Local Recurrence Following Total Marrow Radiation: Implications for Clinical Target Delineation

Abstract

Total marrow radiation is an emerging treatment modality used in patients undergoing stem cell transplantation. We present a rare case of a patient undergoing total marrow irradiation with concurrent ablative stem cell transplantation with local failures in two out-of-field areas that were not included in the clinical target volume A 31-year-old female patient initially presented with abdominal pain secondary to chronic myelogenous leukemia. She underwent dasatinib treatment for years, but subsequently developed recurrence and underwent consolidation systemic chemotherapy followed by allogeneic stem cell transplantation with adjuvant total marrow irradiation. Several months later, she noticed increased left jaw swelling and dysphagia with associated right ankle swelling. Biopsy of the right ankle and left mandible were consistent with recurrent myeloid sarcoma. This case report suggests that inclusion of the mandible and lower extremities may be necessary when performing total marrow radiation.

Keywords: allogeneic bone marrow transplant; bone marrow failure; chronic myelogenous leukemia; hematology-oncology; myeloid sarcoma; radiation oncology; total marrow irradiation; volumetric-modulated arc therapy.

Figure 1. Patient’s planning target volume (PTV) and treatment fields (arcs) of a linac-based volumetric-modulated arc therapy (VMAT) total marrow irradiation plan with three isocenter setups.

Figure 2. Patient’s total marrow irradiation treatment plan with a (A) sagittal view and (B) coronal view.

Figure 3. Representative images of positron emission tomography (PET)/CT at relapse, which shows the (A) mandibular and (B) right ankle 18-F fluorodeoxyglucose (FDG) avidity using an (1) axial view, (2) sagittal view, and (3) coronal view.

Figure 4. Fusion of her original radiation treatment plan with delineated site of recurrence, which shows the mandibular site of relapse lying outside the prescription dose.