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Yang Kwon, Jae Sung Ahn, Sang Ryong Jeon, Jeong Hoon Kim, Chang Jin Kim, Jung Kyo Lee, Byung Duk Kwun, Do Hee Lee and Sun Young Kim

Object. The authors evaluated whether gamma knife radiosurgery (GKS) could be a causative factor in intratumoral bleeding in meningiomas.

Methods. Gamma knife radiosurgery was used in the treatment of 173 meningiomas during a 10-year period. Four patients suffered post-GKS intratumoral hemorrhage. The course in these patients was reviewed.

Four of 173 patients suffered an intratumoral hemorrhage during a follow-up period of 1 to 8 years. The risk of intratumoral bleeding after GKS for meningioma was 2.3%. Intracystic hemorrhage occurred in two patients 1 and 5 years, respectively, after radiosurgery. In the other two cases intratumoral bleeding occurred 2 and 8 years, respectively, after radiosurgery. Histological examination in three cases found no specific findings related to the postradiosurgical changes.

Conclusions. Because the reported risk of spontaneous intratumoral bleeding in meningiomas is 1.3 to 2.7%, the incidence in this series was not unduly high. Radiosurgery itself could not be shown to be a significant factor in the development of the intratumoral bleeding.

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Jung-Ho Yun, Do Hoon Kwon, Eun Jung Lee, Do Heui Lee, Jae Sung Ahn and Byung Duk Kwun

New nidi are rarely found adjacent to the resection margin following treatment for an arteriovenous malformation (AVM), especially in adults. In addition, there are no reports in adults of new nidus formation adjacent to the targeted site of an AVM that angiography has verified to be completely obliterated by radiosurgery. The authors present their experience with recurrent AVMs following AVM radiosurgery in 3 patients whose ages were 9 years, 10 years, and 33 years. None of the patients had been treated with embolization before radiosurgery. Two patients had a history of intracerebral hemorrhage before radiosurgery. New lesions developed around the obliterated nidi in all 3 cases. Angiography performed after the first radiosurgery confirmed complete removal of the nidus in all 3 patients, and new nidus formation was detected 31, 132, and 36 months after the initial GKS. The new lesions were also treated by GKS. Occasionally, in patients with recurrent AVMs, such as those described in this paper, long-term clinical and angiographic follow-up may be required, even if complete occlusion is originally shown on angiograms.

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Eun Suk Park, Do Hoon Kwon, Jun Bum Park, Do Hee Lee, Young Hyun Cho, Jeong Hoon Kim and Chang Jin Kim


Brain metastases from hepatocellular carcinoma (HCC) are rare, and the evidence of the effectiveness of Gamma Knife surgery (GKS) in this disease is lacking. The authors report their institutional experience with GKS in patients with brain metastases from HCCs.


The authors retrospectively reviewed the medical records of 73 consecutive patients who had a combined total of 141 brain metastases arising from HCCs and were treated with GKS. Sixty-four (87.7%) patients were male, and the mean age of the patients was 52.5 years (range 30–79 years). The mean tumor volume was 7.35 cm3 (range 0.19–33.7 cm3). The median margin dose prescribed was 23 Gy (range 15–32 Gy). Univariate and multivariate survival analyses were performed to identify possible prognostic factors of outcomes.


The estimated rate of local tumor control was 79.6% at 3 months after GKS. The median overall survival time after GKS was 16 weeks. The actuarial survival rates were 76.7%, 58.9%, and 26.0% at 4, 12, and 24 weeks after GKS, respectively. In the univariate analysis, an age of ≤ 65 years, Child-Pugh Class A (pertaining to liver function), high Karnofsky Performance Scale score (≥ 70), and low Radiation Therapy Oncology Group recursive partitioning analysis class (I or II) were positively associated with the survival times of patients. No statistically significant variable was identified in the multivariate analysis.


Although survival was extremely poor in patients with brain metastases from HCCs, GKS showed acceptable local tumor control at 3 months after the treatment. The authors suggest that GKS represents a noninvasive approach that may provide a valuable option for treating patients with brain metastases from HCCs.

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Moinay Kim, Wonhyoung Park, Yeongu Chung, Si Un Lee, Jung Cheol Park, Do Hoon Kwon, Jae Sung Ahn and Seungjoo Lee


The current grading system for moyamoya disease (MMD) is focused on angiographic studies with limited clinical application. The authors aimed to determine relevant factors that may impact postoperative outcome and establish a scoring system to predict the functional outcome.


Adult patients with MMD who underwent treatment between 1998 and 2016 were included. Factors such as age, sex, comorbidity, smoking, MMD family history, initial presentation, multimodal imaging modalities, and types of surgical revascularization were thoroughly reviewed. These factors were analyzed to determine possible risk factors related to unfavorable 6-month postoperative outcomes using the modified Rankin Scale (mRS) (unfavorable: mRS score ≥ 3). A scoring system was developed using these independent risk factors to predict the outcome and validated using prospectively collected data from multiple centers between 2017 and 2018.


Of 302 patients for whom applications were submitted, 260 patients (321 hemispheres) met the diagnostic criteria. In multivariate analysis, hyperlipidemia, smoking, cerebral infarction on preoperative CT or MRI, and moderately to severely reduced regional cerebrovascular reserve results from Diamox SPECT were significantly related to unfavorable outcome. The authors developed a scoring system and stratified patients into risk groups according to their scores: low-risk (score 0–3), intermediate-risk (score 4–6), and high-risk (score 7–9) groups. This model demonstrated both good discrimination and calibration using C-statistics and the Hosmer-Lemeshow goodness-of-fit test showing 0.812 (95% CI 0.743–0.881) (p = 0.568) for the development and 0.954 (95% CI 0.896–1) (p = 0.097) for the temporal and external validation cohort.


The authors’ scoring system is readily adoptable to predict the postoperative outcome for MMD. Their data revealed the importance of smoking and hyperlipidemia, which were the only modifiable factors included in the scoring system. The authors validated their scoring system both internally and externally and maintained good performance, highlighting the system’s generalizability and reliability.

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Yang Kwon, Jun Seok Bae, Jae Myung Kim, Do Hee Lee, Soon Young Kim, Jae Sung Ahn, Jeong Hoon Kim, Chang Jin Kim, Byung Duk Kwun and Jung Kyo Lee

✓ Tumors involving the optic nerve (optic glioma, optic nerve sheath meningioma) are benign but difficult to treat. Gamma knife surgery (GKS) may be a useful treatment. The authors present data obtained in three such cases and record the effects of GKS.