Basilar segmentectomy for early-stage non-small cell lung cancer: is it worth preserving the S6 segment?

Even though segmentectomy has become a new standard for early-stage non-small cell lung cancer (NSCLC), the benefits of basilar segmentectomy (BS) remain unclear. This study aims to characterize postoperative lung volume changes following BS compared to lower lobectomy (LL) using three-dimensional computed tomography (3D-CT) analysis.

This is a single-center retrospective study including patients who underwent surgery of the lower lobe for early-stage NSCLC between November 2015 and November 2021. Surgery could either be LL or BS. 3D-CT reconstruction was used to assess lung volumes before and after surgery. Primary outcome was ipsilateral lung volume variation after BS and LL and secondary outcome was total, contralateral and segment volume lung variation.

Forty patients were included (28 LL and 12 BS). No significant difference was found for ipsilateral lung volume variation between BS and LL (-28.1% vs. -31.1%; P=0.56). However, after LL, upper lobe expansion was significantly greater compared to upper lobe expansion after BS (26.3% vs. 0.1%; P<0.001) and compensation was mainly observed in the preserved S6 segment (+79% volume increase). We found no statistically significant contralateral and total lung volume variation.

While BS does not significantly increase overall lung volume preservation compared to LL, it offers a distinct and localized compensatory remodeling of the preserved S6 segment. This specific pattern of lung adaptation helps preserve functional lung tissue, potentially facilitating future surgical interventions for metachronous tumors.