Development and validation of an alternative procedure for quantitative quality control analysis of 99mTc-radiopharmaceuticals using a Geiger Müller counter

BACKGROUND AND OBJECTIVES

In a hospital radiopharmacy with 2a operational level, including the preparation of radiopharmaceuticals from prepared and approved reagent kits, it is common to have a single activimeter or dose calibrator for labeling and fractionation, and to perform the quality controls of the 99mTc-radiopharmaceuticals. In certain cases, the accumulation of radioactive material or accidental contamination of the work area causes the background to exceed the limits to carry out the radiochemical purity analyses and it is necessary to look for viable alternatives. In this work, a Geiger Müller detector (equipped with a probe for measuring surface contamination) frequently used for radioprotection purposes, was validated as an alternative and its performance was compared against the activimeter for 99mTc-radiopharmaceuticals.

MATERIALS AND METHODS

Using [99mTc]pertechnetate, systematic studies of error analyses and detector response to activity concentration, activity and measurement time were carried out in liquid matrices and in paper. The results were compared against an activimeter calibrated for [99mTc]Tc.

RESULTS

The developed method was used to determine the radiochemical purity of the compounds [99mTc]Tc-MDP and [99mTc]Tc-MIBI by ascending paper chromatography tests, obtaining comparable values to those measured with an activimeter in the same system (within 1% uncertainty) and using the method of vial partitioning in a dedicated equipment.

CONCLUSIONS

This work demonstrates that a Geiger Müller detector with a probe for measuring surface contamination can be adequately used to replace other equipment in the control of radiochemical purity in the hospital radiopharmacy.

American Society of Clinical Oncology Road to Recovery Report: Learning From the COVID-19 Experience to Improve Clinical Research and Cancer Care

This report presents the American Society of Clinical Oncology's (ASCO's) evaluation of the adaptations in care delivery, research operations, and regulatory oversight made in response to the coronavirus pandemic and presents recommendations for moving forward as the pandemic recedes. ASCO organized its recommendations for clinical research around five goals to ensure lessons learned from the COVID-19 experience are used to craft a more equitable, accessible, and efficient clinical research system that protects patient safety, ensures scientific integrity, and maintains data quality. The specific goals are: (1) ensure that clinical research is accessible, affordable, and equitable; (2) design more pragmatic and efficient clinical trials; (3) minimize administrative and regulatory burdens on research sites; (4) recruit, retain, and support a well-trained clinical research workforce; and (5) promote appropriate oversight and review of clinical trial conduct and results. Similarly, ASCO also organized its recommendations regarding cancer care delivery around five goals: (1) promote and protect equitable access to high-quality cancer care; (2) support safe delivery of high-quality cancer care; (3) advance policies to ensure oncology providers have sufficient resources to provide high-quality patient care; (4) recognize and address threats to clinician, provider, and patient well-being; and (5) improve patient access to high-quality cancer care via telemedicine. ASCO will work at all levels to advance the recommendations made in this report.

Characteristics of end-of-life (EOL) chemotherapy (CTx) received by patients with advanced cancers and association with EOL emergency department (ED) and intensive care unit (ICU) care

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Background: Use of EOL CTx is an established quality metric in patients with advanced malignancies but less is known about which types of CTx are most commonly used and association with ED and ICU utilization. We sought to describe the different types of EOL CTx and to quantify the frequency of EOL ED and ICU care associated with them. Methods: Patients in the cancer registry of an urban cancer center who died between January 1, 2018 and October 10, 2019, and ever received CTx were included. EOL CTx was defined as any CTx given within 30 days of death, while any ED visits or ICU admissions in the last 30 days of life were defined as EOL ED and ICU care, respectively. CTx was categorized by administration route (intravenous (IV), oral (PO), other), and by type (immunotherapy (IMT), non-immunotherapy biologics (NIB), other). We used Pearson’s chi-squared to measure associations between EOL CTx and EOL ED and ICU care, logistic regression to assess how CTx type modulates those associations, and Mood’s median test to compare median IMT doses between groups. Results: Among 390 eligible patients, 32% received EOL CTx, 30% EOL ED care, and 11% EOL ICU care. Most received IV CTx (78%), and 10% received IMT. Median age at diagnosis was 69 years (interquartile range (IQR) 62 - 77), and median days from diagnosis to death was 390 (IQR 185 - 665). Most common malignancies were pancreatobiliary (40%), other gastrointestinal (15%), lung (13%) and hematologic (6%). Patients treated with EOL CTx were significantly more likely to receive IMT (p = 0.03). Receipt of any EOL CTx was significantly associated with EOL ED care (p < 0.0001) and EOL ICU care (p < 0.0001). Subgroup analyses showed significant modulatory effect of IMT on association of EOL CTx with EOL ED care (b = -0.89, p = 0.046), but was not significant for ICU care (b = -0.67, p = 0.29). Median doses of IMT was 2.5 (IQR 2 - 3.8) among patients who were given EOL IMT and 4 doses (IQR 2 - 6) in those that discontinued IMT before EOL (p = 0.06). Conclusions: EOL CTx is associated with significantly increased rates of EOL ED and ICU care, which may indicate poorer quality of life. While rates of use of other CTx modalities did not significantly differ at EOL, patients were more likely to receive IMT within 30 days of death, which could be due to the belief that IMT is more tolerable or more effective than other CTx modalities at EOL. IMT at EOL is associated with a reduced risk of EOL ED care, but not ICU care. Further research on strategies to reduce EOL CTx and appropriateness of IMT at EOL is warranted.

A randomized phase II study of nivolumab or nivolumab combined with ipilimumab in patients (pts) with melanoma brain metastases (mets): The Anti-PD1 Brain Collaboration (ABC)

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Background: Nivolumab (nivo) and the combination of nivo + ipilimumab (ipi) improve response rates (RR) and progression-free survival (PFS) compared with ipi alone in clinical trials of metastatic melanoma pts, but pts with untreated brain mets were excluded. Brain mets are a major cause of morbidity and mortality in melanoma and their management is critical. We sought to determine the antitumour activity and safety of nivo and nivo+ipi in pts with active melanoma brain mets (NCT02374242). Methods: This open-label, ph II trial enrolled 3 cohorts of pts naïve to anti-PD1/PDL1/PDL2/CTLA4 from Nov 2014 - Feb 2017. Pts with asymptomatic melanoma brain mets with no prior local brain therapy were randomised to cohort A (nivo 1mg/kg + ipi 3mg/kg, Q3W x4, then nivo 3mg/kg Q2W) or cohort B (nivo 3mg/kg Q2W). Cohort C (nivo 3mg/kg Q2W) had brain mets 1) that failed local therapy (new +/- progressed in previously treated met), 2) were neurologically symptomatic and/or 3) with leptomeningeal disease. Prior BRAF inhibitor (BRAFi) was allowed. The primary endpoint was best intracranial response (ICR) ≥ wk12. Secondary endpoints were best extracranial response (ECR), best overall response (OR), IC PFS, EC PFS, overall PFS, OS, and safety. Results: A total of 66 pts (med f/u 14 mo) were included in this analysis of total 76 planned; median age 60y, 77% male. For cohorts A, B and C: elevated LDH 48%, 58% and 19%; V600BRAF 44%, 56% and 81%; prior BRAFi 24%, 24%, 75%. Table shows RR, PFS and OS. ICR in cohort A treatment naïve vs prior BRAFi was 53% vs 16%. Treatment-related gd 3/4 toxicity in cohorts A, B and C were 68%, 40% and 56%, respectively. There were no treatment-related deaths. Conclusions:Nivo monotherapy and ipi+nivo and are active in melanoma brain mets. Ipi+nivo had reduced activity in pts who progressed on BRAFi. Pts with symptomatic brain mets, leptomeningeal mets or previous local therapy responded poorly to nivo alone. Clinical trial information: NCT02374242. [Table: see text]

Early-phase (EP) clinical trials (CTs) in the community: Results from the National Cancer Institute (NCI) Community Cancer Centers Program (NCCCP) Early-Phase Working Group (EPWG) Baseline Assessment Study (BAS)

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Background: The NCCCP is a network of 30 community cancer center (CCC) sites that strive to expand cancer research capacity and deliver advanced care in the community. The EPWG was formed to facilitate NCCCP site participation in EP (phase I-II) CTs, thus allowing patients (pts) to be treated within their communities. This study describes the CT infrastructure at NCCCP sites and its association with EP accrual. Methods: A BAS was conducted to obtain data on NCCCP site CT infrastructure, funding, sponsor affiliations, and barriers to EP CTs. To evaluate EP performance, EP accruals during July 2010-June 2011 were obtained. High accruing sites were those with EP accrual above the median EP accrual per 1,000 new analytical cases seen in 2009 or 2010. Results: 27 sites, caring for ~56,000 new cancer pts annually, participated in the study. Median number of accruing EP trials/site was 6 (mean 7.4). Median EP accrual/site was 14 (mean 16). Median EP accrual rate was 7/1,000. Trials with a phase I component were open at 21 sites. Most sites (24) are members of multiple CGs (median 4) and enroll pts via the CTSU (70%). The more common barriers to EP trial implementation were related to infrastructure (59%), cost (52%), and access to trials (41%). When accrual rates to NCCCP CTEP EP trials only were analyzed, we found that between high vs low accruing sites, respectively, higher accrual rates were associated with higher number of CRAs devoted to EP trials (median 3.25 vs 1; P= .05) and lower proportion of funding from industry (median 18% vs 40%; P=.02). We did not, however, find significant associations when EP trials were examined across all sponsors. Conclusions: CCCs are capable of conducting, and actively participating in, EP trials. Infrastructure and collaborations are critical components of success. Our study provides useful information for those planning to begin EP trials in the community setting. [Table: see text]

Discovery of localized regions of excess 10-TeV cosmic rays

The 7 year data set of the Milagro TeV observatory contains 2.2 x 10(11) events of which most are due to hadronic cosmic rays. These data are searched for evidence of intermediate scale structure. Excess emission on angular scales of approximately 10 degrees has been found in two localized regions of unknown origin with greater than 12sigma significance. Both regions are inconsistent with pure gamma-ray emission with high confidence. One of the regions has a different energy spectrum than the isotropic cosmic-ray flux at a level of 4.6sigma, and it is consistent with hard spectrum protons with an exponential cutoff, with the most significant excess at approximately 10 TeV. Potential causes of these excesses are explored, but no compelling explanations are found.

Evidence for TeV gamma-ray emission from a region of the galactic plane

Gamma-ray emission from a narrow band at the galactic equator has previously been detected up to 30 GeV. We report evidence for a TeV gamma-ray signal from a region of the galactic plane by Milagro, a large-field-of-view water Cherenkov detector for extensive air showers. An excess with a significance of 4.5 standard deviations has been observed from the region of galactic longitude l E (40 degrees, 100 degrees) and latitude /b/ < 5 degrees. Under the assumption of a simple power law spectrum, with no cutoff in the EGRET-Milagro energy range, the measured integral flux is phi gamma(>3.5 TeV) = (6.4 +/- 1.4 +/- 2.1) x 10(-11) cm(-2) s(-1) sr(-1). This flux is consistent with an extrapolation of the EGRET spectrum between 1 and 30 GeV in this galactic region.

Different Molecular Mechanisms of Vitamin D3 Receptor Antagonists

Two structurally different antagonists of the nuclear hormone 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], the 25-carboxylic ester ZK159222 and the 26,23-lactone TEI-9647, have recently been described. In this study, the molecular mechanisms and the efficacy of both antagonists were compared. ZK159222 showed similar potency and sensitivity to 1alpha,25(OH)(2)D(3) in ligand-dependent gel shift assays using the vitamin D receptor (VDR), the retinoid X receptor, and specific DNA binding sites, whereas TEI-9647 displayed reduced potency and >10-fold lower sensitivity in this assay system. Limited protease digestion and gel shift clipping assays showed that the two antagonists stabilized individual patterns of VDR conformations. Both antagonists prevented the interaction of the VDR with coactivator proteins, as demonstrated by GST-pull-down and supershift assays; like the natural hormone, however, they were able to induce a dissociation of corepressor proteins. Interestingly, ZK159222 demonstrated functional antagonism in reporter gene assays both in HeLa and MCF-7 cells, whereas TEI-9647 functioned as a less sensitive antagonist only in MCF-7 cells. In conclusion, the two 1alpha,25(OH)(2)D(3) analogs act in part via different molecular mechanisms, which allows us to speculate that ZK159222 is a more complete antagonist and TEI-9647 a more selective antagonist.

Sleep increase after immobilization stress: role of the noradrenergic locus coeruleus system in the rat

In a preliminary study we showed that the sleep rebound occurring after sleep deprivation is decreased in rats treated with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), a neurotoxic agent specific for the noradrenergic cells of the locus coeruleus (LC). Sleep deprivation methods not only involve sleep loss, but also stress, which per se may induce an increase in sleep duration. Extensive research showed that the locus coeruleus is involved in stress. To evaluate the participation of LC in this mechanism, the effect of DSP-4 treatment was studied on sleep duration following a short intense stress in the absence of sleep loss. The results showed that the augmentation of sleep after 1 h of immobilization stress is lower in DSP-4-treated rats (slow-wave sleep duration, -24%; paradoxical sleep duration, -52%). These findings suggest that the increase in sleep induced by such a stressor is mediated, at least in part, by the noradrenergic LC.

Physiological changes in antioxidant defences in fetal and neonatal rat liver

This study describes the physiological changes in the activities of the hepatic antioxidant enzymes superoxide dismutase isoenzymes (Cu/Zn-and Mn-superoxide dismutase) and catalase, in the glutathione content and in the lipid peroxidation levels in fetal (20 and 21 days of gestation) and neonatal rat liver (Days 1, 8, 15, and 22 post partum). The catalase and superoxide dismutase activities decreased before birth and increased after birth. The oxidized:reduced glutathione (GSSG:GSH) ratio declined before birth, but it increased between Days 1 and 15 post partum and then remained stable. Finally, newborn rat liver from the 1st day of life shows the highest susceptibility to lipid peroxidation. These results suggest that the changes in antioxidant defences could be related mainly to the beginning of diet intake after birth, which entails a higher hepatic metabolism rate, as well as a higher oxygen consumption.

Acquired immunodeficiency syndrome associated with Acanthamoeba infection and other opportunistic organisms

A 29-year-old Haitian man with acquired immunodeficiency syndrome presented with nasal obstruction and epistaxis. A computed tomogram of the head showed thickened nasal and paranasal sinus mucosa. A biopsy specimen of the turbinate disclosed inflammatory tissue containing amoebic trophozoites. The patient was empirically treated with rifampin and ketoconazole. He died four months after biopsy of other complications of acquired immunodeficiency syndrome. At autopsy, the amoebic infection was found only in the paranasal sinuses, a calf nodule, and in an intradermal abscess in the left leg. Pneumocystitis carinii pneumonia, Mycobacterium avium-cellulare in the liver and retroperitoneal lymph nodes, cytomegalovirus infection of the adrenal glands, and Kaposi's sarcoma in the spleen were additionally present. The organism was cultured and studied by electron microscopy, dark-field microscopy, and immunofluorescence.