Anatomy-based Anatomy-based MLC Field Optimization MLC Field Optimization for the Treatment of for the Treatment of Gynecologic Malignancies Gynecologic Malignancies Myriam Bouchard M.D. Myriam Bouchard M.D. Nadeau S, Germain I, Raymond P.E., Nadeau S, Germain I, Raymond P.E., Harel F, Beaulieu F, Beaulieu L, Roy Harel F, Beaulieu F, Beaulieu L, Roy R, Gingras L R, Gingras L Dep. of radiation oncology of L’Hotel-Dieu de Dep. of radiation oncology of L’Hotel-Dieu de Quebec, QC, Canada Quebec, QC, Canada Dep. of Physics, Physics Engineering and Optics, Dep. of Physics, Physics Engineering and Optics, Laval University, Quebec, Canada Laval University, Quebec, Canada
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Anatomy-based MLC Field Optimization for the Treatment of Gynecologic Malignancies
Anatomy-based MLC Field Optimization for the Treatment of Gynecologic Malignancies. Myriam Bouchard M.D. Nadeau S, Germain I, Raymond P.E., Harel F, Beaulieu F, Beaulieu L, Roy R, Gingras L Dep. of radiation oncology of L’Hotel-Dieu de Quebec, QC, Canada - PowerPoint PPT Presentation
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Anatomy-based Anatomy-based MLC Field Optimization MLC Field Optimization
for the Treatment of for the Treatment of Gynecologic MalignanciesGynecologic Malignancies
Myriam Bouchard M.D.Myriam Bouchard M.D.Nadeau S, Germain I, Raymond P.E., Nadeau S, Germain I, Raymond P.E., Harel F, Beaulieu F, Beaulieu L, Roy R, Harel F, Beaulieu F, Beaulieu L, Roy R, Gingras LGingras L
Dep. of radiation oncology of L’Hotel-Dieu de Quebec, Dep. of radiation oncology of L’Hotel-Dieu de Quebec, QC, Canada QC, Canada Dep. of Physics, Physics Engineering and Optics, Laval Dep. of Physics, Physics Engineering and Optics, Laval University, Quebec, CanadaUniversity, Quebec, Canada
IMRT for GYN IMRT for GYN malignanciesmalignancies
Post-operativePost-operative whole-pelvis whole-pelvis radiotherapyradiotherapy– More bowel to spare, bowel replacing More bowel to spare, bowel replacing
uterusuterus– Less organ motionLess organ motion
Good clinical results with IMRT Good clinical results with IMRT 11 – 36 patients, whole-pelvis IMRT36 patients, whole-pelvis IMRT
Median follow-up = 19,6 monthMedian follow-up = 19,6 month
– 13.9% less GI-GII toxicity13.9% less GI-GII toxicity1 MUNDT et al. IJROBP, vol.56 #5 (2003) pp.1354-1360
– Higher potential impact of machine or Higher potential impact of machine or patient positioning errors patient positioning errors
– Increased planning, treatment and Increased planning, treatment and quality assurance timequality assurance time
– Higher impact of organ motionHigher impact of organ motion
BallistaBallistaA new inverse planning A new inverse planning
approachapproach
A dosimetric studyA dosimetric studyApproved by the local institutional committee for medical Approved by the local institutional committee for medical ethicsethics
Materials and methodsMaterials and methods Planning CTscan as usualPlanning CTscan as usual
Conventional planning : Conventional planning : – 4-field plans based on bony landmarks4-field plans based on bony landmarks– Created before other plan conceptionCreated before other plan conception
Enlarged 4-fieldEnlarged 4-field– Aperture shaped to PTVAperture shaped to PTV
Priorities in our studyPriorities in our study First priority on RAR-BFirst priority on RAR-B Bladder Bladder
– Relative important weight given to it…Relative important weight given to it… Organ motion +++Organ motion +++ Eventually replaced by small bowelEventually replaced by small bowel
Bone marrow : when possibleBone marrow : when possible
To enhance sparing…To enhance sparing… Organ motion study necessary Organ motion study necessary 22
– To limit as possible expansion for PTVTo limit as possible expansion for PTV In our study, ITV/PTV limited sparing of In our study, ITV/PTV limited sparing of
Class solutionClass solution Statistic analysis on each beam’s roleStatistic analysis on each beam’s role
– Frequency of utilization of beamFrequency of utilization of beam To spare a determined (part of) OARTo spare a determined (part of) OAR To irradiate a part of the PTVTo irradiate a part of the PTV
Class solution based on «beam’s role»Class solution based on «beam’s role»
Similar plans created without Similar plans created without BallistaBallista Similar planning with other system is possibleSimilar planning with other system is possible
ConclusionsConclusions
BallistaBallistaA new inverse planning approachA new inverse planning approach