| 1. |
- Huss, Marie, et al.
(författare)
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Fractionated SRT using VMAT and Gamma Knife for brain metastases and gliomas - a planning study
- 2015
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Ingår i: Journal of Applied Clinical Medical Physics. - : Wiley. - 1526-9914. ; 16:6, s. 3-16
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Tidskriftsartikel (refereegranskat)abstract
- Stereotactic radiosurgery using Gamma Knife (GK) or linear accelerators has been used for decades to treat brain tumors in one fraction. A new positioning system, Extend™, was introduced by Elekta AB for fractionated stereotactic radiotherapy (SRT) with GK. Another option for fractionated SRT is advanced planning and delivery using linacs and volumetric modulated arc therapy (VMAT). This project aims to assess the performance of GK Extend™ for delivering fractionated SRT by comparing GK treatments plans for brain targets performed using Leksell GammaPlan (LGP) with VMAT treatment plans. Several targets were considered for the planning: simulated metastasis- and glioma-like targets surrounding an organ at risk (OAR), as well as three clinical cases of metastases. Physical parameters such as conformity, gradient index, dose to OARs, and brain volume receiving doses above the threshold associated with risk of damaging healthy tissue, were determined and compared for the treatment plans. The results showed that GK produced better dose distributions for target volumes below 15 cm3, while VMAT results in better dose conformity to the target and lower doses to the OARs in case of fractionated treatments for large or irregular volumes. The volume receiving doses above a threshold associated with increased risk of damage to normal brain tissue was also smaller for VMAT. The GK consistently performed better than VMAT in producing a lower dose-bath to the brain. The above is subjected only to margin-dependent fractionated radiotherapy (CTV/PTV). The results of this study could lead to clinically significant decisions regarding the choice of the radiotherapy technique for brain targets.
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| 2. |
- Sinclair, Georges, et al.
(författare)
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Adaptive radiosurgery based on two simultaneous dose prescriptions in the management of large renal cell carcinoma brain metastases in critical areas: Towards customization
- 2020
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Ingår i: Surgical Neurology International. - : Scientific Scholar. - 2229-5097 .- 2152-7806. ; 11, s. 21-21
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Forskningsöversikt (refereegranskat)abstract
- The long-term benefits of local therapy in metastatic renal cell carcinoma (mRCC) have been widely documented. In this context, single fraction gamma knife radiosurgery (SF-GKRS) is routinely used in the management of brain metastases. However, SF-GKRS is not always feasible due to volumetric and regional constraints. We intend to illustrate how a dose-volume adaptive hypofractionated GKRS technique based on two concurrent dose prescriptions termed rapid rescue radiosurgery (RRR) can be utilized in this particular scenario.Case Description:A 56-year-old man presented with left-sided hemiparesis; the imaging showed a 13.1 cc brain metastasis in the right central sulcus (Met 1). Further investigation confirmed the histology to be a metastatic clear cell RCC. Met 1 was treated with upfront RRR. Follow-up magnetic resonance imaging (MRI) at 10 months showed further volume regression of Met 1; however, concurrently, a new 17.3 cc lesion was reported in the boundaries of the left frontotemporal region (Met 2) as well as a small metastasis (<1 cc) in the left temporal lobe (Met 3). Met 2 and Met 3 underwent RRR and SF-GKRS, respectively.Results:Gradual and sustained tumor ablation of Met 1 and Met 2 was demonstrated on a 20 months long follow- up. The patient succumbed to extracranial disease 21 months after the treatment of Met 1 without evidence of neurological impairment post-RRR.Conclusion:Despite poor prognosis and precluding clinical factors (failing systemic treatment, eloquent location, and radioresistant histology), RRR provided optimal tumor ablation and salvage of neurofunction with limited toxicity throughout follow-up.
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| 3. |
- Stenman, Maria, et al.
(författare)
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Albumin, corticosteroid use and Karnofsky performance status predict outcome of single-fraction gamma knife radiosurgery in clear cell renal cell carcinoma patients with brain metastases
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background and Purpose: To evaluate the effects of single fraction gamma knife radiosurgery (sf-GKRS) on patients with renal cell carcinoma (RCC) brain metastases (BM) in the era of targeted agents (TA).Material and Methods: Clear cell metastatic RCC patients treated with sf-GKRS due to BM in 2005-2014 at three European centres were retrospectively analysed (n=43). Median follow-up was 56 months. Ninety-five percent had prior nephrectomy, 53% synchronous metastasis and 86% extracranial disease at first sf-GKRS. Karnofsky performance status (KPS) ranged from 60-100%. Outcome measures were overall survival (OS), local control (LC) and adverse radiation effects (ARE).Results: One hundred and ninety-four targets were irradiated. Median number of targets at first sf-GKRS were two. The median prescription dose was 22 Gy. Thirty-seven percent had repeated sf-GKRS. Eighty-eight percent received TA. LC at 12 and 18 months were 97% and 90%. Median OS from first sf-GKRS was 15.7 months. Serum albumin (HR 5.3), corticosteroids pre sf-GKRS (HR 5.8) and KPS (HR 9.1) were independent prognostic factors. MSKCC risk group, synchronous metastasis, age, number of BM or extracranial metastases provided no additional prognostic information. Other prognostic scores for BM radiosurgery, including DS-GPA, Renal-GPA, LLV-SIR and CITV-SIR, did not add prognostic value. ARE were seldom symptomatic and were associated with tumour volume, 10-Gy volume and pre-treatment perifocal oedema. ARE were less common among patients treated with TA within one month of sf-GKRS.Conclusions: We identified three independent prognostic factors with potential impact on clinical decision making in patients with clear cell RCC BM.
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| 4. |
- Kanai, M, et al.
(författare)
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- 2023
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swepub:Mat__t
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