Phantom validation of quantitative Y-90 PET/CT based dosimetry in liver radioembolisation

Background PET/CT has recently been shown to be a viable alternative to traditional post-infusion imaging methods providing good quality images of 90Y-laden microspheres after selective internal radiation therapy (SIRT). In the present paper, first we assessed the quantitative accuracy of 90Y-PET using an anthropomorphic phantom provided with lungs, liver, spine, and a cylindrical homemade lesion located into the hepatic compartment. Then, we explored the accuracy of different computational approaches on dose calculation, including (I) direct Monte Carlo radiation transport using Raydose, (II) Kernel convolution using Philips Stratos, (III) local deposition algorithm, (IV) Monte Carlo technique (MCNP) considering a uniform activity distribution, and (V) MIRD (Medical Internal Radiation Dose) analytical approach. Finally, calculated absorbed doses were compared with those obtained performing measurements with LiF:Mg,Cu,P TLD chips in a liquid environment. Results Our results indicate that despite 90Y-PET being likely to provide high-resolution images, the 90Y low branch ratio, along with other image-degrading factors, may produce non-uniform activity maps, even in the presence of uniform activity. A systematic underestimation of the recovered activity, both for the tumor insert and for the liver background, was found. This is particularly true if no partial volume correction is applied through recovery coefficients. All dose algorithms performed well, the worst case scenario providing an agreement between absorbed dose evaluations within 20%. Average absorbed doses determined with the local deposition method are in excellent agreement with those obtained using the MIRD and the kernel-convolution dose calculation approach. Finally, absorbed dose assessed with MC codes are in good agreement with those obtained using TLD in liquid solution, thus confirming the soundness of both calculation approaches. This is especially true for Raydose, which provided an absorbed dose value within 3% of the measured dose, well within the stated uncertainties. Conclusions Patient-specific dosimetry is possible even in a scenario with low true coincidences and high random fraction, as in 90Y–PET imaging, granted that accurate absolute PET calibration is performed and acquisition times are sufficiently long. Despite Monte Carlo calculations seeming to outperform all dose estimation algorithms, our data provide a strong argument for encouraging the use of the local deposition algorithm for routine 90Y dosimetry based on PET/CT imaging, due to its simplicity of implementation

Biosimilars: the paradox of sharing the same pharmacological action without full chemical identity

The use of biotech medicines is increasing, with consequent mounting expenses for National Health Systems (NHSs). Biosimilars should be considered an opportunity to improve access to care. On the other side, the general public might suspect to receive low-quality medicines to save money. Actually, no drugs with a lesser degree of pharmaceutical quality with respect to existing alternatives can be authorized on the ground of a lower price. Biosimilars can be authorized only if their quality is of the same level as that of the originator. There is no chemical identity between biosimilars and the originators: any differences in quality attributes must be justified and shown not to impact on the safety and efficacy of the biosimilar by scientific investigations including pre-approval nonclinical and/or clinical studies. The biosimilar safety profile may be different from the originator or change over time for the same product. Hence caveats limiting the widespread use of biosimilars yet exist and should be solved by education on the main biological issues of biotech medicines, and on continuous update of the rules set up by the Regulatory Authorities to assess biosimilarity and to monitor post-approval safety

OCULAR DISPOSITION OF ACETAMINOPHEN AND ITS METABOLITES FOLLOWING INTRAVENOUS ADMINISTRATION IN RABBITS

Time-courses of both 'total' (unchanged plus metabolized) and unmetabolized acetaminophen were investigated in plasma and ocular tissues of rabbit after intravenous administration. The drug freely diffuses across the haemato-ocular barriers, reaching eye levels equal to those in the plasma; ocular concentrations are higher than those of all other investigated drugs. The time-course in aqueous is superimposable to that observed in the plasma; in other ocular tissues it is much slower. There is evidence of an ocular metabolism or a concentration into the eye of minor metabolites formed elsewhere

OCULAR ABSORPTION AND DISTRIBUTION OF BENDAZAC AFTER TOPICAL ADMINISTRATION TO RABBITS WITH DIFFERENT VEHICLES

Ocular and systemic absorption of bendazac was investigated after topical administration to rabbits of 0.5 % solutions of bendazac lysine in different polysaccharide vehicles. The results show that the drug is absorbed into the retina-choroid via an extracorneal, or sclero-conjunctival route; the iris and the ciliary body are presumably supplied via both the transcorneal and the extracorneal pathways. The extent of absorption via the extracorneal route is not related to vehicle viscosity but rather to the chemical features of vehicle. The transcorneal penetration appears to be hindered by the binding of the drug to corneal tissues

Kounis Syndrome: An analysis of spontaneous reports from international pharmacovigilance database

Introduction The coincidental occurrence of a cardiac symptomatology (e.g. an acute coronary syndrome or a myocardial infarction), during an anaphylactic or anaphylactoid episode is known as Kounis Syndrome. A variety of drugs, substances, food and environmental exposures are associated with this reaction. There is an exponential increase in the number of published scientific articles reports on this syndrome, but since it is rare, the largest case series published so far included only 10 and 6 patients. Methods We searched the global World Health Organization database called VigiBase™ to detect all cases of Kounis Syndrome ever reported (last update December 31st 2014). Results We identified 51 cases of Kounis Syndrome reported to International Pharmacovigilance Agency (VigiBase™). All these cases were reported in the period 2010-2014 and almost half cases (22 reports) belonged to the year 2014. Most cases occurred in the USA and non-steroidal anti-inflammatory drugs were the most frequent trigger drugs. Discussion We collected pharmacovigilance international data representing the largest case series ever published on the recently identified Kounis Syndrome

Comparing safety information of biosimilars with their originators: a cross-sectional analysis of European risk management plans

Biosimilars have been available in the European Union (EU) since 2006. However, their uptake in routine care is heterogeneous across countries. The aim of the present study was to compare the safety information of biosimilars and their originators based on the information in the European risk management plan (RMP). A cross-sectional analysis on publicly available regulatory documents (RMPs and Summaries of Product Characteristics) of biosimilars and corresponding originators up to 1 November 2015 was performed. The safety concerns were extracted and merged into general safety concerns, and clinical relevance was assessed. The frequency of safety concerns and the representation of these safety concerns per general safety concern were assessed by either comparing RMPs of biosimilars and originators (if available for both) or comparing RMPs with the Summary of Product Characteristics of the originator. Nineteen biosimilars and six originators were included. Overall, 55 general safety concerns (12 low, 21 medium and 22 highly clinically relevant) were identified. For all active substances, except for infliximab, no or only one difference was found in the listed general safety concerns. Comparison of regulatory documents for infliximab identified three medium clinically relevant general safety concerns more for infliximab biosimilars and two general safety concerns more for its originator. Based on publicly available information filed for regulatory purposes, no substantial differences were observed in the reporting of safety information for biosimilars and related originators. A direct comparison between biosimilars and related originators through formal postmarketing studies is needed to evaluate specific safety issues emerging during the products' life cycle

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): A National Analysis of Data from 10-Year Post-marketing Surveillance

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare, severe and potentially fatal cutaneous adverse drug reaction (the mortality rate is up to 10 %) associated with numerous and apparently heterogeneous drugs. The aetiology is unknown. To report Italian cases of DRESS over a 10-year period. We searched the National Pharmacovigilance Network (NPN) for the term 'drug reaction with eosinophilia and systemic symptoms' from 1 January 2004 to 1 January 2014, to identify all reports of DRESS. Each case was checked to avoid duplication. In the NPN, we identified 91 serious cases of DRESS: 68 were spontaneous, still-unpublished reports, while 23 additional cases were derived from screening of the scientific literature, performed by marketing authorization holders. Notably, the single common element linking all cases of DRESS was intake of a drug containing an aromatic ring. Thanks to the largest national DRESS case series ever reported, we were able to hypothesize, for the first time, that there is an association between use of drugs containing an aromatic ring in their chemical structure and DRESS. This might aid understanding of the aetiology of DRESS and facilitate diagnosis