scholarly journals Contribution of spectroscopic magnetic resonance imaging to target volume delineation in Gamma Knife Radiosurgery: Myth or reality?

2021 ◽  
pp. 2-2
Keyword(s):  
Magnetic Resonance ◽  
Brain Metastasis ◽  
Gamma Knife ◽  
Tumor Volume ◽  
Gamma Knife Radiosurgery ◽  
Target Volume ◽  
High Grade ◽  
Target Delineation ◽  
Perilesional Edema ◽  
Volume Delineation

Brain malignancies are still associated with poor prognosis despite multimodal radiosurgical therapeutic approach using Gamma Knife (GK), CyberKnife (CK), and linear accelerator-based technologies [1]. These advances have significantly improved the treatment outcome. However, the surgical and radiosurgical concept is still “image-guided”, and the success is closely related to precise tumor volume definition. The gross tumor volume (GTV) is defined as the visible contrast- enhancing lesion on magnetic resonance (MR) images with high three-dimensional spatial accuracy. Target delineation requires always both T2-weighted and volumetric T1-weighted sequences. T2-weighted fluid attenuated inversion recovery (FLAIR) sequences analyze the lesions surrounding brain tissues [2,3]. Objective assessment of apparently healthy tissue surrounding brain tumors seems to be a considerable factor interfering not only with the radiosurgical procedure, but also with the recurrence rate and overall survival. Several studies identified infiltrative spectroscopic pattern of the perilesional edema in more than 96% of high-grade gliomas cases and in 11,5% of patients with brain metastasis [4]. Moreover, some autopsy series of brain metastases confirmed infiltrative growth in radiologically healthy surrounding tissues in more than 60% of cases. This unseen malignant component is responsible of 80 % of “early recurrence” which should be considered as natural evolution of the main tumor [5]. In the management of high grade gliomas, the radiosurgeons are faced either to carcinologic incomplete procedures or to overestimated target irradiation with unbalanced benefit/risk action mostly related to radiation-induced brain necrosis [6]. The delineation of clinical target volume (CTV) which is defined as the volume of tissue that contains the GTV and any microscopic tumor or paths of spread, became a standard for any radio-surgical planning. Since a decade, the magnetic resonance spectroscopy (MRS) was standardized in the target volume assessment. The aim is to establish a metabolic lesional cartography. It had been reported that choline/ N- acetylaspartate (NAA) multivoxel MR spectroscopy index higher that 2,5 is in favor of malignancy in glioma with sensitivity of 90 % and specificity of 85 % [7]. However, NAA/Creatine (Cr) and Choline/Cr ratios are more relevant in the analysis of perilesional edema in brain metastasis cases. The introduction of MRS metabolic cartography concept, the use of relevant metabolite and adapted metabolites ratio estimation contributed to precision in radiosurgery. However, MRS is not used for target delineation for Gamma Knife radiosurgical treatment because of its incompatibility with the Leksell Gamma Knife planning software. Recently, we described the development of the first software allowing the integration of metabolic cartography based on multivoxel spectroscopic MRI in the radiosurgical planning for Leksell Gamma Knife Radiosurgery. The few existing meta-analysis could not lead to gold standard volume delineation techniques despite objective advance in imaging assessment [8,9]. Prospective studies using multimodal imaging data will help to overcome this insufficiency for target delineation in radiosurgery

scholarly journals USE OF PROTON MAGNETIC RESONANCE SPECTROSCOPIC IMAGING DATA IN PLANNING FOCAL RADIATION THERAPIES FOR BRAIN TUMORS

2011 ◽  
Vol 21 (2) ◽  
pp. 69 ◽  
Author(s):  
Edward E Graves ◽  
Andrea Pirzkall ◽  
Tracy R Mcknight ◽  
Daniel B Vigneron ◽  
David A Larson ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Spectroscopic Imaging ◽  
Target Volume ◽  
Magnetic Resonance Spectroscopic Imaging ◽  
Malignant Neoplasms ◽  
Resonance Spectroscopy ◽  
Normal Brain ◽  
Imaging Data

Advances in radiation therapy for malignant neoplasms have produced techniques such as Gamma Knife radiosurgery, capable of delivering an ablative dose to a specific, irregular volume of tissue. However, efficient use of these techniques requires the identification of a target volume that will produce the best therapeutic response while sparing surrounding normal brain tissue. Accomplishing this task using conventional computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI) techniques has proven difficult because of the difficulties in identifying the effective tumor margin. Magnetic resonance spectroscopic imaging (MRSI) has been shown to offer a clinically-feasible metabolic assessment of the presence and extent of neoplasm that can complement conventional anatomic imaging. This paper reviews current Gamma Knife protocols and MRSI acquisition, reconstruction, and interpretation techniques, and discusses the motivation for including magnetic resonance spectroscopy findings while planning focal radiation therapies. A treatment selection and planning strategy incorporating MRSI is then proposed, which can be used in the future to assess the efficacy of spectroscopy-based therapy planning.

scholarly journals Fractionated Gamma Knife radiosurgery for skull base meningiomas: a single-institution experience

2019 ◽  
Vol 46 (6) ◽  
pp. E8 ◽  
Author(s):  
Krishna C. Joshi ◽  
Alankrita Raghavan ◽  
Baha’eddin Muhsen ◽  
Jason Hsieh ◽  
Hamid Borghei-Razavi ◽  
...  
Keyword(s):  
Skull Base ◽  
Gamma Knife ◽  
Tumor Volume ◽  
Gamma Knife Radiosurgery ◽  
Cranial Neuropathy ◽  
High Dose ◽  
Perilesional Edema ◽  
The Mean ◽  
Skull Base Meningiomas

OBJECTIVEGamma Knife radiosurgery (GKRS) has been successfully used for the treatment of intracranial meningiomas given its steep dose gradients and high-dose conformality. However, treatment of skull base meningiomas (SBMs) may pose significant risk to adjacent radiation-sensitive structures such as the cranial nerves. Fractionated GKRS (fGKRS) may decrease this risk, but until recently it has not been practical with traditional pin-based systems. This study reports the authors’ experience in treating SBMs with fGKRS, using a relocatable, noninvasive immobilization system.METHODSThe authors performed a retrospective review of all patients who underwent fGKRS for SBMs between 2013 and 2018 delivered using the Extend relocatable frame system or the Icon system. Patient demographics, pre- and post-GKRS tumor characteristics, perilesional edema, prior treatment details, and clinical symptoms were evaluated. Volumetric analysis of pre-GKRS, post-GKRS, and subsequent follow-up visits was performed.RESULTSTwenty-five patients met inclusion criteria. Nineteen patients were treated with the Icon system, and 6 patients were treated with the Extend system. The mean pre-fGKRS tumor volume was 7.62 cm3 (range 4.57–13.07 cm3). The median margin dose was 25 Gy delivered in 4 (8%) or 5 (92%) fractions. The median follow-up time was 12.4 months (range 4.7–17.4 months). Two patients (9%) experienced new-onset cranial neuropathy at the first follow-up. The mean postoperative tumor volume reduction was 15.9% with 6 patients (27%) experiencing improvement of cranial neuropathy at the first follow-up. Median first follow-up scans were obtained at 3.4 months (range 2.8–4.3 months). Three patients (12%) developed asymptomatic, mild perilesional edema by the first follow-up, which remained stable subsequently.CONCLUSIONSfGKRS with relocatable, noninvasive immobilization systems is well tolerated in patients with SBMs and demonstrated satisfactory tumor control as well as limited radiation toxicity. Future prospective studies with long-term follow-up and comparison to single-session GKRS or fractionated stereotactic radiotherapy are necessary to validate these findings and determine the efficacy of this approach in the management of SBMs.

scholarly journals P03.07 Radiosurgical managementof trigeminal schwannomas: A single center experience

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii26-iii26
Author(s):  
R M Emad Eldin ◽  
A M El-Shehaby ◽  
K Abdel Karim ◽  
W A Reda ◽  
A Nabeel ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Tumor Volume ◽  
Gamma Knife Radiosurgery ◽  
Progression Free Survival ◽  
Target Volume ◽  
Primary Treatment ◽  
Tumor Control ◽  
Single Center Experience ◽  
Primary Treatment Modality ◽  
The Mean

Abstract BACKGROUND Trigeminal schwannomas are a rare form of intracranial schwannomas. They can occur anywhere along the track of the trigeminal nerve, including the middle, posterior fossa or both. It can even extend extracranially. The variability of its location and extent, in addition to its close proximity to critical neurovascular structures makes surgical intervention challenging. Taking from the success of treating vestibular schwannomas with stereotactic radiosurgery, it has been used as an alternative to surgery for the treatment of trigeminal schwannomas. Because these tumors are rare more clinical evidence is required to assess the response of these tumors to stereotactic radiosurgery.The aim of this study was to evaluate the efficacy and complications associated with treatment of the trigeminal schwannomas by gamma knife radiosurgery. MATERIAL AND METHODS The study included 51 patients with trigeminal schwannomas not associated with NF2, treated by Leksell gamma knife. There were 25 males and 26 females. The mean age at presentation was 43 years. The patients underwent a total of 58 gamma knife sessions (44 single and 7 volume-staged sessions). Eight patients had previous surgery. The tumor nature was solid in 46, cystic in 3 and mixed in 2 patients. The mean target volume was 8.5 cc (0.6–30.7 cc) with the mean overall tumor volume being 9.6 cc (0.6–31.1 cc). The mean prescription dose was 12 Gy. RESULTS The mean follow up was 57 months (12–152 months). The tumor shrank in 23 (45%) patients and remained stable in 25 (49%). Tumor progressions occurred in 3 (6%) patients. The tumor control rate was 92%. The progression-free survival at 5,7 and 10 years was 95%, 88% and 79%, respectively. Clinical improvement occurred in 27 (53%) patients and was significantly associated with tumor shrinkage (p 0.03). Twenty patients (39%) remained clinically unchanged. Adverse radiation events occurred in 7 patients and were significantly associated with target and overall tumor volume (p 0.028 and 0.004). CONCLUSION Gamma knife radiosurgery appears to be an effective and safe adjuvant and primary treatment modality for trigeminal schwannomas. Large tumors should be debulked first before radiosurgery, when feasible.

scholarly journals Gamma Knife radiosurgery for brain metastasis: review of 103 patients

2009 ◽  
Vol 28 (04) ◽  
pp. 133-138
Author(s):  
Marcos Antônio Dellaretti Filho ◽  
George de Albuquerque Cavalcanti Mendes ◽  
Nicolas Reyns ◽  
Gustavo Touzet ◽  
François Dubois ◽  
...  
Keyword(s):  
Overall Survival ◽  
Brain Metastasis ◽  
Gamma Knife ◽  
Local Control ◽  
Tumor Volume ◽  
Karnofsky Performance Status ◽  
Performance Status ◽  
Gamma Knife Radiosurgery ◽  
Intracranial Metastasis ◽  
Free Survival

Abstract Objective: To assess clinical and imaging outcomes in patients treated with Gamma Knife stereotactic radiosurgery (SRS) for brain metastasis. Methods: One hundred and three patients with 158 intracranial metastasis consecutively underwent Gamma Knife SRS between January, 2004 and December, 2006. The results were based on last imaging and the date of the last visit. Average age of the patients was 56 years (range 32-84 years). Karnofsky performance status average was 87.6. Fifty-eight (56.3%) patients had single brain metastasis. The average tumor volume was 2.5cc (range 0.02-16.6 cc). The SRS marginal dose average was 23.4 Gy (range 15-25 Gy). Results: Treatment sequence was SRS alone (89 patients) or SRS plus whole-brain radiotherapy (WBRT) (14 patients). The 1-year local control was 80%, being better for tumors with volume <5cc than for ≥5 cc: 86% vs 53% (p<0.05). The 1-year distant brain metastasis-free survival incidence was 73%. The initial number of brain lesions (single vs multiple) was not a significant factor on distant brain metastasis: free survival at 1 year was 75% for single metastases and 70% for multiple lesions. Renal cancer was the only factor with a significant effect on distant brain metastasis. The median overall survival was 15 months. According to unifactorial and multifactorial analysis, three prognostic factors for overall survival were retrieved recursive partitioning analysis (RPA) class, Karnofsky index performance and tumor volume. Conclusion: In this series, SRS provided excellent local control with relatively low morbidity in patients with brain metastases.

Early complications following gamma knife radiosurgery for intracranial meningiomas

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 57-61 ◽  
Author(s):  
V. P. Singh ◽  
S. Kansal ◽  
S. Vaishya ◽  
P. K. Julka ◽  
V. S. Mehta
Keyword(s):  
Gamma Knife ◽  
Tumor Volume ◽  
Gamma Knife Radiosurgery ◽  
Primary Therapy ◽  
Early Complications ◽  
Content Type ◽  
Cavernous Sinus Meningioma ◽  
Perilesional Edema ◽  
Intracranial Meningiomas ◽  
Fine Print

Object. The purpose of this paper was to assess the early complications, defined as occurring within 1 year, following gamma knife radiosurgery (GKS) for the treatment of intracranial meningiomas. Methods. Seventy-seven of 306 patients undergoing GKS in the last 2.5 years harbored meningiomas. There were 35 men and 42 women with a mean age of 32.4 years (range 10–80 years). Tumor volume ranged from 0.35 to 28.6 cm3 (mean 7.9 cm3). Gamma knife radiosurgery was the primary therapy in 28 patients and followed surgery in 49 patients. There were 50 basal and 27 nonbasal meningiomas. The most common sites were parasagittal (23 patients) and cerebellopontine angle (14 patients). Ten to 15 Gy was administered to the tumor margins. Clinical and radiological follow up with a mean duration of 122 months was available in 40 patients. Seizures and increased headache were found in five and four patients, respectively. A temporary worsening of hemiparesis was seen in two patients (both with parasagittal tumors). One patient with a cavernous sinus meningioma developed a herpes labialis eruption. Perilesional edema was demonstrated in nine patients and was symptomatic in six. Six (22%) of the 27 patients with nonbasal tumors had edema (all parasagittal) and four patients were symptomatic. Only three (6%) of the 50 basal meningiomas had edema, and only one patient was symptomatic. The occurence of edema did not correlate with tumor volume, margin or maximum dose, or with radiation received by adjacent brain. A reduction in tumor size was seen in seven patients. In one patient a new recurrent lesion developed adjacent to the previously treated tumor. Conclusions. Although GKS provides good results for selected patients with meningiomas, caution is required in treating patients with parasagittal tumors as the incidence of perilesional edema is considerable.

Survival and pattern of failure in brain metastasis treated with stereotactic gamma knife radiosurgery

2002 ◽  
Vol 97 ◽  
pp. 499-506 ◽  
Author(s):  
Zbigniew Petrovich ◽  
Cheng Yu ◽  
Steven L. Giannotta ◽  
Steven O'day ◽  
Michael L. J. Apuzzo
Keyword(s):  
Breast Cancer ◽  
Brain Metastasis ◽  
Gamma Knife ◽  
Tumor Volume ◽  
Systemic Disease ◽  
Gamma Knife Radiosurgery ◽  
Unknown Primary ◽  
Pattern Of Failure ◽  
Content Type ◽  
Fine Print

Object. Gamma knife radiosurgery (GKS) has become a well-established treatment modality in the management of selected patients with brain metastasis. The authors review the management patients with these tumors treated at a single center. Methods. Between 1994 and 2002, 458 consecutive patients with metastatic brain disease underwent GKS. There were 1305 lesions treated in 680 separate sessions. The histological diagnosis was melanoma in 231 (50%), lung cancer in 94 (20.5%), breast cancer in 38 (8.3%), renal cell carcinoma (RCC) in 29 (6.3%), colon carcinoma in 13 (2.8%), unknown primary site in 14 (3.1%), and other in 39 patients (8.5%). The median tumor volume was 0.9 cm3 and the median volume treated was 2.3 cm3. The median radiation dose was 18 Gy prescribed to a median isodose of 60%; the median dose was 20 Gy in melanoma, sarcoma, and RCC. Whole-brain radiotherapy (WBRT) either prior to or following GKS was performed in 114 patients (25%). Follow up ranged from 3 to 84 months with a median of 9 months. The median survival for all patients was 9 months and depended on tumor histology. Survival ranged from 6 months for patients with colon carcinoma, unknown primary tumors, and other tumors to 17 months for those with breast cancer. Median survival in patients with melanoma was 8 months. In multivariate analysis Karnofsky Performance Scale score (< 70 vs > 70), status of systemic disease (yes vs no), histological diagnosis, and total intracranial tumor volume were the only significant factors influencing survival. The number of brain metastases (one–five), WBRT (yes vs no), and age were not significant. Pattern of failure was different in patients with melanoma compared with those with other diagnoses. Cause of death in patients with melanoma was in 50% of the cases due to systemic disease and in 42% due to central nervous system causes, whereas it was 70% for the former and 23% for the latter in patients with other diagnoses. The treatment was well tolerated with significant late toxicity requiring craniotomy for removal of a necrotic focus in only 20 patients (4.7%). Conclusions. Gamma knife radiosurgery provided an excellent palliation with low incidence of toxicity. A Phase III prospective randomized trial is required to define the role of WBRT in combination with GKS.

scholarly journals Efficacy of Gamma Knife Radiosurgery for Recurrent High-Grade Gliomas with Limited Tumor Volume

2018 ◽  
Vol 61 (4) ◽  
pp. 516-524 ◽  
Author(s):  
Young-Jun Cheon ◽  
Tae-Young Jung ◽  
Shin Jung ◽  
In-Young Kim ◽  
Kyung-Sub Moon ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Tumor Volume ◽  
Gamma Knife Radiosurgery ◽  
High Grade ◽  
High Grade Gliomas

Gamma knife radiosurgery for craniopharyngiomas

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 47-56 ◽  
Author(s):  
Wen-Yuh Chung ◽  
David Hung-Chi Pan ◽  
Cheng-Ying Shiau ◽  
Wan-Yuo Guo ◽  
Ling-Wei Wang
Keyword(s):  
Clinical Outcome ◽  
Gamma Knife ◽  
Tumor Volume ◽  
Gamma Knife Radiosurgery ◽  
Tumor Control ◽  
Content Type ◽  
Stereotactic Aspiration ◽  
Cystic Component ◽  
The Mean ◽  
Fine Print

Object. The goal of this study was to elucidate the role of gamma knife radiosurgery (GKS) and adjuvant stereotactic procedures by assessing the outcome of 31 consecutive patients harboring craniopharyngiomas treated between March 1993 and December 1999. Methods. There were 31 consecutive patients with craniopharyngiomas: 18 were men and 13 were women. The mean age was 32 years (range 3–69 years). The mean tumor volume was 9 cm3 (range 0.3–28 cm3). The prescription dose to the tumor margin varied from 9.5 to 16 Gy. The visual pathways received 8 Gy or less. Three patients underwent stereotactic aspiration to decompress the cystic component before GKS. The tumor response was classified by percentage reduction of tumor volume as calculated based on magnetic resonance imaging studies. Clinical outcome was evaluated according to improvement and dependence on replacement therapy. An initial postoperative volume increase with enlargement of a cystic component was found in three patients. They were treated by adjuvant stereotactic aspiration and/or Ommaya reservoir implantation. Tumor control was achieved in 87% of patients and 84% had fair to excellent clinical outcome in an average follow-up period of 36 months. Treatment failure due to uncontrolled tumor progression was seen in four patients at 26, 33, 49, and 55 months, respectively, after GKS. Only one patient was found to have a mildly restricted visual field; no additional endocrinological impairment or neurological deterioration could be attributed to the treatment. There was no treatment-related mortality. Conclusions. Multimodality management of patients with craniopharyngiomas seemed to provide a better quality of patient survival and greater long-term tumor control. It is suggested that GKS accompanied by adjuvant stereotactic procedures should be used as an alternative in treating recurrent or residual craniopharyngiomas if further microsurgical excision cannot promise a cure.

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