Radiation dose on oesophagus predicts OS in SCLC patients treated with chemoradiotherapy

In patients with small cell lung cancer (SCLC) who undergo chemoradiotherapy (CRT), radiation dose on the oesophagus predicted overall survival (OS) in a retrospective study.

CRT is a standard treatment for most patients with limited-stage SCLC. Recent data in NSCLC suggested that heart dose independently predicts OS after radical CRT [1]. To date, however, limited research has been reported on the impact of heart dose on OS of SCLC patients [2]. Further investigation is needed to determine the predictive value of heart dose and doses to other structures local to the tumour, such as the lungs or oesophagus.

Investigators reviewed the records of 184 SCLC patients treated with radical CRT to determine the impact of heart, lung, and oesophageal dosimetry on the OS. The median age of investigated patients was 65 years; 87.5% of patients were diagnosed with limited-stage SCLC, 9.2% had extensive-stage SCLC. Multiple whole-heart dose-volume histogram (DVH) parameters were extracted for analysis, including the mean dose, volume (%) of heart receiving 5 Gy (V5) in 5 Gy increments up to V50, and the average dose (Gy) received by 5% of the heart (D5) in 5% increments up to D50. The same DVH data was extracted for the lungs and oesophagus. Results were presented by Dr Bilal Tahir (University of Sheffield, United Kingdom) [3].

The median OS was 608 days (range 280–1,854 days); 1-, 2-, and 5-year OS rates were 66.9%, 42.9%, and 25.6%, respectively. Heart, lung, and oesophageal DVH variables were predictors of OS on univariable analysis. However, multivariable analysis only identified oesophageal D50 to be associated with OS. No whole-heart or lung DVH variable was observed to be predictive of OS on multivariable analysis.

Based on these results, Dr Tahir advised to not only minimise incidental dose to the heart and lungs of SCLC patients undergoing radical CRT, but also be cautious to minimise dose to the oesophagus.

1. Bradley JD, et al. Lancet Oncol. 2015;16:187–199.
2. Ni L, et al. J Thorac Dis. 2019;11:2229–2239.
3. Tahir BA, et al. Impact of heart, lung and oesophageal doses on overall survival (OS) of small cell lung cancer (SCLC) patients following radical chemo-radiotherapy (RT). Abstract 146P. ELCC 2022 Virtual Meeting, 30 March–02 April.

 

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Posted on 25 May, 202225 March, 2024