Lacrimal gland Ga-68 PSMA-11 PET/CT radiomic profile: a potential novel imaging biomarker in dry eye disease.

[PURPOSE] This study aimed to investigate the relationship between texture analysis parameters of lacrimal gland activity and dry eye disease (DED) in participants undergoing Gallium-68 labelled Prostate-Specific Membrane Antigen ligand Positron Emission Tomography / Computed Tomography ([68 Ga]Ga-PSMA-11 PET/CT) imaging for prostate cancer (PCa).

[METHODS] A prospective cohort of 56 male patients who underwent [68 Ga]Ga-PSMA-11 PET/CT for PCa at the Department of Nuclear Medicine, Kayseri City Hospital (October 2024-June 2025) were included. Lacrimal gland regions of interest were delineated using LIFEx software with a 40 % maximum standard uptake value (SUVmax) threshold. Texture features (morphological, intensity-based, intensity-histogram) were extracted. An ophthalmological evaluation focused on dry-eye parameters was conducted, which included the Ocular Surface Disease Index (OSDI) scoring, in addition to Schirmer and tear break-up time (TBUT) test. Statistical analyses included Spearman correlation, univariate binary logistic regression, and ROC analysis; p < 0.05 was considered significant.

[RESULTS] Thirty-two participants (57 %) met the criteria for DED. Several intensity-based and histogram parameters were significantly lower in DED participants. SUVmax (cut-off 7.65) demonstrated limited but statistically significant diagnostic potential (AUC = 0.669, p = 0.031; sensitivity 75 %, specificity 50 %). Higher intensity measures correlated with higher TBUT and Schirmer scores and lower OSDI scores.

[CONCLUSIONS] Texture analysis of lacrimal gland activity on [68 Ga]Ga-PSMA-11 PET/CT provides potential, non-invasive quantitative biomarkers for DED. Intensity-based metrics (SUVmean, SUVmax) may reflect functional impairment of the lacrimal gland. Further multicenter validation is warranted.