Journal Article DKFZ-2026-01444

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png
Transformer-based cardiac substructure segmentation from contrast and non-contrast computed tomography for radiotherapy planning.

 ;  ;  ;  ;  ;  ;  ;

2026
Elsevier Science Amsterdam [u. a.]

Physics & Imaging in Radiation Oncology 39, 101011 () [10.1016/j.phro.2026.101011]
 GO

Abstract: Accurate segmentation of cardiac substructures on computed tomography (CT) scans is essential for radiotherapy planning. This study evaluated whether pretrained transformers enabled data-efficient training using a fixed architecture with balanced curriculum learning while achieving robust generalization to imaging and patient variations.A hybrid pretrained transformer-convolutional network, self-distilled masked image transformer (SMIT), was fine-tuned using lung cancer patient scans (Cohort I, training N = 180) and tested on held-out Cohort I lung cancer scans (testing N = 60) and breast cancer scans (Cohort II, N = 65). Two configurations were evaluated: SMIT-Balanced (32 contrast-enhanced CTs, 32 non-contrast CTs) and SMIT-Oracle (180 CTs). Performance was compared with nnU-Net and TotalSegmentator. Segmentation accuracy was assessed primarily using the 95th percentile Hausdorff distance (HD95), along with radiation dose and overlap-based metrics as secondary endpoints.SMIT-Balanced approached SMIT-Oracle performance despite using 64% fewer training scans, with mean HD95 of 6.6 versus 5.4 mm in Cohort I and 10.0 versus 9.4 mm in Cohort II. On the Cohort I held-out test set, SMIT-Balanced mean HD95 was within 1.0 mm of nnU-Net. Cross-cohort testing showed larger accuracy degradation with nnU-Net than SMIT-Balanced (62% versus 50%, absolute change 4.5 mm versus 3.4 mm). Dose metrics derived from SMIT-Balanced were equivalent to manual delineations.Balanced curriculum training reduced labeled data requirements within the SMIT architecture. SMIT-Balanced was comparable to nnU-Net on Cohort I held-out data and showed smaller cross-cohort HD95 degradation.

Keyword(s): Cardiac substructures ; Computed tomography ; Deep learning ; Heart chambers ; Radiotherapy ; Segmentation

Classification:

Contributing Institute(s):
  1. DKTK Koordinierungsstelle Freiburg (FR01)
Research Program(s):
  1. 899 - ohne Topic (POF4-899) (POF4-899)

Appears in the scientific report 2026
Database coverage:
Medline ; DOAJ ; Article Processing Charges ; Clarivate Analytics Master Journal List ; DOAJ Seal ; Emerging Sources Citation Index ; Fees ; IF < 5 ; JCR ; PubMed Central ; SCOPUS ; Web of Science Core Collection
Click to display QR Code for this record

The record appears in these collections:
Document types > Articles > Journal Article
Public records
Publications database

 Record created 2026-06-16, last modified 2026-06-17


Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)