A pilot study of the shapes of ablation lesions in the canine prostate by laser, radiofrequency and microwave and their clinical significance

Abstract

To explore the shape characteristics of ablation lesions created via laser ablation (LA), radiofrequency ablation (RFA) and microwave ablation (MWA) in canine prostates and the clinical significance of these characteristics, six adult male beagles were randomly assigned to the LA, RFA, and MWA groups. These ablations were performed with common parameters applied in clinical practice (LA, 3 W/1200 J; RFA and MWA, 30 W/120 s). One ablation lesion was created in each lobe of the prostate via the ablation technique, resulting in a total of twelve ablation lesions. Transrectal ultrasound (TRUS) was used as guidance during puncture and to monitor changes in the ablation lesions. Finally, the ablation efficacy was assessed using transrectal contrast-enhanced ultrasonography (CEUS), and the transverse diameter (TRD), anteroposterior diameter (APD) and longitudinal diameter (LD) of each ablation lesion were measured. The volume (V) and the ratio (R) value were calculated. R reflects the shape characteristic of the ablation lesion (the R value close to 1.0 indicates a more spherical shape). The R values of the ablation lesions were 0.89 ± 0.02, 0.72 ± 0.01, and 0.65 ± 0.03 for RFA, MWA and LA, respectively, and they were significantly different (P = 0.027). The volumes of the ablation lesions were 2.17 ± 0.10 ml, 1.51 ± 0.20 ml, and 0.79 ± 0.07 ml for MWA, LA and RFA, respectively, and they were also significantly different (P = 0.001). The three abovementioned thermal ablation techniques with common parameters in clinical practice can be used for ablation in the prostate. The shapes and volumes of the ablation lesions of the three techniques were varied: The RFA-created lesions had the lowest volumes and were more spherical in shape, demonstrating that RFA could be used for the treatment of relatively small lesions or tumours adjacent to vital organs. The MWA lesions had the largest size with a spherical shape, which could be advantageous for the ablation of tumours with relatively large sizes. The sizes of the ablation lesions created via LA were between those of RFA and

Dynamic prostatic and laser-ablated lesion volume change after transperineal laser ablation in canine: preliminary observation and its clinical significance

“…The enhanced rims may be the hyperemia zone according to our histopathology results and previous literatures [21]. The shape of laser-ablated lesions was ellipsoidal, which has been described in previous study [25]. In addition, the TPLA needle channel was bright in TR-CEUS, which was the same echo as the prostatic capsule in the two-dimensional ultrasonography and was verified as the carbonized tissue through the histopathology, so this "enhanced" was false appearance.…”

“…After TPLA, each laser-ablated lesion was observed as an avascular defect area within the normal perfused gland on TR-CEUS image. The shape of laser-ablated lesions was round on the transverse and elliptic on the longitudinal section images, so the shape of it was ellipsoidal on the whole, which has been described in the previous study [25]. The follow-up TR-CEUS examination carried out 1 week and 1 month after TPLA displayed the laser-ablated lesions with a demarcated boundary (Figure 2(b-d)).…”

“…Transrectal contrast-enhanced ultrasound (TR-CEUS) examinations were conducted to image the prostate and laser-ablated lesions at about 10 min after TPLA. The details of TR-CEUS examinations were described in the previous article [25]. Briefly, the machine was adjusted to the contrast mode with low mechanical index (0.06).…”

The Design and Rationale of a Multicentre Randomised Controlled Trial Comparing Transperineal Percutaneous Laser Ablation With Transurethral Resection of the Prostate for Treating Benign Prostatic Hyperplasia

“…The use of TRUS guidance with a biplane probe allows repositioning of applicators during the manoeuvre based on the physician experience, and the amount of energy is planned in advance according to the baseline volume of the prostatic lobes (35,38,49). The assessment of the extent of the coagulation zone after ablation with transrectal contrastenhanced ultrasonography is considered a very useful tool for early result assessment (50)(51)(52).…”

Focal Ablation Therapy for Prostate Cancer: A Literature Review

“…In summary, focal ablation therapy should be individualized according to the location, size, and the number of tumors. Recently, Liu et al promise that the appropriate ablation technology can be selected for PCa patients according the shape and volume of ablated lesions through animal experiment results [67].…”