Target ablation--image-guided therapy in prostate cancer

Current treatment options for prostate cancer, other than active surveillance, are limited to entire prostate gland destruction through removal (radical prostatectomy), radiation (external beam, brachytherapy, or a combination of both), or thermal ablation (cryoablation, high-intensity focused ultrasound, or radiofrequency). There has been a demand to develop ablative therapies that attempt to reduce treatment burden while retaining cancer control and avoiding the psychological morbidity associated with surveillance.

We reviewed the literature to concentrate on the practical aspects of focal therapy for Pca with the following key words: photodynamic therapy, HIFU, cryotherapy, focal laser ablation, electroporation, radiofrequency, external beam radiation, organ-sparing approach, focal therapy, prostate cancer. The aim of this article is to review these energy modalities' functional and oncologic results.

Prostatic tumor ablation can be achieved with different energies: freezing effect for cryotherapy, thermal effect using focalized ultrasound for HIFU and using thermal effect of light for FLA and activation of a photosensitizer by light for PDT, among others. Radiofrequency and microwave therapy have been tested in this field and demonstrated their usefulness. Electroporation is currently being developed on preclinical models. External beam radiation with microboost on neoplastic foci is under evaluation. HIFU and cryotherapy require the use of sophisticated and expensive machines. However, series published short term effective with low morbity, reversible therapy.

Several energy modalities are being developed to achieve the trifecta of continence, potency, and oncologic efficiency. Comparison of the different focal approaches is complex owing to important heterogeneity of the trials. In the future, it seems likely that each technique will have its own selective indications.