Magnetic resonance imaging (MRI) compared with computed tomography (CT) for interobserver agreement of gross tumor volume delineation in pancreatic cancer: a multi-institutional contouring study on behalf of the AIRO group for gastrointestinal cancers

Luciana Caravatta, Francesco Cellini, Nicola Simoni, Consuelo Rosa, Rita Marina Niespolo, Marco Lupattelli, Vincenzo Picardi, Gabriella Macchia, Aldo Sainato, Giovanna Mantello, Francesco Dionisi, Maria Elena Rosetto, Vincenzo Fusco, Federico Navarria, Antonino De Paoli, Alessandra Guido, Claudio Vecchi, Raffaella Basilico, Roberta Cianci, Andrea Delli PizziMarta Di Nicola, Gian Carlo Mattiucci, Vincenzo Valentini, Alessio Giuseppe Morganti, Domenico Genovesi

Research output: Contribution to journalArticle

Abstract

BACKGROUND: Due to the high soft tissue resolution, magnetic resonance imaging (MRI) could improve the accuracy of pancreatic tumor delineation in radiation treatment planning. A multi-institutional study was proposed to evaluate the impact of MRI on inter-observer agreement in gross tumor volume (GTV) and duodenum delineation for pancreatic cancer compared with computer tomography (CT).

MATERIAL AND METHODS: Two clinical cases of borderline resectable (Case 1) and unresectable (Case 2) pancreatic cancer were selected. In two sequential steps, diagnostic contrast-enhanced CT scan and MRI sequences were sent to the participating centers. CT-GTVs were contoured while blinded to MRI data sets. DICE index was used to evaluate the spatial overlap accuracy.

RESULTS: Thirty-one radiation oncologists from different Institutions submitted the delineated volumes. CT- and MRI-GTV mean volumes were 21.6 ± 9.0 cm3 and 17.2 ± 6.0 cm3, respectively for Case 1, and 31.3 ± 15.6 cm3 and 33.2 ± 20.2 cm3, respectively for Case 2. Resulting MRI-GTV mean volume was significantly smaller than CT-GTV in the borderline resectable case (p < .05). A substantial agreement was shown by the median DICE index for CT- and MRI-GTV resulting as 0.74 (IQR: 0.67-0.75) and 0.61 (IQR: 0.57-0.67) for Case 1; a moderate agreement was instead reported for Case 2: 0.59 (IQR:0.52-0.66) and 0.53 (IQR:0.42-0.62) for CT- and MRI-GTV, respectively.

CONCLUSION: Diagnostic MRI resulted in smaller GTV in borderline resectable case with a substantial agreement between observers, and was comparable to CT scan in interobserver variability, in both cases. The greater variability in the unresectable case underlines the critical issues related to the outlining when vascular structures are more involved. The integration of MRI with contrast-enhancement CT, thanks to its high definition of tumor relationship with neighboring vessels, could offer a greater accuracy of target delineation.

Original languageEnglish
Pages (from-to)439-447
Number of pages9
JournalActa Oncologica
Volume58
Issue number4
DOIs
Publication statusPublished - Apr 2019

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Keywords

  • Aged
  • Female
  • Follow-Up Studies
  • Gastrointestinal Neoplasms/diagnostic imaging
  • Humans
  • Magnetic Resonance Imaging/methods
  • Male
  • Observer Variation
  • Pancreatic Neoplasms/diagnostic imaging
  • Prognosis
  • Radiotherapy Planning, Computer-Assisted
  • Retrospective Studies
  • Tomography, X-Ray Computed/methods
  • Tumor Burden

Cite this

Caravatta, L., Cellini, F., Simoni, N., Rosa, C., Niespolo, R. M., Lupattelli, M., Picardi, V., Macchia, G., Sainato, A., Mantello, G., Dionisi, F., Rosetto, M. E., Fusco, V., Navarria, F., De Paoli, A., Guido, A., Vecchi, C., Basilico, R., Cianci, R., ... Genovesi, D. (2019). Magnetic resonance imaging (MRI) compared with computed tomography (CT) for interobserver agreement of gross tumor volume delineation in pancreatic cancer: a multi-institutional contouring study on behalf of the AIRO group for gastrointestinal cancers. Acta Oncologica, 58(4), 439-447. https://doi.org/10.1080/0284186X.2018.1546899