Utility of clinical and MRI imaging parameters for prediction and monitoring of response to CAP-TEM in patients with liver metas-tases of neuroendocrine tumors

Clinical and MRI imaging parameters for prediction and monitoring of response to CAPTEM in patients with NELM

Abstract

Background. This study explores the predictive and monitoring capabilities of clinical and multiparametric MRI parameters in assessing CAPTEM therapy response in patients with NET.

Patients and methods. / Materials and methods. This retrospective study (n=44) assessed CAPTEM therapy response in neuroendocrine liver metastases (NELM) patients. Among 33 monitored patients, pretherapeutic and follow-up MRI data (size, ADC values, and signal intensities), along with clinical parameters (CgA and Ki-67%), were analyzed. Progression-Free Survival (PFS) served as the reference. Responders were defined as those with PFS > 6 months.

Results. Most patients were male (75%) and had G2 tumors (76%) with a pancreatic origin (84%). Median PFS was 5.7 months; Overall Survival (OS) was 25 months. Non-responders (NR) had higher Ki-67 in primary tumors (16.5 vs. 10 %, p=0.01) and increased hepatic burden (20% vs. 5 %, p=0.007). NR showed elevated CgA post-treatment, while responders (R) exhibited a mild decrease. ADC changes differed significantly between groups, with NR having decreased ADCmin (-23%) and liver-adjusted ADCmean/ADCmean liver (-16%), compared to R's increases of ADCmin (50%) and ADCmean/ADCmean liver (30%). ROC analysis identified the highest AUC (0.76) for a single parameter for ∆ ADC mean/ Liver ADCmean, with a cut-off of < 6.9 (76% sensitivity, 75% specificity). Combining ∆ Size NELM and ∆ ADCmin achieved the best balance (88% sensitivity, 60% specificity) outperforming ∆ Size NELM alone (69% sensitivity, 65% specificity). Kaplan-Meier analysis indicated significantly longer PFS for ∆ ADCmean/ADCmean liver < 6.9 (p= 0.024) and ∆ Size NELM > 0% + ∆ ADCmin < -2.9% (p= 0.021).

Conclusions. Survival analysis emphasizes the need for adapted response criteria, involving combined evaluation of CgA, ADC values, and tumor size for monitoring CAPTEM response in hepatic metastasized NETs.