The role of ADC value and Ki-67 index in predicting the response to neoadjuvant chemotherapy in advanced stages of olfactory neuroblastoma.

Abstract

To investigate the efficacy of pretreatment ADC and Ki-67 index in the prediction of the response to neoadjuvant chemotherapy (NACT) in advanced olfactory neuroblastoma (ONB) patients. A total of 21 advanced ONB patients (mean 43.48 years ± 14.26; range 25-69 years; 13 men and 8 women) with diffusion-weighted imaging (DWI) before NACT between June 2015 and October 2021 were retrospectively analyzed. Patients were categorized into responders and non-responders according to RECIST 1.1 after two cycles of NACT. The clinical data, ADCmean value, and Ki-67 index were analyzed. Kadish stage, ADCmean value, and Ki-67 index showed statistical significance between responders and non-responders. Patients with Kadish C stage were more likely to respond to platinum-based NACT (p = 0.035). Patients with the lower ADCmean value showed response to NACT (p = 0.002) and the cutoff point was 1.04 × 10-3 mm2/s. Patients with the higher Ki-67 index showed response to NACT (p = 0.003) and the cutoff point was 17.5%. Predictive performance of Ki-67 index and ADCmean value showed no significance between responders and non-responders (p = 0.865). A significant negative correlation was found between ADCmean value and Ki-67 index (r = -0.539, p = 0.038). The pretreatment ADCmean value, Ki-67 index and Kadish stage have the potential to predict the response to NACT in advanced ONB patients. This is the first study that investigated the feasibility of DWI in predicting the response to NACT in ONB patients and showed that Kadish stage, pretreatment ADCmean and Ki-67 index may play an important role in the prediction.