COMMENTS:
CHAPTER 3: PET/CT FACILITY DESIGN
Line 1171: This subtopic extensively covers the shielding requirement for a vault-shielded cyclotron. We would like to suggest adding another subtopic that covers the shielding requirement for a self-shielded cyclotron if possible. Although the shielding requirement for a self-shielded cyclotron was mentioned in general (line 1030 -1033), a more technical requirement shall be mentioned in another subtopic.
Line 1450: The beginning statement for this subtopic should mention the PIC/S GMP guideline on the requirement for a risk assessment to be conducted prior to designing the laboratory facilities, airflow direction, airflow quality and pressure differences in order to not compromise the integrity of sterile product (PIC/S cGMP
Guideline Annex 3: Manufacture of Radiopharmaceuticals).
Line 1451 Under this subtopic, it should be mentioned clearly the requirement for a dedicated and separated heating, ventilation and air-conditioning (HVAC) system for a sterile manufacturing areas / production areas / cleanroom (PIC/S cGMP guideline Part I; Chapter 5.2.1)
Line 1461-1475 : We would like to suggest adding the minimum requirement for a manufacturing area of at least Grade C cleanroom if using a closed automated system for manufacturing. And Grade A for highly critical process such as open-vial filling for dispensing of (PIC/S cGMP Guideline Annex 3: Manufacture of Radiopharmaceuticals).
Line 1472-1475 : We would like to suggest adding the space requirement of at least a 3m2 of free floor area per person should be provided for the laboratory facilities as mentioned in IAEA Technical Report Series no 471; Cyclotron Produced Radionuclides.
Line 1506 : Dispensing of radiopharmaceutical should be done in unclassified controlled area / or at least ISO 9. The type of cabinet is BSC Type II.
3.4 Radiation components of PET/CT imaging
(142): Exposure to 511 keV photons will be almost continuous, but at a relatively low dose rate.
Instead, exposure to x rays will only occur in the scanning room during the relatively short time
(normally less than 1 min per PET/CT procedure) when the CT scan is being performed, but the
un-shielded dose rate levels from a CT scan are significantly higher (up to 4–5 orders of magnitude in the direct beam) than those from a patient to whom a PET radiopharmaceutical has been
administered.(To add informative finding and citation)
Suggest to include : Estimated effective dose for a patient was 10 mSv per study (3 and 7 mSv for PET and CT, respectively).
Impact of FDG PET/CT on management of cancer patients was considerable, as already established, and justification and optimization balancing with patients' benefit were achieved. At the opening of the facility, a nurse in charge of FDG administration and patient care received 2.0 µSv per one patient, which was already quite low as compared to PET facilities without adequate radiation protection measures. Now the exposure of a nurse per one
patient has been reduced to 0.9 µSv by adding shields and improving procedures in handling
patients. (Makoto Hosono et al,.Journal of Nuclear Medicine May 2007, 48 (supplement 2) 209P)
3.5.2. Administering the radiopharmaceutical
(152): The use of syringe shields for administering PET radionuclides can reduce staff finger doses by 80%– 90%. Although the shields need to be thick and the additional weight (up to 0.8 kg) can make injections difficult, they should always be used. (suggest to delete)
(154) : Local procedures and staff expertise will determine the best approach. The use of syringe-drawing devices and semi-automatic injectors can reduce finger doses by 80%–90% and fully automatic dispensers can virtually eliminate hand exposure (Madsen et al., 2006; Mattsson and
Söderberg, 2011).(Maintain this sentences)
3.6.2. Example of PET/CT facility design
(180) : Exposure of individual patients by radiation from other patients (regarded as a public
exposure) is minimal, less than 50 µSv, compared to the internal dose from the radiopharmaceutical (order of 5 mSv). (Suggested to remove 50 uSv, 50 uSv is meaningless)
The suggestion statement: Individual patients' exposure to radiation from fellow patients,
considered as public exposure, is minimal, especially when compared to the internal dose from the radiopharmaceutical, which is on the order of 5 mSv.
6.3. Radiological protection optimisation using both hardware and software
(266) : Using optimal reconstruction parameters helps to obtain better diagnostic image quality with less radiation dose. Image reconstruction techniques such as iterative reconstruction, while requiring more computation, have many advantages over filtered back projection (FBP).(suggested
to include Bayesian penalized Likelihood (BPL) as a new iterative reconstruction method to improve the PET image quality)(Wyrzykowski, M., Siminiak, N., Kaźmierczak, M. et al. Impact of the Q.Clear reconstruction
algorithm on the interpretation of PET/CT images in patients with lymphoma. EJNMMI Res 10,
99 (2020). https://doi.org/10.1186/s13550-020-00690-6)
6.4. The value of DRLs for optimisation of PET and PET/C
(274) : DRL values are not static. As optimisation of examinations continues or hardware and
software improve, DRLs should be updated on a regular basis. The DRL process should be applied in a continual process of quality assurance (QA), with repeat surveys following any optimisation, and then repetition of the whole process after an appropriate time interval. National and regional
DRLs should be revised at regular intervals of 3–5 years, or more frequently when substantial changes in technology, new imaging protocols or improved post processing of images become
available. (Suggest to put citation)
8.1.1. Risk of exposure due to contamination
8.1.1.1. External contamination
(327) : Due to the short range of the 18 F positrons, laboratory gloves can provide a high reduction in the dose rate produced by a droplet. (Suggested to use other term such as automated system,
Laboratory gloves not suitable, not practical)
9.6. QC Testing PET, PET/CT, or PET/MRI
9.6.1. QC Acceptance testing
(488) : 4589 Acceptance testing guideline has been published by several organizations including
AAPM, EANM and IAEA for PET/CT scanners (Table 9.1). (Suggested to include NEMA
publication inside (Table 9.1)
ACKNOWLEDGEMENT:
1. Mohamad Aminudin bin Said
2. Muhammad Fakhrurazi bin Ahmad Fadzil
3. Mahayuddin bin Abdul Manap