Transperineal focal laser ablation (TPLA) has the potential to obtain oncological control, while sparing nearby tissue to preserve continence and erectile function with a low toxicity profile. However, registration and prediction of the ablation zone is essential for TPLA to become a clinal standard of care treatment. In this study we investigated the capability of MRI and CEUS to image the treated volume. We show that the treatment effects of TPLA can reliably be visualized using these techniques and that the results are in good agreement with histopathology. These results are essential first steps towards improved planning and performance of TPLA.
Transperineal laser ablation (TPLA) is a novel minimal invasive treatment of benign prostatic obstruction. TPLA can be performed in an outpatient setting under local anesthesia with optional conscious sedation. The mechanism is based on laser ablation resulting in coagulative necrosis, which is induced by the laser light of 1064 nm. Laser light is delivered in the prostate trough transperineal placed needles. This study treated 20 men using TPLA to evaluate safety, feasibility, and voiding outcomes. TPLA has the potential to become an alternative for standard treatments with urethral approach that require general or spinal anesthesia and hospital admittance.
Transperineal laser ablation (TPLA) treatment of prostate cancer allows for a minimal invasive treatment approach. However, a predictive dosimetry model for accurate treatment planning for prostate cancer is not yet available. Therefore, we simulated TPLA treatments on porcine liver and quantitatively evaluated thermal distribution and histology slides were made. Hereby, we determined the cumulative equivalent thermal isoeffect dose at 43°C (CEM43) that predicts cell death and led to the development of a dosimetry model.
Transperineal laser ablation (TPLA) treatment of prostate cancer allows for a minimal invasive treatment approach. However, understanding of the ablation zone development and the 3D size are crucial for accurate treatment of prostate cancer. Therefore, we developed an ex-vivo experimental focal laser ablation set-up using a 1064nm CW diode laser to simulate a TPLA treatment, using human prostate and porcine liver.
We quantitatively evaluated the thermal distribution and ablation zone volume on high-resolution MR imaging and histopathology to determine the 3D size of the ablation zone. These results allow for development of a dosimetry model of clinical TPLA treatments.
Transperineal laser ablation (TPLA) is a novel minimal invasive treatment of benign prostatic obstruction. TPLA can be performed in an outpatient day-care setting under local anesthesia with optional conscious sedation. The mechanism is bases on thermoablation resulting in coagulative necrosis, which is induced by the laser light of 1064nm. Laser light is delivered in the prostate trough transperineal placed needles. This study aims to treat 20 men by TPLA to evaluate safety and feasibility, and voiding outcomes. TPLA has the potential to become an alternative for standard treatments with urethral approach that require general or spinal anesthesia and hospital admittance.
Diagnostic accuracy of needle-based optical coherence tomography (OCT) for prostate cancer detection by visual and quantitative analysis is defined. 106 three-dimensional (3-D)-OCT data sets were acquired in 20 prostates after radical prostatectomy and precisely matched with pathology. OCT images were grouped per histological category. Two reviewers performed blind assessments of the OCT images. Sensitivity and specificity for malignancy detection were calculated. Quantitative analyses by automated optical attenuation coefficient calculation were performed. OCT can reliably differentiate between fat, cystic, and regular atrophy and benign glands. The overall sensitivity and specificity for malignancy detection was 79% and 88% for reviewer 1 and 88% and 81% for reviewer 2. Quantitative analysis for differentiation between stroma and malignancy showed a significant difference (4.6 mm − 1 versus 5.0 mm − 1 Mann–Whitney U-test p < 0.0001). A Kruskal–Wallis test showed a significant difference in median attenuation coefficient between stroma, inflammation, Gleason 3, and Gleason 4 (4.6, 4.1, 5.9, and 5.0 mm − 1, respectively). However, attenuation coefficient varied per patient and a related-samples Wilcoxon signed-rank test showed no significant difference per patient (p = 0.17). This study confirmed the one to one correlation of histopathology and OCT. Precise matching showed that most histological tissues categories in the prostate could be distinguished by their unique pattern in OCT images. In addition, the optical attenuation coefficient can play a role in the differentiation between stroma and malignancy; however, a per patient analysis of the optical attenuation coefficient did not show a significant difference.
Prostate cancer treatment is shifting from radical to focal therapy. Instant tumor visualization on a microscopic level is crucial for clinical application of focal therapy. Optical coherence tomography (OCT) produces instant tissue visualization on a µm scale and the attenuation of OCT signal as a measure of tissue organization. The objective is to correlate qualitative and quantitative OCT analysis with histopathology.
Twenty prostates were analyzed by needle based OCT after radical prostatectomy. For precise correlation, whole mount histology slides were cut through the OCT trajectory. OCT images were classified in eight histological categories. Two reviewers independently performed assessment of the OCT images into these categories. Quantitative attenuation coefficient was used to discriminate stroma and malignant tissue. Sensitivity and specificity for detection of malignancy on OCT was calculated.
Visual analyses showed that OCT can reliably differentiate between fat, cystic and regular atrophy and benign glands. Differentiation of benign stroma and inflammation and also malignancy Gleason 3 and 4 is more difficult. Sensitivity and specificity for detection of malignancy on OCT were calculated at 77% and 75%. Quantitative analysis by means of the attenuation coefficient for differentiation between stroma and malignancy showed no significant difference (4.39 mm-1 vs. 5.31 mm-1).
Precise correlation of histology and OCT is possible and helps us to understand what we see and measure on OCT. Visual malignancy detection shows reasonable sensitivity and specificity. Our future studies focus on improving discrimination of malignancy with OCT for example by combining an extra imaging modality.
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