Oops, you're using an old version of your browser so some of the features on this page may not be displaying properly.

MINIMAL Requirements: Google Chrome 24+Mozilla Firefox 20+Internet Explorer 11Opera 15–18Apple Safari 7SeaMonkey 2.15-2.23

Poster display session

1413 - Early response evaluation by 18F-FDG-PET influences management in gastrointestinal stromal tumor patients treated with neo-adjuvant intent


11 Sep 2017


Poster display session


Staging Procedures (not Imaging);  GIST


Sheima Farag


Annals of Oncology (2017) 28 (suppl_5): v521-v538. 10.1093/annonc/mdx387


S. Farag1, L. de Geus-Oei2, W.T.A. van der Graaf3, F. Van Coevorden4, D.J. Grunhagen5, A. Reyners6, P. Boonstra6, I. Desar7, H. Gelderblom8, N. Steeghs1

Author affiliations

  • 1 Medical Oncology, The Netherlands Cancer Institute Antoni van Leeuwenhoek Hospital, 1066 CX - Amsterdam/NL
  • 2 Department Of Radiology, Leiden University Medical Center (LUMC), Leiden/NL
  • 3 Sarcoma Unit, The Institute of Cancer Research and the Royal Marsden Hospital , Sutton/GB
  • 4 Surgical Oncology, The Netherlands Cancer Institute Antoni van Leeuwenhoek Hospital, 1066 CX - Amsterdam/NL
  • 5 Surgical Oncology, Erasmus MC - Cancer Institute, 3015 CE - Rotterdam/NL
  • 6 Medical Oncology, University Hospital Groningen (UMCG), 9700 RB - Groningen/NL
  • 7 Medical Oncology, Radboud University Medical Centre Nijmegen, 6500 HB - Nijmegen/NL
  • 8 Medical Oncology, Leiden University Medical Center (LUMC), Leiden/NL


Abstract 1413


Early response evaluation by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is effective in gastrointestinal stromal tumors (GISTs) treated with imatinib and recommended in GISTs treated with neo-adjuvant intent. Yet, it is unclear whether this effects treatment decisions.


All patients in the Dutch GIST Registry treated with imatinib with neo-adjuvant intent were identified. Only FDG-PETs made within 8 weeks after initiation or change (in dose or switch) of imatinib were included. Responses were derived from radiological reports and defined in 3 categories: 1) complete response; 2) partial response; 3) no response. Change in management was defined as a difference between pre-PET and post-PET treatment plans. Four categories were defined: change in 1) surgical management; 2) systemic treatment; 3) treatment objective (from curative to palliative); 4) management regarding a second tumor.


Seventy FDG-PETs for early response evaluation in 63 patients treated with neo-adjuvant intent were identified. Forty-one patients (65.1%) had a KIT exon 11 and 22 (34.9%) had a non-KIT exon 11 mutation (15 other and 7 unknown mutations). Of the 70 scans 64 (87.1%) had a baseline, 50 (71.5%) showed metabolic response (partial and complete), and 18 (25.7%) led to change in management. Change in management was strongly correlated with a lack of response (p 


In contrast to GIST patients harboring a KIT exon 11 mutation, in non-KIT exon 11 mutated GISTs treated with neoadjuvant intent early response evaluation by FDG-PET often leads to change in management.

Clinical trial identification

Legal entity responsible for the study

Neeltje Steeghs


Novartis, Pfizer and Bayer


N. Steeghs: Research grant for the Dutch GIST Registry from Novartis, Pfizer and Bayer. All other authors have declared no conflicts of interest.

This site uses cookies. Some of these cookies are essential, while others help us improve your experience by providing insights into how the site is being used.

For more detailed information on the cookies we use, please check our Privacy Policy.

Customise settings
  • Necessary cookies enable core functionality. The website cannot function properly without these cookies, and you can only disable them by changing your browser preferences.