Can FAPI PET Enhance Pre-Op Evaluation of Peritoneal Carcinomatosis?

Emerging research suggests that (⁶⁸Ga)Ga-FAPI-46 PET/CT may provide improved pre-operative assessment of patients with peritoneal carcinomatosis.

For the study, recently presented at the SNMMI conference, researchers compared (⁶⁸Ga)Ga-FAPI-46 PET/CT to MRI and (¹⁸F)FDG PET/CT for preoperative evaluation of 61 patients with peritoneal carcinomatosis.

The study authors found that (⁶⁸Ga)Ga-FAPI-46 PET/CT demonstrated an 81 percent interclass correlation coefficient (ICC) with the intraoperative peritoneal cancer index (PCI) in comparison to 76 percent for MRI and 54 percent for (¹⁸F)FDG PET/CT.

Additionally, in a sub-analysis of patients who had chemotherapy in the previous three months, the researchers noted a 75 percent ICC for (⁶⁸Ga)Ga-FAPI-46 PET/CT in contrast to 65 percent for MRI and 46 percent for (¹⁸F)FDG PET/CT.

“(⁶⁸Ga)Ga-FAPI-46 PET/CT demonstrated the strongest agreement with surgico-pathological PCI and maintained good agreement after recent chemotherapy,” noted lead study author Ayca Arcay Ozturk, MD, a doctoral research fellow at Institut Jules Bordet in Brussels, Belgium, and colleagues.

(Editor’s note: For additional coverage from the SNMMI conference, click here.)

The researchers noted that (⁶⁸Ga)Ga-FAPI-46 PET/CT demonstrated the highest segment-level sensitivity (77.6 percent) in comparison to MRI (67 percent) and (¹⁸F)FDG PET/CT (47.5 percent), but also had the lowest segment-level specificity (71.2 percent vs. 84.4 percent for MRI and 91.8 percent for (¹⁸F)FDG PET/CT).

The study authors added that (⁶⁸Ga)Ga-FAPI-46 PET/CT offered a significantly higher SUVmax (13 vs. 6.15) and total lesion uptake (193.05 vs. 29.40) than (¹⁸F)FDG PET/CT.

“((⁶⁸Ga)Ga-FAPI-46 PET/CT showed higher detectability than MRI and (¹⁸F)FDG PET/CT, albeit at the expense of lower specificity. These findings support (⁶⁸Ga)Ga-FAPI-46 PET/CT as a promising modality for preoperative PC mapping,” maintained Ozturk and colleagues.

(Editor’s note: For related content, see “Image IQ Quiz: 56-Year-Old Man with Weight Loss and Gradual Abdominal Distention,” “New Meta-Analysis Assesses Impact of 68Ga-FAPI PET CT/MRI for Ovarian Cancer” and “MRI-Based Deep Learning for Lymph Node Metastasis Detection in Colorectal Cancer: What a New Meta-Analysis Reveals.”)

Reference

1. Ozturk AA, Deleu AL, Poenaru R, et al. Preoperative assessment of peritoneal carcinomatosis with (68Ga)Ga-FAPI-46 PET/CT. Presented at the Society of Nuclear Medicine and Molecular Imaging (SNMMI), May 30-June 2, 2026, Los Angeles. Available at: https://jnm.snmjournals.org/content/67/supplement_1/261990 .