Feasibility and Clinical Value of CT-Guided (125)I Brachytherapy for Pain Palliation in Patients With Breast Cancer and Bone Metastases After External Beam Radiotherapy Failure

Objectives: To evaluate the feasibility and clinical value of CT-guided iodine-125 ((125)I) brachytherapy for pain palliation in patients with breast cancer and bone metastases after external beam radiotherapy failure. Methods: From January 2014 to July 2016, a total of 90 patients, who had received the standard therapies for bone metastases but still suffered moderate-to-severe pain, were retrospectively studied. About 42 patients were treated with both (125)I brachytherapy and bisphosphonates (Group A), and 48 patients were treated with bisphosphonates alone (Group B). Results: In Group A, 45 (125)I brachytherapy procedures were performed in 42 patients with 69 bone metastases; the primary success rate of (125)I seed implantation was 92.9%, without severe complications. Regarding pain progression of the two groups, Group A exhibited significant relief in “worst pain,” “least pain,” “average pain,” and “present pain” 3-day after treatment and could achieve a 12-week-remission for “worst pain,” “least pain,” “average pain,” and “present pain.” The morphine-equivalent 24-h analgesic dose at 3 days, 4 weeks, 8 weeks, and 12 weeks was 91 ± 27, 53 ± 13, 31 ± 17, and 34 ± 12 mg for Group A, and 129 ± 21, 61 ± 16, 53 ± 15, and 105 ± 23 mg for Group B. Group A experienced a lower incidence of analgesic-related adverse events and better quality of life than Group B. Conclusion: The CT-guided (125)I brachytherapy is a feasible and an effective treatment for the palliation of pain caused by bone metastases from breast cancer after external beam radiotherapy failure.