Magnetic resonance imaging can give accurate measurements of prostate size, as well as prostatic anatomy which may be important to note during the procedure. Studies have demonstrated the ability of MRI to accurately detect clinically sig­nicant prostate cancer while excluding clinically insignicant prostate cancer [17]. MRI can, there­fore, provide clinicians with valuable information on the size and location of the lesion(s) of interest (LOI), which can help determine the feasibility and technique employment during TULSA.The TULSA-Pro device is a transurethral instrument that uses ultrasound to ablate prostate tissue with a goal temperature of 55*C, a temperature that is 100% lethal to epithelial cells. The treatment range of the TULSA-Pro device is approximately 3 cm, and a lesion of interest >3cm from the ure­thra on MRI may therefore be inadequately ablated. Similarly, a disease that demonstrates evidence of extra- prostatic extension on imaging is likely to be out of the treatment range for the TULSA device, and TULSA may not be effective. Data have shown cell necrosis to occur up to 3mm from the device, beyond which no visible damage to cells occurs [18]. It is therefore recom­mended to conrm that the LOI is greater than 3mm away from the prostatic urethra and exter­nal urinary sphincter to minimize adverse effects that are a result of energy dispersion that may negatively impact critical structures.

during the procedure. Special attention is needed to ensure no damage to the device occurs during device insertion. If there is any concern during device insertion, clinicians should consider per­forming a cystoscopy with catheter placement over a wire to ensure the catheter is in an appro­priate position and not in a false passage. The UA can be manually adjusted to facilitate ablation success during the procedure. For anterior lesions, the clinician should angle the probe downward to stretch the anterior prostate and increase the distance between the pubic bone and the anterior prostate border. Additionally, if a cli­nician is working with a large gland, the gland can be compressed with the device to keep the prostate borders within the 3 cm treatment dis­tance. Adjustments can also be made if one encounters prostate calcications or implants using susceptibility-weighted imaging (SWI) sequences and adjusting the urethral device to minimize their impact on ablation and targeting. For example, one can position the calcication between transducer elements to minimize the degree of ultrasound interference.

If there is too much movement during the pro­cedure, either from enteric organs or from patient activity, TULSA cannot be accurately performed. Movement leads to artifacts on the real-time MRI thermometry, and the TULSA-PRO system will enter an automatic 20-min shut-down and cool­down mode to recalibrate and ensure accurate temperature mapping. During cool-down, images will be recaptured, and treatment borders should be reassessed to ensure the movement has not changed the desired ablation zone. It is therefore important to maintain consistent patient paralysis with the assistance of the anesthesia team to min­imize patient motion. Glucagon, a gastrointesti­nal antispasmodic, is also routinely administered intraoperatively to help decrease rectal wall motion [4].

Another important consideration is the phe­nomenon of gland swelling during TULSA.The gland will swell during heating, which can impact margins obtained during the procedure (Fig. 30.8). Clinicians must dynamically adjust margins based on the degree of swelling visual­ized intraoperatively to achieve satisfactory mar-

We present here two cases: one patient who underwent TULSA as primary treatment for his prostate cancer and one patient who underwent TULSA as salvage treatment in the setting of prostate cancer recurrence after radiation therapy.

A 60-year-old male presents with a PSA of

reviewed subtle shifts in ablation target due to excessive prostate gland swelling, peristaltic recto-sigmoid activity, or minor patient move­ment. This led to malalignment of the prescribed treatment plan and underlying anatomy, resulting ultimately in excessive energy delivered to the external urinary sphincter region, which exceeded the intended prescribed dose. Software modica­tion (including the addition of a “history slider” which helps identify minor target swelling or dis­placement, allowing target boundary adjustments “on the y”) and heightened awareness by the treating physician should minimize the risk of such adverse events in the future. Moreover, focal ablation with external sphincteric region sparing, as opposed to whole gland ablation, should ren­der severe incontinence even less likely.

A minority of patients, although with excel­lent oncologic results and reporting leak-free or pad-free continence, have experienced prolonged (months) periods of irritative or obstructive lower urinary tract symptoms. An illustrative case is detailed below: