Abstracts

Rationale: We perform stereotactic radiofrequency thermocoagulation (SRT) for the treatment of hypothalamic hamartoma (HH) and have achieved excellent seizure outcome. However, large size or complicated shape of HH, especially with attachment to bilateral hypothalamus, is still challenging. Once we performed staged-SRT and sometimes changed the operation side in reoperation. Nowadays we have applied trans-third ventricular approach (TT-SRT) to configure coagulations on the contralateral attachment in a single-staged treatment aiming to reduce reoperations. The purpose of this study is to validate the effectiveness and feasibility of SRT, in particular, of TT-SRT for patients with HH attaching to bilateral hypothalamus. Methods: The clinical records of 150 patients with HH who underwent SRT from 1997 to 2015 were retrospectively reviewed. We extracted patients whose HH had attachment to bilateral hypothalamus, and evaluated clinical features, surgical procedures, outcomes and complications. Results: 68 patients (42 males; age at surgery, 1.7–42 years, median, 5 years) were enrolled in this study. Of these, 21 patients (20.9%) required reoperation for seizure recurrence and residual HH attachment. Consequently, a total of 98 SRTs were performed for those patients. 21 patients with TT-SRT at first surgery resulted in reoperation (n=2, 9.5%) less frequently than those without (19/47, 40.4%) (P=0.011). Six patients (8.8%) underwent SRT with contralateral approach to the previous SRT (bilateral approach; B-SRT) in reoperation. Final overall seizure freedom rates were significantly different among SRT approach; 33/41 (80.5%) in patients who underwent SRT with unilateral approach (U-SRT), 2/6 (33.3) in patient with B-SRT, and 13/21 (61.9%) in patients with TT-SRT (P=0.035). Final freedom rates of gelastic seizure were not significantly different; 39/41 (95.1%) in patients with U-SRT, 5/6 (83.3%) in patients with B-SRT, and 16/21 (76.2%) in patients with TT-SRT (P=0.084). Final freedom rates of other types of seizure were also not different; 28/35 (80.0%) for U-SRT, 3/6 (50.0%) for B-SRT, and 5/11 (45.5%) for TT-SRT (P=0.084). Frequency of various complications of TT-SRT was not different compared with U-SRT (P=0.168), except for transient hyponatremia improving within two weeks (P=0.006). Conclusions: TT-SRT can be safely applied for complex-shaped HH with attachment to bilateral hypothalamus. TT-SRT provides valid surgical outcomes and reduces extra-invasiveness of reoperation. SRT would be a single treatment option for every size, shape and location of HH. Funding: There is no funding for this abstract.