psma pet response guided sabr in high risk pca

Conditions: Prostate Adenocarcinoma

Summary: sequential cohort evaluation of ideal timing of imaging and treatment spacing to discern maximal psma (prostate specific membrane antigen) pet (positron emission tomography) response (psma-11 68ga, illucix) for adaptation of dominant intra-prostatic lesion tumor boost dose


Eligibility criteria:
inclusion criteria: -pathologically confirmed adenocarcinoma of the prostate (within 180 days of registration) of high risk by national comprehensive cancer network (nccn) criteria as determined by \>=ct3a stage (ajcc 8th edition) or psa\>20ng/ml or isup grade group 4-5 (gleason grade 8-10). age ≥ 18 years. * planned for definitive intent stereotactic ablative radiotherapy (sabr) with integrated dose boost to intra-prostatic tumor and androgen deprivation therapy (adt) with baseline aua ipss \<=18 and prostate size \<=100cc * staging 68ga pmsa-11 pet -ct or -mri performed within 90 days of registration and before initiation of anti-androgen or androgen deprivation therapy and demonstrating no evidence of distant metastases by (pmsa avid or non-avid nodes \<=1.5cm short axis allowed). conventional imaging (ct, bone scan, mri) may also be used in addition to pmsa-pet, and definitive findings of distant extra-pelvic metastases on these scans are not allowed for enrollment. * staging 68ga psma-11 pet -ct or -mri demonstrating a psma-avid primary intra-prostatic target lesion amenable at investigator discretion to dose boost * all men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of standard of care sabr and for a period of time of 6 months thereafter as per standard guidelines. should a man's partner become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. * ability to understand and the willingness to sign a written informed consent. exclusion criteria: * prior curative intent local therapy (e.g. prostatectomy, radiotherapy, focal ablative therapy) for prostate cancer is not allowed, with following exceptions regarding androgen deprivation therapy (adt)/anti-androgen therapy (aat): prior androgen deprivation therapy (adt) allowed if \ =3 months prior to registration with demonstration of non-castrate testosterone recovery (\>50ng/dl) and meeting all other inclusion criteria. ongoing androgen deprivation therapy (adt) is allowed if \<=60 days total duration and meeting following criteria: if gnrh agonist used (e.g. leuprolide), bicalutamide must have been used for at least 30 days +/-14 days from start of gnrh agonist. all other inclusion criteria. * subjects may not be receiving any other investigational agents for the treatment of the cancer under study. * history of allergic reactions to pmsa-11 68ga imaging agent. * uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that, in the opinion of the investigator, would limit compliance with study requirements. * prior pelvic radiotherapy other than cutaneous/superficial treatments.