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Li Pan, Nan Zhang, En Ming Wang, Bin Jiang Wang, Jia Zhong Dai and Pei Wu Cai

Object. The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas.

Methods. Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6–72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases.

Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children.

There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed.

Conclusions. Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (≥ 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.

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Nan Zhang, Li Pan, Bin Jiang Wang, En Min Wang, Jia Zhong Dai and Pei Wu Cai

Object. The authors analyzed the outcome of 53 patients with cavernous hemangiomas who underwent gamma knife radiosurgery (GKS) and evaluated the benefit of the treatment.

Methods. From 1994 to 1995, 57 patients were treated with GKS for cavernous hemangiomas. The mean margin dose to the lesions was 20.3 Gy (range 14.5–25.2 Gy) and the prescription isodose was 50 to 80%. The mean follow-up period was 4.2 years. Four patients were lost to follow up. In 18 of 28 patients whose chief complaint was seizures, there was a decrease in seizure frequency. Five of 23 patients with hemorrhage suffered rebleeding 4 to 39 months after GKS. Seventeen patients in whom the hemangiomas were located at the frontal or parietal lobe had neurological disability and in five this was severe. Two patients underwent resection of their hemangioma after GKS. Three experienced visual problems. Follow-up imaging demonstrated shrinkage of the lesion in 19 patients.

Conclusions. A higher margin dose (> 16 Gy) may be associated with a reduction in the incidence of rebleeding after GKS. Higher dosage and severe brain edema after GKS may decrease the frequency and intensity of seizures at least temporarily. Gamma knife radiosurgery may play a role in protection against hemorrhage and in reduction of the rate of seizure in selected cases with the appropriate dose.

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Nan Zhang, Li Pan, Jia Zhong Dai, Bin Jiang Wang, En Min Wang and Pei Wu Cai

Object. The purpose of this study was to evaluate the effect on tumor growth and symptom relief in patients with jugular foramen schwannomas after undergoing gamma knife radiosurgery (GKS).

Methods. Between November 1993 and December 2000, 27 patients were treated for jugular foramen schwannomas. The results of GKS in these cases are reviewed. Twelve patients had undergone previous tumor resection and the others underwent GKS as their primary treatment. The mean tumor volume was 13.5 cm3 (range 4.7–35.7 cm3). The mean margin dose was 14.6 Gy (range 9.8–20 Gy). The mean maximum dose was 32.6 Gy (range 25.4–50 Gy). The prescription isodose was 35 to 55%. Twenty-five patients were followed for a mean period of 38.7 months (range 9–90 months). Tumors shrank in 11 patients, remained stable in 13, and enlarged in one patient who underwent a second GKS procedure. Sixteen patients improved and nine remained at their pre-GKS clinical status. No patient developed new cranial nerve deficits after GKS.

Conclusions. The follow-up results indicate that GKS is a safe and effective primary or adjuvant treatment method for the control of jugular foramen schwannomas.

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Nan Zhang, Li Pan, En Min Wang, Jia Zhong Dai, Bin Jiang Wang and Pei Wu Cai

Object. The authors sought to evaluate the effect of gamma knife radiosurgery (GKS) on growth hormone (GH)—producing pituitary adenoma growth and endocrinological response.

Methods. From 1993 to 1997, 79 patients with GH-producing pituitary adenomas were treated with GKS. Seventysix patients had acromegaly. Sixty-eight patients were treated with GKS as the primary procedure. The tumor margin was covered with a 50 to 90% isodose and the margin dose was 18 to 35 Gy (mean 31.3 Gy). The dose to the visual pathways was less than 10 Gy except in one case. Sixty-eight patients (86%) were followed for 6 to 52 months. Growth hormone levels declined with improvement in acromegaly in all cases in the first 6 months after GKS. Normalization of the hormone levels was achieved in 23 (40%) of 58 patients who had been followed for 12 months and in 96% of cases for more than 24 months (43 of 45), or more than 36 months (25 of 26), respectively. With the reduction of GH hormone levels, 12 of 21 patients with hyperglycemia regained a normal blood glucose level (p < 0.001). The tumor shrank in 30 (52%) of 58 patients who had been followed for 12 months (p < 0.01), 39 (87%) of 45 patients for more than 2 years (p = 0.02), and 24 (92%) of 26 patients for more than 36 months. In the remainder of patients tumor growth ceased.

Conclusions. Gamma knife radiosurgery for GH-producing adenomas showed promising results both in hormonal control and tumor shrinkage. A margin dose of more than 30 Gy would seem to be effective in improving the clinical status, reducing high blood glucose levels, and normalizing hypertension.

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Zhengda Yu, N. U. Farrukh Hameed, Nan Zhang, Bin Wu, Jie Zhang, Junfeng Lu, Tianming Qiu, Dongxiao Zhuang, Hong Chen and Jinsong Wu

Resection of insular tumors in the dominant hemisphere poses a significant risk of postoperative motor and language deficits. The authors present a case in which intraoperative awake mapping and multi-modal imaging was used to help preserve function while resecting a dominant insular glioma. The patient, a 55-year-old man, came to the clinic after experiencing sudden onset of numbness in the right limbs for 4 months. Preoperative MRI revealed a nonenhancing lesion in the left insular lobe. Gross-total tumor resection was achieved through the transcortical approach, and the patient recovered without language or motor deficits. Informed patient consent was obtained.

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Jayapalli Rajiv Bapuraj, Amy K. Bruzek, Jamaal K. Tarpeh, Lindsey Pelissier, Hugh J. L. Garton, Richard C. E. Anderson, Bin Nan, Tianwen Ma and Cormac O. Maher


Current understanding of how the pediatric craniocervical junction develops remains incomplete. Measurements of anatomical relationships at the craniocervical junction can influence clinical and surgical decision-making. The purpose of this analysis was to quantitatively define clinically relevant craniocervical junction measurements in a population of children with CT scans that show normal anatomy.


A total of 1458 eligible patients were identified from children between 1 and 18 years of age who underwent cervical spine CT scanning at a single institution. Patients were separated by both sex and age in years into 34 groups. Following this, patients within each group were randomly selected for inclusion until a target of 15 patients in each group had been reached. Each patient underwent measurement of the occipital condyle–C1 interval (CCI), pB–C2, atlantodental interval (ADI), basion-dens interval (BDI), basion-opisthion diameter (BOD), basion-axial interval (BAI), dens angulation, and canal diameter at C1. Mean values were calculated in each group. Each measurement was performed by two teams and compared for intraclass correlation coefficient (ICC).


The data showed that CCI, ADI, BDI, and dens angulation decrease in magnitude throughout childhood, while pB–C2, PADI, BAI, and BOD increase throughout childhood, with an ICC of fair to good (range 0.413–0.912). Notably, CCI decreases continuously on coronal CT scans, whereas on parasagittal CT scans, CCI does not decrease until after age 9, when it shows a continuous decline similar to measurements on coronal CT scans.


These morphometric analyses establish parameters for normal pediatric craniocervical spine growth for each year of life up to 18 years. The data should be considered when evaluating children for potential surgical intervention.