Steerable needles in prostate brachytherapy

Abstract

Brachytherapy (BT) is a safe and effective technique to treat prostate cancer that has not spread outside the prostate gland (localised prostate cancer). Nonetheless, in current clinical practice hazards can arise in positioning the BT needles in the prostate for the purpose of irradiation. Intermediate structures can block access to the prostate and needle-tissue interactions can result in unexpected deflection of the needle inserted. These situations are undesirable because they lead to insufficient radiation of the prostate, potentially reducing treatment outcomes or resulting in patients being excluded from this treatment. Various techniques have been proposed in the literature to mitigate these hazards, of which actively steerable needles are considered very promising. However, manufacturing and cleaning such designs is often complex, while the low rigidity of the needles limits control and increases the risk of buckling when penetrating stiffer tissues such as the prostate. These factors have made implementation in BT protocols challenging.....