Radiochromic Film Dosimetry in Radiation Therapy

Radiochromic film dosimetry has emerged as a cornerstone technique for verifying and mapping radiation dose distributions in modern radiotherapy. These self-developing films undergo a colour change upon exposure to ionising radiation, enabling high-resolution, two-dimensional dose measurements without the need for chemical processing. Their near tissue-equivalence, minimal energy dependence in the megavoltage range and ease of handling make them particularly well suited for the quality assurance of complex treatments such as intensity-modulated radiotherapy (IMRT), volumetric-modulated arc therapy (VMAT) and stereotactic radiosurgery. Critical considerations in routine use include film calibration, scanner uniformity corrections, post-irradiation colour growth and the mitigation of artefacts due to film curvature or lateral scanner response. Recent advances have focused on extending dynamic dose ranges, refining real-time read-out methodologies and integrating portable optical readers for on-site measurements. Collectively, these developments enhance the precision of patient-specific quality assurance, support the commissioning of high-dose techniques and underpin the safe delivery of conformal and high-precision treatments worldwide.

Research from Nature Portfolio

Recent studies have demonstrated significant strides in portable and real-time radiochromic film analysis. One investigation evaluated combinations of widely used films with compact colourimeters, identifying device configurations that yield reliable dose readings under various irradiation conditions and angular orientations. This work expands the practical scope of on-site dosimetry for both low- and high-dose scenarios. Another report introduced an opto-electronic probe system capable of monitoring film darkening in real time, thereby extending the dynamic range of standard films and enabling immediate feedback during irradiation. This innovation promises to streamline workflow and reduce uncertainties associated with post-exposure scanning delays.

Radiochromic Film Dosimetry in Radiation Therapy publication trend

The graph below shows the total number of articles in radiochromic film dosimetry in radiation therapy across all publications each year (not limited to Nature Index journals).

Technical terms

Radiochromic film: A radiation-sensitive film that darkens upon exposure, providing a spatial map of absorbed dose.

Net optical density (netOD): The logarithmic measure of film darkening change used to quantify absorbed dose.

Intensity-modulated radiotherapy (IMRT): An advanced technique that delivers non-uniform beam intensities to conform dose to target volumes.

Gamma analysis: A comparative metric combining dose difference and spatial distance criteria to assess agreement between measured and planned dose distributions.

Lateral response artefact: A non-uniform scanner sensitivity across the scan width that can distort film-measured dose profiles.

References

1. Energy Dependence of the New Gafchromic EBT3 Film:Dose Response Curves for 50 KV, 6 and 15 MV X-Ray Beams. International Journal of Medical Physics Clinical Engineering and Radiation Oncology (2012).
2. Evaluation and mitigation of potential errors in radiochromic film dosimetry due to film curvature at scanning. Journal of Applied Clinical Medical Physics (2015).
3. Correcting lateral response artifacts from flatbed scanners for radiochromic film dosimetry. Medical Physics (2015).
4. Evaluation of the uncertainty in an EBT3 film dosimetry system utilizing net optical density. Journal of Applied Clinical Medical Physics (2016).
5. Dosimetric characterization and use of GAFCHROMIC EBT3 film for IMRT dose verification. Journal of Applied Clinical Medical Physics (2013).
6. Comparative study on measurements of radiochromic films using portable colorimeters. Scientific Reports (2024).
7. Real-time dosimetry with radiochromic films. Scientific Reports (2019).