Brain Irradiation and Gadobutrol Administration in Pediatric Patients with Brain Tumors: Effect on MRI Brain Signal Intensity

Abstract

Purpose To determine whether treatment affects MRI signal intensity in pediatric patients with primary brain tumors independent of the administration of macrocyclic gadolinium-based contrast agents (GBCAs). Materials and Methods This retrospective, single-center study included 78 patients (mean age, 7.7 years ± 5.4) with primary brain tumors who underwent macrocyclic GBCA-enhanced MRI from 2015 to 2018. Three groups were compared: (a) patients who had undergone radiation therapy (37 patients, 26 of whom had undergone concurrent chemotherapy), (b) patients who had undergone chemotherapy only (17 patients), and (c) patients who had received no treatment ("no-treatment group," 24 patients). The signal intensity in the globus pallidus (GP), thalamus, dentate nucleus (DN), and pons was measured on unenhanced T1-weighted images. GP-to-thalamus and DN-to-pons signal intensity ratios were compared among groups with analysis of variance by using the Kruskal-Wallis test, followed by post hoc pairwise tests with Tukey adjustment, and were analyzed relative to group, total cumulative doses of GBCA, age, and sex with multivariable linear models. Results The mean number of GBCA-enhanced MRI examinations in the radiation therapy, chemotherapy-only, and no-treatment groups was 7.11, 7.29, and 4.96, respectively (P < .01 for the radiation therapy and chemotherapy groups compared with the no-treatment group). The DN-to-pons ratio in the radiation therapy group was higher than that in both the no-treatment group and the chemotherapy-only group (P < .01 for both). There was no significant difference in the DN-to-pons ratios between the chemotherapy-only group and the no-treatment group (P = .99). The GP-to-thalamus ratios did not differ among all three groups (P = .09). There was no dose-dependent effect of GBCA on the DN-to-pons and GP-to-thalamus ratios when adjusting for the effects of treatment (P = .21 and P = .38, respectively). Conclusion Brain irradiation contributes to a higher dentate nucleus signal intensity in pediatric patients with brain tumor independent of the administration of macrocyclic gadolinium-based contrast agents. © RSNA, 2018.

Impact of nasopharyngeal irradiation and gadolinium administration on changes in T1 signal intensity of the dentate nucleus in nasopharyngeal malignancy patients without intracranial abnormalities

“…SI changes in the DN in T 1 WI due to brain irradiation have been reported in previous studies . Kasahara et al were the first to exhibit an association between a history of radiation therapy to the brain and T 1 hyperintensity in the DN, but they did not consider the administration of GBCAs as a potential source of these changes.…”

“…Tamrazi et al postulated that the SI changes described by Kasahara et al might be caused by gadolinium deposition. They also reported that brain irradiation affected the SI in T 1 WI within the DN independent of linear or macrocyclic GBCA administrations in pediatric patients with brain tumor. Additionally, they found there was no significant difference between a radiation therapy‐treated brain tumor group and the nontreated brain tumor group when the number of linear GBCA administrations was 11 to 20 in pediatric patients .…”

“…Irradiation has been considered a critical factor that can influence SI change in the DN . Kasahara et al reported hyperintensity of the DN on unenhanced T 1 WI associated with a history of brain irradiation.…”

“…However, they did not present any information related to the use of GBCAs. Tamrazi et al showed that changes in the SI of the DN on T 1 WI were independent of the linear or macrocyclic GBCA administrations in pediatric patients with brain tumors undergoing brain irradiation. This could be explained, perhaps, by an accelerated gadolinium deposition caused by the brain irradiation.…”

Impact of brain tumors and radiotherapy on the presence of gadolinium in the brain after repeated administration of gadolinium-based contrast agents: an experimental study in rats

“…In several adult patient studies, statistical analysis revealed no significant effect of radiotherapy on SI changes in DN and GP [4, 5, 24]. It was also reported that MRI SI alterations in the DN has been found after radiotherapy independent of GBCA administration [25, 26].…”