Potential benefit of dose-escalated stereotactic body radiation therapy using CyberKnife for early-stage primary lung cancer.

INTRODUCTION: The study aimed to evaluate the efficacy and safety of dose-escalated stereotactic body radiotherapy (SBRT) for primary lung cancer. METHODS: Patients with peripherally located T1-2N0M0 primary lung cancer who underwent SBRT from April 2013 to December 2019 were included. Group A received 60 Gy in five fractions with CyberKnife prescribed at 99% gross tumor volume. Group B received 48 Gy in four fractions by a gantry-mounted linear accelerator, with isocenter prescription. Cumulative incidence of local failure (LF), progression free survival (PFS), overall survival (OS), and toxicity were retrospectively compared. RESULTS: Groups A and B comprised 39 and 36 patients, respectively. Group A had more patients without histological confirmation (p < .001) and showed lower V20 of bilateral lungs (p = .025). The median follow-up duration of Group A and B was 22.0 and 21.5 months, respectively, and the 2-year cumulative incidence of LF, PFS, and OS were .0% versus 11.6% (p = .065), 66.2% versus 62.7% (p = .694), 84.1% versus 81.1% (p = .827), respectively. There was no difference in Grade ≥ 2 toxicity rate between Groups A and B (7.7% vs. 11.1%; p = .704). CONCLUSION: Dose-escalated SBRT using CyberKnife showed reduced lung dose and potential benefits for improved local control with comparable toxicity.

Repeated Stereotactic Body Radiotherapy for Lung Malignancies: Toxicity Can Be Reduced by Sparing Lung Irradiation.

BACKGROUND/AIM: Evidence on the use of repeated stereotactic body radiotherapy (SBRT) is limited. We investigated the efficacy of repeated SBRT and predictors of lung toxicity. PATIENTS AND METHODS: We reviewed 20 patients (27 lesions) with primary or metastatic lung cancer who underwent repeated SBRT with CyberKnife® We generated a composite plan for dosimetric analysis based on equivalent doses in 2.0-Gy fractions (α/ß=3). Predictors of Grade 2+ radiation pneumonitis (RP) were examined. RESULTS: The median follow-up duration was 18.0 months. The 1-year and 2-year local control were both 95.2%. Five patients (25%) developed Grade 2+ RP, including a Grade 5 RP. The Grade 2+ RP group showed higher composite mean lung dose (MLD) and lower lung volumes spared from 5-20 Gy (VS5-VS20). CONCLUSION: Repeated SBRT with CyberKnife® showed favorable local control, but a high rate of Grade 2+ RP. Accumulated MLD and VS5-VS20 may predict RP.

Chemoradiation versus surgery for superficial esophageal squamous cell carcinoma after noncurative endoscopic submucosal dissection: comparison of long-term oncologic outcomes.

BACKGROUND: Esophagectomy is the standard adjuvant treatment for superficial esophageal squamous cell carcinoma (SESCC) following noncurative endoscopic submucosal dissection (ESD). However, recent reports have also shown that ESD with adjuvant chemoradiotherapy (CRT) has promising results. This retrospective study aimed to elucidate the efficacy of CRT compared to surgery in patients with SESCC after noncurative ESD. METHODS: This study retrospectively compared the long-term outcomes of patients who received adjuvant treatment with surgery or CRT after noncurative ESD for SESCC. RESULTS: Data were collected from 60 patients who developed SESCC after noncurative ESD, 34 of whom received adjuvant chemoradiotherapy (CRT) and 26 underwent esophagectomy. The median follow-up periods were 46 and 56 months in the CRT and esophagectomy groups, respectively. The median patient age was significantly higher in the CRT group than in the esophagectomy group (69 vs. 65 years, p = 0.0054). CRT was completed in all patients, and the incidence of grade ≥ 3 nonhematologic adverse events was 6%. The overall and disease-free survival did not significantly differ between the two groups. CONCLUSIONS: CRT following ESD seems a promising nonsurgical strategy for optimizing the selection of therapies for high-risk SESCC and warrant further investigation.

Influence of climate factors on emergency visits for childhood asthma attack.

BACKGROUND: Asthma attack shows strong seasonality. The purpose of the present study was to quantify the contribution of climate variables and other seasonal factors on the incidence of emergency visits for childhood asthma in Tokyo, Japan. METHODS: The number of children who visited emergency rooms at Jikei university hospitals in Tokyo during 1998-2002 (5559 visits) was retrieved retrospectively from files from the Department of Pediatrics, and compared with 45 climate parameters from the Meteorological Agency using multiple regression models with a stepwise backward elimination approach. RESULTS: The number of visits (3.7 +/- 3.1) per night increased significantly when climate conditions showed a rapid decrease from higher barometric pressure, from higher air temperature and from higher humidity, as well as lower wind speed. The best-fit model demonstrated that a 22% variation in the number of visits was explained by a linear relationship with 12 climate variables, which increased to 36% after adjusting for calendar month and day of the week. Moreover, when the number of asthma visits was cut off at nine per night, the area under the receiver operator characteristics curve was 0.91 (95% CI: 0.89-0.94) in the multiple logistic regression model using the same variables. CONCLUSIONS: These results suggest that these models might quantify contributions of specific climate conditions and other seasonal factors on the number of emergency visits per night for childhood asthma attack in Tokyo, Japan.