Evaluation of 70–150-μm doxorubicin-eluting beads for transcatheter arterial chemoembolization in the rabbit liver VX2 tumour model

Aim

To evaluate the pharmacokinetic profile (PK) and embolization effect of 70–150-μm doxorubicin eluting beads (DEBs) following intra-arterial injection (i.a.) in the rabbit liver VX2 tumour model.

Materials and methods

In this ACUC-approved study, 25 white New Zealand rabbits were randomly assigned into a small DEB group (SDB, n?=?7, 70–150-μm DEBs), large DEB group (LDB, n?=?7, 100–300-μm DEBs), untreated controls (n?=?7), and doxorubicin controls (n?=?4, without tumour, received i.a. 12.5 mg doxorubicin). Plasma PK was assessed up to 180 min post-injection. Drug tissue and liver enzyme levels, radiologic tumor response and histopathologic tumour necrosis were assessed at 7 days.

Results

Mean tumour doxorubicin concentrations were 922.83 nM (SD?=?722.05) and 361.48 nM (SD?=?473.23) for the SDB and LDB, respectively (p?=?0.005). There was no statistically significant difference in tumour doxorubicinol, plasma doxorubicin and doxorubicinol PK values. More beads were observed in the SDB tumours (p?=?0.01). Liver enzymes increased and gradually declined over the observation period, with significantly higher values in the SDB.

Conclusion

In this preclinical study, plasma PK of i.a.-injected 70–150-μm DEBs was not different than that of 100–300-μm DEBs. More beads and higher tissue doxorubicin levels were observed in the SDB tumours.

Key Points

? Small and large doxorubicin-eluting beads show similar plasma pharmacokinetic profiles.? Higher tissue doxorubicin levels were observed in the small bead group.? Liver enzymes were overall significantly higher in the small bead group.

     

Scoring systems used for the interpretation and reporting of multiparametric MRI for prostate cancer detection,localization, and characterization: could standardization lead to improved utilization of imaging within the diagnostic pathway?

Multiparametric magnetic resonance imaging (mpMRI) is increasingly being used earlier in the prostate cancer diagnostic pathway in order to detect and localize disease. Its results can be used to help decide on the indication, type, and localization of a prostate biopsy for cancer diagnosis. In addition, mpMRI has the potential to contribute information on the characterization, or aggressiveness, of detected cancers including tumor progression over time. There is considerable variation in the way results of different MRI sequences are reported. We conducted a review of scoring systems that have been used in the detection and characterization of prostate cancer. This revealed that existing scoring and reporting systems differ in purpose, scale, and range. We evaluate these differences in this review. This first step in collating all methods of scoring and reporting mpMRI will ultimately lead to consensus approaches to develop a standardized reporting scheme that can be widely adopted and validated to ensure comparability of research outputs and optimal clinical practice. J. Magn. Reson. Imaging 2013;37:48–58.     

Computer simulated “Virtual TAVR” to guide TAVR in the presence of a previous Starr-Edwards mitral prosthesis

BackgroundWe evaluated the utility of the HeartNavigator III software (Philips Healthcare, Netherlands) to create a patient specific three-dimensional model using ECG-gated CT images to plan Transcatheter Aortic Valve Replacement (TAVR) in a patient with previous Starr-Edwards mitral prosthesis.MethodsA patient with a previous Starr-Edwards mitral prosthesis considered too high risk for conventional surgery required TAVR. It was uncertain whether this would be possible whilst avoiding the complication of the aortic prosthesis interacting with the high-profile Starr-Edwards cage and ball valve mechanism. To ensure it would be feasible and aid in the planning of the procedure a patient specific three-dimensional model was created from ECG-gated CT images using HeartNavigator III software (Philips Healthcare, Netherlands).ResultsThe patient specific model allowed simulated “virtual” TAVR implantations to be performed with different models and sizes of aortic prosthesis. These pre-implant simulations allowed a safe and feasible implant strategy to be chosen. The images were also co-registered with fluoroscopy to guide deployment.ConclusionUsing a patient-specific CT simulation technique we performed TAVR with a high level of precision, achieving a clear margin between a Portico (Abbot Vascular, US) TAVR and the Starr-Edwards cage.     

Contrast-enhanced MR imaging of the spine: when, why and how? How to optimize contrast protocols in MR imaging of the spine

The optimal protocols and the role of contrast agents in spinal MR imaging are controversial. Although the diagnosis of many common spinal diseases can be reliably achieved by means of unenhanced images, contrast use is often necessary to improve lesion detection and differential diagnosis. The heterogeneity of the different spinal compartments and the wide variety of spinal pathology require tailored imaging strategies. Thus, the rules to achieve optimization of contrast protocols for MR imaging of the spine are frequently very different to those for brain imaging, and depend on the location and site of origin of the lesions in a specific spinal compartment, on the findings of unenhanced imaging, and on the concomitant use of fat-suppression techniques. Furthermore, in most cases, the small size of the examined structures requires a meticulous technique, and the administration of a contrast agent with high relaxivity, such as MultiHance, is advisable to enable the detection of tiny areas of contrast enhancement. The applications and clinical utility of post-contrast MR imaging are discussed with regard to different spinal diseases.     

The addition of interstitial needles to intracavitary applicators in the treatment of locally advanced cervical cancer: Why is this important and how to implement in low- and middle-income countries?

PurposeCervical cancer is the leading cause of cancer mortality of women in low-/middle-income countries. Interstitial needles improve outcomes but require resources beyond those available in endemic regions. We conducted a retrospective review of the use of interstitial needles in locally advanced cervical cancer and simulated both 3D planning without needles and 2D planning to explore the benefit of interstitial needles.Methods and Materials57 brachytherapy plans of 17 patients who had intracavitary tandem and ring plus interstitial brachytherapy were reviewed. Prescribed dose was 7 Gy × four fractions. 2D plans prescribed to point A were generated to represent a standard Manchester loading. Dosimetric outcomes to clinical target volume and organs at risk (OARs) were compared with those of 3D-based plans.ResultsHigh-risk clinical target volume coverage was excellent: 93.2% for 2D plans, 93.9% for 3D plans without needles, and 96.2% for 3D with needles. The mean dose to 90% of target was 8.5 Gy/fraction for 2D plans, 7.5 for 3D without needles, and 7.9 Gy/fraction for 3D with needles. However, the 2D plans delivered 12% above recommended dose constraints for OARs (except rectum). Dosimetric differences were found between 3D planning and 3D with needles for target coverage (p = 0.002). Dose to OARs was significantly lower when 3D plans with needles were compared with 2D plans.ConclusionsInterstitial needles provide an optimal therapeutic ratio for patients with high-volume disease or/and unfavorable topography. This justifies additional capital investment in resources for implementation to provide optimal treatment for locally advanced cervical cancer globally.     

A Review of: “Children,Medicine and the Law”

Halley, M.M., Fowks, R.J., Bigler, F.C., Ryan, D.L. (Charles C Thomas, Publishers, Springfield, Illinois, 1990), 289 pages, $49.75.     

“Black bone” MRI: a potential alternative to CT when imaging the head and neck: report of eight clinical cases and review of the Oxford experience

Objective

The potential risks associated with ionising radiation are well documented. We have previously reported the “black bone” MRI sequence, useful when imaging cortical bone. The objective of this paper is to report our initial experience of this technique in patients undergoing imaging of the head and neck region.

Methods

Using the departmental database those patients having had “black bone” sequences of the head and neck performed as part of their MRI examination in the preceding 5 years were identified. The radiological reports were reviewed to identify those cases where “black bone” or conventional MRI sequences had been performed in place of the requested CT, and the patient medical records for these cases were reviewed. Medical record review was also conducted for those cases where it was considered that the pathological condition requiring imaging would ordinarily be investigated with CT.

Results

The “black bone” sequence had been performed in 69 patients as part of routine MRI of the head and neck. Of these, 67% (n=46) were performed in combination with CT imaging, the majority of cases being primary tumours. In four cases, an MRI was performed in place of the requested CT scan. We present eight clinical cases illustrating the potential benefits of the “black bone” sequence.

Conclusions

“Black bone” MRI offers a radiation-free method of imaging the head and neck, and has been successfully utilised in a range of benign and malignant conditions affecting this region.

Advances in knowledge

Adoption of this approach, where feasible, would be a significant advance in radiation protection.Hounsfield, in his 1973 paper on CT, stated that “the exposure of the patient to x-rays must be restricted” [1]. The potential risks of ionising radiation are well documented; however, we continue to fall short of Hounsfield’s advice because of increased imaging demands through a combination of defensive medicine, a decrease in exploratory surgery and the ability to meet the increased requests for CT. The largest increases in CT use have been in paediatric diagnosis and adult screening [2]. Further concern relates to the use of cone-beam CT, with scanners being installed and used in a rapidly increasing number of dental practices within the UK [3]. During the year 2002–3 the National Health Service in England [4] reported 1.7 million CT examinations, representing 8% of all X-ray examinations, and 6% of all imaging investigations. By 2009–10 this had risen to over 3.7 million: 13% and 10%, respectively. The United Nations Scientific Committee estimated that CT constitutes 5% of all X-ray examinations worldwide while accounting for about 34% of the resultant collective dose [5].The consensus among radiology professionals is that steps should be taken to reverse, or at least arrest, radiation exposure from CT [6]; yet for maxillo-cranio-facial imaging this has largely consisted of radiation reduction techniques and the introduction of cone-beam CT. The superior quality of bony imaging on CT and the ability to create three-dimensional (3D) rendered images of the craniofacial skeleton has maintained CT as the gold standard for this region.However, we have been increasingly utilising MRI when imaging the head and neck, following close collaboration between the MRI and oral and maxillofacial departments. In particular, we have previously reported the “black bone” MRI sequence for imaging cortical bone as a potential replacement for CT [7]. The technique utilises a low flip angle, with short repetition and echo times, to produce uniform contrast of the soft tissues, with densely black cortical bone. The imaging parameters are shown in

Role of magnetic resonance imaging in entrapment and compressive neuropathy—what, where, and how to see the peripheral nerves on the musculoskeletal magnetic resonance image: part 2. Upper extremity

The diagnosis of nerve entrapment and compressive neuropathy has been traditionally based on the clinical and electrodiagnostic examinations. As a result of improvements in the magnetic resonance (MR) imaging modality, it plays not only a fundamental role in the detection of space-occupying lesions, but also a compensatory role in clinically and electrodiagnostically inconclusive cases. Although ultrasound has undergone further development in the past decades and shows high resolution capabilities, it has inherent limitations due to its operator dependency. We review the course of normal peripheral nerves, as well as various clinical demonstrations and pathological features of compressed and entrapped nerves in the upper extremities on MR imaging, according to the nerves involved. The common sites of nerve entrapment of the upper extremity are as follows: the brachial plexus of the thoracic outlet; axillary nerve of the quadrilateral space; radial nerve of the radial tunnel; ulnar nerve of the cubital tunnel and Guyon’s canal; median nerve of the pronator syndrome, anterior interosseous nerve syndrome, and carpal tunnel syndrome. Although MR imaging can depict the peripheral nerves in the extremities effectively, radiologists should be familiar with nerve pathways, common sites of nerve compression, and common space-occupying lesions resulting in nerve compression in MR imaging.     

A report on the Academic Emergency Medicine 2015 consensus conference “Diagnostic imaging in the emergency department: a research agenda to optimize utilization”

In May 2015, the Academic Emergency Medicine consensus conference “Diagnostic imaging in the emergency department: a research agenda to optimize utilization” was held. The goal of the conference was to develop a high-priority research agenda regarding emergency diagnostic imaging on which to base future research. In addition to representatives from the Society of Academic Emergency Medicine, the multidisciplinary conference included members of several radiology organizations: American Society for Emergency Radiology, Radiological Society of North America, the American College of Radiology, and the American Association of Physicists in Medicine. The specific aims of the conference were to (1) understand the current state of evidence regarding emergency department (ED) diagnostic imaging utilization and identify key opportunities, limitations, and gaps in knowledge; (2) develop a consensus-driven research agenda emphasizing priorities and opportunities for research in ED diagnostic imaging; and (3) explore specific funding mechanisms available to facilitate research in ED diagnostic imaging. Through a multistep consensus process, participants developed targeted research questions for future research in six content areas within emergency diagnostic imaging: clinical decision rules; use of administrative data; patient-centered outcomes research; training, education, and competency; knowledge translation and barriers to imaging optimization; and comparative effectiveness research in alternatives to traditional computed tomography use.     

Strecker stent migration to the pulmonary artery: long-term result of a “wait-and-see attitude”

Accidental dislodgement of an endoprosthesis into the right cavities or the pulmonary artery is a rarely described complication of percutaneous venous stenting. In such cases the migrated stent needs to be promptly extracted by percutaneous techniques in order to avoid any major complication. We report the first case of a delayed Strecker stent migration from the left inominate vein into the right pulmonary artery, successfully managed with anticoagulant therapy and a “wait-and-see” attitude. The advanced stage-disease (metastatic cancer patient) and the large-caliber stent in a disease-free pulmonary artery led us to adopt this unorthodox attitude, as compared with the current clinical practice. Received: 26 May 2000 Revised: 11 August 2000 Accepted: 11 August 2000     

The “mystery” of the train station: The importance of a forensic approach to a rare case of survival after a train-pedestrian collision

In the early morning a 28-year-old man was found lying on the tracks of a railway station with head injuries and fractures of the cervical spine resulting in permanent quadriplegia. He was in a club about 1 km away until about 2 h earlier and did not have any recollection of what could have happened. Was he the victim of an assault, did he fall down or was he hit by a passing train? The solution to this “mystery” came from a forensic evaluation that included the forensic branches of pathology, chemistry, merceology and genetics as well as the scene evaluation. Through these different steps, the role of a railway collision in determining the injuries was ascertained and a possible dynamic was postulated. The presented case is an expression of the importance of the different forensic disciplines and the difficulties the forensic pathologist encounters when analysing such peculiar and rare cases.