Pilot Study Examining the Use of DCE MRI With Pharmacokinetic Analysis to Evaluate Hypoxia in Prostate Cancer.

Purpose: This study aimed to investigate the association between tumor hypoxia, assessed through anti-HIF (hypoxia-inducible factor) staining, and aggressiveness in prostate cancer using a pharmacokinetic model, particularly those derived from the Tofts model, in predicting tumor aggressiveness.

Material and methods: From January 2019 to April 2021, we conducted a retrospective search of patients with confirmed prostate cancer and a previous magnetic resonance imaging (MRI) examination. After exclusions, a total of 57 consecutive patients were enrolled. Patient data, including demographic, laboratory, and pathologic variables, were collected. MRI acquisition followed PI-RADS guidelines, encompassing T2-weighted, diffusion-weighted imaging, and dynamic contrast-enhanced imaging. An experienced abdominal radiologist conducted both morphologic and quantitative MRI analyses, evaluating parameters such as lesion size, apparent diffusion coefficient values, and the Tofts pharmacokinetics (TF) model. The histopathologic analysis included the International Society of Uropathology (ISUP) score and hypoxia marker immunohistochemistry.

Results: There were no significant demographic and imaging differences between hypoxic and nonhypoxic tumors, except for elevated prostate-specific antigen levels in the latter and decreased normalized apparent diffusion coefficient in the former. Morphologic assessments revealed larger lesions in the hypoxia group. While Ktrans showed a positive association with hypoxia, it did not independently predict high-risk lesions.

Conclusions: Our results suggest that pharmacokinetic analysis by the Tofts model was associated with tumors with hypoxia. However, this parameter was not an independent predictor of more aggressive tumors. Further studies, with a larger number of patients, multi-institutional and prospective, are needed to verify this possible association.