Advanced Physics for Brachytherapy 2018

3D dosimeters

Advantages

Dosimeter is the phantom (negligible to small p phant depending on type) facilitates concurrent measurements and processing for minimizing positional and type A uncertainty 3D character

•

•

f rel

negligible to small

•

(depending on type)

No dose rate dependence (except for methacrylic acid based gels-MAGIC & PRESAGE at very low dose rates)

•

Disadvantages

• Sensitivity varies with type and batch • k rel bq

can be significant for some dosimeters @

low E

• 3D character augments influences and problems similar to that of films increasing type B uncertainty

Figure from: Rogers & Cygler (Eds), Clinical dosimetry measurements in radiotherapy (2009 AAPM Summer School), Monograph No. 34, Medical Physics Publishing 2011