PMC7184842_01
Computed tomography of the affected lung. a A lobulated mass (arrow) stuck to the segmental bronchus was located near the left main pulmonary artery. b Second-line cyclophosphamide chemotherapy brought about marked regression of the tumor (arrow). c Stereotactic body radiotherapy brought about complete response of the tumor, presumably accompanied by radiation-induced fibrosis and/or partial atelectasis (arrow), and a faint radiation-induced fibrosis in the left lung (arrows).
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F1
Follow-up computed tomography (CT) showed a solitary lobulated nodule 28 x 18 mm in size at the hilum of the left lung 44 months after the operation (Fig. 1a). The patient again preferred to receive oral cyclophosphamide (CPA) therapy (100 mg/day), leading to a marked regression of the lung nodule (Fig. 1b) without tumor regrowth and any new cancer foci for 10 months. CT taken 36 months after the completion of SBRT (Fig. 1c) showed no regrowth of the nodule with a faint radiation-induced fibrosis in the left lung.
Isodose lines and dose volume histogram. Gray, blue, pink, and yellow lines indicate 1,000, 2,000, 3,000, and 4,000 cGy, respectively.
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F2
Both to further obtain complete local control and to maintain pulmonary function, we implemented SBRT (51 Gy; equivalent to approximately 80 Gy of conventional radiotherapy; Fig. 2) under breath holding without a localization device to the presumed lung metastasis.