Soo Ki Kim1, Takako Fujii1*, Hisato Kobayashi2, Soo Ryang Kim1, Yu-ichiro Koma3, Tsutomu Kumabe4, Osamu Nakashima5 and Takamichi Murakami6
1Department of Gastroenterology, Kobe Asahi Hospital, Japan
2Department of Radiology, Kobe Asahi Hospital, Japan
3Department of Pathology, Kobe University Graduate School of Medicine, Japan
4Kumabe Clinic, Japan
5Department of Clinical Laboratory Medicine, Kurume University Hospital, Japan
6Department of Radiology, Kobe University Graduate School of Medicine, Japan
We encountered two cases of Hepatocellular Carcinoma (HCC) treated with molecular-targeted therapy such as Lenvatinib (LEN), assessed as complete responders through radiological evaluation with Contrast Enhanced Computer Tomography (CECT) and gadolinium Contrast Enhanced Magnetic Resonance Imaging (CEMRI) according to modified Response Evaluation Criteria in Solid Tumors (mRECIST). Nonetheless, the response was incompatible with histopathological analysis.
In both cases, more than 6 weeks of post-LEN treatment, CECT and CEMRI revealed complete absence of intratumoral arterial contrast enhancement; however, ultrasound guided biopsy revealed moderately differentiated HCC with or without coagulation necrosis.
Subsequent to the total absence of intratumoral arterial contrast enhancement, MRI revealed hyper intensity on Diffusion-Weighted Imaging (DWI) and hypointensity on the Apparent Diffusion Coefficient (ADC) -map.
mRECIST depends on only complete absence of intratumoral arterial enhancement, and has limitations in tumor response assessment of post-molecular-targeted therapy.
MRI on DWI and ADC-map may be useful and more effective when complemented with mRECIST in order to improve the diagnostic accuracy and viability of HCC.
Modified RECIST; Complete response; Coagulation necrosis; Molecular-targeted therapy; Diffusion-weighted imaging
Kim SK, Fujii T, Kobayashi H, Kim SR, Koma Y-I, Kumabe T, et al. Limitation of Modified RECIST - Two Hepatocellular Carcinoma Cases Achieving Radiological Response Incompatible with Histopathological Analysis. Clin Oncol. 2021;6:1848..