Recording the frequency of radiotherapy in Germany

Radiotherapy (teletherapy) Source: Mark Kostich via Getty Images

Background

In accordance with section 125(3) of the Radiation Protection Ordinance (StrlSchV), the BfS determines the medical radiation exposure (frequency and dose) of the population and selected population groups at least every two years. This official task focuses on recording diagnostic radiation applications. However, no detailed information was available regarding therapeutic radiation applications prior to completion of the research project.

All of the data obtained is used in reporting to parliament and to the United Nations (report of the United Nations Committee on the Effects of Atomic Radiation). It serves as the basis for decision-making regarding medical measures to protect patients from radiation.

Objective

Representative data was to be collected on the frequency of radiotherapy treatments and the associated imaging measures in both inpatient and outpatient settings – stratified according to the following questions:

• determination of indication and treatments intended to be palliative or curative
• age and gender
• therapeutic procedures (teletherapy/brachytherapy), irradiation modalities (X-ray/gamma/electron radiation) and techniques (conventional/3D-conformal/intensity-modulated/stereotactic radiotherapy, interstitial brachytherapy)
• • radiotherapy planning: type and scope of imaging techniques.

Methods and implementation

The project centred around data for the year 2016, processed in accordance with the fee structures (Uniform Assessment Standard (EBM) for health insurance scheme patients; Fee Schedule for Doctors (GOÄ) for private patients) and coding system for full inpatient treatment (Operation and Procedure Keys (OPS)). In the first step (a feasibility analysis), the data materials were contrasted and consolidated in a mapping table, leading to the identification of gaps in the billing data. An accompanying survey was conducted to close these gaps. In the second step, all of the collected data was processed and amalgamated.

Datasets were made available to the research contractor by the following institutions:

• the National Association of Statutory Health Insurance Physicians (KBV): data relating to the Uniform Assessment Standard (EBM)
• the Federal Association of Health Clearinghouses (BVVG) and the Association of German Private Healthcare Insurers (PKV): data relating to the Fee Schedule for Doctors (GOÄ)
• the Federal Statistical Office incl. the Research Data Centre: data relating to the Operation and Procedure Keys (OPS).

Results

Following extensive inspection at the time of receipt, as well as test evaluations, the structure and quality of the datasets proved to be highly varied:

• EBM data: anonymised individual datasets of patients or treatment cases from the years 2015 to 2017, which allowed chronological differentiation of one or more radiotherapy treatments
• GOÄ data: processed and anonymised patient datasets from the years 2016 to 2019 with no possibility of chronological differentiation
• OPS data: anonymised datasets relating to hospital stays in the years 2014 to 2016, which did not turn out to be closed treatment cycles.

The data relating to the EBM and OPS was obtained in exhaustive surveys, whereas the data for the GOÄ came from random samples representing the area of activity of the BVVG. The overall data material, which is made up of data material from the individual data owners, was therefore highly heterogeneous in terms of its structural availability and processing, resulting in an unavoidable lack of clarity in the case of consolidation.

Furthermore, an accompanying survey was carried out by the research contractor, providing additional data for 2018. This data was also analysed in terms of its informative value and was included in the overall consideration at the points where gaps needed to be closed. The fact that the survey related to 2018 but the secondary material to 2016 can also be attributed to the lack of clarity that is caused by the methodology.

The total number of radiotherapy treatments in Germany in 2016, as the main reference year of the project, was ultimately determined to be around 470,000. Here, a “radiotherapy treatment” is understood to mean a completed cycle of radiotherapy regardless of the choice of procedure, the number of affected regions of the body, or the irradiated target volume.