Patterns of Reperfusion and Clinical Findings in Repeat Prostate Artery Embolisation for Recurrent Lower Urinary Tract Symptoms in Patients with Benign Prostatic Hyperplasia.

PURPOSE: To present our experience of the patterns of revascularisation of the prostate and efficacy of repeat prostate artery embolisation (rPAE) in patients with recurrence of lower urinary tract symptoms. MATERIALS AND METHODS: We retrospectively analysed 12 patients who underwent rPAE at a single centre between November 2015 and March 2020. The patients had their intraprocedural angiography and cone beam CT images as well as their pre-procedural CT retrospectively reviewed to establish the patterns of revascularisation. Clinical follow-up occurred at a minimum of 3 months. RESULTS: 11/12 patients (91.6%) had significant international prostate symptom score (IPSS) reduction following rPAE with change in mean IPSS from 18.4 to 8.1 at 3 months (p < 0.0001). Mean prostate volume was reduced by 41.6% (p = 0.03). 8/12 (75%) had a complete clinical success. 20/24 hemiprostates demonstrated revascularisation angiographically, of which 16 (80%) had prostatic arterial supply at rPAE by the main prostatic artery. Other mechanisms of revascularisation included supply from capsular prostatic artery branches and supply from other internal iliac pelvic branches. Unilateral embolisation at rPAE, where bilateral embolisation was not feasible (4/12), resulted in no difference in clinical outcomes compared with bilateral rPAE (p = 0.55). CONCLUSION: We have found rPAE to be an effective treatment for recurrent lower urinary tract symptoms in patients who had good clinical response to initial PAE. The mechanisms of revascularisation are variable, but most patients that underwent rPAE had recanalisation of their main prostatic artery.

The Impact of Radiobiologically Informed Dose Prescription on the Clinical Benefit of 90Y SIRT in Colorectal Cancer Patients.

The purpose of this study was to establish the dose-response relationship of selective internal radiation therapy (SIRT) in patients with metastatic colorectal cancer (mCRC), when informed by radiobiological sensitivity parameters derived from mCRC cell lines exposed to 90Y. Methods: Twenty-three mCRC patients with liver metastases refractory to chemotherapy were included. 90Y bremsstrahlung SPECT images were transformed into dose maps assuming the local dose deposition method. Baseline and follow-up CT scans were segmented to derive liver and tumor volumes. Mean, median, and D70 (minimum dose to 70% of tumor volume) values determined from dose maps were correlated with change in tumor volume and volumetric RECIST response using linear and logistic regression, respectively. Radiosensitivity parameters determined by clonogenic assays of mCRC cell lines HT-29 and DLD-1 after exposure to 90Y or external beam radiotherapy (EBRT; 6 MV photons) were used in biologically effective dose (BED) calculations. Results: Mean administered radioactivity was 1,469 ± 428 MBq (range, 847-2,185 MBq), achieving a mean absorbed radiation dose to tumor of 35.5 ± 9.4 Gy and mean normal liver dose of 26.4 ± 6.8 Gy. A 1.0 Gy increase in mean, median, and D70 absorbed dose was associated with a reduction in tumor volume of 1.8%, 1.8%, and 1.5%, respectively, and an increased probability of a volumetric RECIST response (odds ratio, 1.09, 1.09, and 1.10, respectively). Threshold mean, median and D70 doses for response were 48.3, 48.8, and 41.8 Gy, respectively. EBRT-equivalent BEDs for 90Y are up to 50% smaller than those calculated by applying protraction-corrected radiobiological parameters derived from EBRT alone. Conclusion: Dosimetric studies have assumed equivalence between 90Y SIRT and EBRT, leading to inflation of BED for SIRT and possible undertreatment. Radiobiological parameters for 90Y were applied to a BED model, providing a calculation method that has the potential to improve assessment of tumor control.

Long-term radiological and histological outcomes following selective internal radiation therapy to liver metastases from breast cancer.

Liver metastasis from breast cancer is associated with poor prognosis and is a major cause of early morbidity and mortality. When liver resection is not feasible, minimally invasive directed therapies are considered to attempt to prolong survival. Selective internal radiation therapy (SIRT) with yttrium-90 microspheres is a liver-directed therapy that can improve local control of liver metastases from colorectal cancer. We present a case of a patient with a ductal breast adenocarcinoma, who developed liver and bone metastasis despite extensive treatment with systemic chemotherapies. Following SIRT to the liver, after an initial response, the patient ultimately progressed in the liver after 7 months. Liver tumor histology obtained 20 months after the SIRT intervention demonstrated the presence of the resin microspheres in situ. This case report demonstrates the long-term control that may be achieved with SIRT to treat liver metastases from breast cancer that is refractory to previous chemotherapies, and the presence of microspheres in situ long-term.

Optimization of Image Reconstruction for 90Y Selective Internal Radiotherapy on a Lutetium Yttrium Orthosilicate PET/CT System Using a Bayesian Penalized Likelihood Reconstruction Algorithm.

Imaging on a γ-camera with 90Y after selective internal radiotherapy (SIRT) may allow for verification of treatment delivery but suffers relatively poor spatial resolution and imprecise dosimetry calculation. 90Y PET/CT imaging is possible on 3-dimensional, time-of-flight machines; however, images are usually poor because of low count statistics and noise. A new PET reconstruction software using a Bayesian penalized likelihood (BPL) reconstruction algorithm (termed Q.Clear) was investigated using phantom and patient scans to optimize the reconstruction for post-SIRT imaging and clarify whether BPL leads to an improvement in clinical image quality using 90Y. Methods: Phantom studies over an activity range of 0.5-4.2 GBq were performed to assess the contrast recovery, background variability, and contrast-to-noise ratio for a range of BPL and ordered-subset expectation maximization (OSEM) reconstructions on a PET/CT scanner. Patient images after SIRT were reconstructed using the same parameters and were scored and ranked on the basis of image quality, as assessed by visual evaluation, with the corresponding SPECT/CT Bremsstrahlung images by 2 experienced radiologists. Results: Contrast-to-noise ratio was significantly better in BPL reconstructions when compared with OSEM in phantom studies. The patient-derived BPL and matching Bremsstrahlung images scored higher than OSEM reconstructions when scored by radiologists. BPL with a ß value of 4,000 was ranked the highest of all images. Deadtime was apparent in the system above a total phantom activity of 3.3 GBq. Conclusion: BPL with a ß value of 4,000 is the optimal image reconstruction in PET/CT for confident radiologic reading when compared with other reconstruction parameters for 90Y imaging after SIRT imaging. Activity in the field of view should be below 3.3 GBq at the time of PET imaging to avoid deadtime losses for this scanner.

High-frequency jet ventilation under general anesthesia facilitates CT-guided lung tumor thermal ablation compared with normal respiration under conscious analgesic sedation.

PURPOSE: To determine whether technical difficulty of computed tomography (CT)-guided percutaneous lung tumor thermal ablations is altered with the use of high-frequency jet ventilation (HFJV) under general anesthesia (GA) compared with procedures performed with normal respiration (NR) under conscious sedation (CS). MATERIALS AND METHODS: Thermal ablation treatment sessions performed with NR under CS or HFJV under GA with available anesthesia records and CT fluoroscopic images were retrospectively reviewed; 13 and 33 treatment sessions, respectively, were identified. One anesthesiologist determined the choice of anesthesiologic technique independently. Surrogate measures of procedure technical difficulty--time duration, number of CT fluoroscopic acquisitions, and radiation dose required for applicator placement for each tumor--were compared between anesthesiologic techniques. The anesthesiologist time and complications were also compared. Parametric and nonparametric data were compared by Student independent-samples t test and χ(2) test, respectively. RESULTS: Patients treated with HFJV under GA had higher American Society of Anesthesiologists classifications (mean, 2.66 vs 2.23; P = .009) and smaller lung tumors (16.09 mm vs 27.38 mm; P = .001). The time duration (220.30 s vs 393.94 s; P = .008), number of CT fluoroscopic acquisitions (10.31 vs 19.13; P = .023), and radiation dose (60.22 mGy·cm vs 127.68 mGy·cm; P = .012) required for applicator placement were significantly lower in treatment sessions performed with HFJV under GA. There was no significant differences in anesthesiologist time (P = .20), rate of pneumothorax (P = .62), or number of pneumothoraces requiring active treatment (P = .19). CONCLUSIONS: HFJV under GA appears to reduce technical difficulty of CT-guided percutaneous applicator placement for lung tumor thermal ablations, with similar complication rates compared with treatment sessions performed with NR under CS. The technique is safe and may facilitate treatment of technically challenging tumors.

Microwave ablation of pulmonary malignancies using a novel high-energy antenna system.

PURPOSE: To evaluate the technical success, safety, and imaging follow-up of malignant pulmonary nodules treated with a novel high-energy percutaneous microwave ablation (MWA) system. METHODS: Between July 2010 and September 2011, a total of 23 patients, 12 men, mean age 68 (range 30-87) years with 29 pulmonary malignancies of median diameter 19 (range 8-57) mm, underwent computed tomography (CT)-guided MWA with a 16G microwave needle antenna enabling power up to 180 W. Technical success was defined as needle placement in the intended lesion without death or serious injury. Adequacy of ablation was assessed at 24 h on contrast-enhanced CT. Circumferential solid or ground glass opacification >5 mm was used to define an ideal ablation. Local tumor recurrence was assessed at 1, 3, and 6 months after ablation on contrast-enhanced CT. RESULTS: MWA was technically successful in 93 % (n = 27). Mean ablation duration was 3.6 (range 1-9) min. Ten patients (43 %) developed a pneumothorax as a result of the MWA; only 3 (13 %) required placement of a chest drain. Thirty-day mortality rate was 0 %. The mean hospital stay was 1.5 (range 1-7) days. A total of 22 lesions (75 %) were surrounded by ≥5 mm ground glass or solid opacification after the procedure. At a median follow-up of 6 months, local recurrence was identified in 3 out of 26 lesions, giving a local control rate of 88 %. CONCLUSION: MWA using a high-power antenna of pulmonary malignancies is safe, technically achievable, and enables fast ablation times.

Results of a seven-year, single-centre experience of the long-term outcomes of bovine ureter grafts used as novel conduits for haemodialysis fistulas.

PURPOSE: To report the long-term outcomes of bovine ureter grafts as novel conduits for haemodialysis fistulas. MATERIALS AND METHODS: Thirty-five patients underwent placement of a total of 40 SynerGraft 100 (SG100; CryoLife Europa(®), Guildford, UK) bovine ureter grafts between April 2002 and February 2009. Prospective data were collected on all patients, including active surveillance with blood flow studies and 6-monthly duplex ultrasound studies. Main outcome measures were primary and secondary patency rates. RESULTS: Mean follow-up time was 97 weeks (range 4-270). Thirteen patients died from unrelated causes during the study period; 12 of these patients had a functioning graft at the time of death. Five patients underwent transplantation, and all had a functioning graft at transplantation. Twelve patients had a functioning graft at the end of the study period. One hundred and ten stenoses were detected, and 97 venoplasty procedures were performed. Of the stenoses, 41.8% were located at the venous anastomosis, 12.7% within the graft, 17.3% in the outflow veins, and 28.1% in central veins. No arterial stenoses were detected. Primary patency rates were 53% at 6 months and 14% at 1 year. Secondary patency rates were 81% at 6 months, 75% at 1 year, and 56% at 2 years. CONCLUSIONS: Active surveillance and intervention was able to achieve satisfactory long-term secondary patency for these novel conduits compared with those made of PTFE seen in other studies [1].

StarClose vascular closure device: prospective study on 222 deployments in an interventional radiology practice.

The StarClose device (Abbott Vascular Devices; Abbott Laboratories, Redwood City, CA) utilizes an externally placed Nitinol clip to achieve arterial closure following femoral artery puncture. The objectives of this study were to assess the efficacy and complications of the StarClose device in patients undergoing interventional radiological procedures. Preprocedural clotting status, pulse and blood pressure, severity of vessel calcification, sheath size, and time to deployment were recorded. Postdeployment complications immediately postprocedure, at 1 h, at 2 h, and at 1 week were recorded. A duplex scan was performed in the first 10 patients to assess any immediate vascular complications. Deployments were successful in 96% achieving immediate hemostasis. Mean deployment time was 48 s. There were no major complications. The StarClose device was found to have a high technical and clinical efficacy.

Anatomic and functional imaging of metastatic carcinoid tumors.

Carcinoid tumors are a fascinating group of neuroendocrine neoplasms that develop either sporadically or as part of an inheritable syndrome. Many tumors arise in the bronchopulmonary or gastrointestinal tract, but a neuroendocrine tumor can arise in almost any organ. The tumors have varied malignant potential depending on the site of their origin, and the clinical manifestations often are nonspecific. Metastases may be present at the time of diagnosis, which often occurs at a late stage of the disease. Imaging plays a pivotal role in the localization and staging of neuroendocrine tumors and in monitoring the treatment response. Imaging is often challenging, and a combination of anatomic and functional techniques is usually required, depending on the tumor type and location. Techniques include ultrasonography, barium studies, endoscopy, computed tomography, magnetic resonance imaging, somatostatin receptor scintigraphy, iobenguane scintigraphy, and, in select cases, positron emission tomography. Coregistration of structural and functional images is often of incremental value for accurate localization of the primary tumor and any meta-static disease. Radiologists must understand the contribution of each imaging modality in the assessment of different neuroendocrine tumors. In addition, knowledge of the optimal technique for each radiologic and radionuclide imaging examination is essential. Familiarity with the protean imaging appearances of both primary and metastatic disease is essential for accurate staging, treatment monitoring, and surveillance. Finally, an understanding of the wide variety of treatment options for patients with carcinoid tumors is vital for optimal management.

Diagnostic imaging of and radiologic intervention for bovine ureter grafts used as a novel conduit for hemodialysis fistulas.

OBJECTIVE: The objectives of our study were to review the appearances on diagnostic imaging and amenability to imaging-guided intervention of a novel bovine ureter graft (Syner-Graft 100 [SG 100]) for use as a conduit for hemodialysis fistulas. CONCLUSION: The SG 100 shows initial promise as a conduit for hemodialysis fistulas in patients with difficult vascular access. The SG 100 has characteristic appearances on diagnostic imaging and is prone to similar pathologic processes that affect autogenous venous and synthetic grafts. These grafts are readily amenable to imaging-guided percutaneous intervention, which plays a major role in prolonging graft function.

Seizures after aneurysmal subarachnoid hemorrhage treated with coil embolization.

OBJECTIVE: We sought to determine the incidence of seizures among patients treated with endovascular coil embolization for ruptured intracranial aneurysms because data on which to base antiepileptic drug (AED) prescriptions and advice to patients regarding driving motor vehicles and other high-risk activities are currently lacking. METHODS: We conducted a single-institute, single-operator observational study of 243 patients referred for endovascular treatment after aneurysmal subarachnoid hemorrhage. Prospective data collection was performed, and all successfully treated patients were followed. The incidence of seizures was compared with published surgical data, and logistic regression analysis of potential clinical associations was performed. Patients were followed for up to 7.7 years (mean follow-up period, 21.9 mo). RESULTS: Ictal seizures occurred at the time of subarachnoid hemorrhage in 26 (11%) of 243 patients and correlated with middle cerebral artery aneurysm location, loss of consciousness at ictus, and AED prescription. No patients experienced periprocedural seizures during their hospitalization. Seven of 233 successfully treated patients (3%) experienced seizures more than 30 days after treatment: late seizures occurred de novo in four patients (1.7%) and in three patients (1.4%) were caused by preexisting epilepsy. Two patients (0.85%) who had de novo seizures developed epilepsy. Late seizures correlated with a history of previous seizures, the presence of a cerebrospinal fluid shunt, and the use of AEDs. CONCLUSION: The low incidence of seizures does not justify the use of prophylactic AED therapy after aneurysmal subarachnoid hemorrhage in patients treated solely with coil embolization, nor does it justify subsequent restrictions on the driving of motor vehicles if the patient is otherwise fit to drive.