Purpose: <p>To evaluate whether [<sup>68</sup>Ga]Ga-FAPI-46 PET/CT (FAPI PET) is sensitive to neoadjuvant chemotherapy (NAC)-associated changes in peritoneal carcinomatosis (PC) and whether post-NAC FAPI PET parameters and pre-/post-NAC changes are associated with histopathologic and biochemical response.</p> Methods: <p>This exploratory translational sub-cohort analysis was conducted within the prospective phase II FAPeCa trial (NCT06061874) recruiting patients with colorectal or ovarian cancer with known/suspected PC. Patients who received recent chemotherapy were included in the current analysis. PET parameters, including SUVmax, peritoneal tumour volume (PTV), and total lesion uptake (TLF/TLG) were analysed both on FAPI and [<sup>18</sup>F]-FDG PET/CT. Associations with pathological chemotherapy response score (pCRS) and CA-125 change were explored. Pre- and post-NAC paired FAPI PET and FAP immunohistochemical (IHC) analyses were performed. Segment-level correlation between IHC score and FAPI PET uptake was assessed.</p> Results: <p>Twenty-seven patients were included, predominantly with ovarian cancer (26/27), including 10 with paired pre-/post-NAC imaging. All paired FAPI PET parameters declined significantly after NAC. The magnitude of change in paired FAPI PET parameters correlated strongly with pCRS, particularly for SUVmax (ρ=0.866, p=0.005), PTV(2.5) (ρ=0.830, p=0.011), and TLF(2.5) (ρ=0.830, p=0.011), whereas FDG PET parameters and FAPI PTV(40) and TLF(40) showed no significant correlation with pCRS. Changes in FAPI PET parameters also correlated with the CA-125 change. Across the post-NAC cohort, FAPI PET volumetric parameters differed significantly across pCRS categories. Paired IHC demonstrated a significant reduction in FAP expression after NAC, and segment-level FAP IHC score showed a significant moderate correlation with FAPI uptake (SUVmax ρ=0.467, p=0.012; SUVmean ρ=0.554, p=0.005).</p> Conclusions: <p>[<sup>68</sup>Ga]Ga-FAPI-46 PET/CT demonstrated treatment sensitivity after NAC in PC, with concordant reductions in PET parameters and stromal FAP expression. FAPI PET volumetric parameters were associated with histopathologic response and CA-125 change in this exploratory sub-cohort, supporting further investigation of FAPI PET as an imaging biomarker for response assessment in PC.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Effect of neoadjuvant chemotherapy on [68Ga]Ga-FAPI-46 PET/CT in peritoneal carcinomatosis: a prospective translational exploratory sub-cohort analysis

  • Ayça Arçay Öztürk,
  • Gabriel Liberale,
  • Jean Christophe Noël,
  • Wendy Delbart,
  • Anne-Leen Deleu,
  • Erwin Woff,
  • Raluca Poenaru,
  • Laura Polastro,
  • Laurent Theunissen,
  • Paulus Kristanto,
  • Sigrid Vercauteren,
  • Clementine Marin,
  • Loubna Taraji,
  • Patrick Flamen

摘要

Purpose:

To evaluate whether [68Ga]Ga-FAPI-46 PET/CT (FAPI PET) is sensitive to neoadjuvant chemotherapy (NAC)-associated changes in peritoneal carcinomatosis (PC) and whether post-NAC FAPI PET parameters and pre-/post-NAC changes are associated with histopathologic and biochemical response.

Methods:

This exploratory translational sub-cohort analysis was conducted within the prospective phase II FAPeCa trial (NCT06061874) recruiting patients with colorectal or ovarian cancer with known/suspected PC. Patients who received recent chemotherapy were included in the current analysis. PET parameters, including SUVmax, peritoneal tumour volume (PTV), and total lesion uptake (TLF/TLG) were analysed both on FAPI and [18F]-FDG PET/CT. Associations with pathological chemotherapy response score (pCRS) and CA-125 change were explored. Pre- and post-NAC paired FAPI PET and FAP immunohistochemical (IHC) analyses were performed. Segment-level correlation between IHC score and FAPI PET uptake was assessed.

Results:

Twenty-seven patients were included, predominantly with ovarian cancer (26/27), including 10 with paired pre-/post-NAC imaging. All paired FAPI PET parameters declined significantly after NAC. The magnitude of change in paired FAPI PET parameters correlated strongly with pCRS, particularly for SUVmax (ρ=0.866, p=0.005), PTV(2.5) (ρ=0.830, p=0.011), and TLF(2.5) (ρ=0.830, p=0.011), whereas FDG PET parameters and FAPI PTV(40) and TLF(40) showed no significant correlation with pCRS. Changes in FAPI PET parameters also correlated with the CA-125 change. Across the post-NAC cohort, FAPI PET volumetric parameters differed significantly across pCRS categories. Paired IHC demonstrated a significant reduction in FAP expression after NAC, and segment-level FAP IHC score showed a significant moderate correlation with FAPI uptake (SUVmax ρ=0.467, p=0.012; SUVmean ρ=0.554, p=0.005).

Conclusions:

[68Ga]Ga-FAPI-46 PET/CT demonstrated treatment sensitivity after NAC in PC, with concordant reductions in PET parameters and stromal FAP expression. FAPI PET volumetric parameters were associated with histopathologic response and CA-125 change in this exploratory sub-cohort, supporting further investigation of FAPI PET as an imaging biomarker for response assessment in PC.