Imaging Characteristics and Diagnostic Performance of 2-deoxy-2-[18F]fluoro-d-Glucose PET/CT for Melanoma Patients Who Demonstrate Hyperprogressive Disease When Treated with Immunotherapy

Purpose We investigated the ability of baseline 2-deoxy-2-[F-18]fluoro-d-glucose PET/CT parameters, acquired before the start of immunotherapy, to predict development of hyperprogressive disease (HPD) in melanoma patients. We also evaluated the diagnostic performances of ratios of baseline and first restaging PET/CT parameters to diagnose HPD without information of the tumor growth kinetic ratio (TGKR) that requires pre-baseline imaging before baseline imaging (3 timepoint imaging). Procedures Seventy-six patients who underwent PET/CT before and approximately 3 months following initiation of immunotherapy were included. PET/CT parameters, including metabolic tumor volume (MTV) for all melanoma lesions and total measured tumor burden (TMTB) based on irRECIST, were measured from baseline PET/CT (MTV(base)and TMTBbase) and first restaging PET/CT (MTV(post)and TMTBpost). The ratios of MTV (MTVpost/MTVbase, MTVr) and TMTB (TMTBpost/TMTBbase, TMTBr) were calculated. Results MTV(base)of HPD patients (n = 9, TGKR >= 2) was larger than that of non-HPD (n = 67, TGKR < 2) patients (P < 0.05), and HPD patients demonstrated shorter median overall survival (7vs.more than 60 months,P < 0.05). The area under the curve (AUC) of MTVbase(>= 155.5 ml) to predict the risk of HPD was 0.703, with a sensitivity of 66.7 % and specificity of 81.2 %. The AUCs of MTVr (>= 1.25) and TMTBr (>= 1.27) to diagnose HPD without information of TGKR were 0.875 and 0.977 with both sensitivities of 100 %, and specificities of 79 % and 83.9 %, respectively. Conclusions Patients at high risk of developing HPD could not be accurately identified based on baseline PET/CT parameters. The ratios of baseline and first restaging PET/CT parameters may be helpful to diagnose HPD, when patients do not undergo pre-baseline imaging.

Automated summary

Baseline PET/CT parameters may not accurately identify patients at high risk of developing HPD, but the ratios of baseline and first restaging PET/CT parameters may be helpful in diagnosing HPD, especially when patients do not undergo pre-baseline imaging.