Related Experiment Video
Updated: Jul 14, 2026
06:43
Robotic Duodenal Sleeve Resection for Gastrointestinal Stromal Tumor with Rare Exon 8 KIT Mutation Following Neoadjuvant Imatinib
Published on: April 3, 2026
Radiographic Versus Pathology-Integrated Response for Assessing Optimal Surgical Timing After Neoadjuvant Imatinib in
Tannaz Ranjbarian1,2, Michela Del Simone3, Dong-Jin Eastern Kang Sim1,2
1Department of Surgery, Division of Surgical Oncology, University of California San Diego, San Diego, CA.
Annals of Surgery
|July 13, 2026
Summary
Radiographic and pathology-integrated response metrics in gastrointestinal stromal tumor (GIST) treatment show different optimal timing. Pathology-integrated response may better reflect biologic effects than size reduction alone.
Area of Science:
- Oncology
- Medical Imaging
- Pathology
Background:
- Neoadjuvant imatinib is used for gastrointestinal stromal tumor (GIST) treatment.
- Operative timing is typically based on radiographic tumor shrinkage.
- Radiographic response may not fully represent the biologic treatment effect.
Purpose of the Study:
- To compare radiographic and pathology-integrated metrics for defining maximal treatment effect.
- To assess neoadjuvant imatinib efficacy in KIT exon 11-mutant GIST.
- To determine optimal timing for surgical intervention.
Main Methods:
- Retrospective analysis of 131 patients with locally advanced KIT exon 11-mutant GIST.
- Radiographic response assessed by RECIST and tumor shrinkage.
- Pathology-integrated response score (PIRS) derived from shrinkage, viable tumor, and necrosis.
Main Results:
- Radiographic response peaked earlier (4-6 months) than PIRS (10-12 months).
- PIRS better discriminated response duration than RECIST.
- 30.5% of patients with stable disease by RECIST showed major or near-complete PIRS.
Conclusions:
- Radiographic and pathology-integrated metrics identify different windows of maximal treatment effect.
- Tumor size reduction may underestimate biologic response in GIST.
- Later PIRS window did not correlate with recurrence-free survival differences.
