H. Takaki

Performance of intra-procedural 18-fluorodeoxyglucose PET/CT-guided biopsies for lesions suspected of malignancy but poorly visualized with other modalities

PurposeWe sought to evaluate the safety and the diagnostic success rate of percutaneous biopsies performed under intra-procedural 18u2009F-deoxyglucose (FDG) positron-emission tomography/computed tomography (PET/CT) guidance for lesions difficult to see with conventional cross-sectional imaging.MethodsFrom 2011 to 2013, consecutive clinically indicated percutaneous PET/CT-guided biopsies of 106 masses (mean size, 3.3xa0cm; range, 0.7–15.9xa0cm; SD, 2.9xa0cm) in bones (nu2009=u200933), liver (nu2009=u200926), soft tissues (nu2009=u200918), lung (nu2009=u200915) and abdomen (nu2009=u200914) were reviewed. The biopsy procedures were performed following injection of a mean of 255xa0MBq (SD, 74) FDG. Mean maximal standardized uptake value (SUV) of lesions was 8.8 (SD, 6.3). A systematic review of the histopathological results and outcomes was performed.ResultsBiopsies were positive for malignancy in 76 cases (71.7xa0%, 76/106) and for benign tissue in 30 cases (28.3xa0%, 30/106). Immediate results were considered adequate for 100 PET/CT biopsies (94.3xa0%, 100/106) requiring no further exploration, and for the six others (5.7xa0%, 6/106) benign diagnoses were confirmed after surgery (nu2009=u20094) or follow-up (nu2009=u20092). The consequent overall sensitivity and the diagnostic success of biopsy were therefore 100xa0%. No significant differences in terms of detection of malignancy were observed between the different locations. Lesions > 2xa0cm or with SUVu2009>u20094 were not significantly more likely to be malignant. Complications occurred after four biopsies (3.7xa0%, 4/106).ConclusionIntra-procedural PET/CT guidance appears as a safe and effective method and allows high diagnostic success of percutaneous biopsies for metabolically active lesions.

Hepatic artery embolization for liver metastasis of gastrointestinal stromal tumor following imatinib and sunitinib therapy.

PurposeThe purpose of the study is to determine the efficacy of hepatic artery embolization (HAE) as a therapy for gastrointestinal stromal tumor (GIST) in patients who are refractory to imatinib and sunitinib.MethodsAfter institutional review board approval, a retrospective review revealed 11 patients with GIST metastatic to the liver who underwent 15 HAEs between February 2002 and May 2013. These patients were stratified into two groups according to the previous treatment: (a) those treated with HAE as second-line treatment after failing first-line imatinib (nu2009=u20093) and (b) those treated with HAE as third-line therapy after failing first-line imatinib and second-line sunitinib (nu2009=u20098). Initial therapeutic response, overall survival (OS), progression-free survival (PFS), and safety were evaluated.ResultsInitial therapeutic response rates at 3xa0months after HAE were 27.3xa0% (95xa0% confidence interval (CI), 6.0–61.0xa0%) by Response Evaluation Criteria in Solid Tumor (RECIST) version 1.0 and 45.5xa0% (95xa0% CI, 16.7–76.6xa0%) by modified RECIST (mRECIST). The median OS and PFS after HAE were 14.9 and 3.9xa0months in group A and 23.8 and 3.4xa0months in group B, respectively. No procedure-related mortality or major complication was observed.ConclusionsHAE is an effective and well-tolerated therapeutic option for GIST liver metastases. Although larger studies are necessary, HAE should be considered as an alternative or adjuvant to third-line or even second-line systemic treatment.

Liver resection and ablation for metastatic melanoma: A single center experience

The median survival for patients with stage IV metastatic melanoma is usually limited to approximately 1 year. In the case of liver metastasis, resection and ablation can achieve long‐term survival. This study aimed to describe the outcomes after liver resection or ablation for metastatic melanoma to the liver and identify preoperative prognostic factors.

Treatment Effects of WST11 Vascular Targeted Photodynamic Therapy for Urothelial Cell Carcinoma in Swine

PURPOSEnSurgical management of upper tract urothelial carcinoma requires kidney and ureter removal, compromising renal function. Nonsurgical alternatives have potentially prohibitive safety concerns. We examined the feasibility and safety of ablation of the ureter and renal pelvis using endoluminal vascular targeted photodynamic therapy in a porcine model. We also report the efficacy of WST11 vascular targeted photodynamic therapy in a murine model.nnnMATERIALS AND METHODSnAfter receiving approval we performed a total of 28 endoluminal ablations in the ureters and renal pelvis of 18 swine. Intravenous infusion of WST11 (4 mg/kg) followed by 10-minute laser illumination was done via percutaneous access or a retrograde ureteroscopic approach. Animals were followed clinically with laboratory testing, imaging and histology, which were evaluated at several postablation time points. A murine xenograft was created with the 5637 human urothelial cell carcinoma line to determine sensitivity to this therapy.nnnRESULTSnAt 24 hours 50 mW/cm laser fluence produced superficial necrosis of the ureter. Deeper necrosis penetrating the muscularis propria or adventitia was produced by treatment with 200 mW/cm in the ureter and the renal pelvis. At 4xa0weeks superficial urothelium had regenerated over the treatment site. No symptomatic obstruction, clinically relevant hydronephrosis or abnormality of laboratory testing was noted up to 4 weeks. Of the mice 80% had no evidence of tumor 19 days after WST11 vascular targeted photodynamic therapy.nnnCONCLUSIONSnUrothelial cell carcinoma appears to be sensitive to WST11 vascular targeted photodynamic therapy. The depth of WST11 vascular targeted photodynamic therapy treatment effects can be modulated in a dose dependent manner by titrating light intensity. Moreover, when applied to the porcine upper urinary tract, this treatment modality is feasible via antegrade and retrograde access.

Comparison of CT Fluoroscopy-Guided Manual and CT-Guided Robotic Positioning System for In Vivo Needle Placements in Swine Liver

AbstractPurposenTo compare CT fluoroscopy-guided manual and CT-guided robotic positioning system (RPS)-assisted needle placement by experienced IR physicians to targets in swine liver.Materials and MethodsManual and RPS-assisted needle placement was performed by six experienced IR physicians to four 5xa0mm fiducial seeds placed in swine liver (nxa0=xa06). Placement performance was assessed for placement accuracy, procedure time, number of confirmatory scans, needle manipulations, and procedure radiation dose. Intra-modality difference in performance for each physician was assessed using paired t test. Inter-physician performance variation for each modality was analyzed using Kruskal–Wallis test.ResultsPaired comparison of manual and RPS-assisted placements to a target by the same physician indicated accuracy outcomes was not statistically different (manual: 4.53xa0mm; RPS: 4.66xa0mm; pxa0=xa00.41), but manual placement resulted in higher total radiation dose (manual: 1075.77xa0mGy/cm; RPS: 636.4xa0mGy/cm; pxa0=xa00.03), required more confirmation scans (manual: 6.6; RPS: 1.6; pxa0<xa00.0001) and needle manipulations (manual: 4.6; RPS: 0.4; pxa0<xa00.0001). Procedure time for RPS was longer than manual placement (manual: 6.12xa0min; RPS: 9.7xa0min; pxa0=xa00.0003). Comparison of inter-physician performance during manual placement indicated significant differences in the time taken to complete placements (pxa0=xa00.008) and number of repositions (pxa0=xa00.04) but not in other study measures (pxa0>xa00.05). Comparison of inter-physician performance during RPS-assisted placement suggested statistically significant differences in procedure time (pxa0=xa00.02) and not in other study measures (pxa0>xa00.05).ConclusionsCT-guided RPS-assisted needle placement reduced radiation dose, number of confirmatory scans, and needle manipulations when compared to manual needle placement by experienced IR physicians, with equivalent accuracy.

Pleural Puncture that Excludes the Ablation Zone Decreases the Risk of Pneumothorax after Percutaneous Microwave Ablation in Porcine Lung

PURPOSEnTo test the hypothesis that the geometry of probe placement with respect to the pleural puncture site affects the risk of pneumothorax after microwave (MW) ablation in the lung.nnnMATERIALS AND METHODSnComputed tomography-guided MW ablation of the lung was performed in 8 swine under general anesthesia and mechanical ventilation. The orientation of the 17-gauge probe was either perpendicular (90°) or parallel (< 30°) with respect to the pleural puncture site, and the ablation power was 30 W or 65 W for 5 minutes. After MW ablation, swine were euthanized, and histopathologic changes were assessed. Frequency and factors affecting pneumothorax were evaluated by multivariate analysis.nnnRESULTSnAmong 62 lung MW ablations, 13 (21%) pneumothoraces occurred. No statistically significant difference was noted in the rate of pneumothorax between the perpendicular and the parallel orientations of the probe (31% vs 14%; odds ratio [OR], 2.8; P = .11). The pneumothorax rate was equal for 65-W and 30-W ablation powers (21% and 21%; OR, 1.0; P = .94). Under multivariate analysis, 2 factors were independent positive predictors of pneumothorax: ablation zone inclusive of pleural insertion point (OR, 7.7; P = .02) and time since intubation (hours) (OR, 2.7; P = .02).nnnCONCLUSIONSnGeometries where the pleural puncture site excluded the ablation zone decreased pneumothorax in swine undergoing MW ablation in the lung. Treatment planning to ensure that the pleural puncture site excludes the subsequent ablation zone may reduce the rate of pneumothorax in patients undergoing MW ablation in the lung.

Comparison of ablation defect on MR imaging with computer simulation estimated treatment zone following irreversible electroporation of patient prostate

To determine whether patient specific numerical simulations of irreversible electroporation (IRE) of the prostate correlates with the treatment effect seen on follow-up MR imaging. Computer models were created using intra-operative US images, post-treatment follow-up MR images and clinical data from six patients receiving IRE. Isoelectric contours drawn using simulation results were compared with MR imaging to estimate the energy threshold separating treated and untreated tissue. Simulation estimates of injury to the neurovascular bundle and rectum were compared with clinical follow-up and patient reported outcomes. At the electric field strength of 700xa0V/cm, simulation estimated electric field distribution was not different from the ablation defect seen on follow-up MR imaging (pxa0=xa00.43). Simulation predicted cross sectional area of treatment (mean 532.33xa0±xa0142.32xa0mm2) corresponded well with the treatment zone seen on MR imaging (mean 540.16xa0±xa0237.13xa0mm2). Simulation results did not suggest injury to the rectum or neurovascular bundle, matching clinical follow-up at 3xa0months. Computer simulation estimated zone of irreversible electroporation in the prostate at 700xa0V/cm was comparable to measurements made on follow-up MR imaging. Numerical simulation may aid treatment planning for irreversible electroporation of the prostate in patients.