Duration of Twice-Daily Thoracic Radiotherapy and Time From the Start of Any Treatment to the End of Chest Irradiation as Significant Predictors of Outcomes in Limited-Disease Small-Cell Lung Cancer.
The hypothesis of this retrospective study was that the duration of twice-daily (BID) thoracic radiotherapy (TRT) and time from the start of any treatment to the end of chest irradiation (SER) would predict outcomes in limited-disease small-cell lung cancer.



All 81 patients received 45 Gy in 30 fractions BID with a ≥ 6-hour interval and concurrent chemotherapy of platinum and etoposide.



The median radiotherapy duration was 25 days (range, 21-38 days). The 5-year overall survival rates were 26.2% (95% confidence interval [CI], 14.3%-38.0%), and the median survival time was 30 months (95% CI, 15.5-44.5 months). Using multivariate regression analysis, the significant predictors of survival were the sum of the diameters of the primary tumor and metastatic lymph nodes, male gender, age ≥ 60 years, and the duration of BID-TRT (hazard ratio [HR], 1.15; 95% CI, 1.06-1.25; HR, 2.38; 95% CI, 1.13-5.02; HR, 2.38; 95% CI, 1.10-5.17; and HR, 1.08; 95% CI, 1.01-1.15, respectively). A total of 70 of 81 patients (86%) received radiotherapy during the first chemotherapy cycle. The median SER was 29 days (range, 21-109 days). The 5-year local control rate was 48.7% (95% CI, 33.9%-63.6%). The significant predictors of local control were the sum of the diameters of the primary tumor and metastatic lymph nodes, age ≥ 60 years, and SER (HR, 1.18; 95% CI, 1.06-1.31; HR, 4.18; 95% CI, 1.23-14.24; and HR, 1.02; 95% CI, 1-1.04, respectively).



The duration of BID-TRT and SER were identified as one of the significant predictors of survival and local control in limited-disease small-cell lung cancer treated with concurrent chemoradiotherapy at 45 Gy in 30 fractions, respectively.
Department of Radiation Oncology, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Japan; Department of Radiation Oncology, Nara Medical University School of Medicine, Kashihara, Japan. Electronic address: morimoto-knk@umin.ac.jp.
Masahiro
M
Morimoto
Department of Internal Medicine, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Japan.
Kyoichi
K
Okishio
Department of Radiology, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Japan.
Masanori
M
Akira
Department of Internal Medicine, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Japan.
Naoki
N
Omachi
Department of Internal Medicine, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Japan.
Akihiro
A
Tamiya
Department of Internal Medicine, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Japan; Department of Clinical Oncology, Sagamihara-Higashi Clinic, Sagamihara, Japan.
Kazuhiro
K
Asami
Department of Internal Medicine, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Japan; Department of Respiratory Medicine, Graduate School of Medicine, Osaka City University, Osaka, Japan.
Tomoya
T
Kawaguchi
Department of Internal Medicine, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Japan.
Shinji
S
Atagi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D059248:Chemoradiotherapy; D002945:Cisplatin / Q000008:administration & dosage; D005047:Etoposide / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012189:Retrospective Studies; D055752:Small Cell Lung Carcinoma / Q000188:drug therapy / Q000532:radiotherapy* / Q000556:secondary; D015996:Survival Rate; D035441:Thoracic Wall / Q000528:radiation effects*; D013997:Time Factors
D005047:Etoposide; D002945:Cisplatin
Accelerated hyperfractionated thoracic radiotherapy; Interruption; Limited-stage small-cell lung cancer; Overall treatment time; Prolongation