Radiological and clinical assessment of long-term brain tumour survivors after radiotherapy

Abstract

Background and purpose: Late adverse effects of therapeutic brain radiotherapy (RT) may develop after long latency periods and our objective was to assess long-term brain tumour survivors following RT to large partial brain volumes.

Materials and methods: Assessment of MRI, SOMA/LENT score, quality of life and neuroendocrine function was performed in 33 adult brain tumour patients 6-25 years following RT. Fraction dose was 1.8 Gy to a median total dose of 54 Gy (range: 45.0-59.4 Gy). Ten patients had been given two opposing portals including one whole hemisphere, while 23 patients had in addition received an ipsilateral field. In 25 patients the hypothalamic and pituitary area had been included in the RT field. Results were compared within the study group and towards the general population matched for age and gender.

Results: All patients had white matter changes with increased signal intensity on T2 and FLAIR images. Discrete lesions (grade 1), beginning confluence of lesions (grade 2), and large confluent areas (grade 3) were present in 8, 8 and 17 patients, respectively. Patients treated with intra-arterial chemotherapy and patients at higher age at follow-up had significantly more grade 3 changes. Atrophy, lacunar lesions and contrast enhancement was found in 17, 18 and 23 patients, respectively. Significantly worse clinical status and quality of life was found in patients with white matter changes grade 3 or atrophy. Patients given full-dose RT to less volume did not have significantly less toxicity. Two cases of meningioma were found at 16 and 22 years after RT. Nineteen neuroendocrine abnormalities were observed in 16/25 patients.

Conclusions: External radiotherapy to the brain at a standard fractionation regime will cause varying degrees of late neurotoxicity and/or neuroendocrine disturbances in most patients. Life-long follow-up is recommended.