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Nagoya-shi, Japan

Takenaka R.,Narita Memorial Hospital | Takenaka R.,Nagoya City University | Shibamoto Y.,Nagoya City University | Miyakawa A.,Nanbu Tokushukai General Hospital | And 2 more authors.
Clinical Lung Cancer | Year: 2015

Background: After stereotactic body radiotherapy (SBRT) to the lung, radiation pneumonitis and fibrotic changes often develop, and the tumor shadow usually becomes indistinguishable from the fibrotic shadow. Occasionally, however, a residual mass in patients with no or mild radiation pneumonitis will be observed on serial computed tomography (CT) scans. The purpose of the present study was to evaluate the fate of such residual masses and, if possible, to determine the types of tumor at increased risk of local recurrence. Patients and Methods: A total of 50 patients (underlying disease: primary lung cancer in 45, local recurrence in 2, and metastasis in 3) were selected because they had been followed up for > 2 years or until death and had observable CT changes and measurable tumor size for > 1 year, regardless of the influence of radiation pneumonitis. The patients' outcomes were compared according to various patient and tumor characteristics, including the presence and absence of emphysema, tumor size, and tumor shrinkage rate. The median follow-up period was 52 months. Results: Of the 50 patients, only 8 developed local recurrence. The local control rate was 81% at 3 years and 73% at 5 years. The local control rates were similar between patients with a high tumor shrinkage rate and those with a low rate. The patients with emphysema exhibited a lower local control rate. Conclusion: The persistence of lung masses for > 1 year after SBRT is not necessarily indicative of an increased risk of local recurrence. A low tumor shrinkage rate also was not predictive of recurrence. © 2015 Elsevier Inc. Source


Shibamoto Y.,Nagoya City University | Hashizume C.,Radiosurgery Center | Baba F.,Nagoya City University | Ayakawa S.,Red Cross | And 5 more authors.
Journal of Thoracic Oncology | Year: 2015

Introduction: Although the protocol of 48 Gy in four fractions over 4 days has been most often employed in stereotactic body radiotherapy (SBRT) for stage I non-small-cell lung cancer in Japan, higher doses are necessary to control larger tumors, and interfraction intervals should be longer than 24 hours to take advantage of reoxygenation. We report the final results of our study testing the following regimen: for tumors less than 1.5, 1.5-3, and greater than 3 cm in diameter, 44, 48, and 52 Gy, respectively, were given in four fractions with interfraction intervals of greater than or equal to 3 days. Methods: Among 180 histologically proven patients entered, 120 were medically inoperable and 60 were operable. The median patient age was 77 years (range, 29-89). SBRT was performed with 6-MV photons using four noncoplanar and three coplanar beams. Isocenter doses of 44, 48, and 52 Gy were given to four, 124, and 52 patients, respectively. Results: The 5-year overall survival rate was 52.2% for all 180 patients and 66% for 60 operable patients. The 5-year local control rate was 86% for tumors less than or equal to 3 cm (44/48 Gy) and 73% for tumors greater than 3 cm (52 Gy; p = 0.076). Grade greater than or equal to 2 radiation pneumonitis developed in 13% (10% for the 44/48-Gy group and 21% for the 52-Gy group; p = 0.056). Other grade 2 toxicities were all less than 4%. Conclusions: Our first prospective SBRT study yielded reasonable local control and overall survival rates and acceptable toxicity. Refinement of the protocol including dose escalation may lead to better outcome. © 2015 by the International Association for the Study of Lung Cancer. Source


Murai T.,Nagoya City University | Shibamoto Y.,Nagoya City University | Baba F.,Nagoya City University | Hashizume C.,Radiosurgery Center | And 6 more authors.
International Journal of Radiation Oncology Biology Physics | Year: 2012

Purpose: To investigate the relationship between waiting time (WT) and disease progression in patients undergoing stereotactic body radiotherapy (SBRT) for lung adenocarcinoma (AD) or squamous cell carcinoma (SQ). Methods and Materials: 201 patients with Stage I AD or SQ undergoing SBRT between January 2004 and June 2010 were analyzed. The WT was defined as the interval between diagnostic computed tomography before referral and computed tomography for treatment planning or positioning before SBRT. Tumor size was measured on the slice of the longest tumor diameter, and tumor volume was calculated from the longest diameter and the diameter perpendicular to it. Changes in tumor volume and TNM stage progression were evaluated, and volume doubling time (VDT) was estimated. Results: The median WT was 42 days (range, 5-323 days). There was a correlation between WT and rate of increase in volume in both AD and SQ. The median VDTs of AD and SQ were 170 and 93 days, respectively. Thirty-six tumors (23%) did not show volume increase during WTs >25 days. In 41 patients waiting for ≤4 weeks, no patient showed T stage progression, whereas in 25 of 120 (21%) patients waiting for >4 weeks, T stage progressed from T1 to T2 (p = 0.001). In 10 of 110 (9.1%) T1 ADs and 15 of 51 (29%) T1 SQs, T stage progressed (p = 0.002). N stage and M stage progressions were not observed. Conclusion: Generally, a WT of ≤4 weeks seems to be acceptable. The WT seems to be more important in SQ than in AD. Copyright © 2012 Elsevier Inc. Printed in the USA. All rights reserved. Source


Shibamoto Y.,Nagoya City University | Hashizume C.,Radiosurgery Center | Baba F.,Nagoya City University | Ayakawa S.,Red Cross | And 8 more authors.
Cancer | Year: 2012

Background: The most common regimen of stereotactic body radiotherapy (SBRT) for stage I nonsmall cell lung cancer in Japan is 48 grays (Gy) in 4 fractions over 4 days. Radiobiologically, however, higher doses are necessary to control larger tumors, and interfraction intervals should be >24 hours to take advantage of reoxygenation. In this study, the authors tested the following regimen: For tumors that measured <1.5 cm, 1.5 to 3.0 cm, and >3.0 cm in greatest dimension, radiation doses of 44 Gy, 48 Gy, and 52 Gy, respectively, were given in 4 fractions with interfraction intervals of >yen;3 days. Methods: Among 180 patients with histologically proven disease who entered the study, 120 were medically inoperable, and 60 were operable. The median patient age was 77 years (range, 29-92 years). SBRT was performed with 6-megavolt photons using 4 noncoplanar beams and 3 coplanar beams. Isocenter doses of 44 Gy, 48 Gy, and 52 Gy were received by 4 patients, 124 patients, and 52 patients, respectively. Results: The overall survival rate for all 180 patients was 69% at 3 years and 52% at 5 years. The 3-year survival rate was 74% for operable patients and 59% for medically inoperable patients (P =.080). The 3-year local control rate was 86% for tumors >3 cm (44/48 Gy) and 73% for tumors >3 cm (52 Gy; P =.050). Grade â2 radiation pneumonitis developed in 13% of patients (10% of the 44-Gy/48-Gy group and 21% of the 52-Gy group; P =.056). All other grade 2 toxicities developed in <4% of patients. Conclusions: The SBRT protocol used in this study yielded reasonable local control and overall survival rates and acceptable toxicity. Dose escalation is being investigated. © 2011 American Cancer Society. Source

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