Sub‐second photon dose prediction via transformer neural networks

Background Fast dose calculation is critical for online and real‐time adaptive therapy workflows. While modern physics‐based dose algorithms must compromise accuracy to achieve low computation times, deep learning models can potentially perform dose prediction tasks with both high fidelity and speed...

Full description

Saved in:
Bibliographic Details
Published in:Medical physics (Lancaster) 2023-05, Vol.50 (5), p.3159-3171
Main Authors: Pastor‐Serrano, Oscar, Dong, Peng, Huang, Charles, Xing, Lei, Perkó, Zoltán
Format: Article
Language:English
Subjects:
Algorithms
deep learning
dose calculation
Humans
Male
Neural Networks, Computer
Prostate
Radiotherapy Dosage
Radiotherapy Planning, Computer-Assisted - methods
Radiotherapy, Intensity-Modulated - methods
transformer
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Background Fast dose calculation is critical for online and real‐time adaptive therapy workflows. While modern physics‐based dose algorithms must compromise accuracy to achieve low computation times, deep learning models can potentially perform dose prediction tasks with both high fidelity and speed. Purpose We present a deep learning algorithm that, exploiting synergies between transformer and convolutional layers, accurately predicts broad photon beam dose distributions in few milliseconds. Methods The proposed improved Dose Transformer Algorithm (iDoTA) maps arbitrary patient geometries and beam information (in the form of a 3D projected shape resulting from a simple ray tracing calculation) to their corresponding 3D dose distribution. Treating the 3D CT input and dose output volumes as a sequence of 2D slices along the direction of the photon beam, iDoTA solves the dose prediction task as sequence modeling. The proposed model combines a Transformer backbone routing long‐range information between all elements in the sequence, with a series of 3D convolutions extracting local features of the data. We train iDoTA on a dataset of 1700 beam dose distributions, using 11 clinical volumetric modulated arc therapy (VMAT) plans (from prostate, lung, and head and neck cancer patients with 194–354 beams per plan) to assess its accuracy and speed. Results iDoTA predicts individual photon beams in ≈50 ms with a high gamma pass rate of 97.72±1.93%$97.72\pm 1.93\%$ (2 mm, 2%). Furthermore, estimating full VMAT dose distributions in 6–12 s, iDoTA achieves state‐of‐the‐art performance with a 99.51±0.66%$99.51\pm 0.66\%$ (2 mm, 2%) pass rate and an average relative dose error of 0.75 ± 0.36%. Conclusions Offering the millisecond speed prediction per beam angle needed in online and real‐time adaptive treatments, iDoTA represents a new state of the art in data‐driven photon dose calculation. The proposed model can massively speed‐up current photon workflows, reducing calculation times from few minutes to just a few seconds.
ISSN:0094-2405
2473-4209
DOI:10.1002/mp.16231