A technique for the use of afterloading 137Cs brachytherapy in renal-sparing irradiation of bilateral Wilms tumor.

ABSTRACT

PURPOSE: To describe a renal sparing brachytherapy technique for treating patients with bilateral Wilms tumor who have limited residual tumor measuring 2 cm or less after initial chemotherapy. METHODS AND MATERIALS A technique for using brachytherapy in the radiotherapeutic management of bilateral Wilms tumor is described. Three patients with bilateral Wilms tumor were treated at our institutions. All three patients had initial nephrectomy of the contralateral kidney followed by chemotherapy. Local excision of residual tumor in the remaining kidney was done in all three cases. A 137Cs isotopic source was placed in the tumor bed at the time of the second surgery using a simple afterloading applicator. The techniques of applicator placement, localization, and brachytherapy dosimetry are described. The minimum tumor dose varied from 16 to 25 Gy. RESULTS: All three patients are alive and well at 28, 48, and 66 months after the procedure. There were no serious operative or postoperative sequelae. CONCLUSIONS: This simple brachytherapy technique was effective in selected cases of bilateral Wilms tumor where a renal-sparing radiotherapy approach was needed. This technique is most applicable when there is residual intrarenal tumor after partial nephrectomy, when the tumor is unifocal, and when the tumor bed is less than 2 cm diameter.