ABSTRACT
This study aimed to examine the optimal conditions of laser-induced interstitial thermotherapy (LITT) via a single-needle delivery system, and the ablation-related pathological and ultrasonic changes. Ultrasound (US)-guided LITT (EchoLaser system) was performed at the output power of 2-4 Wattage (W) for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers (n=24), and VX2 tumors implanted in the hind limbs of rabbits (n=24). The ablation area was histologically determined by hematoxylin-eosin (HE) staining. Traditional US and contrast enhanced ultrasound (CEUS) were used to evaluate the treatment outcomes. The results showed: (1) In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 min, and it extended slightly with the ablation time. (2) In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. (3) Gross examination of the liver and carcinoma showed three distinct regions: ablation crater/carbonization, coagulation and congestion distributed from the center outwards. (4) Microscopy revealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and congestion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. (5) The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effectively guide and assess the treatment.
Subject(s)
Animals , Cattle , Rabbits , Bone Neoplasms , Diagnostic Imaging , Pathology , Therapeutics , Hindlimb , Pathology , Laser Therapy , Methods , Liver Diseases , Diagnostic Imaging , Therapeutics , Treatment Outcome , Ultrasonic Therapy , Methods , UltrasonographyABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of mesothelin in specimen of pancreas fine-needle aspiration and to evaluate the potential contribution of immunohistochemical labeling of mesothelin to the interpretation of pancreas fine-needle aspiration (FNA).</p><p><b>METHODS</b>Specimens from 27 patients were selected for immunolabeling. Immunohistochemical EnVision method was used to detect the expression of mesothelin in specimen of pancreas fine-needle aspiration. The labeling in each patient was scored as positive or negative. These results were compared with the cytologic diagnosis and the follow-up data.</p><p><b>RESULTS</b>Nineteen of the 27 patients were ultimately shown to have an adenocarcinoma, and 8 had no evidence of malignancy on follow-up. Initial cytologic diagnosis of malignancy correlated with carcinoma on follow-up in 10 of 10 cases, and initial benign cytologic diagnosis correlated with benign follow-up in 4 of 6 cases. Seven of the 11 patients with suspicious cytology were found to have carcinomas on follow-up. Mesothelin labeling was seen in 14 of the 19 patients ultimately shown to have carcinomas and was absent in 7 of the 8 benign lesions (sensitivity, 73.7%; specificity, 87.5%). Five of the 7 cytologically suspicious cases with malignant follow-up labeled for mesothelin. Positive mesothelin labeling was observed in one of the 4 suspicious cases who finally proved to be benign during follow-up.</p><p><b>CONCLUSION</b>Immunohistochemical labeling for mesothelin may be a highly specific tool for the detection of pancreatic adenocarcinoma in FNA specimens and is useful in categorizing cytologically suspicious lesions.</p>