The use of IMRT in Germany

Intensity modulated radiotherapy (IMRT) is frequently used, but there are no data about current frequency regarding specific tumor sites and equipment used for quality assurance (QA).

An online survey about IMRT was executed from April to October 2014 by the collaborative IMRT working group (AK IMRT) of the German Association of Medical Physicists (DGMP).

A total of 23 German institutions took part in the survey. Most reports came from users working with Elekta, Varian, and Siemens treatment machines, but also from TomoTherapy and BrainLab. Most frequent IMRT technology was volumetric modulated arc therapy (58.37 %: VMAT/“rapid arc”), followed by step-and-shoot IMRT (14.66 %), dynamic MLC (dMLC: 14.53 %), TomoTherapy (9.25 %), and 3.2 % other techniques. Different commercial hard- and software solutions are available for QA, whereas many institutes still develop their own phantoms. Data of 26,779 patients were included in the survey; 44 % were treated using IMRT techniques. IMRT was most frequently used for anal cancer, (whole) craniospinal irradiation, head and neck cancer, prostate cancer, other tumors in the pelvic region, gynecological tumors (except for breast cancer), and brain tumors.

An estimated 10 % of all patients treated in 2014 with radiation in Germany were included in the survey. It is representative for the members of the AK IMRT.

IMRT may be on the way to replace other treatment techniques. However, many scientific questions are still open. In particular, it is unclear when the IMRT technique should not be used.