INTRAOPERATIVE RADIOTHERAPY IN THE TREATMENT OF NEUROBLASTOMA - REPORT OF A PILOT-STUDY

Background: External beam radiotherapy in advanced neuroblastoma is li mited by the volume of normal radiosensitive tissues included in the r adiation field. Limitations to external radiation are the late effects to these tissues. Intraoperative radiotherapy (IORT) delivers a singl e high-radiation dose to a tumor while displacing normal tissues that would have been included in an external field. Standard external radio therapy can still be done after ''boost'' IORT. Methods: Eight advance d-stage neuroblastoma patients who received IORT as part of their mult imodality therapy were reviewed to identify the impact of IORT on oper ative time, complications, and tumor control in the treatment field. T he IORT was accomplished by patient transport from the OR to the radia tion therapy suite; these were separated by three floors. Results: IOR T added 30-75 min to the operative procedure. Tumors in the resection/ IORT fields showed no evidence of disease (one), stable tumor size (si x), and tumor recurrence (one). Two complications were identified: a u rinary fistula and CO, retention, which was detected and corrected bef ore the IORT. Neither of these complications was related to the IORT. Two patients who had subsequent tumor resection after IORT demonstrate d tumor differentiation to ganglioneuromatous tissue. Conclusions: IOR T usually can be completed in less than an hour. No IORT-associated co mplications were identified. IORT along with maximal tumor resection, external radiation, and chemotherapy enhances local tumor control.