Reduction of radioactive seed embolization to the lung following prostate brachytherapy

Purpose: Ultrasound-guided interstitial implantation of radioactive seeds i s a common treatment for early stage prostate cancer. One of the risks asso ciated with this therapy is seed embolization to the lung. This paper repor ts on the incidence and possible adverse effects of seed migration. Methods and Materials: Two hundred ninety consecutive patients were treated with permanent radioactive seed brachytherapy for prostate cancer between January 1 and December 31, 1995, One hundred fifty-four patients were treat ed with iodine-125 (I-125), and 136 patients were treated with palladium-10 3 (Pd-103), All but one patient had a routine post implant chest radiograph (CXR), leaving 289 evaluable patients. Results: Twenty radioactive seed pulmonary emboli were identified in 17 pat ients; 3 patients had two emboli each. The radioactive seed pulmonary embol ism rate for the entire group of patients was 5.9%, Acute pulmonary symptom s were not reported by any patient in this series. One hundred forty-six st udy patients were implanted with free seeds alone (136 Pd-103 and 11 I-125) , and 143 were implanted with linked seed embedded in a vicryl suture for t he peripheral portions of their implants, The radioactive seed embolization rate by patient was 11% (16/146) versus 0.7% (1/143) for free seed implant s and implants utilizing linked seeds, respectively. The difference was sta tistically significant, p = 0.0002. No patient had detectable morbidity as a consequence of seed emboli. Conclusion: The use of linked seeds embedded in vicryl sutures for the peri pheral portion of permanent radioactive seed prostate implants significantl y reduced the incidence of pulmonary seed embolization in patients treated with the Seattle technique. (C) 1998 Elsevier Science Inc.