RESUMO
Our aim was to investigate probable biomarkers specific to immune-related central nervous system toxicity (CNST) in cancer patients treated with immune checkpoint inhibitors (ICI) by analysis of 18F-FDG PET/CT images. Methods: Cancer patients receiving ICI treatment were enrolled in a multicenter observational study that analyzed regional metabolic changes before and during CNST onset from January 2020 to February 2022. In 1:1 propensity score-matched pairs, the regional SUVmean of each bilateral brain lobe of CNST patients (CNST+) was compared with that of patients who had central nervous system infections (CNSIs) and patients without CNST or CNSI (CNST-). In a validation cohort, patients were recruited from February 2022 to July 2023 and followed up for 24 wk after the start of ICI. Early changes in regional SUVmean at 5-6 wk after therapy initiation were evaluated for ability to predict later CNST onset. Results: Of 6,395 ICI-treated patients, 2,387 underwent prognostic 18F-FDG PET/CT and 125 of the scanned patients had CNST (median time from ICI treatment to onset, 9 wk; quartile range, 2-23 wk). Regional 18F-FDG PET/CT SUVmean changes were higher in CNST+ than in CNST- patients (117 patient pairs) but were lower than in CNSI patients (50 pairs). Differentiating analysis reached an area under the curve (AUC) of 0.83 (95% CI, 0.78-0.88) for CNST+ versus CNST- and of 0.80 (95% CI, 0.72-0.89) for CNST+ versus CNSI. Changes in SUVmean were also higher before CNST onset than for CNST- (60 pairs; AUC, 0.74; 95% CI, 0.66-0.83). In a validation cohort of 2,878 patients, preonset changes in SUVmean reached an AUC of 0.86 (95% CI, 0.79-0.94) in predicting later CNST incidence. Conclusion: Brain regional hypermetabolism could be detected during and before CNST clinical onset. CNST may be a distinct pathologic entity versus brain infections defined by 18F-FDG PET/CT brain scans. Regional SUV differences may be translated into early diagnostic tools based on moderate differentiating accuracy in our study.
RESUMO
Background: Cancer-related cognitive decline is a serious problem in long-term survival but no pivotal study has investigated whether checkpoint inhibitors (ICI) may be associated with cognitive adverse events. Methods: This propensity score-matched analysis recruited non-small cell lung cancer (NSCLC) patients prescribed with or without ICI monotherapy from three Chinese tertiary hospitals. Patients were excluded from study who developed brain metastasis or had disorders severely affecting cognitive abilities. Primary outcomes were changes in neuropsychological battery test (NBT) at baseline, 6- and 12-month sessions, and any NBT score changes that exceeded 3∗SD of baseline scores would be marked as objective cognitive adverse events (CoAE). Secondary endpoint was the 20-item Perceived Cognitive Impairment (PCI) sub-scale score change in Functional Assessment of Cancer Therapy-Cognitive Function questionnaire, administered at baseline, 3-, 6-, 9-, 12-, and 15-month follow-up session. Per-protocol ICI and control arms were matched with propensity scores that incorporated baseline variables to compare both NBT and PCI assessment results. Patients participating in PCI assessments were analysed in intention-to-treat analysis. Kaplan-Meier survival curves with log-rank tests were adopted to analyse incidence of perceived cognitive decline events (PCDE). Findings: Between March 12, 2020, and March 28, 2021, 908 participants were enrolled. Compared to control, 3 of 4 subtest of NBT scores in ICI arm showed significant cognitive decline in 6- and 12-month sessions, in which Trail Making Test score change (13.56 ± 11.73) reached threshold of cognitive deficit diagnosis in the 12-month session. In 1:1 matched 292 pairs from 908 patients, PCI score changes in ICI arms were -4.26 ± 8.54 (3rd month), -4.72 ± 11.83 (6th month), -6.16 ± 15.41 (9th month), -6.07 ± 15.71 (12th month), and -7.96 ± 13.97 (15th month). The scores were significantly lower than control arm in 3-, 6-, and 12-session follow-up. The result was validated after adjusting quality of life scores and in intention-to-treat analysis. Mean PCI change exceeded 1/2 SD of baseline PCI score (5.81) in 9-, 12-, and 15-month sessions in ICI arm, but not in control arm. PCDE incidence/prevalence was significantly higher in ICI arm (incidence 26.4% vs. 5.1%, and prevalence 16.2% vs. 1.7%). Immune-related adverse events related to incidence of PCDE after adjusting for baseline variables. Interpretation: ICI monotherapy seemed to relate to higher cognitive decline represented by score changes and incidence/prevalence rates. The decline deteriorated as treatment progressed, and immune-related adverse events seemed to be associated with higher cognitive adverse events incidence in the ICI treatment. Funding: The Fellowship of China Postdoctoral Science Foundation and National Natural Science Foundation of China Youth Science Fund Project.