ABSTRACT
Prostate cancer is the most frequent cancer and the second most frequent cause of death for men in North America. Much attention has been focused on the early detection of disease and recent reports appear to indicate that a greater percentage of patients are now detected with early stage disease. Radical prostatectomy and radiotherapy are reported as having good five year survival rates in men with early stage disease (stage≤T2b, PSA<10 ng/mL, and Gleason score≤6), although the advantages and disadvantages are the subject of active debate. There has been a recent resurgence in using permanent interstitial radioactive seed implants for prostate cancer because of advances in transrectal ultrasound (TRUS) and in computed tomography (CT).1-5 Transperineal interstitial permanent prostate brachytherapy (TIPPB) requires an unobstructed access to the prostate. Pelvic bones defining the pubic arch can block access to the anterior aspect of the gland; commonly referred to as ‘pubic arch interference/ overlap’ (PAI/PAO) (Figure 25.1). Assessment of potential PAI is critical when deciding whether or not a patient can be a candidate for a transperineal prostate implant,6 and can be performed with either CT,7-9 or TRUS.10,11 An example of a TRUS image of the pubic arch is shown in Figure 25.2. Androgen suppression treatment can be used to reduce both the size of the gland and the degree of PAI in those patients with significant PAI, although no benefit to reduction in biochemical control has been noted.12
