RESUMO
Objective: The intraoperative identification and preservation of optic radiations (OR) during tumor resection requires the patient to be awake. Different tasks are used. However, they do not grant the maintenance of foveal vision during all testing, limiting the ability to constantly monitor the peripheral vision and to inform about the portion of the peripheral field that is encountered. Although hemianopia can be prevented, quadrantanopia cannot be properly avoided. To overcome these limitations, we developed an intra-operative Visual field Task (iVT) to monitor the foveal vision, alerting about the likelihood of injuring the OR during task administration, and to inform about the portion of the peripheral field that is explored. Data on feasibility and efficacy in preventing visual field deficits are reported, comparing the outcome with the standard available task (Double-Picture-Naming-Task, DPNT). Methods: Patients with a temporal and/or parietal lobe tumor in close morphological relationship with the OR, or where the resection can involve the OR at any extent, without pre-operative visual-field deficits (Humphrey) were enrolled. Fifty-four patients were submitted to iVT, 38 to DPNT during awake surgery with brain mapping neurophysiological techniques. Feasibility was assessed as ease of administration, training and mapping time, and ability to alert about the loss of foveal vision. Type and location of evoked interferences were registered. Functional outcome was evaluated by manual and Humphrey test; extent of resection was recorded. Tractography was performed in a sample of patients to compare patient anatomy with intraoperative stimulation site(s). Results: The test was easy to administer and detected the loss of foveal vision in all cases. Stimulation induced visual-field interferences, detected in all patients, classified as detection or discrimination errors. Detection was mostly observed in temporal tumors, discrimination in temporo-parietal ones. Immediate visual disturbances in DPNT group were registered in 84 vs. 24% of iVT group. At 1-month Humphrey evaluation, 26% of iVT vs. 63% of DPNT had quadrantanopia (32% symptomatic); 10% of DPNT had hemianopia. EOR was similar. Detection errors were induced for stimulation of OR; discrimination also for other visual processing tract (ILF). Conclusion: iVT was feasible and sensitive to preserve the functional integrity of the OR.
RESUMO
PURPOSE: This prospective phase II study assessed safety and feasibility of surgery followed by hypofractionated radiosurgery (HSRS) on the tumor bed in oligometastatic patients with single large brain metastases (BMs). METHODS AND MATERIALS: Between June 2015 and May 2018, 101 patients were enrolled. Oligometastatic disease was defined by a maximum of 5 extracranial metastatic lesions. HSRS was performed within 1 month of surgery and consisted of 30 Gy in 3 fractions. Local control, occurrence of new BMs, overall survival, and treatment-related toxicities were assessed. RESULTS: At a median follow-up time of 26 months, local recurrence occurred in 6 patients (5.9%). Six-month, 1-year, and 2-year local control rates were 100%, 98.9% ± 1.1%, and 85.9% ± 0.6%, respectively. New BMs occurred in 39 patients (38.6%); median brain distant progression time and 6-month, 1-year, and 2-year brain distant progression rates were 39 months (95% CI, 19-39 months), 17% ± 3.7%, 31.4% ± 4.8%, and 42.5% ± 5.9%, respectively. At the last observation time, 50 patients (49.5%) were alive and 51 (50.5%) were dead; 10 patients died owing to neurologic causes and 40 as a result of systemic progression. Median overall survival time and 6-month, 1-year, and 2-year overall survival rates were 22 months (95% CI, 20-30 months), 95% ± 2.1%, 81.9% ± 3.8%, and 46.6% ± 6%, respectively. Infratentorial site, residual tumor volume, longer interval time between primary diagnosis and occurrence of BMs, and oligometastatic disease status significantly influenced outcome. Grade 2 to 3 radionecrosis occurred in 26 patients. Neurocognitive functions remained stable or, in some cases, improved. CONCLUSIONS: Surgery followed by HSRS on the tumor bed is a safe and effective approach, affording good brain control with acceptable toxicities. As for extracranial metastatic sites, patients with BMs can benefit from local ablative treatment in the context of an oligometastatic disease.