Fredric B. Meyer
Yoshihisa Kida, Masayuki Yoshimoto, and Toshinori Hasegawa
The aim of this study was to evaluate the results of radiosurgery in patients with facial schwannoma.
The study population consisted of 14 patients, six men and eight women, with a mean age of 45.4 years. Most of the patients had presented with facial palsy (11 of 14 patients) and/or hearing disturbance (nine of 14 patients). Prior treatment in nine of the 14 cases consisted of tumor resection or tumor biopsy. Tumor volume ranged from 0.98 to 20.8 cm3, and the mean tumor volume was 5.5 cm3. The mean maximum radiation dose and mean tumor margin dose used for radiosurgery were 24.0 and 12.9 Gy, respectively.
During the mean follow-up period of 31.4 months (range 12–120 months), 10 of the tumors shrank and four remained unchanged. The tumor response and tumor control rates were 57 and 100%, respectively. None of the tumors progressed, and no subsequent resection was required. Facial nerve function improved in five cases, remained unchanged in eight, and became worse in one. There was no change in hearing function in any of the patients. Complications developed in only one patient: the onset of facial palsy immediately after treatment, which subsequently recovered to House–Brackmann Grade III.
In summary, radiosurgery was found to be a very useful method of treating facial schwannoma, for both tumor control and functional control. Radiosurgery should therefore be the treatment of first choice for facial schwannomas.
Tatsuya Kobayashi, Yoshihisa Kida, and Toshinori Hasegawa
One hundred seven cases of craniopharyngiomas were treated using gamma knife surgery (GKS) at Komaki City Hospital during the past 12 years. The authors report the long-term results obtained in 100 patients who were followed for 6 to 148 months (mean 65.5 months).
All patients underwent GKS. The mean tumor diameter and volume were 18.8 mm and 5.8 ml, respectively; lesions were treated with a maximum dose of 21.8 Gy and marginal dose of 11.5 Gy (mean isocenters 4.5). Overall tumor responses were complete in 19, partial in 44, no change in 14, and disease progression in 23, yielding a complete response rate of 19%, overall response rate of 63%, control rate of 77%, and progression rate of 23%. Considering factors such as patient age, nature of the tumor (solid, mixed, cystic), frequency of previous treatments, and tumor size, the age and nature of the tumor were significant prognostic factors.
Changes in neurological and pituitary–hypothalamic symptoms after GKS were evaluated in 91 patients. Overall improvement was demonstrated in 17 (18.7%), no change in 59 (64.8%), and deterioration in 15 (16.5%). Outcome was documented in 93 cases: excellent in 42, good in 23, fair in seven, poor in three, and dead in 18 patients.
Stereotactic GKS is a safe and effective treatment as an adjuvant or boost therapy for postresection residual and/or recurrent craniopharyngiomas; the effects are durable and side effects acceptable.
Yoshihisa Kida, Tatsuya Kobayashi, and Yoshimasa Mori
Object. The purpose of this paper is to report the long-term results of gamma knife radiosurgery (GKS) for low-grade astrocytomas.
Methods. Fifty-one patients with low-grade astrocytomas treated with GKS and followed for more than 24 months are reported. Of the 51 patients, 12 harbored Grade I astrocytomas in and around the visual pathways and hypothalamus. The remaining 39 harbored Grade II astrocytomas. The mean patient age at time of GKS was 9.8 years for patient with Grade I and 30.9 years for those with Grade II astrocytomas. The mean tumor diameter was 25.4 mm for Grade I and 23.7 mm for Grade II tumors. The mean margin dose was 12.5 Gy for Grade I and 15.7 Gy for Grade II tumors.
In the mean follow-up period of 27.6 months, both Grade I and Grade II astrocytomas responded well to GKS. Grade I astrocytomas had a response rate of 50% and a control rate of 91.7%. Grade II astrocytomas had a 46.2% response rate and an 87.2% control rate. Statistical analyses concerning the efficacy and related factors showed a significantly better response for patients 10 years of age or older with Grade I and those with a follow-up period of more than 24 months. Complications included radiation-induced edema in 18 (35.3%) of 51 cases, cyst formation or enlargement in five (9.8%), and transient tumor enlargement in three (5.9%).
Conclusions. Radiosurgery can play an important role in the treatment of low-grade astrocytomas, and complete cure of these tumors is expected in at least some of the cases.
Yoshihisa Kida, Tatsuya Kobayashi, Jun Yoshida, Kyouzou Kato, and Naoki Kageyama
✓ Therapeutic results in 17 cases of alpha-fetoprotein (AFP)-secreting tumors of the central nervous system are reported. Twelve of the patients were male and five female. The patients' ages ranged from 5 years to 25 years (mean 13.6 years). The tumors originated in the pineal region in 10 cases, in the suprasellar region in four cases, and in both regions in one case; of the other two tumors, one originated in the basal ganglia and one in the sacrococcygeal region. Extraneural metastases or subarachnoid dissemination occurred in seven cases. Increased AFP titer in the serum or cerebrospinal fluid was verified in 13 cases. The patients were divided into two groups: those treated before (Group A) and those treated after (Group B) the introduction in 1980 of cisplatin as a chemotherapeutic agent. All seven Group A patients died, even after extensive therapy consisting of surgery, radiotherapy, and chemotherapy (ACNU or adriamycin) in some of the cases. The mean survival time following diagnosis for Group A was 23.7 months. Six of the 10 Group B patients died an average of 25.8 months after diagnosis; however, the other four were still alive and well an average of 25.3 months after diagnosis. The tumors responded well to chemotherapy consisting of cisplatin either alone or combined with bleomycin and vinblastine. The initial response rate to treatment in Group B was 100% and five cases had a complete remission, verified by computerized tomography or the serum AFP level. Once the tumor recurred, the response to cisplatin was markedly decreased. It is suggested that an effective therapy must still be sought for recurrent tumors.
Toshinori Hasegawa, Yoshihisa Kida, Masayuki Yoshimoto, and Jouji Koike
Information on outcomes of Gamma Knife surgery (GKS) for patients harboring trigeminal schwannomas is limited because these tumors are rare. The authors evaluated tumor control and functional outcomes in patients who underwent GKS for trigeminal schwannomas to clarify the efficacy of this treatment.
Forty-two patients with trigeminal schwannomas but no evidence of neurofibromatosis Type 2 were treated with GKS at Komaki City Hospital between November 1991 and December 2003. Of these, 37 patients were assessed. The mean tumor volume in these patients was 10 cm3. The mean maximum radiation dose directed to the tumor was 27.9 Gy and the mean dose directed to the tumor margin was 14.2 Gy. The mean follow-up period was 54 months. In four patients (11%) there was complete tumor remission; in 20 (54%) there was partial tumor remission; in eight (22%) the disease remained stable; and in five (14%) the tumor enlarged or uncontrollable facial pain developed with radiation-induced edema requiring resection. The actuarial 5- and 10-year tumor control rates were both 84%. With respect to functional outcomes, 40% of patients noted an improvement in their symptoms, and one patient experienced new symptoms despite good tumor control.
Gamma Knife surgery was a safe and effective treatment for a select group of patients harboring trigeminal schwannomas. Large tumors that compress the brainstem and cause deviation of the fourth ventricle should first be removed surgically and any remnant should be treated by GKS.
Tatsuya Kobayashi, Yoshihisa Kida, and Yoshimasa Mori
Object. The authors sought to analyze the long-term outcome of patients with Cushing disease who underwent gamma knife radiosurgery (GKS) as either an adjuvant or primary treatment.
Methods. Twenty-five patients with Cushing disease were treated by GKS and followed for more than 2.5 years (mean 5.3 years).
The overall results showed a complete response rate of 30%, a response rate of 85%, and a tumor control rate of 100%. Tumor size and radiation dose were the most important factors related to the treatment response. The complete response rate for microadenomas and small adenomas was significantly higher than that for macroadenomas. An 83.2% complete response rate was obtained using a maximum dose of more than 55 Gy and/or a margin dose of more than 40 Gy. Serum adrenocorticotropic hormone and cortisol levels were normalized in 35% of patients, decreased significantly in 60%, and decreased in 85%. Fifty-one of 85 characteristic signs and symptoms of Cushing disease improved without any side effects. The overall outcome was excellent in seven cases, good in six, fair in four, and poor in four cases; one patient died. The initial treatment was GKS in four patients, two of whom had a complete response and two of whom had a partial response. Hormone levels returned to normal in the patients in whom there was a complete response. The results in the six patients in whom Nelson syndrome was present were less favorable; the response rate was only 33%, although the control rate was 100%. Hormone levels decreased in two patients.
Conclusions. Gamma knife radiosurgery is safe and effective for the treatment of Cushing disease as an adjuvant or initial therapy when selective and accurate dose planning is performed.
Toshinori Hasegawa, Yoshihisa Kida, Masayuki Yoshimoto, Joji Koike, Hiroshi Iizuka, and Dai Ishii
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).
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.
The actuarial 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).
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.
Toshinori Hasegawa, Yoshihisa Kida, Masayuki Yoshimoto, Hiroshi Iizuka, Dai Ishii, and Kouta Yoshida
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.
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.
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).
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.
Toshinori Hasegawa, Yoshihisa Kida, Takenori Kato, Hiroshi Iizuka, Shunichiro Kuramitsu, and Takashi Yamamoto
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.
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 cm3 and the median marginal dose was 12.8 Gy.
The median follow-up period was 12.5 years. The actuarial 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%.
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.