The role of stereotactically guided conformal radiotherapy for local tumor control of esthesioneuroblastoma

Abstract

Background: In a retrospective analysis we compared conventional radiotherapy and stereotactically guided conformal radiotherapy (SCRT) in patients with esthesioneuroblastoma.

Patients and methods: Between 1991 and 1999 14 patients with esthesioneuroblastoma underwent radiotherapy at our institution. Median follow-up was 30 months (range 12-107 months). Treatment included adjuvant radiotherapy (9), adjuvant radiochemotherapy (3) or radiotherapy alone (2). Eight patients received SCRT with 3-D treatment planning. For comparison a standard three-field plan for these patients and dose-volume histogram analyses were performed. Median total dose was 64 Gy using SCRT and 56 Gy with standard technique.

Results: Local tumor control rate was 50% with conventional radiotherapy and 75% with SCRT. Overall survival was 33.3% and 62.5%, respectively. Target coverage could be improved statistically significant (p < 0.05) and dose to critical structures was reduced using SCRT. Greatest differences were seen regarding volume above the 30%-isodose as well as mean dose of brain stem (p < 0.05). A reduction of maximum dose was seen using SCRT as consequence of a more homogeneous treatment.

Conclusions: SCRT improves target coverage and sparing of organs at risk. Our clinical data although with low patient numbers suggest that the technical advantage translates into a clinical advantage. The use of SCRT appears to facilitate higher dose prescriptions without risking major acute and late side effects. Thus the risk of complications in this area is minimized. Adjuvant radiotherapy is a save and effective treatment modality for local control of esthesioneuroblastoma.