Characterizing TUNA ablative treatments of the prostate for benign hyperplasia with gadolinium-enhanced magnetic resonance imaging.
OBJECTIVE
Transurethral Needle Ablation of the prostate TUNA has been accepted as an office-based treatment for benign prostatic hyperplasia (BPH) for many years. Clinical outcomes have been reported, but the amount and location of the necrosis produced have yet to be characterized. The necrosis caused by TUNA was evaluated by gadolinium-enhanced magnetic resonance imaging (MRI) of the pelvis.


METHODS
Twelve patients with BPH/lower urinary-tract symptoms underwent standard TUNA, and MRI scans with gadolinium enhancement were performed before and 1 week after treatment. The images were studied using Analyze software to quantify the amount of necrosis compared with the prostatic volume. Transverse, coronal, and sagittal images were obtained to identify the location of the necrosis.


RESULTS
New gadolinium defects were seen in all patients after TUNA. The lesions coalesced into continuous areas of necrosis and correlated with the site of needle placement. The mean volume of necrosis was 6.84 cc and equated to 8.6% of the prostate volume. No lesions were found near the apex, urethra, or rectum; and none extended beyond the prostate capsule.


CONCLUSIONS
Gadolinium-enhanced MRI demonstrates new vascular defects representing necrosis caused by TUNA of the prostate. This therapy for BPH produces necrotic lesions that can be placed strategically by the surgeon. The standard protocol produces lesions that coalesce to create larger lesions. This MRI study has characterized, for the first time, the heating pattern and intraprostatic necrosis of a complete TUNA procedure.
Department of Urology, Mayo Clinic, Rochester, Minnesota, USA.
Lance A
LA
Mynderse
Benjamin
B
Larson
Christian
C
Huidobro
James J
JJ
Meyer
David
D
Busel
Dennis P
DP
Hanson
Thayne
T
Larson
D000368:Aged; D005682:Gadolinium; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000473:pathology; D011467:Prostate / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000473:pathology / Q000601:surgery*; D020728:Transurethral Resection of Prostate / Q000379:methods*
D005682:Gadolinium