Photoacoustic imaging in prostate cancer: a systematic review and meta-analysis

Abstract

Prostate cancer (PCa) is a leading cause of morbidity and mortality among men worldwide. Limitations in current diagnostic methods often lead to overdiagnosis or missed cases. Photoacoustic imaging (PAI), which combines ultrasound and optical imaging, has emerged as a promising tool to enhance PCa detection and management. This systematic review evaluates the diagnostic accuracy, clinical applications, and technical performance of PAI in PCa. A comprehensive literature search was conducted in PubMed, Embase, Scopus, Web of Science, and IEEE through April 2024. Original studies reporting PAI’s diagnostic accuracy, technical performance, or clinical applications in PCa were included. Data on study design, population, PAI specifications, and key outcomes were extracted, and quality was assessed using QUADAS-2 for diagnostic studies and SYRCLE for animal studies. Diagnostic accuracy was assessed using a meta-analysis of sensitivity and specificity and a summary receiver operating characteristic curve. Of the 81 included studies, a meta-analysis of four ex vivo human studies demonstrated high specificity (84%–97%) and variable sensitivity (69%–87%) for PAI in distinguishing malignant from non-malignant prostate tissues. Combined with transrectal ultrasound, PAI improved diagnostic accuracy, biopsy guidance, and treatment monitoring. However, clinical translation of PAI requires standardised protocols, comprehensive in vivo validation, regulatory approvals, and adherence to the International Photoacoustic Standardisation Consortium guidelines. Current limitations, including a lack of standardised protocols and insufficient human in vivo studies reporting key diagnostic metrics, impede clinical adoption of PAI. PAI therefore holds promise as a complementary imaging tool in PCa diagnosis and management, improving biopsy accuracy and treatment monitoring; however, further human in vivo research and protocol standardisation are needed before clinical adoption.