| Chapter | Line no. | Paragraph | Comment |
| General | The report provides an extensive overview of aspects to consider for radiological protection in PET, PET/CT and PET/MRI. The main points are familiar for the Dutch medical physics society, since these have been implemented in local and European regulations. This document can help establish a consistent approach worldwide. To increase the impact and usability of the document, we advise to condense the text and avoid repeating statements. |
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| General | The focus of the document should be 'radiological protection in PET, PET/CT and PET/MRI', however, the document also contains a lot of information that is really not needed when considering radiological protection. For instance, although it is necessary to have a good understanding of the properties of different types of emitted radiation (positrons, (annihilation) photons etc.), it is really not necessary to have a detailed understanding on the (latest) developments on PET detector technology/physics as described in chapter 2. In many chapters, one should consider what information is really necessary in the context of radiological protection and exclude non-relevant information to improve readability of the document. In addition try to avoid repetition throughout the document to condense the text and improve readability. |
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| General | The application of prospective accurate risk assessment is crucial for identification of (unacceptable) risks and to minimize the radiation exposure of personell working with ionising radiation according to the ALARA principles. The document should better emphasize the importance of performing such risk assessments and provide practical guidelines on how such risk assessments should be performed. (e.g. The Dutch committee on radiaction protection has published a model for performing risk assessments in nuclear medicine). In order to facilitate these risk assessments, it would be very helpful to summarize important information (H(10), H(0.07), H(3), dose conversion coefficients for inhalation, ingestion, skin contamination, transmission factor of patients and shielding material) for all relevant radionuclides that are typically encountered in PET. | ||
| Summary | 211 | "resolution" should be replaced by "spatial resolution" | |
| Summary | 212 | "senstivity" should be replaced by "count rate sensitivity" | |
| Summary | 237 | In the disposal of equipment, it is worthwhile to mention the possible nuclear activation of (shielding) material when decommisioning a cyclotron facility | |
| Chapter 1 | 348 | In the optimisation of exposure, it is important to mention the ALARA principle | |
| Chapter 1 | 366 | "untitled" should be "entitled" | |
| Chapter 1 | 432 | It is mentioned that in diagnostic nuclear medicine, the administered activity is preferred to be adjusted to body weight. Although this is the case for many radiotracers, this does not hold true for all radiotracers (e.g. 124I-NaI for thyroid) | |
| Chapter 1 | 1.4 | Much of the data presented in this paragraph is highly outdated | |
| Chapter 1 | 539 | Again outdated (references > 20 years old!) | |
| Chapter 1 | 557 | Here it should be noted that nowadays automated dose dispenser and injector systems are commercially available | |
| Chapter 3 | 1699 | It should be described how to handle extravasal injection of radiotracers. Suggested publication: van der Pol JAJ, Mottaghy FM. Extravasation of Diagnostic Radiopharmaceuticals: A Wolf in Sheep's Clothing? J Nucl Med. 2023 Mar;64(3):491-492. doi: 10.2967/jnumed.122.265038. Epub 2022 Dec 15. PMID: 36522187; PMCID: PMC10071801. | |
| Chapter 3 | 1894 | For FDG, current PET systems facilitate considerable lower amounts of activity to be administered which results in lower effective patient dose (typically 2-5 mSv) | |
| Chapter 3 | 1917 | The reported typical amounts of administered activity are outdated. Current PET scanners facilitate much lower FDG dosing typically in the order of 2-3 MBq/kg. | |
| Chapter 3 | 2097 | For CT, it is indeed useful to use additional lead above 2 m to avoid substantial ceiling scatter. However, for PET it has been demonstrated by Schnerr et al (2017) that radiation dose originating from ceiling scatter is only a relatively small fraction compared to the radiation dose arising from 511 keV photons that penetrate the shielded walls. Taking into consideration that above 2 meters there are typically a lot of air duct/ventilation channels present which are very challenging to shield, it may not be practical to apply large amounts of shielding material above 2 m. Instead it may be more practical/cost effective to accept a certain amount of ceiling scatter from the 511 keV photons, and compensate for this by adding a little bit of extra shielding up to 2 m. Schnerr RS, de Jong AN, Landry G, Jeukens CR, Wierts R. Monte Carlo simulations of ceiling scatter in nuclear medicine: 99m Tc, 131 I and 18 F. Med Phys. 2017 Mar;44(3):1113-1119. doi: 10.1002/mp.12113. PMID: 28097674. |
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| Chapter 3 | 3.7.2 | Software packages that help to optimize shielding are currently available: e.g. https://bitbucket.org/MedPhysNL/pyrateshield/src/master/ | |
| Chapter 4 | 4.5 | Depending on local regulations, the presence of radioactive Lu-176 in LSO/LYSO scintillation crystals have to be considered during disposal of the PET system. | |
| Chapter 6 | It should be noted that according to European legislation (European Council Directive 2013/59/Euratom basic safety standards from protection against the dangers arising from exposure to ionising radiation), the medical physicist is responsible for patient dosimetry and should take part in the protocol optimization proces | ||
| Chapter 6 | 2664 | Calibration of the activity meter should be performed for each radionuclide and measurement geometry used for clinical application. Also refer to the relevant literature: IAEA . Quality assurance for radioactivity measurement in nuclear medicine, Technical reports series no 454. Vienna: International Atomic Energy Agency; 2006. Busemann Sokole E, Plachcínska A, Britten A. EANM Physics Committee. Acceptance testing for nuclear medicine instrumentation. Eur J Nucl Med Mol Imaging. 2010;37:672–681. doi: 10.1007/s00259-009-1348-x. AAPM. The selection, use, calibration and quality assurance of radionuclide calibrators used in nuclear medicine, Report of AAPM Task Group 181. College Park: American Association of Physicists in Medicine; 2012. |
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| Chapter 6 | 6.3 | Try to limit the information in this section to current PET technology. E.g. 2D PET mode is really outdated, ToF and PSF reconstructions are nowadays mainstream on state-of-the-art PET systems. | |
| Chapter 6 | 2479 | Please do not refer to specific PET/CT systems or vendors. The explorer is not the only large axial FOV PET system commercially available. | |
| Chapter 6 | 6.4 | Nowadays, several software packages are commercially available to assess and register the radiation dose (to individual organs) of medical examinations for each individual patient. As these software packages can report radiation dose for different examination types and scanners, this facilitates optimization of protocols and comparison between scanners/operators/centers. | |
| Chapter 9 | 4347 | As PET sensitivity and reconstruction protocols have substantially increased the last decade, the recommendations of this paper are a outdated for current state-of-the-art PET systems. | |
| Chapter 9 | 4502 | According to European Council Directive 2013/59/Euratom basic safety standards from protection against the dangers arising from exposure to ionising radiation, the medical physicist is responsible for patient dosimetry. | |
| Chapter 9 | 9.7 | Accurate performance of radionuclide calibrators is very important to ensure patients are administered with the correct amount of radioactivity which has a direct impact on the effective dose of the patients. In particular, for radionuclides emitting low energy photons (e.g. X-rays in the case of I-124), source geometry (syringe, vial, volume) will have a big impact on the accuracy of measurements. Therefore, the accuracy for each source geometry should be checked (against a primary or secundary standard) for each radionuclide which is clinically used. This aspect should be addressed in this section. | |
| Chapter 9 | 4730 | It is reported that clock accuracy between activity meter, injection time and imaging time should be within one minute to ensure quantitative accuracy. However, this highly depends on the half-life of the radionuclide. For O-15 or N-13 1 minute accuracy is for sure not enough. Perhaps it's better to specify a percentage accuracy that should be achieved. | |
| Chapter 10 | 10.4.2 | According to European Council Directive 2013/59/Euratom basic safety standards from protection against the dangers arising from exposure to ionising radiation, the medical physicist is responsible for patient dosimetry. |