A Phase I/II Study of Salvage High-dose-rate Brachytherapy, ExternAl Beam COmbined and Short-term Hormonal Therapy for the Treatment of Node-positive Locally Recurrent Prostate Cancer After Prior Definitive Radiotherapy

Salvage regional and local radiation is frequently utilized across multiple disease sites in oncology for patients who have failed initial radiotherapy. However, in prostate cancer, due to the concern that nodal involvement is a manifestation of widespread distant disease, this type of approach has not typically been pursued. However, with newer imaging modalities such as fluciclovine PET, PSMA pet, and C11 PET, physicians are identifying nodal disease and excluding distant disease better than they ever have before. Thus, in the modern era regional control may translate to improved long-term biochemical control, and prevent the morbidity and mortality associated with clinical progression of recurrent prostate cancer

Thus, in patients who recur both in the prostate and in the pelvic lymph nodes, treating both with radiation could result in meaningful clinical efficacy for patients-similar to other disease sites. However, there are limited data exploring the feasibility and safety of this combination. Therefore, the investigators are conducting this trial, which combines salvage HDR brachytherapy to the local recurrence of the prostate cancer with EBRT to the pelvic lymph nodes, and short-term hormonal therapy, in this group of patients. The investigators hypothesize that this approach can safely be performed without excess toxicity.

Once a patient is deemed eligible for the study and has signed the informed consent form, the patient will start hormone therapy with a LHRH Agonist medication which is an intramuscular injection which patients will receive every 3-6 months for 6 months. Within 10 days of the LHRH injection the patient must start an anti-androgen pill and will take the pill once a day until the last day of radiation. Radiation Therapy will start approximate 2 months after the start of the hormone therapy. Patients will undergo 2 implants with 1 fraction of 12 Gy delivered with each implant, scheduled 1-2 weeks apart when possible, although longer or shorter intervals are acceptable with PI approval. The implant procedure will be done under general anesthesia. Patients will also receive the external beam radiotherapy (for 5 weeks), starting before or after the brachytherapy treatment. Patients will also be asked to complete 2 short quality of life questionnaires before they receive treatment and at follow up visits. Patient will follow up with the radiation oncologist for an exam at 1 month, 3 months, 6 months and 12 months after treatment and then every 6 months for 4 more years then annually thereafter.