High Dose Rate Prostate (HDR) Brachytherapy Dose Escalation to Dominant Intra-prostatic Nodule for Patients With Intermediate and High Risk Prostate Cancer
Methods: If a dominant nodule is visualized on DCE MRI, it will be contoured in 3D and the
images fused to the planning TRUS study that is done in preparation for brachytherapy (of
any type: seeds or HDR). The patient's treatment will consist of the standard combined
external beam (4600 cGray in 23 fractions) and HDR brachytherapy boost (2 fractions of 1000
cGray given on days 5 and 15 of the external beam course). During each HDR treatment the
plan will be manipulated such that the normally occurring high dose regions (125%, 150%) are
positioned at the site of the identified disease. Normally approximately 60% of the prostate
volume receives 125% of the dose and 30% receives 150%. By ensuring that the inherent
dosimetry favors treatment of the known cancer, no region of the prostate would be
"underdosed". HDR treatments are performed under general anesthesia as an out patient
procedure.
Statistical Analysis: This is a feasibility study and the data reported will be descriptive
including the frequency with which the DIL can be visualized in this population, the DIL
volume compared to total prostate volume, and the isodose that can encompass the DIL without
violating dose constraints to adjacent organs (urethra and bladder). Toxicity will be
monitored and efficacy will be assessed by repeat DCE MRI at 12 months and biopsy at 30
months.
Interventional
Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
Feasibility of delivery of a higher than prescription dose to the dominant intra-prostatic nodule as defined on diffusion contrast-enhanced endo-rectal MRI, while respecting tolerance doses of adjacent normal organs.
Data to be collected are: i) ratio of volume of GTV to prostate volume ii) number of DIL's per prostate iii) isodose encompassing DIL without exceeding critical organ dose constraints (Urethral volume receiving 115%= 0, Dose to 1cc of rectal wall < 7 Gy)
12 months
No
Matthew Schmid, MSc
Principal Investigator
Medical Physicst
Canada: Ethics Review Committee
H12-00557
NCT01605097
May 2012
December 2015
Name | Location |
---|