tomotherapy based image guided imrt
TRANSCRIPT
IMPLEMENTATION OF A TOMOTHERAPY BASED IMAGE- GUIDED IMRT PROGRAM THROUGH A FULL SCOPE OF RADIATION THERAPY PRACTICE MODEL
The Ottawa Hospital Regional Cancer CentreOttawa, Ontario
April 2008
The Ottawa Hospital Cancer Centre• Treats approximately 4000 patients annually• 9 conventional linacs (6 Siemens, 3 Elekta Synergy)• 2 TomoTherapy Hi-ART
Implementation of 1st Unit•Installation = 8 days
•Acceptance and commissioning = 2 weeks
•Therapist training = 2 weeks
•1 week without patients
•1 week with patients
•1st patient = 12 September 2005
•Initially 5-6 patients/day
•2nd
Tomo Unit installed Oct/07
•Currently treat 18-20 patients in 8hr day
•25 min bookings
Patients Treated from Sept 05- Current
Site Number of Patients
H&N 128
PELVIS 83
SPINE 22
CNS 24
LUNG 23
ABDOMEN 7
BREAST 23
TOTAL 311
Treatment and Planning
• Started with three therapist planning and delivering treatments– Selected therapists had no previous treatment planning
experience– Training was excellent– Visited three other Tomo sites to gain knowledge and
experience– Planning is an on-going learning experience
Average Planning Time (min)
Currently, average time = 5.5hrs
Task 1st 3m After 9m
Rad Onc. Targets 70 40**
Work @ Planning Station 86 23ROIs 22 6Beamlets 82 73
Optimization 180 120
Time with Onc 33 6
Physics QA 62 60
Total 535 328
**Some targeting takes longer than 40 mins
Planning
• Therapists like treatment/planning model because: – More knowledgeable when registering MVCT– Therapists are able to adjust treatment plans to
reduce/limit some observed side effects– No ‘hand off’ or transfer of information– Able to contribute to prospective protocols
• We now have 7 therapists for 2 units on ‘Team Tomo’
Cord Not Aligned – Need for PRV
Sup. End ok.
Inf. End of cord not perfectly aligned.
Yellow = PRV cord – good thing
PRV= Planning at Risk Volume (ICRU recommendation)
Tomo Group Meetings
• Radiation Oncologists, Therapists and Physics meet weekly to determine:– Who is eligible for treatment (protocols)– Who can benefit most from IMRT treatment (nonprotocol)
• Potential CTVs are reviewed to determine:– Need for bolus and its placement– Immobilization device requirements
• Review treatment plans of patients on treatment
Therapist Perspective
• Therapists feel they are;– Using full-scope-of-practice– Involved at all levels of decision making
• Patient suitability• Targeting• Planning• Treatment• Education• Research
Additional Responsibilities
• Protocol development • Image-guided treatment delivery • Development of policy and procedures• Research
– Testing of new software– Adaptive planning– Publications
RTOG 0521 66/60/56 in 33Added sparing structures used to reduce toxicities
Unknown Primary 66/60/56 in 33Targets are homogeneous
OTT 06-04 In-house Breast + Nodes(IMC) Protocol
OTT 06-04 In-house Breast + Nodes(IMC) Protocol
V20= 6.8%
V5 = 36%
T2N1MO Squamous cell Anus Three PTV’s 60/55/48 in 30 (+chemo)
Rad Onc initially wanted to treat patient in three phases. Tomo team was able to created plan using alternate fractionation.
Whole Brain 3000/10 + Simultaneous Boost to 3 iso 4500/10 in 1plan (25 min)
**London Protocol
CNS – Avoidance Structure in Mid Brain
Therapist created this distribution. Pt is treated supine and has reduced toxicities
StatRT = Scan/Plan/Treat = 40 min
Scan• Place patient on the couch • Scan selected region • Acquire MVCT image set
Plan• Perform 3D contouring at the Operator Station• Set prescription • Optimize the treatment fraction • Evaluate using isodose distribution and dose volume histograms
(DVHs)Treat
• Helical IMRT delivery• Conformal 3D dose distributions • Simple to complex cases
Clinical Pilot
• 25 palliative patients
• Fractionated and single treatments
– Spine
– Abdo
– Lung
– Pelvis
StatRT - Two Targets Rt Hip and Peri-Rectal mass
StatRT - Two Targets Rt Hip and Peri-Rectal mass
Multiple Targets
Simple Targets
Mycosis Fungoides (20/5 to Blue and 15/5 to Red)
Previous TBE 3500/20 (using 6 or 9 MeV electrons) in 2003
Mycosis Fungoides (20/5 to Blue and 15/5 to Red)
Before and After
before
before
after
Our Team
Radiation Therapy– Lynn Montgomery– Kathy Carty– Greg Fox – Jamie Bahm– Bev Macallum– Karen Vanderwerff– Kirsten Keeler– Andre Patry– Sandra Hamilton
Medical Physics–
Jason
Belec–
Brenda Clark–
Lee Gerig–
Miller MacPherson–
Gosia Niedbala–
Balaz
Nyiri–
Janos Szanto
Radiation Oncology–
Rob MacRae–
Laval Grimard–
Shawn Malone–
Libni Eapen –
And a dozen more
Electronics–
Gaetan Belanger–
Georges Gohier–
Najib Nassar
Questions: [email protected]