A Single-Dose Conformal Delivery of Radiotherapy following Osteoplasty

Abstract

Multiple myeloma (MM) is a very radiosensitive tumor. Fractionated external beam radiation, which takes approximately 2 weeks of therapy, is typically used to irradiate myelomatous bone lesions with the goal of palliation. However, traditional radiotherapeutic techniques are not only lengthy but they also involve a considerable amount of healthy bone marrow in the treatment ports, which may undermine the total marrow reserve of a patient. Because of the limited survival time of patients with metastatic cancer, novel treatment concepts shortening the overall treatment time is desirable. We present an innovative approach of delivering targeted intra-operative radiotherapy to a solitary osteolytic metastasis in one application, while sparing healthy bone marrow from radiation toxicity and substantially reducing the overall treatment time. A 78-year-old Caucasian male with MM, previously treated with chemotherapy, who was off chemotherapy for 2 years due to bone marrow suppression, presented with a solitary recurrence at the left anterior superior iliac spine of the left iliac wing as diagnosed by PET-CT scan. This lesion was treated with a minimally invasive osteoplasty and intra-operative brachytherapy with to a dose of 8 Gy delivered to the surgical cavity only, followed by injection of the bone cement into the cavity. Three months after the procedure, the area of treatment demonstrated no uptake on a follow-up PET-CT scan. At 1.5 years after this procedure, 100% local control continues to persist in the treated area, as evidenced on nuclear imaging. To our knowledge, this is the first case of using focal intraoperative brachytherapy confined to the area of the pelvis in a patient treated for a solitary metastasis from MM. The purpose of the article is to present a novel approach as a more convenient and focal treatment of bony lesions of MM.