impact of physical dose rate effect on the long term results of the cf-252 brachytherapy of cervix...
DESCRIPTION
PURPOSE EVALUATE EFFECT OF Cf-252 DOSE RATE ON THE LONG TERM CLINICAL RESULTS AFTER COMBINED RADIATION THERAPY FOR STAGE IIB AND IIIB OF CERVIX UTERI CARCINOMATRANSCRIPT
IMPACT OF PHYSICAL DOSE RATE EFFECT ON THE LONG TERM RESULTS OF THE CF-252 BRACHYTHERAPY OF CERVIX CARCINOMA
E. Janulionis; K.P.Valuckas; V.Atkocius; V.SamerdokieneInstitute of Oncology, Vilnius University, Lithuania
2011-04-17-21, Porto Alegre, Brazil
PURPOSE
EVALUATE EFFECT OF Cf-252 DOSE RATE ON THE LONG TERM CLINICAL RESULTS AFTER COMBINED RADIATION THERAPY FOR STAGE IIB AND IIIB OF CERVIX UTERI CARCINOMA
PATIENTS 1994-1999
Ca cervicis uteri, IIB and IIIB342 PTS TREATED BY
EBRT (60Co) + 252Cf BRACHYTHERAPYNo chemotherapy
CALCULATION OF THE DOSES FROM 252Cf SOURCES
CfCf
nCf
nCf
isoeffCf dRBEdRBED
1CfRBE
nCfRBE
2.0 :fractions If k
nCf
nCf
kk RBERBE
,958lgW0,698 n
n 117,0lgW0,2628,2
(J.S. Rjabukin, 1985)
Gy/h1027,1W4Gy/h if,6
n
4Gy/hW0,05Gy/h if, n
MOST FREQUENTLY USED 252Cf BRACHY REGIMEN
5 x 8 iGy=40iGy5 x (1,32÷1,44) neutronGy + 5 x (0,88÷0,96) gammaGy
6,6÷7,2 neutronGy + 4,4÷4,8 gammaGy
PATIENTS BY YEAR AND STAGE
YearFIGO
TotalIIB IIIB
1994 25 37 621995 22 53 751996 23 48 711997 20 67 871998 7 27 341999 5 8 13Total 102 240 342
252Cf BRACHYTHERAPY BY FRACTIONATION
FIGOTotalIIB IIIB
5-6 x 8 iGy 90 223 3135 x 9 iGy 8 16 244x 10 iGy 4 1 5
Total 102 240 342
IRRADIATION TIME AND PHYSICAL DOSE RATE
YEARFRACTION DOSE, iGy
PHYSICAL DOSE neutron+gamma,
Gy
IRRADIATION TIME, h
PHYSICAL DOSE RATE AT POINT A,
Gy/h
1994.01 8iGy
2,2-2,4
0,5-0,7 3,7-4,8
1997.01 8iGy 1 2,2
1999.12 8iGy 1,6-2,0 1,2-1,4
LATE COMPLICATIONS, IIB + IIIB, % (GRADE 2-3)
IIB IIIB IIB + IIIB
CYSTITIS 8.4 8.7 8.6
PROCTITIS 2.1 2.6 2.5
TOTAL 10.5 11.3 11.1
LATE COMPLICATIONS (CYSTITIS + PROCTITIS), IIB + IIIB, 1994-1996 vs. 1997-1999
1994-1996 1997-199922+8=30 6+0=6
14,4% 5,2%Statisticaly significant higher late complications rate
in 1994-1996
Exact Sig. (2 sided)Fisher's Exact Test 0.010
SIGNIFICANCE OF SURVIVAL IIB1994, 1995, 1996, 1997, 1998,
1999 no significance
Sig.Log Rank (Mantel-Cox)
0.518
Breslow (Generalized Wilcoxon)
0.422
Tarone-Ware 0.462
1994-1996 vs. 1997-1999 no significance
Sig.Log Rank (Mantel-Cox) 0.921
Breslow (Generalized Wilcoxon) 0.918
Tarone-Ware 0.914
yr
months
yr
months
SIGNIFICANCE OF SURVIVAL IIIB1994, 1995, 1996, 1997, 1998,
1999 no significance
Sig.Log Rank (Mantel-Cox) 0.086Breslow (Generalized Wilcoxon) 0.141
Tarone-Ware 0.109
1994-1996 vs. 1997-1999 statisticaly significant higher
survival in 1997-1999Sig.
Log Rank (Mantel-Cox) 0.035Breslow (Generalized Wilcoxon) 0.053
Tarone-Ware 0.042
yr
months
yr
months
CONCLUSIONS
During period 1994-1999 342 pts with Ca cervicis uteri received combined RT: EBRT(60Co) + Brachytherapy (252Cf)
The brachytherapy physical dose rate (or irradiation time) changed about 4-fold
The overall survival rate was the same for each year of treatment
The statistically significant difference was found for survival of stage IIIB and late complications (1994-1996 vs 1997-1999)
There was not found clinical proof of the Cf-252 dose rate effect on overall survival
Thank you for attention