Radiation-Induced Meningioma following Prophylactic Radiotherapy for Acute Lymphoblastic Leukemia in Childhood

Abstract

Background: Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Although it was considered to be a poor prognostic disease, modern treatment protocols (aggressive chemotherapy and prophylactic cranial irradiation) have resulted in dramatically improved survival rates. In a group of low-risk ALL patients, the 5-year survival rate is estimated to be 85%. However, ALL patients who undergo this treatment are at risk of developing secondary neoplasms related to treatment, which has become an increasingly recognized problem. Case Description: A 3-year-old boy with ALL was successfully treated with chemotherapy (vincristine, prednisolone, mercaptopurine and methotrexate) and prophylactic cranial irradiation (total 18 Gy). At the age of 23, he was admitted to our hospital for weakness in the right leg. Computed tomography and magnetic resonance imaging revealed a parasagittal tumor of the left frontoparietal lobe with perifocal edema. The tumor was completely removed surgically and pathohistologically diagnosed as atypical meningioma. Conclusion: Long-term survivors who received radiotherapy for ALL in childhood are at risk for late complications, including radiation-induced meningioma. Therefore, careful follow-up neurological examinations, for example magnetic resonance imaging, are indicated in these patients. In addition, late complications should be taken into account during the initial planning of prophylactic radiotheraphy dosage, which has implications for informed consent of the patient.

Radiation-Induced World Health Organization Grade II Meningiomas in Young Patients Following Prophylactic Cranial Irradiation for Acute Lymphoblastic Leukemia in Childhood

“…4,16,27) The mean latency of meningiomas after prophylactic irradiation for childhood ALL has been reported as 15 to 19 years. 11,32) In the present cases, meningiomas were found at 12, 18, and 12 years after cranial irradiation. The relatively shorter latency periods in our cases might be related to the particularly malignant biology of the original meningiomas.…”

“…10,16,24,26,27) In meningiomas after prophylactic radiotherapy for childhood acute leukemia, rates of between 13% and 43% have been reported to be atypical. 2,11) Identical rates of grade II or III radiation-induced meningiomas and survival were reported compared to adult primary meningiomas. 28) In our institute, all radiation-induced meningiomas that have been presented to date have been WHO grade II.…”

Intracranial meningiomas in individuals under the age of 30; Analysis of risk factors, histopathology, and recurrence rate

“…Radiation therapy, administered as part of a treatment plan such as for patients with medulloblastomas or pituitary adenomas, may increase the risk of meningioma formation [4,6]. Therapeutic cranial radiation may be administered prophylactically in some instances such as in the treatment of ALL patients at high-risk for CNS relapse or small-cell lung cancer patients [41][42][43][45][46][47][48][49][50][51]. At times, it is considered in the management of non-small-cell lung cancer patients as well [42].…”

“…Exposure below age 20 years may predispose to meningioma development while exposure above the age of 20 years may predispose more towards sarcoma development [50]. Acute lymphoblastic leukemia (ALL) is one of the most common cancers in children and comprises 23% of all mali-gnancies in children <15 years of age [41,45,46]. Risk factors for the development of ALL include prenatal exposure to x-rays or post-natal exposure to high-dose radiation.…”

“…Among genetic factors, NF also confers an increased risk of ALL development. Patients are treated with induction chemotherapy that continues into a consolidation and maintenance phases and >90% achieve remission with >80% expected to be long term survivors [41,45,46]. The CNS, and testes in males, is considered a sanctuary site that is relatively impermeable to the effects of systemic chemotherapy.…”