Скачать с ютуб IMRT Planning Basics for Eclipse TPS users в хорошем качестве

IMRT Planning Basics for Eclipse TPS users

IMRT (Intensity Modulated Radiation Therapy) is the delivery method used to create a highly conformal dose distribution.  Treatment Planning System creates non-uniform fluence for many fields to create uniform dose distribution within the target and spare the critical structures at the same time.  Field is divided into small elements – beamlets. - A Beamlet is the smallest element to be modified. - Size of the beamlet in X- direction is 0.25 cm (at the plane of isocenter) - Size of the beamlet in Y-direction depends on MLC model – represent leaf width at the level of isocenter.  MLC Models are available with different leaf configurations. Leaf width determines the beamlet “height” or width of the beamlet row. - Millennium MLC has 52, 80 and 120 leaf. For the 52 and 80 leaf MLC models: all leaves =1 cm width at isocenter. For the 120 leaf: 1st and last 10 pairs, leaves are 1 cm width at isocenter. Center 40 pairs are 0.5 cm width at isocenter. - Mark Model MLC has 52, 80 leaf, all leaves 1 cm width at isocenter. - HDMLC has 2.5 and 5 mm leaves. Top and bottom 7 cm are 0.5 cm leaves, center 8 cm is 0.25 cm leaves. Maximum length is 22 cm (Y).  Beamlet values can range from 0 – 1: - 0 – intensity – no dose will be delivered through this beamlet. - 1 – intensity –dose will be delivered through this beamlet. - A fluence pattern or intensity map, describes the pattern of changing intensity levels for a particular field.