Secondary Intracranial Tumors Following Radiotherapy for Pituitary Adenomas: A Systematic Review.

Ryuya Yamanaka,Eisuke Abe,Yasuo Takashima,Azusa Hayano,Toshiteru Sato

doi:10.3390/cancers9080103

Ryuya Yamanaka, Eisuke Abe + Show 3 more

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https://doi.org/10.3390/cancers9080103

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Abstract

Pituitary adenomas are often treated with radiotherapy for the management of tumor progression or recurrence. Despite the improvement in cure rates, patients treated by radiotherapy are at risk of development of secondary malignancies. We conducted a comprehensive literature review of the secondary intracranial tumors that occurred following radiotherapy to pituitary adenomas to obtain clinicopathological characteristics. The analysis included 48 neuroepithelial tumors, 37 meningiomas, and 52 sarcomas which were published between 1959–2017, although data is missing regarding overall survival and type of irradiation in a significant proportion of the reports. The average onset age for the pituitary adenoma was 37.2 ± 14.4 years and the average latency period before the diagnosis of the secondary tumor was 15.2 ± 8.7 years. Radiotherapy was administered in pituitary adenomas at an average dose of 52.0 ± 19.5 Gy. The distribution of pituitary adenomas according to their function was prolactinoma in 10 (7.2%) cases, acromegaly in 37 (27.0%) cases, Cushing disease in 4 (2.9%) cases, PRL+GH in 1 (0.7%) case, non-functioning adenoma in 57 (41.6%) cases. Irradiation technique delivered was lateral opposing field in 23 (16.7%) cases, 3 or 4 field technique in 27 (19.6%) cases, rotation technique in 10 (7.2%) cases, radio surgery in 6 (4.3%) cases. Most of the glioma or sarcoma had been generated after lateral opposing field or 3/4 field technique. Fibrosarcomas were predominant before 1979 (p < 0.0001). The median overall survival time for all neuroepithelial tumors was 11 months (95% confidence intervals (CI), 3–14). Patients with gliomas treated with radiotherapy exhibited a non-significant positive trend with longer overall survival. The median overall survival time for sarcoma cases was 6 months (95% CI, 1.5–9). The median survival time in patients with radiation and/or chemotherapy for sarcomas exhibited a non-significant positive trend with longer overall survival. In patients treated with radiotherapy for pituitary adenomas, the risk of secondary tumor incidence warrants a longer follow up period. Moreover, radiation and/or chemotherapy should be considered in cases of secondary glioma or sarcoma following radiotherapy to the pituitary adenomas.

Highlights

Pituitary adenomas which can either be hormone secreting or non-secreting are benign neoplasms of the pituitary gland approximately account for 8% of all primary brain tumors
After articles were excluded based on our present inclusion and exclusion criteria, 87 articles with a total of 137 (48 neuroepithelial tumors, 37 meningiomas, 52 sarcomas) patients in the 1959–2017 period were included in this review, data is missing regarding overall survival and type of irradiation in a significant proportion of the reports (Figure 1, Table 1, Supplementary Table S1) [14–102]
Chemotherapy was administered in 6 cases with a range of protocols performed in 36 cases, and biopsy was performed in 7 cases

Summary

Introduction

Pituitary adenomas which can either be hormone secreting or non-secreting are benign neoplasms of the pituitary gland approximately account for 8% of all primary brain tumors. Radiotherapy is an option only if repeated surgery or medical treatment fails in patients with pituitary adenomas. Radiation-induced intracranial tumors might occur within the brain, the dura mater, leptomeninges, optic sheath, vascular adventitia, or the choroid plexus within the central nervous system (CNS), it is rare. Tumors such as meningiomas, sarcomas, and gliomas are the most frequently reported secondary neoplasms [7–11]

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