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Tracy E. Alpert, Seung S. Hahn, Chung T. Chung, Jeffrey A Bogart, Charles J. Hodge and Craig Montgomery

✓ A primary spindle cell sarcoma of the sella turcica in a patient without a history of radiation treatment is a very rare occurrence. Only one other case has been reported to date, with local recurrence 7 months after the patient underwent subtotal resection and stereotactic radiosurgery of the tumor.

The authors present a case of spindle cell sarcoma of the sella turcica successfully treated by surgery, external-beam radiotherapy, and gamma knife radiosurgery. After 24 months of follow up, the patient continues to show no evidence of disease.

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Joshua T. Billingsley and Brian L. Hoh

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Tracy E. Alpert, Chung T. Chung, Lisa T. Mitchell, Charles J. Hodge, Craig T. Montgomery, Jeffrey A. Bogart, Daniel Y-J. Kim, Danel A. Bassano and Seung S. Hahn

Object. The authors sought to evaluate the initial response of trigeminal neuralgia (TN) to gamma knife surgery (GKS) based on the number of shots delivered and radiation dose.

Methods. Between September 1998 and September 2003, some 63 patients with TN refractory to medical or surgical management underwent GKS at Upstate Medical University. Ten patients had multiple sclerosis and 25 patients had undergone prior invasive treatment. Gamma knife surgery was delivered to the trigeminal nerve root entry zone in one shot in 27 patients or two shots in 36 patients. The radiation dose was escalated to less than or equal to 80 Gy in 20 patients, 85 Gy in 21 patients, and greater than or equal to 90 Gy in 22 patients. Pain before and after GKS was assessed using the Barrow Neurological Institute Pain Scale and the improvement score was analyzed as a function of dose grouping and number of shots.

Sixty patients were available for evaluation, with an initial overall and complete response rate of 90% and 27%, respectively. There was a greater improvement score for patients who were treated with two shots compared with one shot, mean 2.83 compared with 1.72 (p < 0.001). There was an increased improvement in score at each dose escalation level: less than or equal to 80 Gy (p = 0.017), 85 Gy (p < 0.001), and greater than or equal to 90 Gy (p < 0.001). Linear regression analysis also indicated that there was a greater response with an increased dose (p = 0.021). Patients treated with two shots were more likely to receive a higher dose (p < 0.001). There were no severe complications. Five patients developed mild facial numbness.

Conclusions. Gamma knife surgery is an effective therapy for TN. Initial response rates appear to correlate with the number of shots and dose.

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John W. Powell, Chung T. Chung, Hemangini R. Shah, Gregory W. Canute, Charles J. Hodge, Daniel A. Bassano, Lizhong Liu, Lisa Mitchell and Seung S. Hahn

Object

The purpose of this study was to examine the results of using Gamma Knife surgery (GKS) for brain metastases from classically radioresistant malignancies.

Methods

The authors retrospectively reviewed the records of 76 patients with melanoma (50 patients), renal cell carcinoma (RCC; 23 patients), or sarcoma (3 patients) who underwent GKS between August 1998 and July 2007. Overall patient survival, intracranial progression, and local progression of individual lesions were analyzed.

Results

The median age of the patients was 57 years (range 18–85 years) and median Karnofsky Performance Scale (KPS) score was 80 (range 20–100). Sixty-two patients (81.6%) had uncontrolled extracranial disease. A total of 303 intracranial lesions (average 3.97 per patient, range 1–27 lesions) were treated using GKS. More than 3 lesions were treated in 30 patients (39.5%). Median GKS tumor margin dose was 18 Gy (range 8–30 Gy). Thirty-seven patients (48.7%) underwent whole brain radiation therapy. The actuarial 12-month rate for freedom from local progression for individual lesions was 77.7% and was significantly higher for RCC compared with melanoma (93.6 vs 63.0%; p = 0.001). The percentage of coverage of the prescribed dose to target volume was the only treatment–related variable associated with local control: 12-month actuarial rate of freedom from local progression was 71.4% for lesions receiving ≥ 90% coverage versus 0.0% for lesions receiving < 90% (p = 0.00048). Median overall survival was 5.1 months after GKS and 8.4 months after the discovery of brain metastases. Univariate analysis revealed that KPS score (p = 0.000004), recursive partitioning analysis class (p = 0.00043), and single metastases (p = 0.028), but not more than 3 metastases, to be prognostic factors of overall survival. The KPS score remained significant after multivariate analysis. Overall survival for patients with a KPS score ≥ 70 was 7.1 months compared with 1.3 months for a KPS score ≤ 60 (p = 0.013).

Conclusions

Gamma Knife surgery is an effective treatment option for patients with radioresistant brain metastases. In this setting, KPS score appeared to be a more important factor in predicting survival than having > 3 metastases. Higher rates of local tumor control were achieved for RCC in comparison with melanoma, and this may have an effect on survival in some patients. Although outcomes generally remained poor in this study population, these results suggest that GKS can be considered as a treatment option for many patients with radioresistant brain metastases, even if these patients have multiple lesions.

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Diana Margarita Molinares, Timothy T. Davis, Daniel A. Fung, John Chung-Liang Liu, Stephen Clark, David Daily and James M. Mok

OBJECT

The lateral jack-knife position is often used during transpsoas surgery to improve access to the spine. Postoperative neurological signs and symptoms are very common after such procedures, and the mechanism is not adequately understood. The objective of this study is to assess if the lateral jack-knife position alone can cause neurapraxia. This study compares neurological status at baseline and after positioning in the 25° right lateral jack-knife (RLJK) and the right lateral decubitus (RLD) position.

METHODS

Fifty healthy volunteers, ages 21 to 35, were randomly assigned to one of 2 groups: Group A (RLD) and Group B (RLJK). Motor and sensory testing was performed prior to positioning. Subjects were placed in the RLD or RLJK position, according to group assignment, for 60 minutes. Motor testing was performed immediately after this 60-minute period and again 60 minutes thereafter. Sensory testing was performed immediately after the 60-minute period and every 15 minutes thereafter, for a total of 5 times. Motor testing was performed by a physical therapist who was blinded to group assignment. A follow-up call was made 7 days after the positioning sessions.

RESULTS

Motor deficits were observed in the nondependent lower limb in 100% of the subjects in Group B, and no motor deficits were seen in Group A. Statistically significant differences (p < 0.05) were found between the 2 groups with respect to the performance on the 10-repetition maximum test immediately immediately and 60 minutes after positioning. Subjects in Group B had a 10%–70% (average 34.8%) decrease in knee extension strength and 20%–80% (average 43%) decrease in hip flexion strength in the nondependent limb.

Sensory abnormalities were observed in the nondependent lower limb in 98% of the subjects in Group B. Thirty-six percent of the Group B subjects still exhibited sensory deficits after the 60-minute recovery period. No symptoms were reported by any subject during the follow-up calls 7 days after positioning.

CONCLUSIONS

Twenty-five degrees of right lateral jack-knife positioning for 60 minutes results in neurapraxia of the nondependent lower extremity. Our results support the hypothesis that jack-knife positioning alone can cause postoperative neurological symptoms.

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Kirpal S. Mann, Chung P. Yue, Kwan H. Chan, Lily T. Ma and Henry Ngan

✓ Surgical excision followed by radiotherapy has been the recommended treatment for paraplegia due to extramedullary hematopoiesis in patients with beta-thalassemia. The authors report the successful treatment of such a case by partial excision and repeated blood transfusions.

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Motohiro Hayashi, Takaomi Taira, Mikhail Chernov, Seiji Fukuoka, Roman Liscak, Chung Ping Yu, Robert T. K. Ho, Jean Regis, Yoko Katayama, Yoriko Kawakami and Tomokatsu Hori

Object. The authors have treated intractable pain, particularly cancer pain related to bone metastasis, with various protocols. Cancer pain has been treated by gamma knife radiosurgery (GKS), targeted to the pituitary gland—stalk, as an alternative new pain control method. The purpose of this study was to investigate a prospective multicenter protocol to prove the efficacy and the safety of this treatment.

Methods. Indications for patient inclusion in this treatment protocol were: 1) pain related to bone metastasis; 2) no other effective pain treatment options; 3) general condition rated as greater than 40 on the Karnofsky Performance Scale; 4) morphine effective for pain control; and 5) no previous treatment with radiation (GKS or conventional radiotherapy) for brain metastasis. The authors at one institution have treated two patients, who suffered from severe cancer pain related to bone metastasis, by using GKS. The target was the pituitary gland. The maximum dose was 160 Gy with one isocenter of an 8-mm collimator, keeping the radiation dose to the optic nerve less than 8 Gy. At another institution two patients were treated in the same way; an additional five patients were treated similarly with targeting of the pituitary gland with two isocenters of 4-mm collimator.

In all nine cases, pain resolved without significant complication. Pain relief was observed within several days, and this effect was prolonged until the day that they died. At a follow up of 1 to 24 months, no recurrences and no hormonal dysfunction were observed.

Conclusions. Despite insufficient experience, the efficacy and the safety of GKS for intractable pain were demonstrated in nine patients. This treatment has the potential to ameliorate cancer-related pain, and GKS will play a more important role in the treatment of intractable pain. More experience and additional refined study protocols are needed to evaluate which parameters are important, to determine what treatment strategy is the best, and to clarify the safest option for patients with intractable cancer pain.

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Lawrance K. Chung, Nolan Ung, Marko Spasic, Daniel T. Nagasawa, Panayiotis E. Pelargos, Kimberly Thill, Brittany Voth, Daniel Hirt, Quinton Gopen and Isaac Yang

OBJECTIVE

Superior semicircular canal dehiscence (SSCD) is a rare disorder characterized by the formation of a third opening in the inner ear between the superior semicircular canal and the middle cranial fossa. Aberrant communication through this opening causes a syndrome of hearing loss, pulsatile tinnitus, disequilibrium, and autophony. This study analyzed the clinical outcomes of a single-institution series of patients with SSCD undergoing surgical repair by the same otolaryngologist and neurosurgeon.

METHODS

All patients who underwent SSCD repair at the University of California, Los Angeles, between March 2011 and November 2014 were included. All patients had their SSCD repaired via middle fossa craniotomy by the same otolaryngologist and neurosurgeon. Outcomes were analyzed with Fisher's exact test.

RESULTS

A total of 18 patients with a mean age of 56.2 years (range 27–84 years) and an average follow-up of 5.0 months (range 0.2–21.8 months) underwent 21 cases of SSCD repair. Following treatment, all patients (100%) reported resolution in ≥ 1 symptom associated with SSCD. Autophony (p = 0.0005), tinnitus (p = 0.0059), and sound- and/or pressure-induced dizziness (p = 0.0437) showed significant symptomatic resolution. Following treatment, 29% (2/7) of patients developed imbalance, 20% (1/5) of patients developed sound- and/or pressure-induced dizziness, and 18% (2/11) of patients developed aural fullness. Among patients with improved symptoms following surgical repair, none reported recurrence of symptoms at subsequent follow-up visits.

CONCLUSIONS

SSCD remains an underdiagnosed and undertreated condition. Surgical repair of SSCD using a middle fossa craniotomy is associated with a high rate of symptom resolution. Continued investigation using a larger patient cohort and longer-term follow-up could further demonstrate the effectiveness of using middle fossa craniotomy for SSCD repair.