Extrapulmonary soft-tissue fibrosis resulting from hypofractionated stereotactic body radiotherapy for pulmonary nodular lesions.

PURPOSE: To clarify the incidence, symptoms, and timing of extrapulmonary fibrosis developing after hypofractionated stereotactic body radiotherapy. PATIENTS AND METHODS: We analyzed 379 consecutive patients who underwent stereotactic body radiotherapy for lung tumors at four institutions between February 2001 and March 2007. The median follow-up time was 29 months (range, 1-72). We investigated the subjective and objective characteristics of the extrapulmonary masses, redelineated the origin tissue of each on the treatment planning computed tomography scan, and generated dose-volume histograms. RESULTS: In 9 patients (2.4%), extrapulmonary masses were found 3-36 months (median, 14) after irradiation. Coexisting swelling occurred in 3 patients, chest pain in 2, thumb numbness in 1, and arm edema in 1 patient. Extrapulmonary masses occurred in 5 (5.4%) of 92 and 4 (1.4%) of 287 patients irradiated with a 62.5-Gy and 48.0-Gy isocenter dose, respectively. The mean and maximal dose to the origin tissue was 25.8-53.9 Gy (median, 43.7) and 47.5-62.5 Gy (median, 50.2), respectively. In 5 of 9 patients, the standardized uptake values on 18F-fluorodeoxyglucose-positron emission tomography was 1.8-2.8 (median, 2.2). Percutaneous needle biopsy was performed in 3 patients, and all the specimens showed benign fibrotic changes without malignant cells. CONCLUSION: All patients should be carefully followed after stereotactic body radiotherapy. The findings of any new lesion should prompt an assessment for radiation-induced extrapulmonary fibrosis before an immediate diagnosis of recurrence is made. Careful beam-shape modification and dose prescription near the thoracic outlet are required to prevent forearm neuropathy and lymphedema.

Sporadic gastric neurofibroma underneath early cancer: MDCT gastrography and histological findings.

We report the case of a sporadic gastric submucosal neurofibroma underneath a T1 stage cancer. A 61-year-old man underwent gastroscopy because of epigastralgia and was diagnosed as having T1 stage gastric cancer by an experienced gastroenterologist. Subsequently performed computed tomography (CT) showed poorly circumscribed wall thickening underneath the converged folds on three-dimensional images. On a dynamic enhancement study, the thickened wall was seen to be enhanced gradually from the arterial phase to the equilibrium phase. Based on these findings, we diagnosed stage T2 cancer. Total gastrectomy was performed, and the surgically removed specimen revealed that the wall thickening was caused by a submucosal neurofibroma and that cancer existed in this neurofibroma, invading the submucosa. This patient had no family history of neurofibromatosis, and so the lesion was diagnosed as early gastric cancer with a sporadic submucosal neurofibroma. Coexistence of gastric cancer and a submucosal tumor is rare, but such a case is one of the pitfalls of a CT diagnosis of T stage gastric cancer.