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Absorbed radiation doses are essential in assessing the effects, e.g. safety and efficacy, of radiopharmaceutical therapy (RPT). Patient-specific absorbed dose calculations in the target or the organ at risk require multiple inputs. These include the number of disintegrations in the organ, i.e. the time-integrated activities (TIAs) of the organs, as well as other parameters describing the process of radiation energy deposition in the target tissue (i.e. mean energy per disintegration, radiation dose constants, etc). TIAs are then estimated by incorporating the area under the radiopharmaceutical's time-activity curve (TAC), which can be obtained by quantitative measurements of the biokinetics in the patient (typically based on imaging data such as planar scintigraphy, SPECT/CT, PET/CT, or blood and urine samples). The process of TAC determination/calculation for RPT generally depends on the user, e.g., the chosen number and schedule of measured time points, the selection of the fit function, the error model for the data and the fit algorithm. These decisions can strongly affect the final TIA values and thus the accuracy of calculated absorbed doses. Despite the high clinical importance of the TIA values, there is currently no consensus on processing time-activity data or even a clear understanding of the influence of uncertainties and variations in personalised RPT dosimetry related to user-dependent TAC calculation. As a first step towards minimising site-dependent variability in RPT dosimetry, this work provides an overview of quality assurance and uncertainty management considerations of the TIA estimation.

Introduction: The activity meter is used to determine the activity of delivered radiopharmaceuticals, administered activity to patients and reference activity when gamma-cameras are calibrated prior to imaged-based dosimetry. The aim is to describe a procedure for cross-calibration of activity meters at different clinical sites, and report on 177Lu activity results when using factory-set calibration factors compared to when calibration is performed with traceability to a primary standard. Methods: Thirty activity meters placed at seven hospitals in Norway and Sweden from four manufacturers: Capintec, Commecer, NuviaTech and Veenstra were included. A stock solution with 177Lu was prepared at the local sites and measured in each activity meter with factory settings. The solution was shipped to the reference site at Lund University for measurements in a secondary standard activity meter. Deviations between local and reference activity measurements were determined for three geometries: 25-mL vial, 10-mL syringe and 1-mL syringe. Results: The median of the deviations was 6.4 % for the 25 mL vial, 5.9 % for the 10 mL syringe and 6.8 % for the 1 mL syringe. The median of the deviations for the 25 mL vial, was 1.5 % for activity meters from Capintec, 7.0 % for Comecer, 11.0 % for NuviaTech and 2.4 % for Veenstra. The majority of the deviations were positive and the maximum deviation was 14.5 %. Conclusion: The activity of 177Lu measured in an activity meter with factory-set dial settings may yield deviations up to 14.5%, compared to activities measured with traceability to a primary standard. This would imply an undertreatment of patients.

Dosimetry can be a useful tool for personalization of molecular radiotherapy (MRT) procedures, enabling the continuous development of theranostic concepts. However, the additional resource requirements are often seen as a barrier to implementation. This guide discusses the requirements for dosimetry and demonstrates how a dosimetry regimen can be tailored to the available facilities of a centre. The aim is to help centres wishing to initiate a dosimetry service but may not have the experience or resources of some of the more established therapy and dosimetry centres. The multidisciplinary approach and different personnel requirements are discussed and key equipment reviewed example protocols demonstrating these factors are given in the supplementary material for the main therapies carried out in nuclear medicine, including [131I]-NaI for benign thyroid disorders, [177Lu]-DOTATATE and 131I-mIBG for neuroendocrine tumours and [90Y]-microspheres for unresectable hepatic carcinoma.

Dosimetry can be a useful tool for personalization of molecular radiotherapy (MRT) procedures, enabling the continuous development of theranostic concepts. However, the additional resource requirements are often seen as a barrier to implementation. This guide discusses the requirements for dosimetry and demonstrates how a dosimetry regimen can be tailored to the available facilities of a centre. The aim is to help centres wishing to initiate a dosimetry service but may not have the experience or resources of some of the more established therapy and dosimetry centres. The multidisciplinary approach and different personnel requirements are discussed and key equipment reviewed example protocols demonstrating these factors are given in the supplementary material for the main therapies carried out in nuclear medicine, including [131I]-NaI for benign thyroid disorders, [177Lu]-DOTATATE and 131I-mIBG for neuroendocrine tumours and [90Y]-microspheres for unresectable hepatic carcinoma.

Omkring 10% av befolkningen lider av defekt färgseende. De flesta, upptill 99%, av dessa är röd-grön färgblinda. Den sista procenten delasmellan totalt färgblinda och de med gul-blå färgblindhet. I studienidentifieras riktlinjer för hur färgsättning av diagram och kurvor ska görasför att även de med någon av de nämnda typerna av defekt färgseende skakunna tillgodogöra sig informationen i till exempel diagram. Baserat påteorier, samt egen personlig erfarenhet skapades bilder på färgsattakurvdiagram anpassade för personer med röd-grön färgblindhet. Dessahar testats och utvärderats av informanter som lever med den typen avdefekt färgseende. Detsamma gäller för skapandet av bilder för de medblå-gul färgblindhet. En färgsättning med enbart grundfärgerna gul, rödoch blå tillsammans med svart visade sig fungera för båda typerna avdefekt färgseende. Dessa färger tillsammans med svart mot en vitbakgrund ger inte bara ett tydligt intryck utan är också estetiskttilltalande.Genom att göra olika markeringar av linjerna i form av olika typer avsträckningar eller punkter, kan lätt fler än fyra kurvor finnas i sammadiagram. I studien presenteras möjliga färgkombinationer ochförklaringar kring varför de fungerar ihop. Detta bör vara tidsbesparandeoch kostnadseffektivt vid färgsättning av diagram likväl som webbsidoroch grafiska användargränssnitt mm. Informanternas tips och idéer på hurman ytterligare kan underlätta för de med defekt färgseende finns ocksåmed i rapporten., Approximately 10% of the population suffer from defective color vision. Up to 99%of these persons suffer from red-green defective color vision. The last percentage isshared between those that are totally colorblind and those suffering from yellow-bluecolor defective color vison. This study identifies how correct use of colors will makesure that people suffering from any of the above-mentioned types of defective colorvision conditions will be able to assimilate the information given in, for example, adiagram. Based on theories, as well as personal experience, images were created oncolored curve diagrams adapted for people with red-green color blindness. These havebeen tested and evaluated by informants living with that type of defective colorvision. The same applies when it comes to the creation of the pictures for thosesuffering from blue-yellow defective color vision.A color scheme using only the primary colors yellow, red and blue together withblack proved to work for both types of defective color vision. These colors togetherwith black on a white background not only give a clear impression but are alsoaesthetically appealing. By making different markings of the lines in the form ofdashed lines or dots, more than four curves can easily be found in the same diagram.The study presents possible combinations of colors and explanations to why theywork together. This should be time saving and cost effective when coloring diagrams and also when for example coloring webpages and graphical user interfaces. The tipsand ideas given by the informants how to further facilitate for the persons sufferingfrom defective color vision is also found in the report.