Immune Checkpoint Inhibitors in Advanced NSCLC: [18F]FDG PET/CT as a Troubleshooter in Treatment Response

Abstract

Introduction: The aim of this study was to investigate whether [18F]FDG PET/CT-derived semi-quantitative parameters can predict immunotherapy treatment response in non-small cell lung cancer (NSCLC) patients. Secondly, immune-related adverse events (irAEs) and lymphoid cell-rich organs activation were evaluated. Materials and Methods: Twenty-eight patients who underwent [18F]FDG PET/CT scans before and at first restaging therapy with immuno-checkpoint inhibitors (ICIs) were retrospectively analyzed. PET-based semi-quantitative parameters extracted from both scans were respectively: SUVmax and SUVpeak of the target lesion, whole-body metabolic tumor volume (MTVWB), and whole-body total lesion glycolysis (TLGWB), as well as their interval changes (ΔSUVmaxTL, ΔSUVpeakTL, ΔMTVWB, ΔTLGWB). These PET-derived parameters were correlated to controlled disease (CD) assessed by RECIST 1.1. IrAEs, if present, were also described and correlated with clinical benefit (CB). SUVmax of the spleen and bone marrow at restaging scans were also correlated to CB. Results: The CD was achieved in 54% of patients. Out of 28 eligible patients, 13 (46%) experienced progressive disease (PD), 7 showed SD, 7 had PR, and only in one patient CR was achieved. ΔSUVmaxTL (p = 0.002) and ΔSUVpeakTL (p < 0.001) as well as ΔMTVWB (p < 0.001) and ΔTLGWB (p < 0.005) were significantly associated with PD vs. non-PD. IrAEs and lymphoid cell-rich organs activation did not correlate with CB. Conclusions: [18F]FDG PET/CT by using interval changes of PET-derived semi-quantitative parameters could represent a reliable tool in immunotherapy treatment response evaluation in NSCLC patients.

Predictive value of baseline metabolic tumor volume for non-small-cell lung cancer patients treated with immune checkpoint inhibitors: A meta-analysis

“…All of them classified responses to ICIs as complete remission (CR), partial response (PR), stable disease (SD), and progression of disease (PD) based on the Response Evaluation Criteria In Solid Tumors (RECIST) 1.1. Four articles demonstrated that none of the PET/CT parameters significantly correlated with ICIs response ( 17 , 23 , 28 , 29 ). However, the other four studies showed that NSCLC patients who achieved CR, PR, or SD after ICIs treatment had significantly lower median MTV values than those with PD ( 16 , 26 , 27 , 30 ).…”

“…Eight studies assessed the objective response based on RECIST 1.1. Four studies showed NSCLC patients who achieved CR, PR, or SD after ICIs treatment had significantly lower median MTV values than those with PD ( 16 , 26 , 27 , 30 ), while four demonstrated no significant correlation ( 17 , 23 , 28 , 29 ). More studies with consistent response assessments are needed to determine whether MTV is associated with the objective response of ICIs.…”

“…As shown, the overall risk of bias was relatively low, and the overall quality met the requirements of the meta-analysis. (17,23,28,29). However, the other four studies showed that NSCLC patients who achieved CR, PR, or SD after ICIs treatment had significantly lower median MTV values than those with PD (16,26,27,30).…”

The Association between the Body Mass Index, Chronic Obstructive Pulmonary Disease and SUV of the Non-Tumorous Lung in the Pretreatment [18F]FDG-PET/CT of Patients with Lung Cancer

“…Recently, several studies investigated the pre-therapeutic standardized uptake value (SUV) of non-tumorous lung tissue in [ 18 F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) as a potential predictive biomarker for the risk of developing radiation therapy-associated and immune checkpoint inhibitor associated pneumonitis [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. In individuals undergoing radiation therapy, a significant partial correlation exists between an increased pre-radiotherapeutic PET-measured glucose uptake and an elevated risk of radiation-induced pneumonitis [ 12 , 15 ].…”

“…In individuals undergoing radiation therapy, a significant partial correlation exists between an increased pre-radiotherapeutic PET-measured glucose uptake and an elevated risk of radiation-induced pneumonitis [ 12 , 15 ]. However, most studies focusing on the predictability of immunotherapy-associated pneumonitis failed to establish a significant correlation between pre-therapeutic FDG uptake and the risk of therapy-related pneumonitis [ 16 , 17 , 18 , 19 , 20 , 21 ]. In the studies referenced, the impact of patients’ comorbidities on the SUV was not incorporated into the analyses.…”