Imaging Assessment of the Pituitary Gland and Long-Term Endocrinological Abnormalities in Pediatric Brain Cancer Survivors.

Abstract

Background: Pediatric brain cancer survivors often experience hypothalamic-pituitary dysfunction due to cranial irradiation and chemotherapy. While hormone deficiencies have been studied, the changes in pituitary size and shape on long-term MRI and their relationship to endocrine dysfunction remain under-explored.

Purpose: To evaluate pituitary gland height, volume, and shape in relation to long-term endocrine abnormalities in pediatric brain tumor survivors.

Study type: Retrospective cohort study.

Population: A total of 56 pediatric brain tumor survivors (50% male) with an average follow-up of 10.8 ± 1.6 years; 44.6% underwent radiotherapy, and 48% were treated with chemotherapy. One-third of the cohort experienced at least one pituitary hormone deficiency.

Field strength/sequence: 3 T, including volumetric 1 mm sagittal post-contrast T1 images.

Assessment: Pituitary height, volume, and shape (concave, horizontal, convex) were measured. Endocrine abnormalities were diagnosed through routine serum hormone testing.

Statistical tests: The t test, chi-square test, and Pearson test with significance at P < 0.05 were used. Receiver-operating characteristic (ROC) analysis assessed the association of imaging parameters and pituitary dysfunction.

Results: Radiation and chemotherapy treatment were significantly associated with pituitary hormone deficiencies. There were significant differences in pituitary height and volume in patients with pituitary hormone deficiencies compared with normal pituitary function (4.0 ± 1.3 vs. 5.5 ± 1.5 mm, and 354.2 ± 198.0 vs. 568.3 ± 184.4 mm³, respectively). There was a significant association between radiation therapy and pituitary gland shape, with 60.0% of patients who received radiation therapy exhibiting a pituitary shape categorized as concave, 32.0% as horizontal, and 8.0% as convex, compared to 9.7%, 74.2%, and 16.1%, respectively. ROC analysis for association with pituitary hormone deficiency was 0.81, 0.8, and 0.74 for pituitary height, volume, and shape, respectively.

Data conclusion: Cranial irradiation and chemotherapy in pediatric brain tumors are associated with endocrine dysfunction, with decreased pituitary height, volume, and concave shape in long-term MRI surveillance are associated with such late endocrine dysfunction.

Level of evidence: 4 TECHNICAL EFFICACY: Stage 2.