Reduction of contrast medium volume in abdominal aorta CTA: Multiphasic injection technique versus a test bolus volume

Objective:\ud The purpose of this study is to reduce the administered contrast medium volume in abdominal CTA by using a test bolus injection, with the preservation of adequate quantitative and qualitative vessel enhancement.\ud \ud Study design:\ud For this technical efficacy study 30 patients, who were referred for a CTA examination of the abdominal aorta, were included. Randomly 15 patients were assigned to undergo a multiphasic injection protocol and received 89 mL of contrast medium (Optiray 350) (protocol I). Fifteen patients were assigned to the test bolus injection protocol (protocol II), which implies injection of a 10 mL test bolus of Optiray 350 prior to performing CTA with a 40 mL of contrast medium. Quantitative assessment of vascular enhancement was performed by measuring the amount of Hounsfield Units in the aorta at 30 positions from the celiac trunk to the iliac arteries in both groups. Qualitative assessment was performed by three radiologists who scored the images at a 5-point scale.\ud \ud Results:\ud Quantitative assessment showed that there was no significant difference in vascular enhance- ment for patients between the two protocols, with mean attenuation values of 280.9±50.84HU and 258.60 ± 39.28 HU, respectively. The image quality of protocol I was rated 4.31 (range: 3.67/5.00) and of protocol II 4.11 (range: 2.67/5.00). These differences were not statistically significant.\ud \ud Conclusion:\ud This study showed that by using a test bolus injection and the administration of 50 mL of con- trast medium overall, CTA of the abdominal aorta can reliably be performed, with regard to quantitative and qualitative adequate vessel enhancement

Is IORT ready for roll-out?

Two large randomised controlled trials of intraoperative radiotherapy (IORT) in breast-conserving surgery (TARGIT-A and ELIOT) have been published 14 years after their launch. Neither the TARGIT-A trial nor the ELIOT trial results have changed the current clinical practice for the use of IORT. The in-breast local recurrence rate (LRR) after IORT met the pre-specified non-inferiority margins in both trials and was 3.3% in TARGIT-A and 4.4% in the ELIOT trial. In both trials, the pre-specified estimates for local recurrence (LR) with external beam radiation therapy (EBRT) significantly overestimated actual LRR. In the TARGIT-A trial, LR with EBRT was estimated at the outset to be 6%, and in the ELIOT trial, it was estimated to be 3%. Surprisingly, LRR in the EBRT groups has been found to be significantly lower, 1.3% in the EBRT arm of the TARGIT-A and 0.4% in the EBRT arm of the ELIOT trial, respectively. Median follow-up was 2.4 years for the TARGIT-A trial and 5.8 years for the ELIOT trial. However, the initial cohort of patients in the TARGIT-A trial (reported in 2010) now have a median follow-up of 3.8 years and data on LR were available at 5 years follow-up on 35% of patients (18% who received IORT). Although further follow-up will increase confidence with the data, it will also further delay clinical implementation. By carefully weighing the risks and benefits of a single-fraction radiation treatment with patients, IORT should be offered within agreed and strict protocols. Patients deemed at low risk of LR or those deemed suitable for partial breast irradiation, according to the GEC-ESTRO and ASTRO recommendations, could be considered as candidates for IORT. These guidelines apply to all partial breast irradiation techniques, and more specific guidelines for IORT would assist clinicians

Reduced contrast medium in abdominal aorta CTA using a multiphasic injection technique

Purpose: The purpose of this study was to determine if with a multiphasic injection technique the admin- istered amount of contrast medium for abdominal computerized tomographic angiography (CTA) can be decreased, whilst improving CT image quality. Materials and methods: In 30 patients a multiphasic injection method was compared to the standard uniphasic contrast medium injection protocol. Fifteen patients underwent abdominal CTA with a standard uniphasic injection protocol (protocol I) receiving 100 mL of a non-ionic radiopaque contrast agent (Iover- sol). The second group of 15 patients underwent CTA with a multiphasic injection protocol (protocol II) receiving a total of 89 mL Ioversol. Vascular contrast enhancement and difference in enhancement uni- formity were assessed quantitatively and image quality was assessed by three independent radiologists. Results: Quantitative assessment of the vascular contrast enhancement showed that there was no signif- icant difference in enhancement uniformity for patients between the protocols. The image quality was rated as being good to excellent in 81.8% and 88.0% of the scans, for protocol I and protocol II, respectively. However these differences were not statistically significant.\ud Conclusion: By using a multiphasic injection technique with CTA of the abdominal aorta a reduction of 11 percent of contrast medium can be realized. Enhancement patterns are quantitatively as well as qualitatively comparable to the standard contrast medium injection protocol

Comparison of three magnetic nanoparticle tracers for sentinel lymph node biopsy in an in vivo porcine model

INTRODUCTION: Breast cancer staging with sentinel lymph node biopsy relies on the use of radioisotopes, which limits the availability of the procedure worldwide. The use of a magnetic nanoparticle tracer and a handheld magnetometer provides a radiation-free alternative, which was recently evaluated in two clinical trials. The hydrodynamic particle size of the used magnetic tracer differs substantially from the radioisotope tracer and could therefore benefit from optimization. The aim of this study was to assess the performance of three different-sized magnetic nanoparticle tracers for sentinel lymph node biopsy within an in vivo porcine model. MATERIALS AND METHODS: Sentinel lymph node biopsy was performed within a validated porcine model using three magnetic nanoparticle tracers, approved for use in humans (ferumoxytol, with hydrodynamic diameter d(H) =32 nm; Sienna+(®), d(H) =59 nm; and ferumoxide, d(H) =111 nm), and a handheld magnetometer. Magnetometer counts (transcutaneous and ex vivo), iron quantification (vibrating sample magnetometry), and histopathological assessments were performed on all ex vivo nodes. RESULTS: Transcutaneous “hotspots” were present in 12/12 cases within 30 minutes of injection for the 59 nm tracer, compared to 7/12 for the 32 nm tracer and 8/12 for the 111 nm tracer, at the same time point. Ex vivo magnetometer counts were significantly greater for the 59 nm tracer than for the other tracers. Significantly more nodes per basin were excised for the 32 nm tracer compared to other tracers, indicating poor retention of the 32 nm tracer. Using the 59 nm tracer resulted in a significantly higher iron accumulation compared to the 32 nm tracer. CONCLUSION: The 59 nm tracer demonstrated rapid lymphatic uptake, retention in the first nodes reached, and accumulation in high concentration, making it the most suitable tracer for intraoperative sentinel lymph node localization

Optimising Magnetic Sentinel Lymph Node Biopsy in an in vivo Porcine Model

The magnetic technique for sentinel lymph node biopsy (SLNB) has been evaluated in several clinical trials. An in vivo porcine model was developed to optimise the magnetic technique by evaluating the effect of differing volume, concentration and time of injection of magnetic tracer. A total of 60 sentinel node procedures were undertaken. There was a significant correlation between magnetometer counts and iron content of excised sentinel lymph nodes (SLNs) (r = 0.82; P < 0.001). Total number of SLNs increased with increasing volumes of magnetic tracer (P < 0.001). Transcutaneous magnetometer counts increased with increasing time from injection of magnetic tracer (P < 0.0001), plateauing within 60 min. Increasing concentration resulted in higher iron content of SLNs (P = 0.006). Increasing magnetic tracer volume and injecting prior to surgery improve transcutaneous ‘hotspot’ identification but very high volumes, increase the number of nodes excise