ttm ftp*
plloator. Dioiwtratoa th« outline of the radiationfield, tocposuroe * $ and to tee. Sour** i*
-40-
§* ftM M
-OA-
Figure U ia • portion of the series of autoradlographs
ottalned by stacking &-ray film and remitting the beta ray bean
from Source 2 (in holder) to penetrate through the pile. Densl-
tonetrlc data are ehotm in Figure 7* The contact exposure shows
the rather slight fringing at the edge of the applicator which
can be greatly reduced by additional colligation.
Figure 12 la an edge exposure and Is, in effect, a
photographic reproduction of Figure 8* This mm greatly over*
exposed in order to denonatrate the outline of the entire beta
field,
MQlQgto«L3t)atrTjUgM»
The observations Included here are presented in diary
fom for convenience of interpretation* Elapsed tine is computed
from the tine at which the applicator* containing Source 2* was
Mounted on the test aninal*
ElapsedDate and Tine tine
1540, 25 April Applied source to the shaved nape of rab-bit1 a neck with adhesive tape* Hebreaks in the skis were observable*
0720, 26 April 15HQ No observable effect at renovel ofapplicator*
1600, 27 April 48t20 Definite erytheae existed over an area theslse and ahape of a kidney bean, correspond-ing to the aore active portion of the ap-plicator (see Fig* 2}* The coloration wasabout that of a Moderately severe sunburn.
<« *wwxpc* «&fe# nut sJt SI #sjk
-•-..•*• ^DNW Mi .'-,v ' PUpJlMJ
::.;• •.-.•:.... '...: ^-Ll
Mtrfwoo c - t ->#f<icpnilnl io imnwltwirroo to! «M&
*In« #••# *d# is©
. ...
••I f«*c»*rfo nm mMm «4* ai wU-^wf
1» Uvroaun *i #•***• AJ«n»«k) o* 0*«ei XitqA <* ,ORTO
mmm ,nt xprfi u»» wit
**.-'«> t M«) Y0#*9t£q
-J,
0815, 2S April 64135
0815, 30 April 112135
12A5, 1 Kay Uli05
1300, 3 May 189.20
1300, 5 May 213»20
0900, 12 May 37?«20
Complete erythema existed over an area27 tm in diaraeUr. The entire areawas of the ease color previously ob-served, except that the area noted 27April had become a deep marenta andport lone t>jerecf had become necrotic*There wee no discoloration observableoutside an area equivalent to the exposedemitting material of the applicator*
Severe necrosis was evident over theentire area, with some sloughing in thearea corresponding to the more denselyplated portion of the source*
the necrotic area appeared generally theseas, with the addition of two openlesions srr roxtmtely Ins la disaster,which were present in the aoat Intenselyirradiated area* A slid erythaaa hadappeared in a band about 1 But widesurrounding the necrotic area, apparent*ly due to the low intensity fringingnoted in Figure ft*
The entire ar*« appeared tfen esse as OB1 Key, with sowe additional lose ofskin ne*r the edges of the necrotic
if end in the spots previously noted*
so a rerent change*
So further sloughing of skin was observed*The necrotic area was the sane else* Theerythematous area noted on 1 May appearedto have returned to normal* The hairsurrounding the necrotic area had grown1/S tolA inch* lucre wae no apparenthair growth in the injured area, nor wasthere any observable eplllatiem*
At ell times during these observations, the animal appeared
to be otherwise completely normsl*
From the observation of this t«st animal, it is mmsjmmm)
that any radiation damage to tissue subjected to irradiation by a
•4ft,
-.
&<
mM *m: . mam *dt uv *a*o s£*«wo*a wf?
mm pt/»-
0MO ••#Mi
-
la*
•ilfrtirt off
Jtu-fth apflioator of this type ie confined to the ar«a iwaedlately
adjacent to the eaitting turface, and that any fringing affects
ara of United eererity and heal rapidly*
So histological aeetlone vera studied la a United test
of this nature* They should, v owe*er, certainly be included In
the extensive aninal etudiea which must be done before thia beta-
ray applicator any raceire any extensive clinical use*
-4>
1"? iJMhife&iftftUrf «i
CflBBTJBlQHIXmEmiiSSmSSSi
Consideration of the lsedose and panetratlon tateneity
earwes far ooft tiesns, obtained In this study, shews a in 106,
Rh 206 applicator to be wary eatlafaetory for nee Is radiation
therapy*
Properly eolUmeted, the high energy bete particles emp-
pliod by Rh 106 provide a strong radiation field to a depth at mere
thaa 5 am. Goo of thio lootopo dees not entail heavy sarfaee
nooroolo doe to a low-energy bota particle from tho paront Ha 106,
nor does It require appreciable attontaatlon of tho usable boan to
filter out lew-energy particles. Inns, for troataost of onrfaoo
laoleno to a depth of several nUliastero, an adequate flaid aan
be aatabllahad without tho introduction of othor pathological con-
ditions* For treatment of superficial snrfaoa conditions, snoh aa
fonfsa infections, tho 0.9-mm 100* dose-rate rogloa poralto high-
Intensity, snrfaoa Irradiation without causing extensive damago to
tho underlying tissue.
Proper colllaatlon of tho beta-ray boom to aula tha
thorapantla probloa aan readily ba obtalnod by variation of tho
aoohanloal etrueturv of tho applicator holder.
Although gamma radiation la inboront In tho nso of this
lootopo family, tho intensity thoroof Is below ostabUahod fan— rsy
tolaranoe values for sonroos hawing beta-ray doss rates In tho normal
therapeutic range, Tho gamma-cay Intensity iron Rh 106 Is
IttftNi H I M WiHHl
M0MIM rf Mi *•- :.'«#M(lii-f «ft '!-• Hi -
J MfMfrfltM *0i --
~^ra MMiH **«^ ^ ."Wv*?%iiJ 9&* «6Mi
%• 4MM a •# Limit imltittoi w****
JiU *« rtrw w* awft afaMiq *** till it « •# •»*
•# rated tMNv m^# 1* ifciiJiite tliialmiqi #ni#p#n
,. . -,;.,
.. v: -.-> 9-yJ ....• •• -
silt* Hi MliMi •'•*+ 3" W»4OT
•Ut lo »«j It at fnufct tl flafcftftfcfcat mmm% 4§tf«
MMICdafig mM tl Im iM yfilmam&aX
| IM MMH
lower than that fron radiua aourcsa of taa sum bata-ray intensity*
Dr. aaary*30 * baa coapilad tba ratio of th intensities of the6*
two radiations for typical r^diua plaques and also tba gradient of
doaa rata vith depth* Ha has stated!
"Th* value of tha bata-iraaawt ratio for a full-strengthapplicator with surfaaa dose-rate about 5.000 r/hr iaof tha ordar of 25"
and
"Tha moat striking feature la tha vary rapid fall-off oftha depth doaap e.g., only about 90 par oant at 1 saw"
A similar coztputetlon for &u 106 appliestore, baaad on the* raluea
obtained herein (sea Preparation of Applicator) showai
beta/gaaraa ,Ql)t7lS ,,, * bate fogf FaWaft0« 127x1(7"-' gaana dosa rete/aC
• 5.63 x 10^ for hu 136. Kb 106.
It is readily seen that, fron tha point of panatration of
bata partiolaa. Uu 106 is greatly auporior to both radium and Sr 90
applicator* as currantly prepared, and has a bsta~gaasn ratio advarv-
taga ovar radius by a factor of 210* It is belierad that tha advan-
tagas of tba fiu 106 beta-ray panatration pattarn ara so suparior to
thoaa of Sr 90 that tha low gamma-ray intensity which is introduced
nay b* tolerated, aapaclally in riaw of tha intensity currantly
tolerated ia tha usa of radian*
fta 106 is also suparior to radiua in that no gas-leakage
hasard exists. ,_-45-
3M#Si
*
•
f*\
Breneetrahluag eaa be materially reduead by aagleyaeiifc of
plating bases and eoatainers of lew atoalo aaaber eleaeatt. Of the
lower etoaio rwtot if materials* b<*.rylliue i» the aeet satluTaetatjr la
that It it * light, strong solid, and is not nearly i# ehealcaily
^B^SS eraOW^ ^W ^MOW OT•^O^e^W WO OO'^^aF OB^a'SU^H^a'aMe'r^F ^W <^Ona ^^BW^e fc*^Wfc ^&w^O^BJPW ^FaSa^PaOr^p!w ^O ^SSJF ^PaWSa^^PBW
effeete eon bo readily prevented by proper handling*
the naif life of *a 106 1* leaf enee** that on epplieeter
ooaetmeted thereof hot aa output of saffi&lent mistiaay far noraal
thorapetttie use* A simple deeey curve baaed oa lie initial eallfara-
tloa value in adequate to determine the doeo rate at the start of a
treatment* Seen a eaall portion of one half-life transpiree daring
the few hoare of a treatment period aa to permit the astusptlen of
ooaetaney of output far the period la question*
Examination of the 11aHH available blologioal data
described indicates the true tissue effeet te bo ae predicted by
the maeaureaente la the tissue pbantea and by the autoradiography
.
«^C-
•to**
TIM problo* of tbo doptb doaaf a^ntribojUoa dua to Oota
o«rtie** irradiation fron soorooa of «a 106 in oquiiibriwi with
H© 106 U atndlod la km of lonlaatlon-thaaaor naaouroaonts in
a tlaaua-nquiwalnnt, watar pbaatonw
Umi oonlanont and aothodo wm»lajfad ara doaorlbod 1a
dotal! for too aaoiotaaeo of tfeooo who nay do forthor otadloe of
tola aort.
axillary data ara provldod by aatoradloaraohla atadioo
aeing tho varioua aoaraao aoallahlo.
Caloalatioo* ara shown to ba la aooord with tbo awailabla
axpariaantal data on tbo aoaraao atadlad, fbo roonlto of tbo oal-
eolationa and axpariaantal data doaonatrata 8a 106 applioatora to
bo oraotloablo soarooa of lilgh laargy bata raya for aao 1st radia-
tion thorapy, Thm alaatfitpoMo radiation larolTOd in itt km
io aaall and amy bo fnrttior ainlalaod by ana of straataral notorial*
of low atoaio traaHtr* Tbo foil off of botanray doao rata with
tiooao danth orowidoo a ration of O.Ohbp dopth at 100£ of tbo aarfaeo
dooo rata, and a loforlthaio dooliao frno 0*0 at> to t&L at $ an*
Examination of liaitod biolofioal wldaaoa oonfirawd tbo
aatieipatod rooulto aa to araa affootod and dopth of tloatm roaotlon.
-47-
ftjfoti I•S.r- *a*«r
•
"'"
trit
tat .^I'jsr.w.'* i -vtetf. '^-.-ct -*.»•
Mil);
MMMfe
•Jab **«*> Mir TT fc**ii
9H% MM* x*** f
.«*r 2 #» Wt • « t.O wwft ate
-T,
w^mSJffWS0 A <jpHn^WPy m t» :*V_ » "a^JUpa^Bawt ? Q> ^Wwr 4k
fta 106 bota-ray mwws h**t tew a&owa to tot physlaally
aoooptablo for thorapoutie uoo9 Initial biolotioal onaoko aavo
oonfiraad tho pfeyaieal ttuaioa* Bafero tola r&dioaaix * oloaant My
bo plaeod ia gtoaral oliniaal aoo, adaitiaotl biological atadlao mast
bo parforaod and anaiyaod* beta as to tho offoottvoaoea of tola typo
of aoslieator on aonaal tiaaao mad oa iaaor tiaaao* In iriow of tho
failure of tho borylliaa-baiod aoaroo to arrivo ia tlao for ota4y#
this work anot also bo earrlod oat. Additional daaign work
bo doao wita roapoat to applicator aaapo and aatoriala*
-4*-
i(J '•*; Ml "? j STMMte l(MNf WRM MN9MWI ^MPNVIH *£
iMHMCl Wl#wmifci i ft :.'.*rv -v ;; ^. c iMtejfll MM ImrI
•*-
kllilRll I
-49-
Bibliography
1. Q* D. Adams, 0. Alagr, $• Danooff, A. Hanaoo, D. torsi, R. Koch,
I. Lanal, K. Lang* and J. Laughlinj Taohniqnaa far ApaUaatloaaf the Batatrm to Mailcal Tharapyj la. J. Boantfaa. iad. Ihar*& 15V? Ung. 19W. ^
2. M. Ulan and J. S« Saithj BaU-ray Maas*raa»nta and Dnitaj
>• 6, 6?»7* ( «fcma l$fe0; •Haoleonlca 2# »0«
Slatopatbolagy of Irradlai
roaa, 'ladrSStlll (1&2).3, W. Blood; HiatopaihoXaflr of Irradiation fro* Bxtarnal and la-
tarnal Seuraaai
a. P. Brown; /airleia Bartyra to Solanca Through fr*a/i 0* 0*Xheau Co, (1?3©J
.
5* 4» G. Burr and t. M, Garriaonf Tha gffaot »t Radiation on thaPhyataal Propartiaa of Flaatloa f aTO-WB (%•> MM),
6. 5. Cadaj Malignant Dlaaaaa and Ita Traataant byftadiuaiWiUia** anTmHaaCo.a^J, **~
7* *'• E. Oohai Toxicity of Inaalad or Ingaatad Badlaaatlva frrodaota i
WiDlaoolaa ^ lo. 1/81 (Stf).
8* A* 8. (taaptcn and 6. X. Alliaonj X-ray» in Thaary and Kaparl-ajanti Yan Soatrand (1*J*) .
9* D. T. tgfaai A Stady of ftadloactivltlaa in tha &afcnanltai Bagionjph. j>Jt£mU;
i
b. £V(i*w. — =a2=i
10. ft. D. Svana} BadioaotlTlty Unlta and Standard^ tfaolaonlea i,
Ho. 2, 3« (OetTTSWn
11. 0. Failla, M. ftoaai, ft, Clark* and II* Bailjrj tfca Maaauramaat ofTlaaaa Doaa of ionlalng Radiattenai AXCD-2U*2 iDao. 1*>7)«
12. 1. Farmit yoolaar Phyaioa t Ooapilad by J, Oraar, at al, 9ni-Taraity of Chia&go Praaa (ly50).
U. D. 0. rardi Tha Oha^iatry, of frithaniaa; IP-U0b, toivaraity of(1950).
-50-
a; MM ,d ,1) ,1
.
Xb* K. F. FrouadlloAj A Mwr Bata-ray Applicator Uaing FloalonProduct*; Satara 1&, 56WS (ilg.*!$&-.
*—*
i>» a* L. flriodoll, C. it Thorn; and J. S. firohaarj gota BayApplication tc tno gyo aiti; Saacrifrtion of an Applicator
16. H. L. F*iad«ll, C. X* Taoaaa, and 4. 3. Srohawr} Dasarlptloaof a 3r £0 Applicator and Its 0oa on tfaa afroi An. •*• iaaatfoia.
gad. ^Wepy'llrgg l?tb> iff*).^
17* 0* Glasaor, od.f Madleal ttiyalca , Vol. I| Toar Book Publisher*<l*a9).
^*
*
18. L. 2. Oloodanniaj Pataffalaation of too Snargy of 3ata Partial—and Fhotono by Aoaorpiicmt WaoIibnUo g, WoTl, IT (Jon. XfW.
!•• A. X. Hatkj iota Irradte tlon ao o Poaalblo Tharapoutlo Agant InOlanooaa, a>: J. 6pihal^W &> "J^g
1
(flot. ISW.
tO. 4m C. Hamilton* ilotaboUan of 8adlo-Strontliai audi Badlo-Otrlmi^-..j. --~„, —— IIMII I
I mill II——W—
»
I I ! —i—*———
r
KDDC-1000, U. S. A. £• G.
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116 6 8
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ThesisB829S Buchanan
15601601
A study of ruthenimum106 as a beta source inradiation therapy. tsta
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0PRES3 BINDERO. BGS 2507 EMBOSSED
O PRODUCTS INCORPORATED