Kita Sallabanda

Long-Term Outcomes of Stereotactic Radiosurgery for Treatment of Cavernous Sinus Meningiomas

PURPOSE Patients with cavernous sinus meningiomas (CSM) have an elevated risk of surgical morbidity and mortality. Recurrence is often observed after partial resection. Stereotactic radiosurgery (SRS), either alone or combined with surgery, represents an important advance in CSM management, but long-term results are lacking. METHODS AND MATERIALS A total of 88 CSM patients, treated from January 1991 to December 2005, were retrospectively reviewed. The mean follow-up was 86.8 months (range, 17.1-179.4 months). Among the patients, 22 were followed for more than 10 years. There was a female predominance (84.1%). The age varied from 16 to 90 years (mean, 51.6). In all, 47 patients (53.4%) received SRS alone, and 41 patients (46.6%) had undergone surgery before SRS. A dose of 14 Gy was prescribed to isodose curves from 50% to 90%. In 25 patients (28.4%), as a result of the proximity to organs at risk, the prescribed dose did not completely cover the target. RESULTS After SRS, 65 (73.8%) patients presented with tumor volume reduction; 14 (15.9%) remained stable, and 9 (10.2%) had tumor progression. The progression-free survival was 92.5% at 5 years, and 82.5% at 10 years. Age, sex, maximal diameter of the treated tumor, previous surgery, and complete target coverage did not show significant associations with prognosis. Among the 88 treated patients, 17 experienced morbidity that was related to SRS, and 6 of these patients spontaneously recovered. CONCLUSIONS SRS is an effective and safe treatment for CSM, feasible either in the primary or the postsurgical setting. Incomplete coverage of the target did not worsen outcomes. More than 80% of the patients remained free of disease progression during long-term follow-up.

Outcome for Patients with Essential Trigeminal Neuralgia Treated with Linear Accelerator Stereotactic Radiosurgery

Background: Stereotactic radiosurgery (SRS) is one option for treatment of trigeminal neuralgia, after unsuccessful conservative approaches. Objectives: The objective of this study was to retrospectively evaluate our institutional results in the management of patients with idiopathic trigeminal neuralgia treated with linear accelerator SRS. Methods: Fifty-two patients were treated between January 1998 and December 2009 and were followed for more than 6 months (median: 26.6 months). Forty-seven patients (90%) had undergone previous surgery before SRS. The target dose ranged from 50 to 80 Gy. Results: After SRS, 9 patients presented complete remission of the pain, and 21 were pain free but still under medication. Eleven patients reported a relief of more than 50% in crisis frequency. In 9 patients, no significant improvements were seen, and 2 presented an exacerbation of the pain. After an average period of 20 months, 15 patients reported pain recurrence. Results were better in patients older than 60 years (p = 0.019). Nineteen patients presented facial numbness after SRS, with a trend toward favorable treatment response (p = 0.06). Conclusion: SRS is an effective alternative to the treatment of essential trigeminal neuralgia, with long-lasting pain relief in more than 50% of the patients. Better results were seen with patients aged more than 60 years.

Preliminary results of helical tomotherapy in patients with complex-shaped meningiomas close to the optic pathway.

Meningiomas are the most common benign intracranial tumor. Meningiomas close to the optic pathway represent a treatment challenge both for surgery and radiotherapy. The aim of this article is to describe early results of helical tomotherapy treatment in complex-shaped meningiomas close to the optic pathway. Twenty-eight patients were consecutively treated. All patients were immobilized with a thermoplastic head mask and planned with the aid of a magnetic resonance imaging-computed tomography fusion. All treatments included daily image guidance. Pretreatment symptoms and acute toxicity were recorded. Median age was 57.5 years, and 92.8% patients had Eastern Cooperative Oncology Group performance status scale ≤1. The most common localizations were the sella turcica, followed by the cavernous sinus and the sphenoid. The most common symptoms were derived from cranial nerve deficits. Tomotherapy was administered as primary treatment in 35.7% of patients, as an adjuvant treatment in 32.4%, and as a rescue treatment after postsurgical progression in 32.1% patients. Most patients were either inoperable or Simpson IV. Total dose varied between 5000 and 5400 cGy; fractionation varied between 180 and 200 cGy. Median dose to the planning target volume was 51.7 Gy (range, 50.2-55.9 Gy). Median coverage index was 0.89 (range, 0.18-0.97). Median homogeneity index was 1.05 (range, 1-1.12). Acute transient toxicity was grade 1 and included headache in 35.7% patients, ocular pain/dryness in 28.5%, and radiation dermatitis in 25%. Thus far, with a maximal follow-up of 3 years, no late effects have been seen and all patients have a radiological stabilization of the disease. Helical tomotherapy offered a safe and effective therapeutic alternative for patients with inoperable or subtotally resected complex-shaped meningiomas close to the optic pathway. Acceptable coverage and homogeneity indexes were achieved with appropriate values for maximal doses delivered to the eyes, lenses, and chiasm, despite the proximity of the tumor to these structures.

Linac Stereotactic Radiosurgery for the Treatment of Small Arteriovenous Malformations: Lower Doses Can Be Equally Effective

Objective: The purpose of this study was to examine the efficacy and toxicity of treating small arteriovenous malformations (AVMs) (≤3 cm in diameter) with a median marginal applied dose of 14 Gy. Methods: Two hundred and thirteen patients diagnosed with AVMs were treated between January 1991 and December 2005. Seventy-three percent of the patients had hemorrhaged prior to treatment, 13% had had previous surgery and 19.2% had had previous embolization. The median follow-up duration was 48.1 months. Results: The Kaplan-Meier analysis estimated that the 36-month obliteration rate was 65.5% for patients undergoing their first stereotactic radiosurgery (SRS) and 68.3% for those undergoing repeated SRS. The Kaplan-Meier analysis estimated the 60-month AVMs obliteration rate for the entire cohort to be 82.4%. The median time to AVM obliteration was 40 ± 2.8 months. We found a statistically significant relationship between the time of obliteration and the following factors: site of the AVMs (sites other than brainstem), a higher prescribed dose and a positive history of previous hemorrhage. Thirteen patients (7.6%) experienced toxicities. Conclusions: SRS was an effective and safe treatment for AVMs ≤3 cm in diameter, with acceptable toxicity.

Robotic Radiosurgery for the Treatment of Intramedullary Spinal Cord Metastases: A Case Report and Literature Review.

Modern technologies allow the delivery of high radiation doses to intramedullary spinal cord metastases while lowering the dose to the neighboring organs at risk. Whether this dosimetric advantage translates into clinical benefit is not well known. This study evaluates the acute and late toxicity outcomes in a patient treated with robotic radiosurgery for an intramedullary spinal cord metastasis. A 50-year-old woman diagnosed in May 2006 with invasive ductal carcinoma of the right breast T2N3M1 (two liver metastases) received chemotherapy with a complete response. Subsequently, she underwent adjuvant whole-breast radiotherapy, along with tamoxifen. After several distant relapses, treated mainly with systemic therapy, the patient developed an intramedullary lesion at the C3-C4 level and was referred to our CyberKnife unit for assessment. A total dose of 14 Gy prescribed to the 74% isodose line was administered to the intramedullary lesion in one fraction. One hundred and two treatment beams were used covering 95.63% of the target volume. The mean dose was 15.93 Gy and the maximum dose, 18.92 Gy. Maximum dose to the spinal cord was 13.96 Gy, V12 ~ 0.13 cc and V8 ~ 0.43 cc. Three months after treatment, magnetic resonance imaging showed a reduction in size and enhancement of the intramedullary lesion with no associated toxicity. During this period, the patient showed a good performance status without neurological deficits. Currently, with a follow-up of 37 months, the patient has the ability to perform activities of daily life. Intramedullary spinal cord metastases is a rare and aggressive disease, often treatment-refractory. Our case demonstrates that radiation therapy delivery with robotic radiosurgery allows the achievement of a high local control without adding toxicity.

Stereotactic radiosurgery in patients with multiple intracranial meningiomas

PURPOSE Stereotactic radiosurgery (SRS) delivers a potent, highly focused dose of radiation to the tumor while sparing the surrounding normal tissues. The purpose of this study was to assess the outcome of patients with intracranial meningiomas treated with SRS. METHODS A total of 73 patients with 221 benign meningiomas treated between 1991 and 2005 with SRS and followed up for more than a year were reviewed. Fifty patients (68%) were treated with SRS to the primary meningioma while 23 (32%) received SRS to relapsing tumors adjacent or distant from the site of the initial meningioma that was previously treated with surgery alone. Mean tumor margin dose was 14 Gy (range 10-16). SRS was delivered after surgery in 117 meningiomas (55 patients). RESULTS The median age at diagnosis was 47 years (range 16-74) and the median follow-up 5.8 years (range 1-13.6). The 3- and 5-year overall survival (OS) rates for all patients were 95% and 90%, respectively. The mean gross tumor volume decreased from 4.17 cm3 to 3.23 cm(3) after SRS (p=0.057). Twenty-two (10%) meningiomas increased after SRS. In addition, clinical symptoms improved in 36% and remained stable in 45% of the patients. With regard to morbidity of SRS, only 7 patients (9.6%) had late complications, including edema (N=4), brain necrosis (N=4), gliosis (N=1), and paresis of the III pair nerve (N=1). There was no treatment-related mortality. CONCLUSION SRS for patients with multiple intracranial meningiomas is effective yielding a high rate of local tumor control, whereas treatment-related morbidity remains low.