Intraoperative radiotherapy in the treatment of neuroblastoma: Report of a pilot study

Background: External beam radiotherapy in advanced neuroblastoma is limited by the volume of normal radiosensitive tissues included in the radiation field. Limitations to external radiation are the late effects to these tissues. Intraoperative radiotherapy (IORT) delivers a single high-radiation dose to a tumor while displacing normal tissues that would have been included in an external field. Standard external radiotherapy can still be done after "boost" IORT. Methods: Eight advanced-stage neuroblastoma patients who received IORT as part of their multimodality therapy were reviewed to identify the impact of IORT on operative time, complications, and tumor control in the treatment field. The IORT was accomplished by patient transport from the OR to the radiation therapy suite; these were separated by three floors. Results: IORT added 30-75 min to the operative procedure. Tumors in the resection/IORT fields showed no evidence of disease (one), stable tumor size (six), and tumor recurrence (one). Two complications were identified: a urinary fistula and CO₂ retention, which was detected and corrected before the IORT. Neither of these complications was related to the IORT. Two patients who had subsequent tumor resection after IORT demonstrated tumor differentiation to ganglioneuromatous tissue. Conclusions: IORT usually can be completed in less than an hour. No IORT-associated complications were identified. IORT along with maximal tumor resection, external radiation, and chemotherapy enhances local tumor control.