title: Tumor response assessment by measuring the single largest lesion per organ in patients with advanced non-small cell lung cancer.
abstract: BACKGROUND
  The criterion of two target lesions per organ in the RECIST 1.1 is an arbitrary one, not being supported by any objective evidence. We compared tumor responses, respectively, using the RECIST 1.1 (measuring two target lesions per organ) and modified RECIST 1.1 (measuring the single largest lesion in each organ) in patients with advanced non-small cell lung cancer (NSCLC).
  
  
  METHODS
  We reviewed medical records of patients with advanced NSCLC who received a first-line chemotherapy between January 2004 and December 2013 and compared tumor responses according to the two criteria using computed tomography.
  
  
  RESULTS
  A total of 64 patients who had at least two target lesions in any organ according to the RECIST 1.1 were included in the study. The differences in the percentage changes of the sum of tumor measurements between the RECIST 1.1 and mRECIST 1.1 were all within 10%. Thirty-three patients (51.6%) showed an increase in the absolute value of the percentage change when adopting the mRECIST 1.1, instead of the RECIST 1.1. The tumor responses showed high concordance between the two criteria (k=0.899). Only three patients (4.7%) showed disagreement of the responses between the RECIST 1.1 and mRECIST 1.1. The overall response rates (20.3% vs. 20.3%) and disease control rates (89.1% vs. 90.6%) of first-line chemotherapy were not significantly different between the two criteria.
  
  
  CONCLUSIONS
  The modified RECIST 1.1 was comparable to the original RECIST 1.1 in the response assessment of patients with advanced NSCLC. Our result suggests that it may be possible to measure the single largest target lesion per organ for evaluation of the best tumor response.
authors: Department of Internal Medicine, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Hyeong Su
authors: HS
authors: Kim
authors: Department of Internal Medicine, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul 150-950, Republic of Korea. Electronic address: harricil@hotmail.com.
authors: Jung Han
authors: JH
authors: Kim
authors: Department of Radiology, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Ik
authors: I
authors: Yang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden
keywords: Lung cancer; Modified RECIST 1.1; RECIST 1.1; Target lesion; Tumor measurement; Tumor response