Toxicity and outcome of pelvic IMRT for node-positive prostate cancer

Background and purpose

This study reports on the treatment techniques, toxicity, and outcome of pelvic intensity-modulated radiotherapy (IMRT) for lymph node-positive prostate cancer (LNPPC, T1-4, c/pN1 cM0).

Patients and methods

Pelvic IMRT to 45–50.4?Gy was applied in 39?cases either after previous surgery of involved lymph nodes (n?=?18) or with a radiation boost to suspicious nodes (n?=?21) with doses of 60–70?Gy, usually combined with androgen deprivation (n?=?37). The prostate and seminal vesicles received 70–74?Gy. In cases of previous prostatectomy, prostatic fossa and remnants of seminal vesicles were given 66–70?Gy. Treatment-related acute and late toxicity was graded according to the RTOG criteria.

Results

Acute radiation-related toxicity higher than ?grade?2 occurred in 2?patients (with the need for urinary catheter/subileus related to adhesions after surgery). Late toxicity was mild (grade 1–2) after a median follow-up of 70?months. Over 50% of the patients reported no late morbidity (grade 0). PSA control and cancer-specific survival reached 67% and 97% at over ?5?years.

Conclusion

Pelvic IMRT after the removal of affected nodes or with a radiation boost to clinically positive nodes led to an acceptable late toxicity (no grade 3/4 events), thus justifying further evaluation of this approach in a larger cohort.