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If a given material has a 0.18 cm-1 linear attenuation coefficient for a 3 MeV monoenergetic gamma source. What is the half-value layer thickness for this material?

A patient being treated for a large hilar region, which includes the draining lymph nodes and an area of predicted spread, will have a 3-D non-IMRT AP treatment portal with a 45-degree toe in wedge to accommodate for the rapid fall off in the superior region of the treatment portal. The wedge transmission factor 0.87.  The AP treatment portal will measure 10.7 cm x 11.2 cm. In addition, an off-cord LAO with a 30-degree toe in wedge with a transmission factor of 0.89 is prescribed. The treatment portal measures 12.7 cm x 10.8 cm. To accommodate for the correct output for these treatment portals, what are the equivalent squares for the AP portal? 

The RBE for proton beams is

EXTRA CREDIT FROM STANTON AND STINSON HOMEWORK: A patient is treated with an oblique field of 10 degrees using a gantry angle of 190 degrees. In order to take an orthogonal image, what will the gantry angle be? (There are to possible angles, only answer using one angle).  _______ .

The Parker-Patterson system establishes a set of guidelines that, that if followed, will provide a dose of ___________ within the implanted area.

If the output measured for an open beam treatment portal is measured at 850 cGy/minute, what would be the output of the beam if a 45-degree hard wedge with an attenuation factor of 1.089 is added to the treatment portal?

EXTRA CREDIT FROM THE STANTON AND STINSON HOMEWORK: If a patient is treated with a four-field box for a daily fractional dose of 180 cGy. What is the dose delivered through the AP/PA if each field is weighted 1:1:1.2:1.2 for the AP, PA, right lateral, left lateral respectively? _______ .

Dynamic step and shoot refers to a method of radiation delivery where

The parameter/s that is least likely to effect a single-beam isodose distribution is the:            

Which of the following most significantly effects brachytherapy dose distributions?