Itonaga T, Mikami R, Okubo M, Saito T, Shiraishi S, Sugahara S, Tokuuye K, Saito K. Prognostic impact of solid tumor component diameter in early-stage non-small cell lung carcinoma treated with intensity-modulated fractionated radiotherapy: a retrospective analysis impact of solid tumor component diameter in NSCLC treated with IMRT.
Br J Radiol 2020;
93:20191027. [PMID:
32125893 PMCID:
PMC7217577 DOI:
10.1259/bjr.20191027]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/06/2020] [Accepted: 02/17/2020] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE
To investigate the suitability of the new diameter-based subgroupings of the eighth edition Tumor Node Metastasis (TNM) classification system regarding radiotherapy treatment for early-stage non-small-cell lung cancer (NSCLC), we retrospectively re-analyzed the clinical data of patients treated with intensity-modulated radiotherapy using non-coplanar beams (ncIMRT) for Stage I NSCLC.
METHODS
Between March 2011 and March 2018, 92 patients with 94 tumors who were diagnosed with Stage I NSCLC according to the seventh edition TNM classification system were enrolled and underwent ncIMRT of 75 Gy in 30 fractions. Local control (LC), progression-free survival (PFS), and overall survival (OS) were retrospectively investigated according to the T-classification subdivisions of the eighth edition and maximal solid tumor component diameter.
RESULTS
The median follow-up period was 32.5 months. The median maximum tumor and solid tumor component diameters were 22 mm and 18 mm, respectively. 3-year LC, PFS, and OS rates were 84.1%, 69.4%, and 85.3%, respectively. The 3-year LC rates were 91.0 and 76.8% in the groups with tumor diameter ≤2 cm and >2 cm, corresponding to the T1c and T1b subdivisions of the eighth edition, respectively (p = 0.24). In the ≤2 cm and >2 cm solid tumor component groups, the 3 year LC rates were 93.6 and 63.2%, respectively, which were significantly different (p = 0.007).
CONCLUSION
LC rates after radiotherapy in patients with Stage I NSCLC were correlated with solid tumor component diameter. High LC rates in patients with solid tumor components <2 cm in diameter were associated with high PFS and OS rates.
ADVANCES IN KNOWLEDGE
This study suggests that the eighth edition TNM classification system, which focuses on solid tumor components rather than tumor diameter, can be applied to radiotherapy.
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