RAD 1801: Pilot Study of Intra-Urethral Radiotransponder Beacon Guided Focal Prostate Stereotactic Body Radiotherapy

This study offers focal stereotactic body radiotherapy for prostate cancer by using an
intra-urethral radiotransponder placed temporarily during each of the 5 radiotherapy
treatments. The study aims to improve the risk-benefit ratio of therapy for early prostate
cancer and potentially lessen symptom burden over time while also accessing early efficacy,
late toxicity, and overall quality of life post-treatment. Patients will be followed for 24
months (2 years) with follow-up appointments at 3, 6, 9, 12, 18, and 24 months.

Inclusion Criteria:

- All patients must have histologically confirmed adenocarcinoma of the prostate, with
biopsies obtained within 12 months of registration

- Gleason score 3+3 or 3+4

- PSA <10 ng/mL within 3 months of enrollment

- Clinical stage T1a-T2a by digital rectal exam

- Up to 2 intraprostatic nodules visible on MRI, with combined volume <50% of the
total prostate volume

- Karnofsky Performance Status (KPS) >70%.

- Life expectancy >10 years

- Age ≥ 19 years

- Subjects given written informed consent

Exclusion Criteria:

- >2 MRI defined nodules representing prostate cancer

- Total volume of MRI nodules exceeding 50% of total prostate volume

- Positive biopsy core in sextant region without MRI defined nodule (i.e. biopsy proven
MRI occult prostate cancer)

- American Urological Association (AUA) urinary score ≥ 18.

- History of inflammatory bowel disease.

- Prior pelvic surgery

- Prior treatment for prostate cancer

- Patients using immunosuppressive medications or other medications that may increase
radiation toxicity such as methotrexate, sirolimus, tacrolimus, or colchicine that are
unable to discontinue these medications during SBRT course. Use of corticosteroids is
not considered an exclusion criteria.

- Platelet count < 70,000/µL

- Patients unable to discontinue anti-platelet or anti-coagulant medicine such as
clopidogrel, dabigatran, warfarin, or low molecular weight heparin. Use of aspirin is
not an exclusion criteria.

- Contraindication to MRI such as implanted devices.

- Metallic pelvic implants resulting in imaging artifact within the prostate on MRI or
CT