Salvage Moderate Hypofractionated Versus Ultrahypofractionated Radiotherapy for Biochemical Recurrence After Radical Prostatectomy in Prostate Cancer

Moderate hypofractionated radiotherapy (Moderate-hypoRT): 60 Gy in 24 fractions, delivered once daily, 5 days per week (on weekdays), over a total of 5-6 weeks.

Ultra-hypofractionated radiotherapy (Ultra-hypoRT): 31 Gy in 5 fractions, delivered every other day (2-3 fractions per week), over a total of 2 weeks.

Inclusion criteria

• Patients who have undergone radical prostatectomy for prostate cancer
• Age ≥ 20 years
• Persistent prostate-specific antigen (PSA) elevation after radical prostatectomy, defined as prostate-specific antigen (PSA) levels of 0.1-1.0 ng/mL with at least three consecutive increases
• Patients who have undergone prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) for evaluation of prostate-specific antigen (PSA) elevation
• Good performance status (ECOG performance status 0-1)

Exclusion criteria

• Radiologic or clinical evidence of gross local recurrence, lymph node metastasis, or distant metastasis, including findings on prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT), as determined by the treating physician
• Presence of lymph node metastasis or distant metastasis at the time of radical prostatectomy
• History of prior pelvic radiotherapy
• Diseases associated with a high risk of radiation toxicity (e.g., inflammatory bowel disease, systemic lupus erythematosus, scleroderma, or other connective tissue diseases)
• History of another malignancy diagnosed or recurrent within the past 3 years (except for skin cancer and thyroid cancer)
• Uncontrolled acute or chronic conditions deemed inappropriate for study participation by the investigator (e.g., dementia, Alzheimer's disease, cerebral infarction, etc.)