Figure 2.

Radiotherapy plan and tumor response 1 month after SFRT. Left panel: A 56-year-old woman with recent stage IIIb MCC developed shortness of breath associated with a subcarinal paraesophageal lymph node metastasis (tumor outlined in blue, surrounding the aorta which is contrast-enhanced). She underwent SFRT, experienced no side effects from therapy, had full resolution of symptoms by day 5 after treatment, and by 1 month had a complete response as documented by CT scan (right panel). The red line represents the RT dose covering the tumor and the green dashed lines depict the nine RT beam angles directed at the tumor. The 95% isodose line in the radiotherapy plan closely conforms to the treated tumor in three dimensions, and dose was minimized to surrounding critical structures including spinal cord, heart and lungs. This tumor is included as lesion #23 in Table S1, and had not recurred as of the end of study period (11 months) or at last follow-up (22 months after SFRT). SFRT, single-fraction radiation therapy; MCC, Merkel cell carcinoma.