The role of 18-FDG PET/CT assessment of functional brain metabolism in cancer patients after chemotherapy

Abstract

Background Most neuropsychological studies on chemotherapy (CHT)-treated cancer survivors reported cognitive impairments in multiple domains such as executive functions, learning, memory, attention, verbal fluency, and speed of information processing. The CHT effects range from small to moderate, involving mostly the cognitive functions sub-served by frontal lobe. This study aimed to evaluate the role of PET/CT in the assessment of the effect of chemotherapy on the glucose metabolism in the brain in cancer patients after the chemotherapy treatment. Results This was a prospective study carried out in 2 years for patients who have done PET/CT scans for assessment of the change of the glucose uptake in the brain in pre- and in post-therapeutic state. A total number of 30 patients, 8 males and 22 females, were examined. The age of the patients ranged from 29 to 79 years (mean 57.9). Each patient underwent at least two PET/CT scans, first before the initiation of the therapy, and second was at least 3 months after starting the chemotherapy regimen. This study employed an adaptive threshold method, SCENIUM version 2.0.1. Automatic ROI identification was performed through around 10 regions of the brain. After segmentation of FDG uptake in the different brain regions of each subject, we measured average glucose uptake (SUVmean), registered by SCENIUM software. Conclusion There was significant reduction in the brain metabolism “FDG uptake” in all regions of the brain, mainly at the mesial temporal lobes as well as the frontal lobes. This metabolic change proves that chemotherapy has an adverse effect on the brain that can be objectively assessed with modern imaging techniques.

Frontal and anterior temporal hypometabolism post chemoradiation in head and neck cancer: A real‐world PET study

“…Postchemotherapy FDG PET studies of the brain after treatment for various other cancers have also shown effects in these regions, with the frontal and temporal lobes most consistently affected across various cancers. [25][26][27][28][29] Thus, as one of the larger FDG PET studies in this arena, our study contributes to, validates, and corroborates the small but growing body of literature showing that the frontal and temporal lobes may be particularly vulnerable to cancer therapy. One limitation of our use of SPM default relative threshold masking is that some periventricular white matter is excluded from analysis.…”

Influence of metabolic tumor burden on reference tissues’ standardized uptake values in 18F-FDG PET/CT sequential imaging

“…Our study did have some limitations, other confounding variables were not considered such as effects of interval chemotherapy; studies have shown a significant reduction in brain metabolism after chemotherapy, which in turn decreases normal FDG uptake within the brain [23]; however, the most affected regions were found to be the mesial temporal lobes as well as the frontal lobes, neither region were used in our study to draw ROIs [24]. The number of patients in each response group was not equal, with predominance of regression group, metabolic flare phenomenon which is a potential pitfall in progression group were not evaluated, there was predominance of certain malignancies such as lymphoma, breast, lung over others such as pancreatic and gastric.…”

Follow-Up of a Cohort of Patients with Post-Acute COVID-19 Syndrome in a Belgian Family Practice

“…In daily practice, the selection bias is the rule as the doctor is searching for cases and a 29/32 (90%) efficiency is hence very surprising. 18FDG PET-CT allows brain metabolism to be directly assessed [59]. In a recent study by Verger et al, 47% of the scans of 143 patients with suspected neurological PACS were visually interpreted as abnormal [51].…”