Palliative treatment of pelvic bone tumors using radioiodine (I) brachytherapy.

Background: Complete resection of pelvic bone tumors, especially recurrent and metastatic ones, is often impossible to achieve using conventional surgery. This study aimed to assess the benefits and adverse effects of computed tomography (CT)-guided radioiodine (I) brachytherapy for inoperable recurrent and metastatic bone tumors of the pelvis.

Methods: This was a retrospective study of 22 patients with confirmed pelvic bone tumors (10 females and 12 males; 15-84 years; 21 with primary pelvic tumor and one with pelvic metastasis). CT-guided I brachytherapy was performed using 9-21 I seeds (radioactivity of 0.5-0.7 mCi). Seed implantation was validated by postoperative CT scanning. Complications, pain, survival, and CT-estimated tumor size were carried out to evaluate the therapeutic benefits.

Results: Postoperative CT scans revealed satisfactory I seed implantation, and the radiation dose delivered to 90% of the target area (D90) was higher than the prescription dose (PD). No obvious complications were observed. Pain was reported by 19 of 22 patients, but 17 reported pain relief after implantation. Follow-up ranged 8-27 (median, 19) months. Tumor size was reduced in 11 patients within 1 month after surgery, nine patients showed no change, and tumor size increased in two patients. Finally, 1- and 2-year survival was 81.8 and 45.5%, respectively; 1- and 2-year local tumor control rates were 59.1 and 36.4%, respectively.

Conclusions: I seed implantation significantly reduced bone tumor size and relieved pain, with a low complication rate. These findings suggest that I brachytherapy treatment could be a useful palliative approach for pelvic bone tumor treatment.