IQM in Action at GenesisCare Spain – Shifting Paradigms in Treatment Verification

We are proud to present a remarkable study by Alberto Gómez Barrado and Alicia Sánchez Jiménez from GenesisCare La Milagrosa (Madrid), recently presented as a poster at SEFM 2025. Their work demonstrates the clinical value of the IQM System as an advanced dosimetric verification tool in radiotherapy.

This multicentre evaluation involved 18 linear accelerators, all equipped with IQM for both pre-treatment and online verification. The IQM System, a transmission chamber mounted directly on the treatment head, calculates a predicted dose-area product for each segment of the radiation field before treatment and compares it in real time to the measured signal during irradiation.

Implementation of a transmission chamber (IQM) as a dosimetric system for verifying radiotherapy treatments” (poster presented at SEFM 2025)

To validate IQM’s performance, the team performed a wide range of quality tests — including signal reproducibility, linearity, dose rate dependence, background reading, and transmission. IQM’s performance was then compared with conventional dosimetry systems, such as MobiusFX (Varian), ArcCheck and MapCheck (Sun Nuclear), and Octavius SRS (PTW Freiburg). The analysis covered 106 high-precision treatments in SRS and SBRT, chosen as representative of their clinical workload.

The results were impressive:

IQM delivered stable, reproducible, and highly linear measurements across all LINACs.
Comparisons with traditional systems showed excellent agreement, with all results within established tolerance limits (>95% gamma pass rate at 3%-1mm for SRS systems and 3%-2mm for ArcCheck).

Table from the SEFM Poster highlighting the IQM System’s signal reproducibility, MU linearity, dose rate dependence and background readings realized at the 18 GenesisCare linear accelerators examined in the study.

Most importantly, the study demonstrated that IQM integrates seamlessly into a busy clinical environment. It provides immediate verification without slowing down the workflow, making it ideal for high-volume centers that require both speed and accuracy for complex treatment techniques.

As Alberto Gómez Barrado and Alicia Sánchez Jiménez conclude, IQM is a reliable, easy-to-use, and time-efficient system that works equally well for standard and complex treatment techniques. For clinics aiming to enhance patient safety, optimize resources, and maintain rigorous quality assurance, IQM offers a truly innovative solution.

Congratulations to the GenesisCare Spain team for showcasing such a compelling example of how IQM is redefining treatment verification in radiotherapy practice.