Addition of MRI for CT-based pancreatic tumor delineation: a feasibility study

Authors

  • Oliver J. Gurney-Champion Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands;  Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Eva Versteijne Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Astrid van der Horst Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Eelco Lens Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Heidi Rütten Department of Radiation Oncology, Radboud University Medical Center, Nijmegen, the Netherlands
  • Hanne D. Heerkens Department of Radiotherapy, University Medical Center Utrecht, Utrecht, the Netherlands
  • Gabriel M. R. M. Paardekooper Department of Radiotherapy, Isala Clinics Zwolle, Zwolle, the Netherlands
  • Maaike Berbee Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, the Netherlands
  • Coen R. N. Rasch Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Jaap Stoker Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Marc R. W. Engelbrecht Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Marcel van Herk Faculty of Biology, Medicine & Health, Division of Cancer Sciences, University of Manchester and Christie NHS Trust, Manchester, UK
  • Aart J. Nederveen Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Remy Klaassen Department of Medical Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Hanneke W. M. van Laarhoven Department of Medical Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Geertjan van Tienhoven Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
  • Arjan Bel Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands

DOI:

https://doi.org/10.1080/0284186X.2017.1304654

Abstract

Purpose: To assess the effect of additional magnetic resonance imaging (MRI) alongside the planning computed tomography (CT) scan on target volume delineation in pancreatic cancer patients.

Material and methods: Eight observers (radiation oncologists) from six institutions delineated the gross tumor volume (GTV) on 3DCT, and internal GTV (iGTV) on 4DCT of four pancreatic cancer patients, while MRI was available in a second window (CT + MRI). Variations in volume, generalized conformity index (CIgen), and overall observer variation, expressed as standard deviation (SD) of the distances between delineated surfaces, were analyzed. CIgen is a measure of overlap of the delineated iGTVs (1 = full overlap, 0 = no overlap). Results were compared with those from an earlier study that assessed the interobserver variation by the same observers on the same patients on CT without MRI (CT-only).

Results: The maximum ratios between delineated volumes within a patient were 6.1 and 22.4 for the GTV (3DCT) and iGTV (4DCT), respectively. The average (root-mean-square) overall observer variations were SD = 0.41 cm (GTV) and SD = 0.73 cm (iGTV). The mean CIgen was 0.36 for GTV and 0.37 for iGTV. When compared to the iGTV delineated on CT-only, the mean volumes of the iGTV on CT + MRI were significantly smaller (32%, Wilcoxon signed-rank, p < .0005). The median volumes of the iGTV on CT + MRI were included for 97% and 92% in the median volumes of the iGTV on CT. Furthermore, CT + MRI showed smaller overall observer variations (root-mean-square SD = 0.59 cm) in six out of eight delineated structures compared to CT-only (root-mean-square SD = 0.72 cm). However, large local observer variations remained close to biliary stents and pathological lymph nodes, indicating issues with instructions and instruction compliance.

Conclusions: The availability of MRI images during target delineation of pancreatic cancer on 3DCT and 4DCT resulted in smaller target volumes and reduced the interobserver variation in six out of eight delineated structures.

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Published

2017-07-03

How to Cite

Gurney-Champion, O. J., Versteijne, E., van der Horst, A., Lens, E., Rütten, H., Heerkens, H. D., … Bel, A. (2017). Addition of MRI for CT-based pancreatic tumor delineation: a feasibility study. Acta Oncologica, 56(7), 923–930. https://doi.org/10.1080/0284186X.2017.1304654

Issue

Vol. 56 No. 7 (2017): Acta Oncologica

Section

Articles