Results of Surgical Resection for Progression of Brain Metastases Previously Treatedby Gamma Knife Radiosurgery

Abstract

Surgical intervention of progressive brain metastases after GKR in selected patients leads to a meaningful improvement in survival rates. Further studies are necessary to determine the role of MRS/P in the postradiosurgery surveillance of brain metastases.

Diagnostic Pitfalls of Brain Metastases After Brain Irradiation

“…Following subtotal or gross-total resection, it is now a standard practice for patients to receive adjuvant postoperative radiation therapy in order to lower the recurrence rate -patients who receive radiation therapy are significantly less likely to suffer a treatment failure in the brain, both at the original resection cavity as well as at distant sites, compared with those who do not receive radiation. (6,7,12,13,20,23) Stereotactic radiosurgery delivered to the tumor resection cavity after gross-total resection is another approach for preventing local tumor recurrence. The benefits from using GKS instead of WBRT is to lower the incidence of the complications that often follow RT.…”

“…(27) So the two major challenges of management of brain metastases after stereotactic radio surgery and WBRT are 1) differentiating tumor progression from radiation necrosis and 2) deciding when surgical intervention is necessary. (7,20) Computerized tomography, MR imaging, SPECT and PET scanning are essential in the evaluation of metastatic brain tumors. Nevertheless, a differential diagnosis between tumor recurrence and radiation necrosis is difficult after radiotherapeutic treatment of brain tumors by using these modalities.…”

“…(3,8) However pathological specimens still remain the gold standard for distinguishing tumor from necrosis, because non of the imaging modalities is possible to reliably differentiate necrosis from progression in 100% of the cases. (20) Since currently one can not reliably make differentiation between tumor progression and radiation effect noninvasively, delayed neurosurgical resection does need to be considered for patients with symptomatic progression of intracerebral lesion after GKS.…”

“…Usually after the surgical resection of BMs , the patients are irradiated -whole brain radiation therapy (WBRT) or Gamma Knife surgery (GKS). (6,7,12,13,20,23,24) With the present report we try to elaborate on the value of the modern diagnostic tools in differentiating between tumor progression versus radiation necrosis in irradiated patients with brain metastases.…”

Stereotactic biopsy combined with stereotactic 125iodine brachytherapy for diagnosis and treatment of locally recurrent single brain metastases

“…However, most of these studies combined both distant progression and local recurrence of cerebral disease, although differentiating between these may be of diagnostic and therapeutic importance [2][3][4][5]. In comparison with distant cerebral progression, local changes (reappearance/enlargement of contrast enhancement on MRI/computed tomography (CT)) of previously irradiated (SRS, WBRT) metastases more frequently led to problems differentiating between radiation necrosis and tumor re-growth [6][7][8][9].…”