The objective of this study was to evaluate the safety and feasibility of 99mTc-based prostate-specific membrane antigen (PSMA) robot-assisted–radioguided surgery to aid or improve the... Show moreThe objective of this study was to evaluate the safety and feasibility of 99mTc-based prostate-specific membrane antigen (PSMA) robot-assisted–radioguided surgery to aid or improve the intraoperative detection of lymph node metastases during primary robot-assisted radical prostatectomy (RARP) for prostate cancer (PCa). Methods: Men with primary high-risk PCa (≥ cT3a, International Society of Urological Pathology (ISUP) grade group ≥ 3 or prostate-specific antigen of ≥ 15 ng/mL) with potential lymph node metastasis (Briganti nomogram risk > 10% or on preoperative imaging) were enrolled in the study. Patients underwent staging 68Ga-PSMA PET/CT scanning. Preoperatively, a 99mTc-labeled PSMA ligand (99mTc PSMA I&S; 500 MBq) was administered followed by SPECT/CT. A RARP including extended pelvic lymph node dissection was performed, with intraoperative tracing of PSMA-avid tissues using a prototype DROP-IN γ-probe. Resected specimens were also measured ex vivo. Histopathologic concordance with probe findings was evaluated. A radiotracer count of ≥ 1.5 times the background reference (in vivo), and ≥ 10 (absolute count) in the ex vivo setting, was considered positive. Results: Twelve patients were included (median age, 68 y, and prostate-specific antigen, 9.15 ng/mL). Most of the patients harbored ISUP 5 PCa (75%) and had avid lymph nodes on preoperative PSMA PET (64%). The DROP-IN probe aided resection of PSMA-avid (out-of-template) lymph nodes and residual disease at the prostate bed. Eleven metastatic lymph nodes were identified by the probe that were not observed on preoperative 68Ga-PSMA PET/CT. Of the 74 extraprostatic tissue specimens that were resected, 22 (29.7%) contained PCa. The sensitivity, specificity, positive predictive value, and negative predictive value of inpatient use of the γ-probe were 76% (95% CI, 53%–92%), 69% (95% CI, 55%–81%), 50%, and 88%, respectively. Ex vivo, the diagnostic accuracy was superior: 76% (95% CI, 53%–92%), 96% (95% CI, 87%–99%), 89%, and 91%, respectively, for sensitivity, specificity, positive predictive value, and negative predictive value. Of the missed lymph nodes in vivo (n = 5) and ex vivo (n = 5), 90% were micrometastasis (≤3 mm). No complications greater than Clavien–Dindo Grade I occurred. Conclusion: Robot-assisted 99mTc-based PSMA-radioguided surgery is feasible and safe in the primary setting, optimizing the detection of nodal metastases at the time of RARP and extended pelvic lymph node dissection. Further improvement of the detector technology may optimize the capabilities of robot-assisted 99mTc-based PSMA-radioguided surgery. Show less
Investigating the in vivo effects of miR-494 inhibition on progression and stability of advanced atherosclerotic lesions.LDLr-/- mice were fed a Western Type Diet (WTD) for 10 weeks to induce... Show moreInvestigating the in vivo effects of miR-494 inhibition on progression and stability of advanced atherosclerotic lesions.LDLr-/- mice were fed a Western Type Diet (WTD) for 10 weeks to induce atherosclerosis. Semi-constrictive collars were placed around both carotid arteries 4 weeks after start of WTD and 6 weeks after collar placement, a subset of mice (N=10) was sacrificed to analyze baseline plaque size and composition. For the remaining mice, WTD was replaced by normal chow and 3rd Generation Antisense (3GA) against miR-494 (3GA-494; N=10) or negative control (3GA-ctrl; N=10) were administered (i.v., 1 mg/mouse) immediately after and at 2 and 4 weeks after diet switch. Mice were sacrificed one week after final injection.3GA-ctrl mice showed increased carotid artery plaque size compared to baseline, indicating continued atherogenesis, even after lowering plasma cholesterol levels by diet-replacement (before: 863±115 mg/dL vs. after: 214±13 mg/dL). 3GA-494 mice however, showed a significant decrease in carotid artery plaque size compared to control; in fact, 3GA-494 mice had similar plaque sizes to baseline mice (baseline: 30±8*103 µm2, 3GA-ctrl: 56±16*103 µm2 vs. 3GA-494: 23±9*103 µm2, P<0.05). Relative intra-plaque collagen content and macrophage infiltration remained unaltered after treatment. In the aortic root, we did not observe differences in plaque size between the 3GA-treated groups, however, plaque stability was significantly increased upon 3GA-494 treatment. Intra-plaque collagen content was increased in 3GA-494 mice (3GA-ctrl: 37±3% vs. 3GA-494: 52±4%, P<0.05), whereas necrotic core size remained similar (3GA-ctrl: 20±2 vs. %3GA-494: 16±3%). Blood analysis revealed a significant decrease in platelet count in the 3GA-494 group (3GA-ctrl: 1097±109*109 /L vs. 3GA-494: 288±64*109 /L, P<0.05), as well as a further reduction in plasma cholesterol (3GA-ctrl: 214±13 mg/dL vs. 3GA-494: 154±6 mg/dL, P<0.05).These results show that treatment with 3GA-494 halts plaque progression in the carotid artery and increases plaque stability in aortic root plaques. Furthermore, 3GA-494 treatment reduces the platelet count, as well as plasma cholesterol levels, which is an additional improvement of cardiovascular risk factors. Show less
We aimed at investigating the role of 14q32 microRNAs in intimal hyperplasia and accelerated atherosclerosis; two major contributors to restenosis. Restenosis occurs regularly in patients treated... Show moreWe aimed at investigating the role of 14q32 microRNAs in intimal hyperplasia and accelerated atherosclerosis; two major contributors to restenosis. Restenosis occurs regularly in patients treated for coronary artery disease and peripheral arterial disease. We have previously shown that inhibition of 14q32 microRNAs leads to increased post-ischemic neovascularization, and microRNA miR-494 also decreased atherosclerosis, while increasing plaque stability. We hypothesized that 14q32microRNA inhibition has beneficial effects on intimal hyperplasia, as well as accelerated atherosclerosis.Non-constrictive cuffs were placed around both femoral arteries of C57BL/6J mice to induce intimal hyperplasia. Accelerated atherosclerotic plaque formation was induced in hypercholesterolemic ApoE mice by placing semi-constrictive collars around both carotid arteries. 14q32 microRNAs miR-329, miR-494 and miR-495 were inhibited in vivo using Gene Silencing Oligonucleotides (GSOs). GSO-495 administration led to a 32% reduction of intimal hyperplasia. Moreover, the number of macrophages in the arterial wall of mice treated with GSO-495 was reduced by 55%. Inhibition of miR-329 and miR-494 had less profound effects on intimal hyperplasia. GSO-495 administration also decreased atherosclerotic plaque formation by 52% and plaques of GSO-495 treated animals showed a more stable phenotype. Finally, cholesterol levels were also decreased in GSO-495 treated animals, via reduction of the VLDL-fraction. GSO-495 administration decreased our primary outcomes, namely intimal hyperplasia, and accelerated atherosclerosis. GSO-495 administration also favourably affected multiple secondary outcomes, including macrophage in flux, plaque stability and total plasma cholesterol levels. We conclude that 14q32 microRNA miR-495 is a promising target for prevention of restenosis. Show less
