The effect of flight line spacing on radioactivity inventory and spatial feature characteristics of airborne gamma-ray spectrometry data

Airborne Gamma Spectrometry (AGS) is well suited to the mapping of radioactivity in the environment. Flight parameters (e.g. speed and line spacing) directly affect the rate of area coverage, cost, and data quality of any survey. The influences of line spacing have been investigated for data from inter‐tidal, coastal and upland environments with a range of <sup>137</sup>Cs activity concentrations and depositional histories. Estimates of the integrated <sup>137</sup>Cs activity (‘inventory’) within specified areas and the shapes of depositional features were calculated for subsets of the data at different line spacings. Features with dimensions greater than the line spacing show variations in inventory and area of less than 3%, and features with dimensions less than the line spacing show larger variations and a decreased probability of detection. The choice of line spacing for a task is dependent on the dimensions of the features of interest and required edge definition. Options for line spacing for different tasks are suggested. It is noted that for regional mapping, even 5–10 km line spacing can produce useful data

European Medicines Agency review of ixazomib (Ninlaro) for the treatment of adult patients with multiple myeloma who have received at least one prior therapy

On 21 November 2016, the European Commission issued a marketing authorisation valid throughout the European Union for ixazomib in combination with lenalidomide and dexamethasone for the treatment of adult patients with multiple myeloma who have received at least one prior therapy. Ixazomib was evaluated in one, randomised, double-blind, phase III study comparing ixazomib plus lenalidomide and dexamethasone (n=360; ixazomib arm) versus placebo plus lenalidomide and dexamethasone (n=362; placebo arm) in adult patients with relapsed and/or refractory multiple myeloma who had received at least one prior therapy. The median progression-free survival (PFS) in the intent-to-treat population was 20.6 months in patients treated with ixazomib compared with 14.7 months for patients in the placebo arm (stratified HR=0.742, 95% CI 0.587 to 0.939, stratified p-value=0.012). The most frequently reported adverse reactions (≥20%) within the ixazomib and placebo arms were diarrhoea (42% vs 36%), constipation (34% vs 25%), thrombocytopaenia (28% vs 14%), peripheral neuropathy (28% vs 21%), nausea (26% vs 21%), peripheral oedema (25% vs 18%), vomiting (22% vs 11%) and back pain (21% vs 16%). The scientific review concluded that the gain in PFS of 5.9 months observed with ixazomib was considered clinically meaningful. Concerning the possible uncertainty about the magnitude of the effect, this uncertainty was acceptable given the favourable toxicity profile, and considering that ixazomib is the first agent to allow oral triple combination therapy in this patient population which represents a therapeutic innovation in terms of convenience for patients. Therefore, the benefit-risk for ixazomib in combination with lenalidomide and dexamethasone was considered positive, although the efficacy evidence was not as comprehensive as normally required

How to calculate the dose of chemotherapy

Body surface area-dosing does not account for the complex processes of cytotoxic drug elimination. This leads to an unpredictable variation in effect. Overdosing is easily recognised but it is possible that unrecognised underdosing is more common and may occur in 30% or more of patients receiving standard regimen. Those patients who are inadvertently underdosed are at risk of a significantly reduced anticancer effect. Using published data, it can be calculated that there is an almost 20% relative reduction in survival for women receiving adjuvant chemotherapy for breast cancer as a result of unrecognised underdosing. Similarly, the cure rate of cisplatin-based chemotherapy for advanced testicular cancer may be reduced by as much as 10%. The inaccuracy of body surface area-dosing is more than an inconvenience and it is important that methods for more accurate dose calculation are determined, based on the known drug elimination processes for cytotoxic chemotherapy. Twelve rules for dose calculation of chemotherapy are given that can be used as a guideline until better dose-calculation methods become available. Consideration should be given to using fixed dose guidelines independent of body surface area and based on drug elimination capability, both as a starting dose and for dose adjustment, which may have accuracy, safety and financial advantages