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Sarkar B.,Advanced Medicare and Research Institute Cancer Center | Goswami J.,Westbank Hospital andul Road | Basu A.,Westbank Hospital andul Road | Sriramprasath S.,Advanced Medicare and Research Institute Cancer Center
Polish Journal of Medical Physics and Engineering | Year: 2012

Treatment of high-grade gliomas continues to be frustrating for the clinician as the medial survival stands at a dismal 14.5 months for glioblastoma multiforme (GBM) with the current standard of care. Given the high dose and generous margins required to be irradiated, three dimensional conformal radiotherapy (3DCRT) has become standard practice. Radiation dose escalation beyond 60 Gy, by means of stereotactic or intensity modulated radiotherapy (IMRT) boost, has not yielded clinically significant benefits in terms of local control or survival. At the same time, the potential of IMRT to spare normal tissues such as the brain stem and the optic apparatus makes it an attractive tool for modern radiation oncologists in seeking to improve post-radiotherapy quality of life. At our centre, we have been treating a large number of cases of high grade glioma with 3DCRT and IMRT for the last several years. The present study has been an effort to understand any potential benefits that IMRT, even without dose escalation, can offer.

Sarkar B.,Advanced Medicare and Research Institute Cancer Center | Ghosh B.,Saha Institute of Nuclear Physics | Sriramprasath,Advanced Medicare and Research Institute Cancer Center | Mahendramohan S.,Advanced Medicare and Research Institute Cancer Center | And 3 more authors.
Journal of Medical Physics | Year: 2010

The study was aimed to compare accuracy of monitor unit verification in intensity modulated radiation therapy (IMRT) using 6 MV photons by three different methodologies with different detector phantom combinations. Sixty patients were randomly chosen. Zero degree couch and gantry angle plans were generated in a plastic universal IMRT verification phantom and 303030 cc water phantom and measured using 0.125 cc and 0.6 cc chambers, respectively. Actual gantry and couch angle plans were also measured in water phantom using 0.6 cc chamber. A suitable point of measurement was chosen from the beam profile for each field. When the zero-degree gantry, couch angle plans and actual gantry, couch angle plans were measured by 0.6 cc chamber in water phantom, the percentage mean difference (MD) was 1.35%, 2.94 % and Standard Deviation (SD) was 2.99%, 5.22%, respectively. The plastic phantom measurements with 0.125 cc chamber Semiflex ionisation chamber (SIC) showed an MD=4.21% and SD=2.73 %, but when corrected for chamber-medium response, they showed an improvement, with MD=3.38 % and SD=2.59 %. It was found that measurements with water phantom and 0.6cc chamber at gantry angle zero degree showed better conformity than other measurements of medium-detector combinations. Correction in plastic phantom measurement improved the result only marginally, and actual gantry angle measurement in a flat- water phantom showed higher deviation.

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