Second Gamma Knife Treatment for Trigeminal Neuralgia: Anterior Target Spacing and 25 Gy as the Second Dose.

Objective Gamma Knife® radiosurgery (GKRS) has been demonstrated to be a well-known approach for treating patients with medical refractory trigeminal neuralgia (TN). Herein, the authors review the outcomes of pain among a large cohort of patients who had undergone a second GKRS delivered at a significantly reduced dose. Methods The authors conducted a prospective analysis of patients who have undergone two GKRS procedures between the years 2012 to 2021 at one institution. Baseline characteristics, radiosurgical dosimetry and technique, pain outcomes, and adverse effects were reviewed. Pain outcomes were measured with the Barrow Neurological Institute (BNI) pain intensity scale, which included the best BNI attained after the last treatment and recurrence. Results A total of 202 patients were identified, including 55 males and 147 females. Pain recurrence was reported in all patients prior to the second GKRS treatment (median = 4 months). Pain recurrence in the preceding Japan Neuroscience Society (JNS) 2021 study was also reported in all patients after each GKRS with a median value of 20 months between the second and third procedures. Complete to partial pain relief (BNI ≤ III) was achieved in 80% of patients after the second treatment. Over a median of 12 months of follow-up, 60% of patients maintained complete to partial pain relief compared to 77% of patients over the course of three treatments. In the present study, one patient developed facial spasms while 10 patients experienced persistent facial tingling. Subjective mild numbness was also found to be present in 16% of patients, with only 2% being bothersome, as compared to the JNS study, where subjective mild numbness was found to be present in 14%, with only 14.3% being bothersome. Among the 202 patients, 74 (37%) patients had undergone subsequent additional procedures such as a third GKRS, microvascular decompression (MVD), or other percutaneous procedures. Conclusion The authors describe the largest study to date of patients undergoing a second GKRS treatment for type 1 medical refractory trigeminal neuralgia. A reduced dose of radiation for a second treatment may produce outcomes similar to those of three consecutive treatments in regard to limiting recurrence and adverse effects.

Gamma knife radiosurgery of epidermoid tumors: an analysis of treatment results of eight patients.

BACKGROUND: Epidermoid tumors (ETs) of the central nervous system (CNS) are rare tumors that typically occur in the 4th decade. They typically grow around vital neurovascular structures which makes surgical treatment difficult. The objective of this paper is to report on the effectiveness and safety in the management of epidermoid tumors with gamma knife surgery (GKS). MATERIALS AND METHODS: This is a retrospective study of the medical records of 8 patients treated with GKS for epidermoid tumors between July 2010 to June 2019. The median prescription dose was 11 Gy, ranging from 10 to 12 Gy, 5 patients received the total dose target to the 50% line and 3 to the 55% isodose line. The mean tumor volume was 12.4 cc ranging from 4.4 to 24.8cc. The median follow-up time was 33.7 months and ranged from 0.9 to 58.8 months. At follow-up, patients were evaluated for neurological signs and symptoms and radiographic evidence of progression of disease. Two patients were treated after failure of linac stereotactic radiosurgery. One patient underwent stereotactic radiosurgery prior to GKS, and the other had failed surgical resection prior to GKS. RESULTS: The median age was 33 years old. There were two males and six females. The most common presenting manifestation was headaches followed by vision and hearing problems. Symptoms were resolved in all cases, except for one who had partial control of trigeminal neuralgia. All patients were locally controlled by imaging and neurological examination at first follow-up. CONCLUSION: Gamma knife surgery is a safe and effective alternative treatment in patients with CNS epidermoid tumors and should be included in the initial recommendation.

Long-Term Results of Gamma Knife Radiosurgery for Glomus Tumors: An Analysis of 32 Patients.

Background Glomus jugulare tumors are rare slow-growing hypervascular tumors that arise from the paraganglia of the chemoreceptor system within the jugulare foramen of the temporal lobe. The historical standard treatment has been surgical resection, but because of their high vascularity and involvement with cranial nerves (CNs), Gamma Knife radiosurgery (GKRS) has been advocated as an alternative. The goal of this study is to update and report long-term results of GKRS to achieve local control and symptomatic improvement and to reduce morbidity and mortality when treating glomus jugulare tumors. Materials and Methods This study retrospectively collected and reviewed clinical and radiographic data of 32 patients with glomus jugulare tumors treated with GKRS at the Miami Neuroscience Center, South Miami, FL, from 1995 to 2019. For the 32 patients, the mean volume treated was 13.9 cc (0.23 to 40.0 cc), with an average of 8.6 isocenters. The median prescription dose was 12.84 Gy ± 2.07 Gy (range: 10-20 Gy). Follow-up data were available for 29 out of 32 patients, with a median clinical follow-up time of 37.3 months (range: 4.3-169.1 months). At follow-up, patients were evaluated for neurological signs and symptoms and radiographic evidence of progression of disease. Results The median age of the cohort treated with GKRS was 60 years (range: 14-83 years). There were three males and 27 females. Presenting symptomatology was available for 30 out of 32 patients. The most common presenting symptom was hearing loss (21/30) and the most common CN deficit was in CN VIII (19/30). Out of 29 of the patients followed up, 28 patients had improvement (20/29) or resolution (8/29) of symptoms. At the most recent evaluation or contact, patients were without symptomatic progression of CN deficits. Radiographic tumor control was achieved in 28 out of 29 patients. One patient had a recurrence seven years after GKRS, which was treated with surgery. There were no complications, radionecrosis, or mortality reported from GKRS. Conclusion These data confirm that GKRS is a reasonable upfront treatment option for glomus jugulare tumors. GKRS should be considered more frequently given its excellent long-term local control with low morbidity and risk of complications.

Radiosurgery for brain metastases from ovarian cancer: an analysis of 25 years' experience with Gamma Knife treatment.

PURPOSE: We present our results in the treatment of brain metastases (BM) from ovarian cancer using Gamma Knife Radiosurgery (GKRS) over the last 25 years in a single institution. BACKGROUND: Gamma Knife Radiosurgery has become increasingly important in the management of brain metastases from ovarian cancer due to improving results from systemic disease and the need for better outcomes. MATERIAL AND METHODS: The medical records of 9 patients with brain metastases from ovarian cancer treated with GKRS between 1993 and 2018 were reviewed. Median age at first treatment was 57 years (range 39-76). Forty-two brain metastases were treated with 16 procedures. Median tumor volume was 1.8cc ranging from 0.2 to 30.3cc (there were five patients with a tumor volume exceeding 10cc). Median prescription dose was 16 Gy. RESULTS: Using Kaplan Meier estimates, the median OS after diagnosis was 48.1 months and the median OS after GKRS was 10.6 months (ranging from 2.5 to 81 months). The Kaplan Meier survival rates were 31.3%, and 6.5% at 2 and 5 years after GKRS, respectively. Treatment procedure was well tolerated and no patient presented with acute or chronic toxicity. Two of 9 patients had a tumor requiring retreatment (local control of 95% 40/42). Two out of the 7 patients evaluated for cause of death expired due to progression of brain metastases and the remaining ones died of systemic disease with brain control. CONCLUSIONS: GKRS for BM from ovarian cancer is a safe and effective modality. Our findings are in agreement with the recent literature indicating that women with brain metastases from ovarian cancer will benefit with radiosurgery and may achieve long term survival with brain control.

Primary Central Nervous System Lymphoma (PCNSL): Analysis of Treatment by Gamma Knife Radiosurgery and Chemotherapy in a Prospective, Observational Study.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is a rare cancer accounting for less than 3% of primary brain and central nervous system (CNS) tumors. Tissues involved include the brain parenchyma, leptomeninges, eyes, and spinal cord. High-dose methotrexate (MTX) is the gold standard for newly diagnosed PCNSL. However, Gamma Knife radiosurgery (GKRS) may be efficacious as a co-adjuvant treatment. The purpose of this prospective observational cohort study is to determine the effectiveness of MTX in combination with GKRS in the treatment of PCNSL. METHODS: This is a prospective, observational cohort study evaluating the treatment of histologically confirmed PCNSL with MTX as a single agent in a dose of 8 g/m2 (control) and treatment with MTX, plus GKRS. Strict inclusion and exclusion criteria were employed. Primary outcomes were measured by survival rate. Secondary outcomes were assessed by the tumor's responsiveness to treatment and reduction in size as noted on imaging. RESULTS: Between January 2007 and January 2012, 128 charts were evaluated. Included in this evaluation were 73 chemotherapy (control) and 55 chemotherapy, plus GKRS, patients (variable). The follow-up period was 24 to 49 months (mean: 36.9 months). There were no statistically significant differences in patient demographics or histology diagnosis. Patients were treated with GK doses ranging from 11 Gy to 16 Gy (median: 11 Gy). The median survival rate from initial diagnosis was 26.8 months in the chemotherapy group and 47.6 in the chemotherapy, plus GKRS, group (p-value: 0.0034). All lesions showed a complete response after GKRS when evaluated using magnetic resonance imaging after three to eight weeks (mean range: 6.3 weeks). CONCLUSIONS: The use of GKRS is non-invasive, safe, and shows rapid success, improving the prognosis of the patient. This noninvasive treatment modality should be considered as an option for patients with PCNSL. In our study, GKRS as a co-adjuvant therapy to high-dose methotrexate was statistically significant for greater tumor control, enhanced overall survival period, and a lesser number of complications.

Pineal tumors: analysis of treatment results in 20 patients.

OBJECT: The authors evaluate their results when using gamma knife surgery (GKS) in the management of patients with tumors in the pineal region. METHODS: This is a retrospective clinical evaluation of 20 patients with primary tumors of the pineal region treated with GKS from November 1994 through August 2003. There were 13 germ cell tumors, two pineoblastomas, two low-grade gliomas, one primitive neuroectodermal tumor, one teratoma, and one pineocytoma. There were 10 male and 10 female patients. Their median age was 15.5 years (range 5-71 years). The median margin dose was 11 Gy (range 8-20 Gy). The median target volume was 3.1 cm3 (range 0.1-49.9 cm3). Five patients received sequential systemic chemotherapy and four underwent adjuvant conventional radiation therapy. Seventeen (85%) of 20 patients are alive with a median survival of 30.4 months (range 0-85.7 months). Two patients required retreatment. Three patients died: one of unrelated causes, one who presented with extensive local disease, and the other of meningeal carcinomatosis with local control of the primary tumor. No complications from GKS were noted. CONCLUSIONS: This initial experience suggests that GKS is a valuable treatment modality for the management of pineal region tumors. This technique offers excellent local tumor control and minimal patient morbidity, allowing for immediate use of systemic chemotherapy and/or conventional radiation if indicated.

Role of radiosurgery in craniopharyngiomas: a preliminary report.

PURPOSE: The purpose of this retrospective review is to evaluate our experience using radiosurgery in the management of craniopharyngiomas. MATERIALS AND METHODS: Fourteen patients, 6 males and 8 females, ages ranging from 3 to 44 years of age, were treated with radiosurgery from February 1994 through December 2000 for primary or recurrent craniopharyngioma. There were two adults and 12 children. All patients were treated with the Leksell Gamma units Model U or C. The mean minimum dose was 14 Gy ranging from 11 to 20 Gy and the mean maximum dose was 29 Gy ranging from 24 to 40 Gy. Volume of treatment ranged from 0.1 to 26.5 cm(3). The dose to critical structures was below 8 Gy to the optic chiasm and below 14 Gy to the brain stem. One of the 14 patients had previous conventional radiation therapy. RESULTS: All patients are alive and with out evidence of recurrent disease 6-86 months after treatment. Only two patients required retreatment. CONCLUSIONS: Although craniopharyngioma is a benign tumor, its location makes even advanced microsurgical techniques difficult to perform. Radiosurgery obviates the shortcomings of surgical resection near the hypothalamic-pituitary axis without the morbidity of open surgery.