Treatment of Recurrent HGGs
In spite of maximal surgical and chemoradiation therapy, tumor progression is inevitable in the vast majority of patients with HGG. Survival for patients with recurrent HGGs remains poor, at 3–9 months.[5,21] There is little consensus on the optimal management strategy for recurrent HGGs. Several retrospective Level of Evidence III–IV studies support repeat tumor resections, as long as the patient's performance status is not low and preoperative tumor volume is not excessive.[1,5,16,26,30,55] A randomized, double-blind, placebo-controlled control trial also supported the implantation of carmustine (BCNU) wafers in tumor cavities after repeat operation. Although salvage temozolomide had previously been used for recurrent GBM,[9,56,80] recent Level II evidence clinical studies in patients with recurrent GBM have demonstrated that salvage chemotherapy combining bevacizumab, an antiangiogenic agent, with cytotoxic drugs can extend progression-free survival and overall survival to 6.1 and 9.2 months, respectively.[21,75,82] Finally, emerging agents that target tumorigenesis pathways, such as new angiogenesis inhibitors and other novel agents, show promise as therapeutic options. In select patients, salvage chemotherapy for recurrent HGGs is optimally preceded by repeat resection.[1,5,16,26,30,55,74,81] However, for a range of reasons, there are subsets of patients who are not ideal candidates for traditional open surgery, and many patients decline open surgery due to associated morbidity. For these patients, LITT has been considered a reasonable option for many reasons (Fig. 2C).
There are several advantages and arguments for the use of LITT in select patients with recurrent HGGs. First, recurrent lesions that are small, focal, and nodular are particularly amenable to a focal therapy. Given that recurrence is local in the majority of patients, LITT can target these areas focally. Second, reoperation in many patients with recurrent HGG can lead to more morbidity because of the patient's frailty and higher risk for wound healing complications after prior radiation and chemotherapy. Third, salvage chemotherapy may achieve better efficacy following maximal safe cytoreduction. Fourth, a cytoreductive approach provides the best option in tumors in which other therapies have been exhausted. Finally, LITT can be used repeatedly because there is no demonstrable dose toxicity (as with radiation) and the tumor does not develop resistance to LITT (as seen with chemotherapy).
Neurosurg Focus. 2014;37(6):e1 © 2014 American Association of Neurological Surgeons