Prognostic significance of 18F-FDG PET/CT indices in metastatic renal cell cancer and evaluation of revised IMDC risk model by including 18F-FDG PET-CT parameters

Abstract

Background Prognostic markers in metastatic renal cell cancer (mRCC) are still insufficient. Any prognostic model objectively determines disease burden. Purpose To investigate the relationship between 18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) parameters and outcomes in mRCC, and to define a revised International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model for the intermediate-risk group. Material and Methods A retrospective study of mRCC was conducted. To investigate the prognostic significance of 18F-FDG PET/CT parameters, maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), and metabolic tumor volume (MTV) were determined in pre-treatment images. Cutoff values were defined by ROC curve analyses and their association with outcomes was analyzed. Additionally, a TLG-adjusted IMDC model was created by stratifying intermediate-risk group patients according to TLG levels. Results The study included 52 patients. The disease control rate (DCR) was 61.5% and median overall survival (OS) was 18 months (95% confidence interval=9.2–25.8). In the univariate analyses, IMDC score, MTV, and TLG were prognostic factors for Disease Control Rate (DCR), and Eastern Cooperative Oncology Group (ECOG)-Performance Status (PS), IMDC score, lactate dehydrogenase (LDH), treatment option, MTV, and TLG were prognostic factors for OS ( P < 0.05 each). In the multivariate analyses, MTV was an independent prognostic factor for DCR, and ECOG-PS, LDH, IMDC score, and TLG were independent prognostic factors for OS. According to the revised-IMDC model, the intermediate-favorable group showed longer OS than the intermediate-unfavorable group. Conclusion Pretreatment MTV was independent prognostic factor for DCR and ECOG-PS, LDH, IMDC score, and TLG were independent prognostic factors for OS. Revised-IMDC model could identify patients with a worse prognosis among the IMDC intermediate-risk group.

Pre‐ and post‐treatment FDG PET‐CT as a predictor of patient outcomes in anal squamous cell carcinoma: A systematic review and meta‐analysis

“…Output metrics from FDG PET-CT have previously been shown useful as prognostic measures for renal cell cancer patients, further highlighting its prognostic role beyond ASCC. 30 It is evident that pre-and post-FDG PET-CT has been found to be prognostically significant in some studies. Examining the data presented, pre-treatment FDG PET-CT metrics were found to contain prognostic significance in two studies.…”

“…As such, this study presents synthesized evidence regarding the role FDG PET‐CT may play in improving patient outcomes before and after treatment when used for prognostic purposes. Output metrics from FDG PET‐CT have previously been shown useful as prognostic measures for renal cell cancer patients, further highlighting its prognostic role beyond ASCC 30 …”

PNI as a Potential Add-On Biomarker to Improve the IMDC Intermediate Prognostic Score

“…On the other hand, the IMDC and Memorial Sloan Kettering Cancer Center models stratify patients with 1 or 2 risk factors as intermediate prognoses. The intermediate-risk score has heterogeneity that may influence the response to TKIs and the prognosis of these patients may be similar to either a poor-risk score or a favorable-risk score [11,12]. There is a need for a better stratification factor to segregate these heterogeneous groups as favorable or unfavorable prognoses.…”