Bridging the Gap Between Radiology and Microscopy Using microCT: Implications for Neoplastic and Non-neoplastic Lung Disease.

Abstract

Purpose: Accurate lung cancer TNM staging depends on macroscopic and microscopic tumor evaluation of resection specimens. However, small nodules (<1 cm) are difficult to extract and correlate with in vivo imaging. We investigated whether microCT could better localize lesions or guide pathology to otherwise undetected abnormalities.

Materials and methods: Paired ex vivo CT and microCT were performed after inflating and freezing surgically removed lung lobes (resolution 80 to 120 µm). Rigorous matching between CT, microCT, and histopathology was performed on areas containing abnormalities on microCT.

Results: A total of 57 lobectomy specimens were analyzed. MicroCT-guided microscopic examination led to 2 additional primary carcinomas, 2 separate tumor nodules from the primary lung tumor, and 1 atypical adenomatous hyperplasia lesion that were not evident before surgery. For both patients with separate tumor nodules, the cT1 stage was upgraded to a pT3. In addition, the microCT provided insight into underlying structural disease (ie, emphysema and fibrosis).

Conclusions: In 5 out of 57 resection specimens (9%), microCT showed additional (pre-)cancerous lesions. This explorative study suggests that lobar microCT could serve as a valuable guide for pathologists by pointing them toward areas that may warrant further investigation. In this way, it is a practical and beneficial tool, capable of facilitating a more precise TNM classification in tumor resection specimens, which needs further validation in a prospective study.