Radiation dose and incidence of new metastasis in the anterior temporal lobe structures of radiosurgically treated patients

2010 ◽  
Vol 112 (1) ◽  
pp. 122-129 ◽  
Author(s):  
Bhuvaneswara R. Basina ◽  
Claire Olson ◽  
Dibyendu Kumar Roy ◽  
Chun-Po Yen ◽  
David Schlesinger ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Mr Imaging ◽  
Brain Tissue ◽  
Gamma Knife ◽  
Brain Lesions ◽  
Gamma Knife Surgery ◽  
Temporal Lobes ◽  
Temporal Structures ◽  
The Brain

Object Gamma Knife surgery (GKS) is frequently used to treat patients with metastasis to the brain. Radiosurgery seeks to limit radiation to the brain tissue surrounding the metastatic deposits. In patients with such lesions, a low radiation dose to the eloquent brain may help to prevent adverse effects. In this study the authors aimed to quantify the radiosurgical dose delivered to the anterior temporal structures in cases of metastatic brain lesions. They also evaluated the incidence and timing of new metastases in the anterior temporal lobes (ATLs) in patient cohorts that underwent GKS with or without whole-brain radiation therapy (WBRT). Methods The authors retrospectively analyzed 100 patients with metastatic brain lesions treated with GKS at the University of Virginia Health System. The anterior 5 cm of the temporal lobes and the hippocampi within the ATLs were contoured on the Gamma Knife planning station. Using the dose-volume histogram function in GammaPlan, treatment parameters for the metastases as well as radiation doses to the contoured ATLs and hippocampi were measured. Patients had clinical and MR imaging follow-ups at 3-month intervals. The ATLs and hippocampal regions were evaluated for the formation of new metastases on follow-up imaging. Results The demographic data—age, sex, Karnofsky Performance Scale score, number of temporal metastases at the time of GKS, total volume of metastatic tumors per patient, and number of intracranial metastatic deposits—were similar in the 2 cohorts. In patients without an ATL metastasis at the time of GKS, the mean maximum, 50% volume, and integral doses of radiation to the anterior temporal structures were very low: 2.6 Gy, 0.6 Gy, and 36.3 mJ in the GKS cohort and 2.1 Gy, 0.6 Gy, and 40.9 mJ in the GKS+WBRT cohort, respectively. Among the ATLs that had not shown a brain metastasis at the time of GKS, 8 of 92 temporal lobes in the GKS cohort and 10 of 89 in the GKS+WBRT cohort demonstrated a new anterior temporal lesion on follow-up MR imaging. Conclusions Gamma Knife surgery delivered a low dose of background radiation to the ATLs and hippocampi. The incidence of a new ATL metastasis in the GKS cohort was not higher than in the GKS+WBRT cohort. Gamma Knife surgery in the management of brain metastases limits the delivery of radiation to eloquent brain tissue without evidence of an appreciable propensity to develop new metastatic disease in the ATLs or hippocampi. This therapeutic approach may help to avoid unintended neurological dysfunction due to nonspecific delivery of radiation to eloquent brain tissues.

Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 87-97 ◽  
Author(s):  
Wen-Yuh Chung ◽  
Kang-Du Liu ◽  
Cheng-Ying Shiau ◽  
Hsiu-Mei Wu ◽  
Ling-Wei Wang ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Gamma Knife ◽  
Vestibular Schwannoma ◽  
Tumor Volume ◽  
Radiation Effect ◽  
Gamma Knife Surgery ◽  
Homogeneous Distribution ◽  
Content Type ◽  
Fine Print

Object. The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation. Methods. A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3 (range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months. A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a median follow-up period of 31 months resection was avoided in 96.8% of cases. Uncontrolled tumor swelling was noted in five patients at 3.5, 17, 24, 33, and 62 months after GKS, respectively. Twelve of 20 patients retained serviceable hearing. Two patients experienced a temporary facial palsy. Two patients developed a new trigeminal neuralgia. There was no treatment-related death. Histopathological examination of specimens in three cases (one at 62 months after GKS) revealed a long-lasting radiation effect on vessels inside the tumor. Conclusions. Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.

A simple treatment planning strategy for patients with multiple metastases treated with Gamma Knife surgery

2006 ◽  
Vol 105 (Supplement) ◽  
pp. 2-4 ◽  
Author(s):  
James G. Douglas ◽  
Robert Goodkin
Keyword(s):  
Mr Imaging ◽  
Treatment Planning ◽  
Gamma Knife ◽  
Gamma Knife Surgery ◽  
Planning Method ◽  
Cns Metastases ◽  
Cell Lung Carcinoma ◽  
Dose Volume Histograms ◽  
Number Of Patients ◽  
The Brain

ObjectIn a substantial number of patients treated at the authors' facility for brain metastases, additional lesions are identified at the time of Gamma Knife surgery (GKS). These lesions are often widely dispersed and may number over 10, which is the maximal number of matrices that can be currently placed for treatment with Leksell Gamma-Plan 4C. The authors describe a simple planning method for GKS in patients with multiple, widely dispersed central nervous system (CNS) metastases.MethodsTwo patients presented with three to five identified recurrent metastases from non–small cell lung carcinoma and breast carcinoma after having received whole-brain radiotherapy. At the time of treatment with GKS in each patient, spoiled-gradient Gd-enhanced magnetic resonance (MR) imaging revealed substantially more metastases than originally thought, which were widely scattered throughout all regions of the brain. The authors simplified the treatment planning approach by dividing the entire CNS contents into six contiguous, nonoverlapping matrices, which allowed for the planning, calculation, and treatment of all lesions.Two patients were successfully treated with GKS for more than 10 CNS metastases by using this simple planning method. Differing peripheral doses to varied-size lesions were delivered by prescribing to different isodose curves within any given matrix when required. Dose–volume histograms showed brain doses as follows: 10% of the total brain volume received 5 to 6.4 Gy; 25% received 3.8 to 4.8 Gy; 50% received 2.7 to 3.1 Gy; and 75% received 2.2 to 2.5 Gy.Conclusions The delineation of more metastases than appreciated on the diagnostic MR imaging is a common occurrence at the time of GKS at the authors' institution. The treatment of multiple (>10), widely dispersed CNS metastases can be simplified by the placement of multiple, contiguous, non-overlapping matrices, which can be employed to treat lesions in all areas of the brain when separate matrices cannot be utilized.

Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases

2005 ◽  
Vol 102 ◽  
pp. 87-97 ◽  
Author(s):  
Wen-Yuh Chung ◽  
Kang-Du Liu ◽  
Cheng-Ying Shiau ◽  
Hsiu-Mei Wu ◽  
Ling-Wei Wang ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Gamma Knife ◽  
Vestibular Schwannoma ◽  
Tumor Volume ◽  
Radiation Effect ◽  
Gamma Knife Surgery ◽  
Homogeneous Distribution ◽  
Content Type ◽  
Fine Print

Object.The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation.Methods.A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3(range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months.A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a median follow-up period of 31 months resection was avoided in 96.8% of cases. Uncontrolled tumor swelling was noted in five patients at 3.5, 17, 24, 33, and 62 months after GKS, respectively. Twelve of 20 patients retained serviceable hearing. Two patients experienced a temporary facial palsy. Two patients developed a new trigeminal neuralgia. There was no treatment-related death. Histopathological examination of specimens in three cases (one at 62 months after GKS) revealed a long-lasting radiation effect on vessels inside the tumor.Conclusions.Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.

scholarly journals CT versus MR Imaging in Estimating Cochlear Radiation Dose during Gamma Knife Surgery for Vestibular Schwannomas

2018 ◽  
Vol 39 (10) ◽  
pp. 1907-1911 ◽  
Author(s):  
A.M. Faramand ◽  
H. Kano ◽  
S. Johnson ◽  
A. Niranjan ◽  
J.C. Flickinger ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Mr Imaging ◽  
Gamma Knife ◽  
Gamma Knife Surgery ◽  
Vestibular Schwannomas

Gamma Knife surgery for pituitary adenomas: factors related to radiological and endocrine outcomes

2011 ◽  
Vol 114 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Jason P. Sheehan ◽  
Nader Pouratian ◽  
Ladislau Steiner ◽  
Edward R. Laws ◽  
Mary Lee Vance
Keyword(s):  
Pituitary Adenoma ◽  
Radiation Dose ◽  
Tumor Growth ◽  
Gamma Knife ◽  
Pituitary Adenomas ◽  
Gamma Knife Surgery ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Pituitary Hormone Deficiency

Object Gamma Knife surgery (GKS) is a common treatment for recurrent or residual pituitary adenomas. This study evaluates a large cohort of patients with a pituitary adenoma to characterize factors related to endocrine remission, control of tumor growth, and development of pituitary deficiency. Methods A total of 418 patients who underwent GKS with a minimum follow-up of 6 months (median 31 months) and for whom there was complete follow-up were evaluated. Statistical analysis was performed to evaluate for significant factors (p < 0.05) related to treatment outcomes. Results In patients with a secretory pituitary adenoma, the median time to endocrine remission was 48.9 months. The tumor margin radiation dose was inversely correlated with time to endocrine remission. Smaller adenoma volume correlated with improved endocrine remission in those with secretory adenomas. Cessation of pituitary suppressive medications at the time of GKS had a trend toward statistical significance in regard to influencing endocrine remission. In 90.3% of patients there was tumor control. A higher margin radiation dose significantly affected control of adenoma growth. New onset of a pituitary hormone deficiency following GKS was seen in 24.4% of patients. Treatment with pituitary hormone suppressive medication at the time of GKS, a prior craniotomy, and larger adenoma volume at the time of radiosurgery were significantly related to loss of pituitary function. Conclusions Smaller adenoma volume improves the probability of endocrine remission and lowers the risk of new pituitary hormone deficiency with GKS. A higher margin dose offers a greater chance of endocrine remission and control of tumor growth.

Gamma Knife surgery for low-flow cavernous sinus dural arteriovenous fistulas

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 21-27 ◽  
Author(s):  
Hyun Ho Jung ◽  
Jong Hee Chang ◽  
Kum Whang ◽  
Jin Soo Pyen ◽  
Jin Woo Chang ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Cavernous Sinus ◽  
Transarterial Embolization ◽  
Gamma Knife Surgery ◽  
Low Flow ◽  
Close Monitoring ◽  
Arteriovenous Fistulas ◽  
Ocular Symptoms ◽  
Dural Arteriovenous Fistulas

Object The purpose of this study was to assess the efficacy of Gamma Knife surgery (GKS) for treating cavernous sinus dural arteriovenous fistulas (CSDAVFs). Methods Of the 4123 GKSs performed between May 1992 and March 2009, 890 procedures were undertaken to treat vascular lesions. In 24 cases, the vascular lesion that was treated was a dural arteriovenous fistula, and in 6 of these cases, the lesion involved the cavernous sinus. One of these 6 cases was lost to follow-up, leaving the other 5 cases (4 women and 1 man) to comprise the subjects of this study. All 5 patients had more than 1 ocular symptom, such as ptosis, chemosis, proptosis, and extraocular movement palsy. In all patients, CSDAVF was confirmed by conventional angiography. Three patients were treated by GKS alone and 2 patients were treated by GKS combined with transarterial embolization. The median follow-up period after GKS in these 5 cases was 30 months (range 9–59 months). Results All patients experienced clinical improvement, and their improvement in ocular symptoms was noticed at a mean of 17.6 weeks after GKS (range 4–24 weeks). Two patients received embolization prior to GKS but did not display improvement in ocular symptoms. An average of 20 weeks (range 12–24 weeks) was needed for complete improvement in clinical symptoms. There were no treatment-related complications during the follow-up period. Conclusions Gamma Knife surgery should be considered as a primary, combined, or additional treatment option for CSDAVF in selected cases, such as when the lesion is a low-flow shunt without cortical venous drainage. For those selected cases, GKS alone may suffice as the primary treatment method when combined with close monitoring of ocular symptoms and intraocular pressure.

Gamma knife surgery for trigeminal neuralgia: improved initial response with two isocenters and increasing dose

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 185-188 ◽  
Author(s):  
Tracy E. Alpert ◽  
Chung T. Chung ◽  
Lisa T. Mitchell ◽  
Charles J. Hodge ◽  
Craig T. Montgomery ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Linear Regression Analysis ◽  
Initial Response ◽  
Gamma Knife Surgery ◽  
Invasive Treatment ◽  
Content Type ◽  
Improvement Score ◽  
Fine Print

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.

Incidence, timing, and treatment of new brain metastases after Gamma Knife surgery for limited brain disease: the case for reducing the use of whole-brain radiation therapy

2011 ◽  
Vol 115 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Stephen Rush ◽  
Robert E. Elliott ◽  
Amr Morsi ◽  
Nisha Mehta ◽  
Jeri Spriet ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Brain Metastases ◽  
Gamma Knife ◽  
Gamma Knife Surgery ◽  
Whole Brain Radiation Therapy ◽  
Leptomeningeal Disease ◽  
Whole Brain ◽  
Whole Brain Radiation ◽  
Brain Radiation

Object In this paper, the authors' goal was to analyze the incidence, timing, and treatment of new metastases following initial treatment with 20-Gy Gamma Knife surgery (GKS) alone in patients with limited brain metastases without whole-brain radiation therapy (WBRT). Methods A retrospective analysis of 114 consecutive adults (75 women and 34 men; median age 61 years) with KPS scores of 60 or higher who received GKS for 1–3 brain metastases ≤ 2 cm was performed (median lesion volume 0.35 cm3). Five patients lacking follow-up data were excluded from analysis. After treatment, patients underwent MR imaging at 6 weeks and every 3 months thereafter. New metastases were preferentially treated with additional GKS. Indications for WBRT included development of numerous metastases, leptomeningeal disease, or diffuse surgical-site recurrence. Results The median overall survival from GKS was 13.8 months. Excluding the 3 patients who died before follow-up imaging, 12 patients (11.3%) experienced local failure at a median of 7.4 months. Fifty-three patients (50%) developed new metastases at a median of 5 months. Six (7%) of 86 instances of new lesions were symptomatic. Most patients (67%) with distant failures were successfully treated using salvage GKS alone. Whole-brain radiotherapy was indicated in 20 patients (18.3%). Thirteen patients (11.9%) died of neurological disease. Conclusions For patients with limited brain metastases and functional independence, 20-Gy GKS provides excellent disease control and high-functioning survival with minimal morbidity. New metastases developed in almost 50% of patients, but additional GKS was extremely effective in controlling disease. Using our algorithm, fewer than 20% of patients required WBRT, and only 12% died of progressive intracranial disease.

Gamma Knife surgery for invasive pituitary macroadenoma

2006 ◽  
Vol 105 (Supplement) ◽  
pp. 26-30 ◽  
Author(s):  
Mooseong Kim ◽  
Sunghwa Paeng ◽  
Seyoung Pyo ◽  
Yeonggyun Jeong ◽  
Sunil Lee ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Cavernous Sinus ◽  
Pituitary Adenomas ◽  
Gamma Knife Surgery ◽  
Tumor Control ◽  
Pituitary Macroadenoma ◽  
Female Ratio ◽  
Fractionated Radiotherapy ◽  
The Mean

ObjectPituitary adenomas have been treated using a variety of modalities including resection, medication, fractionated radiotherapy, and stereotactic radiosurgery. The policy has been that all adenomas should first be treated with resection to reduce the volume of the tumor. The authors' study was conducted to determine the efficacy of using Gamma Knife surgery (GKS) for pituitary adenomas invading the cavernous sinus.MethodsOf 397 patients with pituitary tumors who underwent GKS between October 1994 and October 2005, 68 patients had pituitary macroadenomas invading the cavernous sinus. Sixty-seven cases were available for follow up. The mean age of the patients in these cases was 42.8 years (range 14–73 years). The male/female ratio was 0.8:1. The mean adenoma volume was 9.3 cm3. A total of 24 patients had undergone craniotomies and resection, and 11 patients had undergone transsphenoidal surgery prior to GKS. The mean follow-up period was 32.8 months. Tumor control was defined as a decrease or no change in tumor volume after GKS. Endocrinological improvement was defined as a decline in hormone levels to below 50% of the pre-GKS level.Tumor control was achieved in 95.5% of the cases. Endocrinological improvement was achieved in 68% of 25 patients. One patient suffered hypopituitarism after GKS.Conclusions Gamma Knife surgery is a safe and effective treatment for invasive pituitary macroadenoma with few complications.

Gamma Knife surgery in the management of orbital tumors

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 34-38 ◽  
Author(s):  
Desheng Xu ◽  
Dong Liu ◽  
Zhiyuan Zhang ◽  
Yipei Zhang ◽  
Yanhe Li ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Gamma Knife ◽  
Target Volume ◽  
Gamma Knife Surgery ◽  
Orbital Tumors ◽  
Acute Side Effect ◽  
Choroidal Melanomas ◽  
Excellent Preservation ◽  
Severe Deterioration

Object The authors evaluated the results they obtained using Gamma Knife surgery (GKS) in patients with orbital tumors. Methods This is a retrospective clinical evaluation of 202 patients with orbital tumors who were treated with GKS between September 1995 and October 2008. The series included 84 men and 118 women with a mean age of 39.5 ± 14.6 years (range 5–85 years). The diagnoses were determined based on pathological analyses in 113 patients and presumed based on characteristic clinical and imaging findings in 89 patients. There were 84 meningiomas, 38 epithelial tumors of the lacrimal gland, 23 schwannomas, 18 malignant choroidal melanomas, 12 optic nerve gliomas, 11 orbital metastases, 10 pseudotumors of the orbit, 3 retinoblastomas, and 3 cases of fibromatosis. The median target volume was 5.4 cm3 (range 0.04–35.6 cm3). The tumor margin dose ranged from 10 to 40 Gy. Results At a median follow-up period of 34.5 ± 14.7 months (range 12–114 months), tumor shrinkage was observed in 118 patients (58.4%) and stable tumor size in 71 patients (35.1%). Regularly scheduled neuroimaging studies demonstrated evidence of tumor progression in only 13 patients (6.4%): 9 of these patients underwent repeated GKS and 4 received surgical treatment. Visual acuity was preserved in 129 patients. Seventy-two patients experienced some degree of improvement in vision. Severe deterioration of visual acuity was found in 18 of 147 patients who had useful vision before treatment. Nineteen patients (9.4%) experienced transient conjunctival edema; no other serious acute side effect was observed. Conclusions Gamma Knife surgery provides an effective management strategy in patients with orbital tumors; it achieves excellent preservation of neurological function and is associated with few treatment-related complications.

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