Treatment Effect of Neoadjuvant Chemoradiation Therapy for Non-small Cell Lung Cancer Evaluated by Multimodality Imaging and Histopathological Analyses

Abstract

Purpose/Objective(s): To assess treatment effect of neoadjuvant chemoradiation therapy (NACRT) for locally advanced non-small cell lung cancer (LA-NSCLC) by multi-modality imaging and histopathological diagnosis including molecular biological analyses. Materials/Methods: We retrospectively reviewed the radiation oncology and histopathological records of 11 patients who underwent NACRT for LA-NSCLC and contrast enhanced computed tomography (CECT), magnetic resonance imaging (MRI), and positron emission tomography CT before and after NACRT between 2007 and 2010. There were 10 males and 1 female with a median age of 68 years (range, 54 to 76). Eight had squamous cell carcinomas, one had large cell carcinoma, one had adenocarcinoma, and one was unclassified. NACRT consisted of 2 cycles of cisplatin and vinorelbine-based chemotherapy given concurrently with 3D conformal radiation therapy of 40 Gy in 20 fractions within 4 weeks. Changes of tumor findings on imaging were compared with histopathological diagnosis including molecular biological analyses using immunostaining technique of the surgical specimens. Results: Histopathological manifestation of the Hematoxylin-Eosin stained surgical specimens showed Effect 3 (Ef. 3: no viable tumor cells) in 6 and Effect 2 (Ef. 2: small amount of remnant viable tumor cells) in 5, and negative surgical margin was observed in all cases. Positive ratios of growing cell in remnant viable tumor cells of Ef. 2 cases were less than 15% and positive ratios of double strand breaks were more than 50%. Mean reduction ratio of tumor size on CECT in cases of Ef. 2 and EF. 3 were 38% and 55%. Mean reduction ratios of SUV in cases of Ef. 2 and EF. 3 were 56% and 83%. One case with EF. 3 showed persistent Ffluorodeoxy glucose accumulation at margin of tumor due to inflammatory cells infiltration around necrosis. Signal intensity changes of tumor on diffusion weighted images of MRI did not correlate with histopathological treatment effect. Conclusions: High reduction ratio of tumor size and SUV tended to correlate with good histopathological treatment effect of NACRT for NSCLC. Even if the remnant viable tumor cells were present morphologically in the surgical specimens, more than 50% of them had double strand breaks of DNA and growing cell ratios were less than 15%. Author Disclosure: H. Ikushima: None. K. Kondo: None. Y. Otomi: None. H. Maezawa: None.