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Real-Time In Vivo Dosimetry With Mosfet Detectors In Serial Tomotherapy For Head And Neck Cancer Patients, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Almon Shiu, Michael Lerch, Peter Metcalfe, Anatoly Rosenfeld, Tomas Kron

Michael L.F. Lerch

Purpose

A real-time dose verification method using a recently designed metal oxide semiconductor field effect transistor (MOSFET) dosimetry system was evaluated for quality assurance (QA) of intensity-modulated radiation therapy (IMRT).

Methods and Materials

Following the investigation of key parameters that might affect the accuracy of MOSFET measurements (i.e., source surface distance [SSD], field size, beam incident angles and radiation energy spectrum), the feasibility of this detector in IMRT dose verification was demonstrated by comparison with ion chamber measurements taken in an IMRT QA phantom. Real-time in vivo measurements were also performed with the MOSFET system during serial tomotherapy …

In Vivo Verification Of Superficial Dose For Head And Neck Treatments Using Intensity-Modulated Techniques, Zhen-Yu Qi, Xiao-Wu Deng, Shao-Min Huang, Li Zhang, Zhi-Chun He, X. Allen Li, Ian Kwan, Michael Lerch, Dean Cutajar, Peter Metcalfe, Anatoly Rosenfeld

Michael L.F. Lerch

Skin dose is one of the key issues for clinical dosimetry in radiation therapy. Currently planning computer systems are unable to accurately predict dose in the buildup region, leaving ambiguity as to the dose levels actually received by the patient’s skin during radiotherapy. This is one of the prime reasons why in vivo measurements are necessary to estimate the dose in the buildup region. A newly developed metal-oxide-semiconductor-field-effect-transistor (MOSFET) detector designed specifically for dose measurements in rapidly changing dose gradients was introduced for accurate in vivo skin dosimetry. The feasibility of this detector for skin dose measurements was verified in …

Miniature Semiconductor Detectors For In Vivo Dosimetry, Anatoly Rosenfeld, Dean Cutajar, Michael Lerch, George Takacs, Iwan Cornelius, M Yudelev, M Zaider

Michael L.F. Lerch

Silicon mini-semiconductor detectors are found in wide applications for in vivo personal dosimetry and dosimetry and microdosimetry of different radiation oncology modalities. These applications are based on integral and spectroscopy modes of metal oxide semiconductor field effect transistor and silicon p–n junction detectors. The advantages and limitations of each are discussed.