Abstract:

Objective This study aims to investigate the value of ³¹P magnetic resonance spectroscopy imaging (³¹P MRSI) in evaluating the therapeutic efficacy of the first cycle of hepatic arterial infusion chemotherapy (HAIC) for patients with hepatocellular carcinoma (HCC). Methods A total of 13 male patients (mean age: 54±14 years) with Barcelona Clinic Liver Cancer-C stage HCC intended to receive HAIC at Ruijin Hospital were prospectively and consecutively enrolled from November 2023 to August 2024. Each patient underwent ³¹P MRSI before the first cycle [mean (1±1) d] and after the first HAIC cycle [mean (24±6) d]. After the 6th HAIC [median 151 d since the first HAIC (interquartile range, 123-179 d)] or after conversion surgery [median 94 d since the first HAIC (interquartile range, 66-106 d)], patients were divided into response group (n=6) and nonresponse group (n=7) according to modified response evaluation criteria in solid tumor (mRECIST) or pathological assessment criteria. The phosphomonoester (PME)/phosphodiester (PDE) and phosphoethanolamine (PE)/PDE ratios in patients with HCC, as well as their changes and change amplitude (ΔPME/PDE and ΔPE/PDE), were analyzed. Differences in these indicators before and after the first cycle of HAIC were compared between the response and nonresponse groups. The area under the receiver operating characteristic (ROC) curve was used to evaluate the value of these indicators derived from ³¹P MRSI in predicting HAIC efficacy. Results In the response group, the PME/PDE and PE/PDE ratios showed no change before and after HAIC, whereas it significantly increased in the nonresponse group. Before the first cycle of HAIC, the ratios of PME/PDE (0.97 vs. 1.91, P=0.027) and PE/PDE (0.55 vs. 1.23, P=0.014) in the nonresponse group were lower than those in the response group. In the nonresponse group, the mean ratios of PME/PDE (3.04 vs. 0.97, P=0.006) and PE/PDE (2.03 vs. 0.55, P=0.014) increased significantly after HAIC compared with those before treatment. After the first cycle of HAIC, ΔPME/PDE and ΔPE/PDE (1.69 vs. 0.40, P=0.029; 1.80 vs. 0.47, P=0.032) were significantly greater in the nonresponse group than in the response group. The area under the curve (AUC) values for predicting nonresponders were 0.83, 0.91, 0.86, and 0.83, for the PME/PDE ratio <0.91, and PE/PDE ratio <0.74 before the HAIC, ΔPME/PDE≥0.4 and ΔPE/PDE≥2.2, respectively. Conclusions In patients who do not respond to HAIC, the PME/PDE and PE/PDE ratios increase after the first cycle of HAIC. Baseline PME/PDE and PE/PDE ratios or after the first cycle of HAIC may be useful for predicting the efficacy of HAIC.

Key words: Hepatocellular carcinoma, ³¹P magnetic resonance spectroscopic imaging, Hepatic arterial infusion chemotherapy, Therapeutic response evaluation