Niezink AGH, et al. – Study's objective was to summarize the available evidence about the effect of dose on the lung in thoracic radiotherapy on forced expiratory volume in one second (FEV1) and diffusion capacity (DLCO) in patients with lung and esophageal cancer treated with curative intent. As per findings, pulmonary function declined after RT in a dose-dependent manner. However, solid data about lung dose-volume histogram (DVH) parameters predicting changes in pulmonary functions test (PFT) results were scarce. Wide variety of methods used, frequently lacking multivariable analyses were major disadvantage.

Methods

• Researchers conducted a systematic review following the PRISMA guidelines, using MEDLINE and including clinical studies using (chemo)radiotherapy (CRT) or stereotactic ablative radiotherapy (SABR) for lung or CRT for esophageal cancer that reported both lung dose-volume histogram (DVH) parameters and changes in PFT results.
• Lung and esophageal neoplasms, respiratory function tests, and radiotherapy, were search terms.

Results

• Inclusion criteria were met by fifteen studies.
• In PFT results, seven out of 13 studies on lung cancer reported significant declines (defined as a p value<.05).
• Moreover, both esophageal studies reported significant DLCO declines.
• As per the one SABR study low lung-dose parameters were correlated to FEV1 decline.
• In eight studies analyzing CRT, relations between decline of FEV1 (three studies) or decline of DLCO (five studies), respectively, and DVH parameters were found.
• In the selected studies, a heterogeneous range of clinical risk factors for pulmonary function changes were reported.