A case report on a novel use of intraoperative Intrabeam™ radiation therapy for a recurrent malignant peripheral nerve sheath tumor with sciatic nerve involvement.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNST) are sarcomas that arise from peripheral nerves. They generally have a poor prognosis which is exacerbated by high local recurrence rates. This case report discusses the treatment of a patient with a MPNST with local recurrence. This case report is novel due to the use of intraoperative Intrabeam™ (Zeiss, Dublin, CA) radiation therapy use in the protection of neurovascular structures such as the sciatic nerve. CASE PRESENTATION: The patient was a 65-year-old male who noticed a right posterior thigh mass slowly increasing in size over two months. A planned positive margin wide-resection excision was performed due to sciatic nerve abutment. The mass was determined to be a MPNST via postoperative pathology with positive margins along the sciatic nerve. The patient began adjuvant radiation therapy to the upper and lower thigh fields over a period of three months. Thirty-two months later, the patient was found to have a hypermetabolic mass with venous congestion and hyperemia at the prior surgical site which was confirmed by core needle biopsy to be local recurrence of the MPNST. Re-excision of the tumor was planned and performed followed by intraoperative Intrabeam™ radiation therapy. At two years of follow-up, the patient was doing well with minimal pain in his right buttock region with no new or recurrent neurological deficits. Radiologic imaging was negative for local recurrence of the MPNST. CONCLUSION: We believe this case report demonstrates a novel treatment strategy for sarcoma management. The unique use of intraoperative Intrabeam™ radiation therapy, which had not previously been used for this indication, may be efficacious in cases involving neurovascular structures. In this case, focal radiation from the intraoperative Intrabeam™ radiation device was used in a way to affect the recurrent tumor yet protect the sciatic nerve.

Survival benefit for early hormone ablation in biochemically recurrent prostate cancer.

PURPOSE: To determine whether early initiation of androgen ablation in patients with biochemically recurrent prostate cancer, but without clinically evident metastases, is associated with improved overall or disease-specific survival. To describe subgroups, based on PSA kinetics, which are most likely to benefit from early androgen ablation. MATERIALS AND METHODS: A retrospective cohort of 124 patients, who were definitively treated by external beam radiotherapy between 1988 and 1999, and subsequently received androgen ablation for biochemical (92 patients) or clinically metastatic (32 patients) failure, was reviewed. Median follow-up time was 6.2 years. Overall survival, disease-specific survival, and hormonal control were examined and compared for patients whose hormone ablation was started early (prostate-specific antigen [PSA] 7 months) or late in the course of their biochemical failure. RESULTS: All patients had biochemical response to hormone initiation, with a median PSA nadir of 0.05 ng/ml. Early initiation of hormone ablation resulted in statistically significant improvement in all outcome measures. Multivariate analysis indicated that PSA doubling time at hormone initiation was the most consistent predictor of outcome. The 5-year overall survival was 78% for patients whose androgen ablation was initiated at doubling time 7 months. Mean survival improved from 84.9 +/- 4.6 (doubling time 7). Survival for patients started on hormones with doubling time <5 months was similar to that of patients with clinical metastases. CONCLUSIONS: This survival benefit justifies the use of androgen ablation in patients whose doubling time approaches 7 months. A randomized trial is needed to confirm these findings, investigate potential benefit for patients with longer doubling times, and gather data on the morbidity of early hormone ablation, including quality of life issues.