Best Practices for Radiographers During the COVID-19 Pandemic

Radiographers or Radiological Technologists (RTs) as health professionals are calledupon to stand up to the circumstances and to modify practical applications to dealwith suspected and confirmed cases of Corona Virus Disease 19 (COVID-19). Theyperform chest X-ray examinations and Computed Tomography scans, which are keytools for diagnosing and monitoring patients with Severe Acute Respiratory SyndromeCoronavirus 2 (SARS-CoV-2). They are also an integral part of the departments ofMagnetic Resonance Imaging, Nuclear Medicine, Radiotherapy, Mammography, Orthopantomography- Cephalometric, Bone Density Measurement, and InterventionalRadiology – Hemodynamic. The purpose of this article is to provide RTs guidancethroughout the scope of their work and to keep the Hospital community informed.They are required to fully adhere to personal protective equipment (PPE) practices,such as the use of gloves, high-protection mask, special clothing, eye and feet protection.They should maintain safety distance and come into as little contact as possiblewith the patients. It is necessary to thoroughly disinfect and use protection for all theirwork components, stable or not. There should be separated spaces, in the presencesuspicious and confirmed cases, as well as the rational distribution of staff in theirworkstations and their continuous training and briefing. RTs are present in mediumand high-risk zones. As they are potential virus carriers in hospital units, PPE mustbe applied and strictly monitored. Moreover, workplaces should adapt to the currentprecautionary measures to ensure personal and occupational safety

Imaging performance of a CaWO4/CMOS sensor

The aim of this study was to investigate the modulation transfer function (MTF) and the effective gain transfer function (eGTF) of a non-destruc­­tive testing (NDT)/industrial inspection complementary metal oxide semi­conductor (CMOS) sensor in conjunction with a thin calcium tungstate (CaWO4) screen. Thin screen samples, with dimensions of 2.7x3.6 cm2 and thick­ness of 118.9 μm, estimated from scanning electron microscopy-SEM im­ages, were extracted from an Agfa Curix universal screen and coupled to the active area of an active pixel (APS) CMOS sensor. MTF was assessed using the slanted-edge method, following the IEC 62220-1-1:2015 method. MTF values were found high across the examined spatial frequency range. eGTF was found maximum when CaWO4 was combined with charge-coupled devices (CCD) of broadband anti-reflection (AR) coating (17.52 at 0 cycles/mm). The com­bi­nation of the thin CaWO4 screen with the CMOS sensor provided very pro­mis­ing image resolution and adequate efficiency properties, thus could be also con­sidered for use in CMOS based X-ray imaging devices, for various applications

Patient-specific Dosimetry in predicting renal toxicity with Y-90-DOTATOC: Relevance of kidney volume and dose rate in finding a dose-effect relationship

Nephrotoxicity is the major limiting factor during therapy with the radiolabeled somatostatin analog Y-90-1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA)-D-Phe(1)-Tyr(3)-octreotide (DOTATOC). Pretherapeutic assessment of kidney absorbed dose could help to minimize the risk of renal toxicity. The aim of this study was to evaluate the contribution of patient-specific adjustments to the standard dosimetric models, such as the renal volume and dose rate, for estimating renal absorbed dose during therapy with Y-90-DOTATOC. In particular, we investigated the correlation between dose estimates and effect on renal function after therapy. Methods: Eighteen patients with neuroendocrine tumors (9 men and 9 women; median age, 59 y) underwent treatment with 90Y-DOTATOC (8.1-22.9 GBq) after pretherapeutic biodistribution study with Y-86-DOTATOC. Kidney uptake and residence times were measured and the absorbed dose (KAD) was computed using either the MIRDOSE3.1 software assuming a standard kidney volume (KAD(StdVol)) or the MIRD Pamphlet 19 values and the actual kidney cortex volume determined by pretherapeutic CT (KAD(CTVol). For each patient, the biologic effective dose (BED) was calculated according to the linear quadratic model to take into account the effect of dose rate and fractionation. Renal function was evaluated every 6 mo by serum creatinine and creatinine clearance (CLR) during a median follow-up of 35.5 mo (range, 18-65 mo). The individual rate of decline of renal function was expressed as CLR loss per year. Results: KAD(CTVol) ranged between 19.4 and 39.6 Gy (mean, 28.9 +/- 5.34 Gy). BED, obtained from KAD(CTVol), ranged between 27.7 and 59.3 Gy (mean, 40.4 +/- 10.6 Gy). The CLR loss per year ranged from 0% to 56.4%. In 12 of 18 patients, CLR loss per year was 20% received a BED >45 Gy. Patients who were treated with low fractionation were those with the highest rate of renal function impairment. Conclusion: Radiation nephrotoxicity after 90Y-DOTATOC therapy is dose dependent. Individual renal volume, dose rate, and fractionation play important roles in an accurate dosimetry estimation that enables prediction of risk of renal function impairment

Patient-specific dosimetry in predicting renal toxicity with (90)Y-DOTATOC: relevance of kidney volume and dose rate in finding a dose-effect relationship.

Nephrotoxicity is the major limiting factor during therapy with the radiolabeled somatostatin analog (90)Y-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)-d-Phe(1)-Tyr(3)-octreotide (DOTATOC). Pretherapeutic assessment of kidney absorbed dose could help to minimize the risk of renal toxicity. The aim of this study was to evaluate the contribution of patient-specific adjustments to the standard dosimetric models, such as the renal volume and dose rate, for estimating renal absorbed dose during therapy with (90)Y-DOTATOC. In particular, we investigated the correlation between dose estimates and effect on renal function after therapy. METHODS: Eighteen patients with neuroendocrine tumors (9 men and 9 women; median age, 59 y) underwent treatment with (90)Y-DOTATOC (8.1-22.9 GBq) after pretherapeutic biodistribution study with (86)Y-DOTATOC. Kidney uptake and residence times were measured and the absorbed dose (KAD) was computed using either the MIRDOSE3.1 software assuming a standard kidney volume (KAD(StdVol)) or the MIRD Pamphlet 19 values and the actual kidney cortex volume determined by pretherapeutic CT (KAD(CTVol)). For each patient, the biologic effective dose (BED) was calculated according to the linear quadratic model to take into account the effect of dose rate and fractionation. Renal function was evaluated every 6 mo by serum creatinine and creatinine clearance (CLR) during a median follow-up of 35.5 mo (range, 18-65 mo). The individual rate of decline of renal function was expressed as CLR loss per year. RESULTS: KAD(CTVol) ranged between 19.4 and 39.6 Gy (mean, 28.9 +/- 5.34 Gy). BED, obtained from KAD(CTVol), ranged between 27.7 and 59.3 Gy (mean, 40.4 +/- 10.6 Gy). The CLR loss per year ranged from 0% to 56.4%. In 12 of 18 patients, CLR loss per year was 20% received a BED >45 Gy. Patients who were treated with low fractionation were those with the highest rate of renal function impairment. Conclusion: Radiation nephrotoxicity after (90)Y-DOTATOC therapy is dose dependent. Individual renal volume, dose rate, and fractionation play important roles in an accurate dosimetry estimation that enables prediction of risk of renal function impairment