Arm-Behind-the-Back Position for Breast Cancer Radiotherapy in Patients with Lupus Erythematosus and Shoulder Arthropathy: A Case Report

BACKGROUND When 3-dimensional conformal radiation therapy (3DCRT) for postoperative breast cancer is performed in the supine position, patients are required to raise their arms to spare the arms from the irradiation field. However, patients with collagen vascular disease can experience severe joint symptoms. CASE REPORT A 43-year-old woman with a history of systemic lupus erythematosus (SLE) 10 years ago received a diagnosis of invasive ductal carcinoma of the left breast. Breast-conserving surgery and sentinel lymph node biopsy were performed. The pathological stage was IA. Physical and immunological examinations indicated that SLE disease activity was stable preoperatively and postoperatively. She had difficulty holding her left arm in a raised position because of arthritis related to SLE and steroid therapy. For postoperative radiation therapy, we developed an arm-behind-the-back position, in which a platform was placed between the patient's body and couch. In this position, the patient's arm was lowered behind the back, such that the arm did not interfere with the irradiation field of 3DCRT. The treatment plan achieved an acceptable homogeneity index, low dose to the lungs and heart, and no problematic hotspots. Although the time required for position matching and irradiation tended to be longer than that in the regular supine position, scheduled irradiation was safely completed. Grade 2 radiation dermatitis was observed. The patient showed no signs of local recurrence or distant metastases after 15 months. No radiation pneumonitis was observed. CONCLUSIONS The ingenuity of positioning can achieve radiotherapy in patients with collagen vascular disease and shoulder joint symptoms.