Testis Tumors

The testicle appears as an ideal organ for extracorporeal high-intensity focused ultrasound as it is easily accessible, even for transducers with short focal lengths, with almost no interfering acoustical interphases, and because ultrasonography permits superb visualization of testicular tumors. Clearly, a unilateral testicular tumor in the presence of a normal contralateral testicle would always be treated by orchiectomy. About 2% of all malignant testicular tumors are bilateral, either synchronous or metachronous. To avoid anorchia organ sparing tumor excision and subsequent irradiation of the residual testis with 16-20 Gy to eradicate Ca in situ is usually considered the therapy of choice (70). Although the recurrence rate is <6% with this approach, ~20% of the patients ultimately loose the testis and need permanent androgen replacement therapy (70).

Using a high-intensity focused ultrasound system originally developed for transrectal high-intensity focused ultrasound, Madersbacher et al. exposed four patients with metastatic prostate cancer to transcutaneous high-intensity focused ultrasound prior to orchiectomy. The scrotum was submerged in saline, the testicle immobilized with a sling around the base of the scrotum, and target lesions within the testicle of 8 X 8 mm ablated at a frequency of 4.0 MHz and site intensity of 1680 W/cm2. Histology showed definite signs of necrosis, with detachment of the germinal epithelium, shrinkage of nuclei and cell disintegration in the target zone, and targeted lesion and obtained lesion corresponding in size and location (71).

A clinical phase II study in patients with tumors in the solitary testis in whom the contralateral testis had been removed for a malignant tumor demonstrated the possibility of cure with high-intensity focused ultrasound and postoperative irradiation (71).

Percutaneous techniques using either cryoablation or thermal coagulation are widely employed for this today but the need to puncture the tumor with the potential risk of hemorrhage and tumor spillage raises some caveats. Transrectal high-intensity focused ultrasound systems operating in the 4MHz range have been modified for laparo-scopic use.

In a curative attempt in vivo in a patient with three tumors in a solitary kidney, two were completely ablated by extracorporeal high-intensity focused ultrasound, with a follow-up of six months.

In the meantime, seven patients with tumors in a solitary testis were treated in this manner, with a mean follow-up of 42 months and follow-up over five years in four patients (61). The only patient to develop a recurrent tumor in the series refused postoperative irradiation. This testicle was removed and histology showed the recurrent tumor to be an embryonal carcinoma in a different location, with the high-intensity focused ultrasound-treated area tumor free. All other patients remain tumor free, with normal levels of serum testosterone and no need for androgen replacement (61).

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