Biomedical subjects
Publications and source records attributed to F Ameye.
A retrospective study of 70 patients who underwent a radical prostatectomy in 1989 and 1990 was done. The significance of CT-scan in preoperative lymph node assessment should be reconsidered. The correct examination of the resection margins is very important: the pathologist should clearly distinguish between capsular invasion and capsular penetration or transgression. The etiology of local failure and its treatment are discussed.
Transurethral microwave hyperthermia is a new conservative treatment modality for benign prostatic hyperplasia. We treated 15 patients with 915 MHz. microwaves delivered transurethrally by a helical applicator. Of the patients 12 showed substantial objective and subjective improvement of obstructive outflow parameters. Significant improvement in objective study parameters included increased mean flow rate (p less than 0.00021), decreased mean residual volume (p less than 0.00001) and decreased mean prostatic volume (p less than 0.0077). Analysis of patterns of failure showed chronic bladder atony, prostate asymmetry and middle lobe configuration as important factors that could explain the failure of hyperthermia in 3 patients. Toxicity was mild, consisting of bladder spasms, perineal pain, dysuria and hematuria. Hyperthermia-induced pathological changes in prostatic tissues, causing periurethral shrinking and secondary dilatation of the prostatic urethra, are described. The reported clinical results of this phase I study are preliminary due to the short followup. A phase II study to optimize transurethral hyperthermia currently is underway. A phase III study is to be phased in comparing hyperthermia with transurethral resection of the prostate.
A new applicator for intraurethral hyperthermic treatment of benign prostatic hyperplasia is described. The applicator uses an insulated helical antenna wound on the outer surface of a silicone urological (Foley) balloon catheter. The balloon catheter assures rapid and reproducible localization of the antenna in the prostatic urethra. Two small cannulae are fixed to the exterior surface of the applicator. One holds a temperature control sensor at a fixed location, the other is used to map temperature along the applicator. Two-dimensional SAR and steady-state temperature distributions measured in a plane tangent to the applicator in a tissue-equivalent phantom are presented, as well as longitudinal temperature distributions measured in situ at the applicator-urethral interface. Prostatic temperatures were also measured intraoperatively. The applicator appears to be capable of elevating temperature to greater than 42 degrees C in a cylindrically symmetric volume of about 4 cm length and about 0.5 cm radial penetration surrounding the antenna. The heating characteristics of this applicator are similar to an earlier design that employed an array of three dipoles. The helical applicator is narrower, more flexible and simpler to use than the earlier design.