Prostate Cancer Subclinical Metastatic Ablative MR-guided Radiotherapy

In the clinical scenario of recurrent prostate cancer (PCa) post local therapy, current standard studies (bone scan and computed tomography) commonly fail to identify the recurrent disease location. In this study the investigator aims to prospectively map recurrent disease with the unique combination of whole-body MR anatomical imaging combined with a new high-sensitivity and PCa-specific PET probe (PSMA-targeted: \[18F\]DCFPyL) to provide precise localization information to target disseminated tumor deposits in men presenting with rising PSA after prostatectomy and radiotherapy (maximal local therapies). Moreover, we will consequently treat all identified disease with image-guided stereotactic ablative radiotherapy (SABR), which has shown tantalizing results achieving excellent tumor eradication rates with minimal toxicities. This study is uniquely positioned to enable the discovery of new biomarkers and the correlation of prognostic tests (e.g. genomic signatures) from the initial prostatectomy specimen with the PET-MR/CT imaging results and curative-intent treatment outcomes.

The significance of the proposed work towards a measurable impact in PCa care is important to emphasize. The study team believes this novel curative-intent approach will transform lives, as opposed to therapies that transiently impact incurable disease stages. Herein, the focus is on patients at the earliest point of the disease spectrum of recurrent PCa after curative-intent treatments. Our hypothesis is that PSMA-targeted \[18F\]DCFPyL PET-MR/CT allows earlier detection and localization of defined metastatic targets in these patients, at a stage amenable to image-guided curative-intent therapy.


Eligibility Criteria:
* ECOG performance status of 0-2
* Absence of significant comorbidities rendering patient nor suitable for curative ablative approaches
* No history of non-skin malignancy
* Histological evidence of prostate adenocarcinoma on previous radical prostatectomy.
* No use of any form of hormonal therapy in the previous 12 months, or intention to start HT at time of enrollment.
* Normal serum testosterone level ascertained within 4-6 weeks of enrollment
* Absence of known metastatic disease
* Radiological studies without evidence of regional or distant metastases: CT abdomen-pelvis and bone scan within previous 3 months
* Able to lie supine at least 60 minutes to comply with imaging and treatment.
* Absence of impaired renal function (calculated GFR \> 30mL/min)
* Absence of sickle cell disease or other hemoglobinopathies
* No other medical conditions deemed by the PI to make patient ineligible for PET/MR scanning or SABR

No contraindications to MRI:

* Subject must weigh \<136kg (scanner weight limit)
* Subject must not have pacemakers, cerebral aneurysm clips, shrapnel injury, or implantable electronic devices not compatible with MRI
* Prior anaphylactic reaction to gadolinium

Rising PSA after maximal local therapies (radical prostatectomy and either adjuvant or salvage radiotherapy):

* Three documented PSA rises, at least 1 month apart from post radiotherapy.
* PSA value \>0.1 and \< 3 ng/mL, within 4-6 weeks of enrollment
* No use of any forms of ADT in the previous 12 months nor contemplated to be used at time of study enrollment. Salvage ADT to be started when PSA reaches a value of 6.0ng/ml or greater.