Effect of transurethral microwave thermotherapy. An evaluation with MR imaging.
OBJECTIVE
To detect morphological changes in the prostate, as depicted with MR imaging, in order to clarify the effects of transurethral microwave thermotherapy (TUMT).


METHODS
Twenty patients with prostatism and a prostatic volume of 30-71 cm3 underwent MR examination before, the day after, and 6 months after treatment. TUMT was carried out with a Prostatron. A method to detect oedematous changes on heavily T2-weighted MR images was developed and used as an indicator of morphological changes.


RESULTS
The study showed some correlation (r=0.59) between the energy given at TUMT and an increased T2 signal. All patients with increased T2 signal except one were found among those who received the highest amount of energy to the prostate. Of 8 patients, 6 showed a symptomatic response to the treatment and 2 did not. There was a weak statistical correlation (r=0.41) between treatment response and increased T2 signal.


CONCLUSIONS
The study does not support the view that TUMT leads to significant necrosis in the prostate with loss of tissue and retraction. We theorize that the response to TUMT may be caused by a denervation of the prostate.
Nordenstam
G
G
Department of Radiology, Karolinska Institute, Huddinge Hospital, Sweden.
Aspelin
P
P
Isberg
B
B
Svensson
L
L
Hallin
A
A
Berlin
T
T
D006801:Humans; D006979:Hyperthermia, Induced; D008279:Magnetic Resonance Imaging; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D011467:Prostate / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000175:diagnosis / Q000628:therapy*