Hypofractionated Postoperative IMRT in Prostate Carcinoma: A Phase I/II Study.

Area of Science:

• Radiation Oncology
• Urologic Oncology
• Medical Physics

Background:

• Radical prostatectomy (RP) is a primary treatment for prostate cancer (PCa).
• Adjuvant or salvage radiotherapy is indicated for high-risk patients post-RP.
• Hypofractionated radiotherapy offers potential for treatment intensification and improved patient convenience.

Purpose of the Study:

• To evaluate the outcomes of hypofractionated radiotherapy using simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) in patients with prostate cancer (PCa) after radical prostatectomy (RP).
• To assess the toxicity profile and biochemical relapse-free survival (bRFS) associated with this treatment regimen.

Main Methods:

• A cohort of 124 patients with PCa at high risk of relapse post-RP or with biochemical relapse received SIB-IMRT.
• The prescribed radiation dose was 62.5 Gy to the prostate bed and 45 Gy to pelvic nodes in 25 fractions.
• Androgen-suppressive therapy was administered based on National Comprehensive Cancer Network risk categories.

Main Results:

• Median follow-up was 30 months.
• A low incidence of severe acute toxicity was observed: grade 3 skin toxicity in 0.8% and grade 4 genitourinary (GU) toxicity in 0.8% of patients.
• Five-year rates for grade 2 or higher gastrointestinal (GI) and GU toxicity were 1.1% and 7.3%, respectively.
• The five-year biochemical relapse-free survival rate was 86.5%.

Conclusions:

• Hypofractionated SIB-IMRT is a feasible and effective treatment option for prostate cancer patients after RP.
• The technique demonstrates a favorable toxicity profile, with low rates of severe acute and late toxicity.
• Encouraging biochemical relapse-free survival rates suggest the efficacy of this approach in managing high-risk PCa post-prostatectomy.