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  1. Wroe AJ, McAuley G, Teran AV, Wong J, Petasecca M, Lerch M, et al.
    J Appl Clin Med Phys, 2017 Sep;18(5):315-324.
    PMID: 28719019 DOI: 10.1002/acm2.12120
    As technology continues to develop, external beam radiation therapy is being employed, with increased conformity, to treat smaller targets. As this occurs, the dosimetry methods and tools employed to quantify these fields for treatment also have to evolve to provide increased spatial resolution. The team at the University of Wollongong has developed a pixelated silicon detector prototype known as the dose magnifying glass (DMG) for real-time small-field metrology. This device has been tested in photon fields and IMRT. The purpose of this work was to conduct the initial performance tests with proton radiation, using beam energies and modulations typically associated with proton radiosurgery. Depth dose and lateral beam profiles were measured and compared with those collected using a PTW parallel-plate ionization chamber, a PTW proton-specific dosimetry diode, EBT3 Gafchromic film, and Monte Carlo simulations. Measurements of the depth dose profile yielded good agreement when compared with Monte Carlo, diode and ionization chamber. Bragg peak location was measured accurately by the DMG by scanning along the depth dose profile, and the relative response of the DMG at the center of modulation was within 2.5% of that for the PTW dosimetry diode for all energy and modulation combinations tested. Real-time beam profile measurements of a 5 mm 127 MeV proton beam also yielded FWHM and FW90 within ±1 channel (0.1 mm) of the Monte Carlo and EBT3 film data across all depths tested. The DMG tested here proved to be a useful device at measuring depth dose profiles in proton therapy with a stable response across the entire proton spread-out Bragg peak. In addition, the linear array of small sensitive volumes allowed for accurate point and high spatial resolution one-dimensional profile measurements of small radiation fields in real time to be completed with minimal impact from partial volume averaging.
    Matched MeSH terms: Radiosurgery/instrumentation*; Radiosurgery/methods
  2. Reduan Abdullah, Ahmad Zakaria, Nur Iziana Mohsin, Nik Ruzman Nik Idris, Ahmad Lutfi Yusof, Mazurawati Mohamed
    MyJurnal
    The fi rst part of this study was about measurement of dosimetric parameters for small photon beams to be used as input
    data for treatment planning computer system (TPS) and to verify the dose calculated by TPS in Stereotactic Radiosurgery
    (SRS) procedure. The beam data required were percentage depth dose (PDD), off-axis ratio (OAR) and scattering factor.
    Small beams of 5 mm to 45 mm diameter from a circular cone collimator in SRS were used for beam data measurements.
    Measurements were made using pinpoint ionisation chamber (0.016cc). In the second part of this study, we reported
    the important of carrying out quality assurance (QA) procedures before SRS treatment which were found to infl uence the
    accuracy of dose delivery. These QA procedures consisted of measurements on the accuracy in target localization and
    treatment room laser alignment. The calculated TPS dose for treatment was verifi ed using pinpoint ionisation chamber
    and thermoluminescent detector (TLD) 100H. The deviation mean between measured and calculated dose was -3.28%.
    The measured dose obtained from pinpoint ionisation chamber is in good agreement with the calculated dose from TPS
    with deviation mean of 2.17%. In conclusion, pinpoint ionisation chamber gives a better accuracy in dose calculation
    compared to TLD 100H. The results are acceptable as recommended by International Commission on Radiation Units
    and Measurements (ICRU) Report No. 50 (1994) that dose delivered to the target volume must be within ± 5% error.
    Matched MeSH terms: Radiosurgery
  3. Bin Rosli FJ, Mohammed Haspani MS, Izaini Ab Ghani AR
    Asian J Neurosurg, 2016 Jan-Mar;11(1):22-8.
    PMID: 26889274 DOI: 10.4103/1793-5482.172595
    Intracranial arteriovenous malformations (AVMs) of Spetzler-Martin grades (SMGs) I-III are treated using either monomodality treatments of microsurgical excision, embolization or stereotactic radiosurgery (SRS), or a combination of two or more of these treatment options. At Hospital Kuala Lumpur, we still practice monomodality treatments for AVMs of these three grades. In this study, we wanted to achieve an understanding whether monomodality treatments can achieve a satisfactory outcome of AVM nidi for patients, for up to 3 years, and to gather an objective data for AVM treatment for the Malaysian population.
    Matched MeSH terms: Radiosurgery
  4. Yahya N, Manan HA
    World Neurosurg, 2019 Oct;130:e188-e198.
    PMID: 31326352 DOI: 10.1016/j.wneu.2019.06.027
    BACKGROUND: Diffusion tensor imaging (DTI), which visualizes white matter tracts, can be integrated to optimize intracranial radiation therapy (RT) and radiosurgery (RS) treatment planning. This study aimed to systematically review the integration of DTI for dose optimization in terms of evidence of dose improvement, clinical parameter changes, and clinical outcome in RT/RS treatment planning.

    METHODS: PubMed and Scopus electronic databases were searched based on the guidelines established by PRISMA to obtain studies investigating the integration of DTI in intracranial RT/RS treatment planning. References and citations from Google Scholar were also extracted. Eligible studies were extracted for information on changes in dose distribution, treatment parameters, and outcome after DTI integration.

    RESULTS: Eighteen studies were selected for inclusion with 406 patients (median study size, 19; range: 2-144). Dose distribution, with or without DTI integration, described changes of treatment parameters, and the reported outcome of treatment were compared in 12, 7, and 10 studies, respectively. Dose distributions after DTI integration improved in all studies. Delivery time or monitor unit was higher after integration. In studies with long-term follow-up (median, >12 months), neurologic deficits were significantly fewer in patients with DTI integration.

    CONCLUSIONS: Integrating DTI into RT/RS treatment planning improved dose distribution, with higher treatment delivery time or monitor unit as a potential drawback. Fewer neurologic deficits were found with DTI integration.

    Matched MeSH terms: Radiosurgery/methods*
  5. Jong WL, Ung NM, Vannyat A, Jamalludin Z, Rosenfeld A, Wong JH
    Phys Med, 2017 Jan;33:127-135.
    PMID: 28089106 DOI: 10.1016/j.ejmp.2016.12.020
    Dosimetry in small radiation field is challenging and complicated because of dose volume averaging and beam perturbations in a detector. We evaluated the suitability of the "Edge-on" MOSkin (MOSFET) detector in small radiation field measurement. We also tested the feasibility for dosimetric verification in stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT). "Edge-on" MOSkin detector was calibrated and the reproducibility and linearity were determined. Lateral dose profiles and output factors were measured using the "Edge-on" MOSkin detector, ionization chamber, SRS diode and EBT2 film. Dosimetric verification was carried out on two SRS and five SRT plans. In dose profile measurements, the "Edge-on" MOSkin measurements concurred with EBT2 film measurements. It showed full width at half maximum of the dose profile with average difference of 0.11mm and penumbral width with difference of ±0.2mm for all SRS cones as compared to EBT2 film measurement. For output factor measurements, a 1.1% difference was observed between the "Edge-on" MOSkin detector and EBT2 film for 4mm SRS cone. The "Edge-on" MOSkin detector provided reproducible measurements for dose verification in real-time. The measured doses concurred with the calculated dose for SRS (within 1%) and SRT (within 3%). A set of output correction factors for the "Edge-on" MOSkin detector for small radiation fields were derived from EBT2 film measurement and presented. This study showed that the "Edge-on" MOSkin detector is a suitable tool for dose verification in small radiation field.
    Matched MeSH terms: Radiosurgery/methods*
  6. Zamzuri I, Rahman GI, Muzaimi M, Jafri AM, Nik Ruzman NI, Lutfi YA, et al.
    Med J Malaysia, 2012 Feb;67(1):121-2.
    PMID: 22582564 MyJurnal
    High grade gliomas, frequently with their infiltrative nature, often make the outcome from neurosurgical intervention alone unsatisfactory. It is recognized that adjuvant radiochemotherapy approaches offer an improved prognosis. For these reasons, we opted for surgical debulking, intraoperative radiation therapy (IORT) in combination with whole brain irradiation therapy and chemotherapy (temozolamide cycles) in the management of a 42 year-old lady with Glioblastoma Multiforme (GBM). Her troublesome symptoms improved after 3 months of this polymodal therapy and remained independently functional for more than two years.
    Matched MeSH terms: Radiosurgery
  7. Al-Edrus, S. A., Suhaimi, S. N., Noor Azman, A. R., Latif, A. Z., Sobri, M.
    MyJurnal
    Introduction: An arteriovenous malformation (AVM) is an abnormal collection of blood vessels in which arterial blood flows directly into the draining vein without the normal interposed capillaries. The Spetzler-Martin grading system has been widely accepted worldwide to estimate the pretreatment risks and predict the outcome of patients with intracranial AVM. In Malaysia, we still do not have the baseline data of this grading system. Methods: A total of 33 patients from a tertiary referral hospital diagnosed with intracranial AVM based on neuroimaging findings over a 4-year period were studied. Medical
    records were traced and neuroimaging findings were analysed. The AVMs were graded according to the Spetzler-Martin grading system and Fisher’s exact test was used to assess statistical difference between the grades of the AVM and management plan for the patients. Results: Four patients were graded as Grade 1, 9 patients as Grade II, 10 patients as Grade III, 6 patients as Grade IV and 4 patients as Grade V. Ten patients were treated conservatively; six patients underwent surgery and embolisation respectively. Four patients underwent radiosurgery and a combination of embolisation while surgery and radiosurgery were given to 5 patients and 2 patients respectively. Statistically significant difference (p=0.016) was found between the Spetzler-Martin grading system and the management of intracranial AVMs. Conclusion: The management decision was not made based on the
    grading of the AVMs. It is recommended that all AVM patients be routinely graded according to this system prior to treatment.
    Matched MeSH terms: Radiosurgery
  8. Zamzuri I, Badrisyah I, Rahman GI, Pal HK, Muzaimi M, Jafri AM, et al.
    Med J Malaysia, 2011 Oct;66(4):346-9.
    PMID: 22299555 MyJurnal
    Stereotactic radiosurgery uses a single fraction high dose radiation while stereotactic radiotherapy uses multifractionated lower dose focused radiation.
    Matched MeSH terms: Radiosurgery*
  9. Goh ASC, Kim YD, Woo KI, Lee JI
    Ophthalmology, 2013 Mar;120(3):635-641.
    PMID: 23149128 DOI: 10.1016/j.ophtha.2012.08.015
    OBJECTIVE: The orbital apex is an important anatomic landmark that hosts numerous critical neurovascular structures. Tumor resection performed at this complex region poses a therapeutic challenge to orbital surgeons and often is associated with significant visual morbidity. This article reports the efficacy and safety of multisession gamma knife radiosurgery (GKRS) in benign, well-circumscribed tumors located at the orbital apex.

    DESIGN: Retrospective interventional case series.

    PARTICIPANTS: Five patients with visual disturbances resulting from a benign, well-circumscribed orbital apex tumor (3 cases of cavernous hemangioma and 2 cases of schwannoma).

    METHODS: Each patient treated with GKRS with a total radiation dose of 20 Gy in 4 sessions (5 Gy in each session with an isodose line of 50%) delivered to the tumor margin.

    MAIN OUTCOME MEASURES: Best-corrected visual acuity, visual field changes, orbital imaging, tumor growth control, and side effects of radiation.

    RESULTS: All patients demonstrated improvement in visual acuity, pupillary responses, color vision, and visual field. Tumor shrinkage was observed in all patients and remained stable until the last follow-up. No adverse events were noted during or after the radiosurgery. None of the patients experienced any radiation-related ocular morbidity.

    CONCLUSIONS: From this experience, multisession GKRS seems to be an effective management strategy to treat solitary, benign, well-circumscribed orbital apex tumors.

    Matched MeSH terms: Radiosurgery*
  10. Lim SY, Hodaie M, Fallis M, Poon YY, Mazzella F, Moro E
    Arch. Neurol., 2010 May;67(5):584-8.
    PMID: 20457958 DOI: 10.1001/archneurol.2010.69
    Gamma knife thalamotomy (GKT) has been used as a therapeutic option for patients with disabling tremor refractory to medications. Impressive improvement of tremor has been reported in the neurosurgical literature, but the reliability of such data has been questioned.
    Matched MeSH terms: Radiosurgery/adverse effects; Radiosurgery/methods; Radiosurgery/statistics & numerical data*
  11. Appalanaido GK, Bahajjaj SIBZ, Shukor SA, Ahmad MZ, Francis HCH
    Oxf Med Case Reports, 2021 Apr;2021(4):omab016.
    PMID: 33948189 DOI: 10.1093/omcr/omab016
    Liver is the most common site for metastasis from colorectal cancer (CRC). Non-surgical treatment options for oligometastatic CRC confined to the liver which represents an intermediate state in the metastatic cascade are fast expanding. Currently, several liver-directed local therapeutic options are available, such as hepatic arterial infusion (HAI) therapy, radio-frequency ablation (RFA), transarterial chemoembolization (TACE), stereotactic body radiotherapy and high dose rate brachytherapy (HDRBT). Many factors such as patient's fitness, liver function (LF), tumour size, location of the tumour in the liver and scheduling of systemic therapy need to be considered when selecting patients for surgery or local liver-directed therapy. This case report illustrates a successful local treatment with staged HDRBT for a large and unresectable, liver only oligometastatic disease from CRC. This patient underwent 4 cycles of chemotherapy (FOLFOX 4) followed by primary tumour resection and first stage of HDRBT to liver for a residual 14 cm tumour after the chemotherapy. After completing a further 4 cycles of chemotherapy with the same regimen, the tumour remained stable at 8 cm. She underwent a second stage of HDRBT to the same lesion and a repeat PET-CT scan done 8 weeks after the second HDRBT showed complete metabolic response. To our knowledge, this is the largest CRC metastatic liver lesion that has been successfully treated with HDRB.
    Matched MeSH terms: Radiosurgery
  12. Zamzuri I, Idris NR, Mar W, Abdullah JM, Zakaria A, Biswal BM
    Med J Malaysia, 2006 Dec;61(5):621-5.
    PMID: 17623965 MyJurnal
    Precision Radiotherapy at high doses require a fixed, referable target point. The frame system fulfills the required criteria by making the target point relocatable and fixed within a stereotactic space. Since December 2001, we have treated 28 central and peripheral nervous system lesions using either radiosurgery as a single high dose fraction or fractionated 3-dimensional conformal radiotherapy using a lower dose and a multi-leaf collimator. Various pathological lesions either benign or malignant were treated. Eighty six percent of our treated lesions showed growth restraint, preventing them from causing new symptoms with a median follow-up duration of 20.5 months. However, the true benefit from this technique would require a long-term follow-up to document the progress.
    Matched MeSH terms: Radiosurgery*
  13. Cheah SK, Matthews T, Teh BS
    Asian Pac J Cancer Prev, 2016;17(9):4233-4235.
    PMID: 27797223
    BACKGROUND: Whole brain radiotherapy (WBRT) and stereotactic radiosurgery were frequently used to palliate patients with brain metastases. It remains controversial which modality or combination of therapy is superior especially in the setting of limited number of brain metastases. The availability of newer medical therapy that improves survival highlighted the importance of reducing long term radiation toxicity associated with WBRT. In this study, we aim to demonstrate the hippocampal sparing technique with whole brain and integrated simultaneous boost Materials and Methods: Planning data from 10 patients with 1-5 brain metastases treated with SRS were identified. Based on the contouring guideline from RTOG atlas, we identified and contoured the hippocampus with 5mm isocentric expansion to form the hippocampal avoidance structure. The plan was to deliver hippocampal sparing whole brain radiotherapy (HSWBRT) of 30 Gy in 10 fractions and simultaneous boost to metastatic lesions of 30 Gy in 10 fractions each.

    RESULTS: The PTV, hippocampus and hippocampal avoidance volumes ranges between 1.00 - 39.00 cc., 2.50 - 5.30 cc and 26.47 - 36.30 cc respectively. The mean hippocampus dose for the HSWBRT and HSWBRT and SIB plans was 8.06 Gy and 12.47 respectively. The max dose of optic nerve, optic chiasm and brainstem were kept below acceptable range of 37.5 Gy.

    CONCLUSIONS: The findings from this dosimetric study demonstrated the feasibility and safety of treating limited brain metastases with HSWBRT and SIB. It is possible to achieve the best of both worlds by combining HSWBRT and SIB to achieve maximal local intracranial control while maintaining as low a dose as possible to the hippocampus thereby preserving memory and quality of life.

    Matched MeSH terms: Radiosurgery*
  14. Sayuthi S, Tharakan J, George J, Pieter MS, Salmah WM, Madhavan M, et al.
    Med J Malaysia, 2006 Aug;61(3):374-6.
    PMID: 17240596 MyJurnal
    Two rare cases of intractable epilepsy caused by Dysembryoplastic Neuroepithelial Tumours (DNET) are reported and their different management discussed. The first case required vagal nerve stimulation and radiosurgery while the later was operated with the help of neuronavigation. Both had good outcome according to Engel classification after a one year follow up.
    Matched MeSH terms: Radiosurgery
  15. Jafari SM, Jordan TJ, Distefano G, Bradley DA, Spyrou NM, Nisbet A, et al.
    Br J Radiol, 2015;88(1055):20140804.
    PMID: 26258442 DOI: 10.1259/bjr.20140804
    To investigate the feasibility of using glass beads as novel thermoluminescent dosemeters (TLDs) for radiotherapy treatment plan verification.
    Matched MeSH terms: Radiosurgery
  16. Subramaniam SM, Ishii K, Sheng CJ, Nakatomi H, Takai K, Saito N
    Surg Neurol Int, 2019;10:251.
    PMID: 31893152 DOI: 10.25259/SNI_516_2019
    Background: Spinal arteriovenous fistulas (AVFs) are vascular lesions that often pose significant surgical challenges. This is particularly true for those located close to the anterior spinal artery. Here, we analyzed the surgical options for treating an anterior perimedullary AVF (pAVFs).

    Case Description: A 66-year-old male with the right lower extremity weakness was diagnosed with a spinal dural AVF at the L1 level. It was initially treated with open surgery followed by CyberKnife radiosurgery at another institution. Five years later, he presented with a persistent pAVF fistula now involving the T11 level; the major feeder originated on the left at the T7-T8 level (e.g., involving a left-sided "duplicated" anterior spinal artery). Utilizing a three-dimensional (3D) computer tomography (CT) guided approach; he underwent a left-sided posterolateral T10-T12 laminectomy, sufficient to allow for 30-40° of anterior spinal cord rotation. This was performed under neurophysiological monitoring without any significant changes. Surgery included indocyanine green video angiography, temporary feeder clipping, and complete occlusion of the AVF, followed by complete clipping/resection as confirmed on postoperative magnetic resonance imaging.

    Conclusion: Utilizing a 3D CT image, a ventral pulmonary arteriovenous malformation was excised utilizing a left-sided posterolateral approach allowing for 30-40° of cord rotation.

    Matched MeSH terms: Radiosurgery
  17. Tang WH, Alip A, Saad M, Phua VC, Chandran H, Tan YH, et al.
    Asian Pac J Cancer Prev, 2015;16(5):1901-6.
    PMID: 25773842
    BACKGROUND: Brain metastases occur in about 20-40% of patients with non-small-cell lung carcinoma (NSCLC), and are usually associated with a poor outcome. Whole brain radiotherapy (WBRT) is widely used but increasingly, more aggressive local treatments such as surgery or stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) are being employed. In our study we aimed to describe the various factors affecting outcomes in NSCLC patients receiving local therapy for brain metastases.

    MATERIALS AND METHODS: The case records of 125 patients with NSCLC and brain metastases consecutively treated with radiotherapy at two tertiary centres from January 2006 to June 2012 were analysed for patient, tumour and treatment-related prognostic factors. Patients receiving SRS/SRT were treated using Cyberknife. Variables were examined in univariate and multivariate testing.

    RESULTS: Overall median survival was 3.4 months (95%CI: 1.7-5.1). Median survival for patients with multiple metastases receiving WBRT was 1.5 months, 1-3 metastases receiving WBRT was 3.6 months and 1-3 metastases receiving surgery or SRS/SRT was 8.9 months. ECOG score (≤2 vs >2, p=0.001), presence of seizure (yes versus no, p=0.031), treatment modality according to number of brain metastases (1-3 metastases+surgery or SRS/SRT±WBRT vs 1-3 metastases+WBRT only vs multiple metastases+WBRT only, p=0.007) and the use of post-therapy systemic treatment (yes versus no, p=0.001) emerged as significant on univariate analysis. All four factors remained statistically significant on multivariate analysis.

    CONCLUSIONS: ECOG ≤2, presence of seizures, oligometastatic disease treated with aggressive local therapy (surgery or SRS/SRT) and the use of post-therapy systemic treatment are favourable prognostic factors in NSCLC patients with brain metastases.

    Matched MeSH terms: Radiosurgery
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