Lesions of canine prostate underwent laser ablation, radiofrequency ablation, and microwave ablation: Lesions’ shapes and clinical significances

Objective To explore the shapes and clinical significances of the lesions of canine prostate underwent laser ablation (LA), radiofrequency ablation (RFA), and microwave ablation (MWA). Methods Here, 6 male Beagle dogs were randomly assigned to LA, RFA, and MWA groups, respectively. The ablations were conducted with the doses commonly applied in clinical practice (LA: 3 W/1200 J; RFA and MWA: 30 W/120 s) for one region in the left and right lobes of the prostate, which totally resulted in 12 lesions. An energy transmitter was inserted via the perineum under the guidance of transrectal ultrasound (TRUS) and the ablation process was observed dynamically. After ablation, the efficacy was assessed by contrast-enhanced ultrasonography (CEUS), and transverse diameter (TRD), anteroposterior diameter (APD), and longitudinal diameter (TRD) were measured. Then, the volume (V) was calculated according to the following formulae, V = 1/6 × π × (MLD × APD × LD), and ratio (R) R =[(MLD + APD)/2 × LD], which was used to show the shape of the lesion (The closer R is to 1, the more spherical it is). Results The shapes and sizes of the lesions underwent the three techniques varied under the clinically commonly used doses. The R values, reflecting the changes in shapes of lesions, were 0.89±0.02, 0.72±0.01, and 0.65±0.03 for RFA, MWA, and LA, respectively, which were significantly different ( P =0.027). The volumes of the lesions underwent the three ablation techniques significantly varied as well (P=0.001), which were 2.17±0.10, 1.51±0.20, and 0.79±0.07 ml for MWA, LA, and RFA, respectively. Conclusion: The above-mentioned three techniques could be used for ablation of prostate cancer using the clinically commonly used doses. The shapes of the lesions underwent the three ablation techniques varied evidently, with the lesions received RFA and LA were more spherical and oval, respectively, while the shapes of lesions underwent MWA were between spherical and oval. The lesions received MWA and RFA had the largest and smallest sizes, respectively, while sizes of lesions underwent LA were in the middle. These findings may assist physicians to select an appropriate therapeutic method for treatment of prostate disease.