Risk Factors for Radiation Necrosis in Patients Undergoing Cranial Stereotactic Radiosurgery

Abstract

Purpose: single-staged stereotactic radiosurgery (SRS) is an established part of the multimodal treatment in neuro-oncology. Radiation necrosis after high-dose irradiation is a known complication, but there is a lack of evidence about the risk factors. The aim of this study was to evaluate possible risk factors for radiation necrosis in patients undergoing radiosurgery. Methods: patients treated with radiosurgery between January 2004 and November 2020 were retrospectively analyzed. The clinical data, imaging and medication were gathered from electronic patient records. The largest diameter of the tumors was measured using MRI scans in T1 weighted imaging with gadolinium and the edema in T2 weighted sequences. The diagnosis of a radiation necrosis was established analyzing imaging criteria combined with clinical course or pathologically confirmed by subsequent surgical intervention. Patients developing radiation necrosis detected after SRS were compared to patients without evidence of an overshooting irradiation reaction. Results: 388 patients were included retrospectively, 61 (15.7%) of whom developed a radiation necrosis. Median follow-up was 24 (6–62) months with a radiation necrosis after 8 (6–12) months. The most frequent tumors were metastases in 47.2% of the cases, followed by acoustic neuromas in 32.2% and meningiomas in 13.4%. Seventy-three (18.9%) patients already underwent one or more previous radiosurgical procedures for different lesions. The mean largest diameter of the tumors amounted to 16.3 mm (± 6.1 mm). The median—80%—isodose administered was 16 (14–25) Gy. Of the radiation necroses, 25 (43.1%) required treatment, in 23 (39.7%) thereof, medical treatment was applied and in 2 (3.4%) cases, debulking surgery was performed. In this study, significantly more radiation necroses arose in patients with higher doses (HR 1.3 [CI 1.2; 1.5], p < 0.001) leading to a risk increment of over 180% between a radiation isodose of 14 and 20 Gy. The maximum diameter was a second significant risk factor (p = 0.028) with an HR of 1065 for every 1 mm increase in multivariate analysis. Conclusion: large diameter and high doses were reliable independent risk factors leading to more frequent radiation necroses, regardless of tumor type in patients undergoing radiosurgery. Alternative therapeutic procedures may be considered in lesions with large volume and an expected high radiation doses due to the increased risk of developing radiation necrosis.

Management of High-Grade Meningioma: Present, Past and Promising Future

“…No matter the type of tumor in patients having radiosurgery, large diameter and high doses were reliable independent risk factors that led to more often occurring radiation necroses. Due to the increased risk of developing radiation necrosis, other therapeutic approaches may be taken into account in lesions with a large volume and an anticipated high radiation dosage [90]. Grade III anaplastic meningiomas are malignant (cancerous) and associated with cranial radiation exposure.…”

The Clinical Frailty Scale as useful tool in patients with brain metastases

“…These treatments are suitable for small to medium size metastases, but large metastases with mass effect and neurological deficits due to compression are poorly treated by radiotherapy [ 13 , 19 , 20 ]. Surgical excision of symptomatic BMs leads to the fast relief of symptoms and diminishes the need of corticosteroids.…”

A Multi-Disciplinary Approach to Diagnosis and Treatment of Radionecrosis in Malignant Gliomas and Cerebral Metastases

“…SRS is now also considered a viable and safe treatment option for up to and sometimes exceeding 10 brain metastases [ 1 ]. The increasing application of SRS has also put radiation necrosis into the spotlight [ 2 ], since the risk increases with the number of irradiated metastases and the volume of co-irradiated brain tissue. RN represents the main dose-limiting complication in SRS.…”