Comparison of two Different Radiotherapy Schedules for Spinal Cord Compression in Prostate Cancer

Abstract

Aims and background

To assess the clinical outcome and toxicity of two different radiotherapy (RT) schedules for the management of metastatic spinal cord compression from prostate cancer, we performed a prospective analysis of 44 patients with the complication.

Methods

Two different RT schedules were adopted, a split-course regimen of 5 Gy x 3, 4 days rest, and then 3 Gy x 5, and a short-course regimen of 8 Gy, 7 days rest, and then 8 Gy. The split-course RT was adopted for all prostate cancer patients referred to our center between 1986 and 1992. Starting in 1993, the short-course RT was added for patients with a poor prognosis (i.e., paresis or paraplegia, low performance status, and/or short life expectation), whereas others still underwent the split-course regimen. So, 27 (61%) patients were treated with the split-course and the other 17 (39%) with the short-course regimen. Medium follow-up was 48 months (range, 6 to 123).

Results

Back pain total response rate was 82%. Effectiveness of RT on motor and bladder capacity was conditioned by pretreatment status of patients. All 20 (100%) walking cases maintained the function, whereas 11 of 24 (46%) with motor impairment regained the ability. The difference in response rate was statistically significant (P<0.001). All 36 (100%) patients, able to void at presentation preserved the capacity, whereas 3 of 8 (38%) with sphincter dysfunction no longer needed an indwelling catheter. Posttreatment neurologic status was the only factor found to affect survival. Median survival, 9 months for the whole group, was 10 and 2 months for posttreatment walking and nonwalking patients, respectively (10 vs 2 months, P<0.001). Neither presence of other metastases nor RT regimen used (split vs short-course) conditioned response rate, duration of response or survival. Acute or late, severe toxicity was never recorded. No patient complained of spinal cord morbidity.

Conclusions

Both split-course and short-course RT schedules were effective and without complications. Early diagnosis was the most important prognostic factor, but there was also recovery of function in about half of the patients unable to walk, and about one-third of patients with bladder dysfunction before treatment. Since length of the course of therapy is a factor with an important impact on the patient's quality of life, the short-course RT regimen adopted in the trial merits further investigation.