Purpose To investigate pulmonary function test (PFT) and arterial blood gas changes (complete PFT) following stereotactic body radiation therapy (SBRT) and to see whether baseline PFT correlates with lung toxicity and overall survival in medically inoperable patients receiving SBRT for early stage, peripheral, non-small cell lung cancer (NSCLC). Methods and materials During the 2-year follow-up, PFT data was collected for patients with T1-T2N0M0 peripheral NSCLC who received effectively 18 Gy × 3 on Phase II North American multicenter study (RTOG 0236). Pulmonary toxicity was graded utilizing the RTOG SBRT pulmonary toxicity scale. Paired Wilcoxon signed rank test, Logistic Regression model, and Kaplan-Meier method were used for the statistical analysis. Results At 2 years, mean % predicted FEV1 and DLCO declines were 5.8% and 6.3%, respectively, with minimal changes of arterial blood gases, and no significant decline of oxygen saturation. Baseline PFT was not predictive of any pulmonary toxicity following SBRT. Whole lung V5, V10, V20 and mean dose to the whole lung were almost identical between patients who developed pneumonitis and patients who were pneumonitis-free. Poor baseline PFT did not predict decreased overall survival. Patients with poor baseline PFT as a reason for medical inoperability had higher median and overall survivals than patients with normal baseline PFT but with cardiac morbidity. Conclusions Poor baseline PFT did not appear to predict toxicity, or decreased overall survival after SBRT in this medically inoperable population. Poor baseline PFT alone should not be used to exclude patients with early stage lung cancer from treatment with SBRT.

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Background: We report the first application of Gamma Knife radiosurgery (GKR) for recurrent glossopharyngeal neuralgia (GN) after microvascular decompression (MVD). The patient is a 51-year-old male with left-sided GN. He underwent MVD and did well for almost 4 years. Later on, the patient started to experience recurrent intolerable throat pain, frequently 10/10 in intensity. Based on the application of radiosurgery for trigeminal neuralgia, GKR was offered to the patient. Methods: After careful identification of the nerve with the assistance of a neuroradiologist, we targeted the nerve root complex, which is the cisternal portion of the nerve, using the Coherent Oscillatory State Acquisition for the Manipulation of Image Contrast (COSMIC) pulse sequence with contiguous 1-mm slices obtained by an 1.5 Tesla MRI. The radiosurgery was planned utilizing the Leksell Gamma Plan version 8.1. A single shot with a 4-mm collimator was used to deliver 80 Gy to the 100% isodose line. Results: Four weeks after the treatment, the patient began to notice significant pain relief. At the 12-month follow-up, the patient’s pain, which was intolerable prior to radiosurgery, was mild and occasional. Conclusion: GKR, which is now widely used for refractory trigeminal neuralgia, can be considered for refractory or recurrent GN. With a multidisciplinary approach and advanced neuroimaging, GKR is feasible for GN after MVD, despite the shortness of the intracranial cisternal nerve portion. Further studies are necessary to establish the role of GKR for refractory GN after MVD; however, given its rarity and the lack of experience with GKR for this condition, retrospective studies with dozens of patients are almost impossible at this time.

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