Ablation energies for focal treatment of prostate cancer

Abstract

Context: In recent years, focal therapy has emerged as a treatment option for a selected group of men with localized prostate cancer. Cryotherapy and high-intensity focused ultrasound (HIFU) are the most investigated types of focal treatment with other options currently under evaluation.

Objective: The objective of the study was to give a comprehensive overview of six available focal treatment options for prostate cancer with their rationale, delivery mechanism, and outcomes.

Information acquisition: The SIU ICUD chapter on available Energies to Treat Prostate Cancer was used as a guide to describe the different technologies. For outcomes, a literature search was conducted using PubMed key words including focal therapy, HIFU, cryotherapy, irreversible electroporation, vascular-targeted photodynamic therapy, laser interstitial therapy, radiofrequency ablation, microwave therapy, and their synonyms in MeSH terms.

Conclusion: Focal therapy appears to have encouraging outcomes on quality of life and urinary and erectile function. For oncological outcomes, it is challenging to fully interpret the outcomes due to heterogeneity in patient selection and short-term follow-up.

Keywords: Ablation; Focal therapy; Localized; Prostate cancer.

Fig. 1

HIFU causes vascular damage at high-intensity and cavitation at ultrahigh intensity

Fig. 2

Cryotherapy causes tissue damage and vascular injury around the cryoneedle

Fig. 3

Cryoneedle placement and critical distances

Fig. 4

Cryotherapy stages

Fig. 5

Radical oxygen causing vascular occlusion upon illumination around the fiber tips

Fig. 6

Irreversible electroporation between needles causing cell death

Fig. 7

Laser therapy causing thermal damage and cavitational stress, both resulting in cellular damage