Machine Learning Features from Proton Therapy Treatment Simulations with the Bergen DTC Prototype for Range Verification

Extracted features from the simulation data found at DOI: 10.5281/zenodo.8192778

Each simulation constitutes a single data sample. The following features were extracted.

Detector features:

Total number of active pixels

Total number of clusters (hits)

Number of clusters over threshold (5, 20 pixels)

Mean and standard deviation of cluster sizes

The number of clusters of any given size (1–72)

Mean and standard deviation of x- and y-coordinates over each layer (0–42), and the entire detector

Number of active pixels in each layer (0–42)

Number of clusters (hits) in each layer (0–42)

Total energy deposition of the hits in each layer (0–42)

Higher-level detector features, i.e., function fits (linear, cubic, exponential) with their mean squared residuals over the following quantities:

Active pixels over layer

Number of clusters over layer

Total deposited energy over layer

201 RSP features extracted from the beam spot, the phantom rotation, and its 3D RSP image.

Two datasets are included in two separate archive files:

features.tar.gz: 715-HN phantom by CIRS Inc. (Norfolk, VA, United States), digitized by Giacometti et al. (2017).

features-vhf.tar.gz: The Visible Human Female (VHF) Head phantom (Ackermann et al. 1995), courtesy of the U.S. National Library of Medicine, resampled to 1 mm voxels and scaled down to 80% size in the simulation.

After extracting features, some outliers were removed from the datasets: 14 samples for 715-HN and 3 samples for VHF. The rest of the samples were split into train (70%), validation (10%), and test (20%) sets, for both phantoms separately, which can be found in separate CSV files: features_train.csv, features_val.csv, features_test.csv (715-HN) and features-vhf_train.csv, features-vhf_val.csv, features-vhf_test.csv (VHF).

The last file (features_shifted_test.csv (715-HN) and features-vhf_shifted_test.csv (VHF)) contains 40 additional samples for each data point in the respective test set, representing a simulated lateral shift between 1 mm and 10 mm in 1 mm intervals in all directions along the x- and y-axis of the beam.