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http://www.webmedcentral.com/images/Header_Logo.giftext/html2010-10-10T18:11:28+01:00http://www.webmedcentral.com/Dr. Tejpal GuptaMeningeal Hemangiopericytoma With Delayed Extra-neuraxial Metastases: Diagnostic Conundrum And Management Using High-precision Simultaneous Multi-target Irradiation On Helical Tomotherapy
http://www.webmedcentral.com/article_view/949
Introduction: Intracranial meningeal hemangiopericytoma is a rare tumor with variable biological behaviour. Though generally locally aggressive, a subset may fail distantly in the neural axis and even develop delayed extra-neuraxial metastases. It is often difficult to differentiate this entity morphologically from similar lesions such as meningioma, solitary fibrous tumor, and synovial sarcoma with hemangiopericytomatous pattern.Aims: To highlight the malignant potential of intracranial hemangiopericytoma, associated challenges and dilemmas in accurate diagnosis, and use of helical tomotherapy for simultaneous irradiation of symptomatic metastases.Case report: A 21-year old man diagnosed previously as a right cerebellopontine angle hemangiopericytoma, treated with surgery followed by post-operative adjuvant stereotactic conformal radiation therapy with no clinico-radiological evidence of progression at the index site, presented 5-years later with disseminated extra-neuraxial metastatic disease. Biopsy from metastatic site was suggestive of synovial sarcoma with hemangiopericytomatous vasculature. Immunohistochemistry profile was overlapping, necessitating molecular genetic studies. Reverse transcriptase polymerase chain reaction did not reveal a SYT-SSX translocation; thereby favouring a diagnosis of hemangiopericytoma over synovial sarcoma. In view of good performance status and long disease-free interval, he was treated with simultaneous multi-target irradiation of symptomatic metastatic sites using image-guided intensity-modulated radiation therapy on helical tomotherapy with good symptomatic relief.Conclusion: Intracranial meningeal hemangiopericytoma is generally a locally aggressive tumor, but can have variable biological behaviour including delayed extra-neuraxial metastases. Immunohistochemistry and molecular genetic studies are helpful in differentiating it from morphologically similar tumors. There is a potential role of high-precision radiotherapy for targeting multiple metastatic lesions simultaneously for durable symptom control.
text/html2010-11-13T17:30:42+01:00http://www.webmedcentral.com/Dr. Chia Chun HuangThe Role Of Image Guided And Intensity Modulated Stereotactic Radiotherapy For Patients With Metastatic And Locally Advanced Cancers
http://www.webmedcentral.com/article_view/1153
Background Intensity-modulated stereotactic radiotherapy achieves improvements in the ability to produce conformal stereotactic dose distributions by modulation of the intensity of individually delivered beamlets of radiation. Image-guided intensity-modulated stereotactic radiotherapy has emerged as a new treatment option in the multidisciplinary management of metastatic and locally advanced cancers.Methods From July 2009 to February 2010, 34 patients with metastatic and locally advanced cancers were treated with an image-guided intensity-modulated stereotactic radiation system, Axesse (Elekta, Crawley, England). The patient position was verified using CBCT of the Elekta Axesse. Patient setup errors were calculated using automatic image registration of the planning CT scan and verification CBCT scan using the Elekta XVI software. Errors were corrected on-line before each treatment.ResultsThe group mean errors were ? 1 mm and ? 1°. Radiologic complete response was achieved in 8 patients (23.5%). Radiologic partial response was achieved in 25 patients (73.6%). Development of new intracranial lesion was noted in one patient with brain metastasis from lung cancer (2.9%). Radiologic local control was achieved in 33 patients (97.1%). Clinical symptom improvement, including relief of pain and other symptoms, was achieved in all patients.Conclusion Image-guided intensity-modulated stereotactic radiotherapy used in the treatment of patients with metastatic and locally advanced cancer appears to be safe and effective both in terms radiographic tumor control and pain relief. Clinical trials providing standards on treatment parameters, physics quality assurance benchmarks, and tools to measure outcomes are warranted.
text/html2012-03-04T08:01:56+01:00http://www.webmedcentral.com/Dr. Faycal KharfiFeasibility of BNCT and Neutron Imaging with 1Hz, 5kJ Plasma Focus Neutron Source at the ICTP-MLAB Laboratory
http://www.webmedcentral.com/article_view/3130
Plasma Focus (PF) devices operated in Deuterium mode (D-D) can be advantageously used as a high intensity short-duration neutron source for many original medical and new imaging applications. At the Multidisciplinary Laboratory (MLAB) of the International Centre for Theoretical physics (Trieste, Italy), a low cost compact and efficient 1 Hz, 5kJ Plasma Focus source was designed and manufactured. This device will be used in several domains of science and basis research. The purpose of the implementation of Plasma Source Device (PFD) at the MLAB is not only to further investigate the physics of the plasma focus; its uniqueness derives from the creation of a source of radiation and particle beams for diagnostic and technology development as well as applications to interdisciplinary projects such as cultural heritage, biology and medicine. This source allows a neutron yield of ~108 per shot (pulse). The duration of the pulse is about 10 ns. In this paper, a general description of this source and its mode of operation are presented. The main characterises of neutrons produced by the Plasma Focus chamber will be outlined. A proposition and a draft design concerning a Boron Neutron Capture Therapy (BNCT) and neutron imaging exposure systems that can be implemented around this source are presented in details. The advantages and limitations such as resolution and pulse mode of operation affecting the utilisation of this kind of source for BNCT and neutron imaging are also discussed.Keywords: Dense Plasma Focus, BNCT, MCNP, Neutron Imaging.