Focal Radiation Therapy (HDR-Brachytherapy) for the Treatment of Prostate Cancer

Phase II Trial of Focal Radiation Therapy in Patients With Prostate Cancer

This clinical trial tests the effect of focal radiation therapy, high dose rate-brachytherapy (HDR-BT), in treating patients with prostate cancer. Prostate cancer is the most diagnosed cancer in men and there are many treatments available, including surgery and radiation therapy. Although surgery and radiation therapy improve survival urinary and sexual function can be significantly affected and can be long lasting. HDR-BT, a type of focal radiation therapy also known as internal radiation therapy, uses radioactive material placed directly into or near a tumor to kill tumor cells. Giving HDR-BT may be effective in providing local control while reducing side effects in patients with prostate cancer.

PRIMARY OBJECTIVES:

I. Estimate local control. II. Estimate acute/late grade 2+ genitourinary (GU)/gastrointestinal (GI) toxicity.

SECONDARY OBJECTIVES:

I. Prostate specific antigen (PSA) response at 6 weeks after radiation therapy (RT), every 3 months for 24 months, every 6 months to 60 months, then every 8-12 months until 5 years.

II. Clinical progression free survival/biochemical progression free survival at 5 years.

III. Distant metastasis free survival. IV. Development of castration-resistant disease. V. Overall survival. VI. Changes in quality of life VIa. Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire; VIb. Expanded Prostate Cancer Index Composite Short Form (EPIC-26) questionnaire.

OUTLINE:

Patients undergo HDR-BT to dominant prostate lesion on day 1. Treatment repeats at least 3 weeks apart for up to 2 fractions in the absence of disease progression or unacceptable toxicity. Patients also undergo blood sample collection, multiparametric (mp) magnetic resonance imaging (MRI) and optionally prostate-specific membrane antigen (PSMA) positron emission tomography (PET) throughout the study. Additionally, patients may undergo tumor biopsy as clinically indicated throughout the study.

After completion of study treatment, patients are followed up at 6 weeks, every 3 months for the first 2 years, every 6 months for years 3 and 4, then annually thereafter.

Inclusion Criteria:

• Histologically confirmed diagnosis of prostate adenocarcinoma within 90 days prior to registration via systematic biopsy

• Multiparametric MRI (mp-MRI) confirmed lesion(s)

• No distant or locally advanced disease on standard staging exams as indicated

  • Bone scan and abdominopelvic computed tomography (CT)/MRI OR
  • PSMA PET

• Eastern Cooperative Oncology Group (ECOG)/Zubrod performance status 0/1 within 60 days prior to enrollment

• Age ≥ 40

Exclusion Criteria:

• Radiographic nodal or distant metastatic disease
• Lesion(s) comprising > 40% of total prostate volume
• Prior radiotherapy to the pelvis
• Gleason score > 6 disease outside intended gross target volume (GTV)/target region(s)