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Long-term safety and efficacy of stereotactic radiosurgery for vestibular schwannomas: evaluation of 440 patients more than 10 years after treatment with Gamma Knife surgery

Clinical article

Toshinori Hasegawa, Yoshihisa Kida, Takenori Kato, Hiroshi Iizuka, Shunichiro Kuramitsu, and Takashi Yamamoto

Object

Little is known about long-term outcomes, including tumor control and adverse radiation effects, in patients harboring vestibular schwannomas (VSs) treated with stereotactic radiosurgery > 10 years previously. The aim of this study was to confirm whether Gamma Knife surgery (GKS) for VSs continues to be safe and effective > 10 years after treatment.

开云体育世界杯赔率

A total of 440 patients with VS (including neurofibromatosis Type 2) treated with GKS between May 1991 and December 2000 were evaluable. Of these, 347 patients (79%) underwent GKS as an initial treatment and 93 (21%) had undergone prior resection. Three hundred fifty-eight patients (81%) had a solid tumor and 82 (19%) had a cystic tumor. The median tumor volume was 2.8 cm3and the median marginal dose was 12.8 Gy.

Results

平均随访期为12.5年。交流tuarial 5- and ≥ 10-year progression-free survival was 93% and 92%, respectively. No patient developed treatment failure > 10 years after treatment. According to multivariate analysis, significant factors related to worse progression-free survival included brainstem compression with a deviation of the fourth ventricle (p < 0.0001), marginal dose ≤ 13 Gy (p = 0.01), prior treatment (p = 0.02), and female sex (p = 0.02). Of 287 patients treated at a recent optimum dose of ≤ 13 Gy, 3 (1%) developed facial palsy, including 2 with transient palsy and 1 with persistent palsy after a second GKS, and 3 (1%) developed facial numbness, including 2 with transient and 1 with persistent facial numbness. The actuarial 10-year facial nerve preservation rate was 97% in the high marginal dose group (> 13 Gy) and 100% in the low marginal dose group (≤ 13 Gy). Ten patients (2.3%) developed delayed cyst formation. One patient alone developed malignant transformation, indicating an incidence of 0.3%.

Conclusions

In this study GKS was a safe and effective treatment for the majority of patients followed > 10 years after treatment. Special attention should be paid to cyst formation and malignant transformation as late adverse radiation effects, although they appeared to be rare. However, it is necessary to collect further long-term follow-up data before making conclusions about the long-term safety and efficacy of GKS, especially for young patients with VSs.

InJournal of Neurosurgery Volume 118 (2013): Issue 3 (Mar 2013)

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Long-term outcomes of Gamma Knife surgery for cavernous sinus meningioma

Toshinori Hasegawa, Yoshihisa Kida, Masayuki Yoshimoto, Joji Koike, Hiroshi Iizuka, and Dai Ishii

Object

The aim of this study was to evaluate long-term outcomes, including tumor control and neurological function, in patients with cavernous sinus meningiomas treated using Gamma Knife surgery (GKS).

开云体育世界杯赔率

One hundred fifteen patients with cavernous sinus meningiomas, excluding atypical or malignant meningiomas, were treated with GKS between 1991 and 2003. Forty-nine patients (43%) underwent GKS as the initial treatment. The mean tumor volume was 14 cm3, and the mean maximum and margin doses applied to the tumor were 27 and 13 Gy, respectively. The median follow-up period was 62 months. During the follow-up, 111 patients were able to be evaluated with neuroimaging.

Results

交流tuarial 5- and 10-year progression-free survival rates were 87 and 73%, respectively. Similarly, the actuarial 5- and 10-year focal tumor control rates were 94 and 92%, respectively. Regarding functional outcomes, 43 patients (46%) experienced some degree of improvement, 40 (43%) remained stable, and 11 (12%) had worse preexisting or newly developed symptoms. Patients who underwent GKS as the initial treatment experienced significant improvement of their symptoms (p = 0.006).

Conclusions

Gamma Knife surgery is a safe and effective treatment over the long term in selected patients with cavernous sinus meningiomas. Tumor progression is more likely to occur from the lesion margin outside the treatment volume. In small to medium-sized tumors, GKS is an excellent alternative to resection, preserving good neurological function. For relatively large-sized tumors, low-dose radiosurgery (≤ 12 Gy) is acceptable for the prevention of tumor progression.

InJournal of Neurosurgery Volume 107: Issue 4 (Oct 2007)

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Gamma Knife surgery for skull base chordomas and chondrosarcomas

Toshinori Hasegawa, Dai Ishii, Yoshihisa Kida, Masayuki Yoshimoto, Joji Koike, and Hiroshi Iizuka

Object

The purpose of this study was to evaluate radiosurgical outcomes in skull base chordomas and chondrosarcomas, and to determine which tumors are appropriate for stereotactic radiosurgery as adjuvant therapy following maximum tumor resection.

开云体育世界杯赔率

Thirty-seven patients (48 lesions) were treated using Gamma Knife surgery (GKS); 27 had chordomas, seven had chondrosarcomas, and three had radiologically diagnosed chordomas. The mean tumor volume was 20 ml, and the mean maximum and marginal doses were 28 and 14 Gy, respectively. The mean follow-up period was 97 months from diagnosis and 59 months from GKS.

Results

交流tuarial 5- and 10-year survival rates after GKS were 80 and 53%, respectively. The actuarial 5- and 10-year local tumor control (LTC) rates after single or multiple GKS sessions were 76 and 67%, respectively. All patients with low-grade chondrosarcomas achieved good LTC. A tumor volume of less than 20 ml significantly affected the high rate of LTC (p = 0.0182). No patient had adverse radiation effects, other than one in whom facial numbness worsened despite successful tumor control.

Conclusions

As an adjuvant treatment after resection, GKS is a reasonable option for selected patients harboring skull base chordomas or chondrosarcomas with a residual tumor volume of less than 20 ml. Dose planning with a generous treatment volume to avoid marginal treatment failure should be made at a marginal dose of at least 15 Gy to achieve long-term tumor control.

InJournal of Neurosurgery Volume 107: Issue 4 (Oct 2007)

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Gamma Knife surgery for convexity, parasagittal, and falcine meningiomas

Clinical article

Toshinori Hasegawa, Yoshihisa Kida, Masayuki Yoshimoto, Hiroshi Iizuka, Dai Ishii, and Kouta Yoshida

Object

The aim of this study was to evaluate the outcomes in patients with convexity, parasagittal, or falcine meningiomas treated using Gamma Knife surgery (GKS) and to determine management strategy considering a risk of radiation-induced edema.

开云体育世界杯赔率

One hundred twelve patients who harbored 125 convexity, parasagittal, or falcine meningiomas were assessed. Forty-six patients underwent GKS as the initial treatment. The median tumor diameter was 25 mm, and median tumor volume was 8 cm3. The median maximum and margin doses were 30 and 16 Gy, respectively.

Results

The median follow-up period was 72 months. The actuarial 5- and 10-year progression-free survival rates were 78% and 55%, respectively. The actuarial 5- and 10-year local tumor control rates were 87% and 71%, respectively. Of 29 tumors that developed postradiosurgical edema, 7 were symptomatic. The actuarial symptomatic radiation-induced edema rate was 7%. The incidence of this complication was significantly higher in patients who underwent GKS as the initial treatment. Six of 46 patients for whom GKS was the initial treatment had preradiosurgical edema. Of these 6 patients, 4 developed severe panhemispheric edema after GKS (2 patients with parasagittal tumors, 1 with a falx tumor, and 1 with a convexity tumor).

Conclusions

Gamma Knife surgery is an effective treatment for convexity, parasagittal, and falcine meningiomas as the initial or adjuvant treatment. However, GKS should be restricted to small- to medium-sized tumors, particularly in patients with primary tumors, because radiation-induced edema is more common in convexity, parasagittal, and falcine meningiomas than skull base meningiomas.

InJournal of Neurosurgery Volume 114 (2011): Issue 5 (May 2011)

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听力保护的相关因素tion after Gamma Knife surgery for vestibular schwannomas in patients who retain serviceable hearing

Clinical article

Toshinori Hasegawa, Yoshihisa Kida, Takenori Kato, Hiroshi Iizuka, and Takashi Yamamoto

Object

Gamma Knife surgery (GKS) has been a safe and effective treatment for small- to medium-sized vestibular schwannomas (VSs) over relatively long-term outcomes. However, even with recent radiosurgical techniques, hearing results following GKS remain unsatisfactory. The purpose of this study was to evaluate the hearing preservation rate as well as factors related to hearing preservation in patients with VSs and serviceable hearing who were treated with GKS.

开云体育世界杯赔率

Among patients with Gardner-Robertson (GR) Class I or II serviceable hearing and VSs treated with GKS between 1991 and 2009, 117 were evaluable via periodic MR imaging and audiometry.

Results

The median age at the time of GKS was 52 years. Four patients (3%) had undergone prior surgery. Fifty-six patients (48%) had GR Class I hearing and 61 (52%) had GR Class II hearing at the time of GKS. The median tumor volume was 1.9 cm3. The median maximum and tumor margin radiation doses were 24 and 12 Gy, respectively. The median follow-up periods for MR imaging and audiometry were 74 and 38 months, respectively. The overall tumor control rate was 97.5%. Actuarial 3-, 5-, and 8-year hearing preservation rates were 55%, 43%, and 34%, respectively. On multivariate analysis, GR hearing class at the time of GKS and the mean cochlear dose affected hearing preservation significantly. In a limited number of patients who were treated using the most recent dose planning techniques and who had GR Class I hearing before treatment, the 3- and 5-year hearing preservation rates increased to 80% and 70%, respectively.

Conclusions

For the majority of patients with small- to medium-sized VSs, GKS was an effective and reasonable alternative to resection with satisfactory long-term tumor control. Factors related to hearing preservation included a GR Class I hearing pre-GKS and a lower mean cochlear radiation dose. To retain serviceable hearing, it is important to apply GKS treatment while patients retain GR Class I hearing.

InJournal of Neurosurgery Volume 115 (2011): Issue 6 (Dec 2011)

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