Postoperative or Salvage Proton Radiotherapy for Prostate Cancer After Radical Prostatectomy

Area of Science:

• Oncology
• Radiation Oncology
• Proton Therapy

Background:

• Postprostatectomy radiation therapy is crucial for disease control.
• Limited data exist on the efficacy and toxicity of proton therapy in this setting.

Purpose of the Study:

• To evaluate the outcomes, toxicities, and quality of life in patients treated with proton therapy after prostatectomy.

Main Methods:

• Retrospective review of 102 patients treated with double-scattered proton therapy.
• Analysis of adjuvant and salvage radiation cases, including prostate bed and pelvic node treatments.
• Assessment of toxicities using Common Terminology Criteria for Adverse Events (CTCAE) v4.0 and patient-reported quality of life.

Main Results:

• Five-year biochemical relapse-free survival was 57% overall, and distant metastases-free survival was 97% overall.
• Low rates of severe (grade 3+) acute and late genitourinary toxicity (1% and 7%).
• No grade 3+ gastrointestinal toxicity observed; low rates of grade 2 GI toxicity (5% acute, 2% late).

Conclusions:

• High-dose postprostatectomy proton therapy demonstrates effective long-term biochemical control and metastasis prevention.
• Proton therapy is associated with low rates of acute and late gastrointestinal and genitourinary toxicity.
• Patient-reported quality of life measures remained stable or improved over time.