Surgery and radiotherapy: complementary tools in the management of benign intracranial tumors

Abstract

<jats:p>✓ Historically, radiation therapy has been used extensively in the treatment of malignant and aggressive intracranial tumors, and the importance of its role has been repeatedly verified by prolonged patient survival rates and increased tumor control. As more modern capabilities are employed in surgery and radiotherapy, attention is being directed to the utility of radiation as either primary or secondary treatment of benign tumors. Specifically, primary treatment encompasses irradiation of small benign tumors without biopsy confirmation of tumor type; secondary treatment involves postoperative radiation therapy, with the possibility that less-aggressive tumor resection may be performed in areas that have a higher probability of resultant neurological deficit. Current literature suggests that this is not only a possible treatment strategy, but that it may be superior to more radical resection in some cases, for example, in vestibular schwannomas and meningiomas. This article provides an overview of factors to consider in the use of radiation therapy and reviews the relationships between radiation and surgery, notably the unique complementary role each plays in the treatment of benign intracranial tumors.</jats:p>

Outcome and survival following primary and repeat surgery for World Health Organization Grade III meningiomas

“…These outcomes compare favorably with those in many other patients with high-grade intracranial neoplasms, for whom the prognosis, even with aggressive resection, is far more grim. 13,16 At our institution, the mean number of procedures (open surgery, radiosurgery) for patients with primary surgery and a diagnosis of malignant meningioma was 2.8. Clearly the bias here is to be aggressive with surgical and radiosurgical methods, because the success rate when using chemotherapy agents such as hydroxyurea and adriamycin/dacar bazine has been determined to be modest at best.…”

Human Schwannomas Express Activated Platelet-Derived Growth Factor Receptors and c-kit and Are Growth Inhibited by Gleevec (Imatinib Mesylate)

“…1). Currently, actively growing and clinically symptomatic schwannomas are managed with surgery or radiosurgery, each with some short-and long-term risks (4)(5)(6)(7)(8)(9). A management alternative that could blunt or regress the growth of the schwannoma, and be taken on a prolonged basis, would potentially stabilize the clinical symptoms and defray active intervention, especially in high-risk patients.…”

“…For example, in NF2 patients, prolonged hearing preservation is a prime management objective due to the bilateral nature of the VS in addition to often multiple other schwannomas. Although in specialized centers technical improvements have occurred in surgery and radiosurgery to minimize risks, there still exists significant limitation in our ability to preserve long-term hearing, in addition to small but potential critical risks such as radiation-induced carcinogenesis (4)(5)(6)(7)(8)(9). This study is limited by its in vitro nature due to lack of readily available xenograft or transgenic models of schwannomas.…”

“…These growth spurts can be associated with clinical symptoms due to brain stem compression, compromise of adjacent cranial nerve function ( Fig. 1), and often precipitate active intervention in the form of surgery or radiosurgery, each with their short-and longterm risks (4)(5)(6)(7)(8)(9). The etiology of these growth spurts, which rarely represents malignant transformation, is not well understood.…”

Intracranial metastatic disease rarely involves the pituitary: retrospective analysis of 935 metastases in 155 patients and review of the literature

“…A significant number of patients with limited stage small cell lung cancer who receive prophylactic cranial irradiation may also survive long enough for this late toxicity to become relevant [45]. Dosimetric exclusion of this region may also be of benefit in pediatric patients and patients treated for low grade gliomas, meningiomas, and a number of other skull base tumors as a number of these patients will survive long enough to manifest this toxicity [46][47][48][49][50][51][52].…”