Skip to main content

Patient-adapted organ absorbed dose and effective dose estimates in pediatric 18F-FDG positron emission tomography/computed tomography studies

Abstract

Background

Organ absorbed doses and effective doses can be used to compare radiation exposure among medical imaging procedures, compare alternative imaging options, and guide dose optimization efforts. Individual dose estimates are important for relatively radiosensitive patient populations such as children and for radiosensitive organs such as the eye lens. Software-based dose calculation methods conveniently calculate organ dose using patient-adjusted and examination-specific inputs.

Methods

Organ absorbed doses and effective doses were calculated for 429 pediatric 18F-FDG PET-CT patients. Patient-adjusted and scan-specific information was extracted from the electronic medical record and scanner dose-monitoring software. The VirtualDose and OLINDA/EXM (version 2.0) programs, respectively, were used to calculate the CT and the radiopharmaceutical organ absorbed doses and effective doses. Patients were grouped according to age at the time of the scan as follows: less than 1 year old, 1 to 5 years old, 6 to 10 years old, 11 to 15 years old, and 16 to 17 years old.

Results

The mean (+/− standard deviation, range) total PET plus CT effective dose was 14.5 (1.9, 11.2–22.3) mSv. The mean (+/− standard deviation, range) PET effective dose was 8.1 (1.2, 5.7–16.5) mSv. The mean (+/− standard deviation, range) CT effective dose was 6.4 (1.8, 2.9–14.7) mSv. The five organs with highest PET dose were: Urinary bladder, heart, liver, lungs, and brain. The five organs with highest CT dose were: Thymus, thyroid, kidneys, eye lens, and gonads.

Conclusions

Organ and effective dose for both the CT and PET components can be estimated with actual patient and scan data using commercial software. Doses calculated using software generally agree with those calculated using dose conversion factors, although some organ doses were found to be appreciably different. Software-based dose calculation methods allow patient-adjusted dose factors. The effort to gather the needed patient data is justified by the resulting value of the characterization of patient-adjusted dosimetry.

Peer Review reports

Background

About half of the ionizing radiation exposure to the United States population is estimated to be from medical imaging procedures, including radiopharmaceutical imaging and computed tomography [1]. Through the combination of physiological information from positron emission tomography (PET) and anatomical information from computed tomography (CT), PET-CT has become established prominently in the diagnosis and treatment monitoring of many types of cancer. The sequential acquisition of PET and CT images in 2–18-Fluoro-2-deoxy-D-glucose (18F-FDG) PET-CT results in patient radiation dose from both imaging modalities but the risk incurred from this radiation dose is generally thought to be justified by the benefit of the diagnostic information obtained from the scan. Previous studies of 18F-FDG PET-CT dosimetry have reported adult effective dose (E) of 13 to 32 mSv and pediatric (E) of 7 to 29 mSv [2,3,4,5,6]. The wide range of reported PET-CT effective doses reflects varying conventions and technical parameters of use of CT in PET-CT examination, variations in injected 18F-FDG activity, range of patient age and body sizes as well as varying dosimetry methodologies. With radiation dose from each scan and multiple scans over the course of disease management, optimization of radiation dose in 18F-FDG PET-CT is especially important for children, who have longer life expectancy over which to undergo multiple scans and are generally thought to be more radiosensitive than adults [7]. While E is useful for comparison of ionizing radiation procedures, it should not be used to assess individual detriment and is used most appropriately in radiation protection for setting secondary limits for intakes of radionuclides and for ensuring that exposure limits for radiation workers are not exceeded [8, 9]. Tissue weighting factors, based on population-averaged values, as used in the calculation of E, make E no more a reliable indicator of individual detriment than population-based organ-specific factors [10]. In the current paradigm of radiation protection, the known relationship between dose and risk at higher radiation dose is assumed to extrapolate linearly to that at lower dose, and children are considered to be at greater risk of developing radiation-induced tumors due to their life expectancy and higher radiosensitivity of select tissues [7, 10,11,12]. The basis for the belief of relatively higher risk for children demonstrated in a report by the National Research Council is challenged by some in light of their view that the risks at low radiation doses such as those incurred during medical imaging procedures are not unequivocally supported by current epidemiological data [13, 14]. The limitations of popular approaches to risk quantification are widely recognized. In their overview of the debate surrounding the use of the linear no-threshold dose-response model, Zanzonico and Weber acknowledge that the uncertainty in correlation between diagnostic radiation dose and detriment propagates to the process of making clinical decisions for individual patients [15].

Despite debated cogency of linear extrapolation of risk from known, higher doses to that at diagnostic imaging levels, and despite critical acceptance of the relative radiosensitivity of the pediatric population, various ongoing efforts attempt to optimize and limit pediatric medical imaging radiation dose. The Image Gently Alliance advocates for safe and effective imaging care of children and raising awareness in the imaging community of the need to adjust radiation dose when imaging children [16]. The Image Gently campaign addressed radiation dose from both CT and PET scans through guidelines brought forth by founding and alliance organizations. Image Gently maintains published suggestions for either developing CT protocols for children or verifying that current pediatric protocols are appropriate, and the Alliance for Quality Computed Tomography of the American Association of Physicists in Medicine (AAPM) has developed reference pediatric CT protocols [17, 18]. The American College of Radiology (ACR) introduced the CT Dose Index Registry in 2011 to facilitate the collection and comparison of CT dose indices, although pediatric data are not currently included [19]. In 2008 the European Association of Nuclear Medicine (EANM) first published suggested pediatric nuclear medicine injected activities, and in 2011 the North American consensus guidelines recommended a similar set of administered activities for pediatric nuclear medicine. The pediatric radiopharmaceutical administered activity currently recommended by Image Gently is based on the 2016 update to the North American Consensus Guidelines and notes the EANM dosage card may also be used for some radiopharmaceuticals [20]. Such efforts to make available typical radiation doses and standardize some aspects of pediatric medical imaging provide a framework for optimization, with the intent that patient radiation dose is minimized while maintaining diagnostic utility of the resulting images. In previous studies of optimization of pediatric PET-CT, including non-18F-FDG PET-CT, other authors recognize the contribution of both modalities to total patient radiation dose and the authors reveal opportunities to optimize aspects of both [21, 22]. For example, patient preparation, immobilization, use of recommended administered activities, and careful selection of CT protocol all ensure image quality while optimizing patient radiation [23]. In an exploration of operational and dosimetric aspects of pediatric PET-CT, the challenges of imaging children are recognized along with optimization opportunities, with an emphasis on the importance of understanding the role of CT in this examination [24]. CT technique is chosen based on the objective of the examination, which may require high-resolution delineation of organs, bones, soft tissue or blood vessels. In the case of PET-CT, x-rays from CT are used to construct an attenuation map of density differences throughout the body that can then be used to correct for the absorption of the photons emitted from 18F decay. This process of so-called CT attenuation correction (CTAC) is indirectly related to image formation and delivers less radiation dose than a CT technique intended to primarily provide images with useful diagnostic information. Previous studies have reported adult CT E from CTAC-only as 1.3 to 4.5 mSv, and one estimate of pediatric diagnostic whole-body CT E as high as 28 mSv [21, 25, 26].

Dose estimation methodology itself is integral to optimization and understanding the role of the many factors contributing to patient radiation dose in medical imaging [27]. A dosimetry method may consist of a dose coefficient applied to an examination-specific parameter such as injected activity or may employ computer simulation data based on a simplistic or anatomically realistic phantom. CT radiation dose, for example, may be estimated based on a singular CT dose metric or a computer simulation of the radiation from the specific CT model and using an anatomically realistic phantom. The latest versions of commercially available internal dose estimation software remain rooted in the methodology developed by the Medical Internal Radiation Dose (MIRD) Committee of Society of Nuclear Medicine and Molecular Imaging and offer a choice of many anatomically realistic phantoms with the latest tissue weighting factors, while reporting both organ and E for many radionuclides [28]. Likewise, modern CT dosimetry software is based on a comprehensive database of organ doses derived from Monte Carlo simulations involving a library of anatomically realistic phantoms [29]. A dosimetry method utilizing exam-specific information is more precise and therefore more valuable than one that does not. In this sense, the investigation of results utilizing the latest methodology is a pursuit of more valuable information.

The purpose of this study was to take advantage of the pediatric oncology patient population at our institution and available dosimetry software to evaluate a large pediatric patient cohort with patient-adjusted information. Patient-adjusted organ dosimetry of pediatric oncology patients undergoing 18F-FDG was performed utilizing patient-size parameters, individual injected activity and actual scan parameters. The PET portion was evaluated using OLINDA/EXM version 2.0 (OLINDA 2.0, Vanderbilt University), while the CT portion was evaluated using VirtualDose CT (Virtual Phantoms, Inc.). The results of this study are useful to evaluate the practicality of these methods and to characterize our patient population and reveal opportunities for optimization.

Methods

Organ absorbed doses and E were calculated for 429 pediatric 18F-FDG PET-CT examinations performed over a 2-year period, comprised of 198 unique patients. A waiver of informed consent was obtained from the Institutional Review Board for retrospective review of patient data. GE DoseWatch software (GE Healthcare, Waukesha, WI) was used to identify pediatric PET-CT protocols in the desired examination date range. The following patient-adjusted and examination-specific information was recorded from the patient medical record and CT dose monitoring software: Age at scan time, gender, body mass, injected activity (MBq), x-ray tube voltage (kVp), x-ray tube current (mA), mAs/rotation, mAs-normalized weighted CT dose index (CTDIw/100 mAs), pitch, and volume CT dose index (CTDIvol). 18F-FDG activity to be administered (Ainj) was determined for pediatric patients as the ratio of patient body surface area (BSAped, m2) to that of adult body surface area, multiplied by the nominal adult injected activity of 12 mCi (444 MBq) [30].

$$ {\mathrm{A}}_{\mathrm{inj}}\ \left(\mathrm{MBq}\right)=\left({\mathrm{BSA}}_{\mathrm{ped}}/1.77\right)\ast 444 $$

Injected activity is summarized in Table 1.

Table 1 Injected Activity

Patients were divided into five groups according to age at the time of the examination: less than 1 year old (< 1), one to 5 years old (1–5), six to 10 years old (6–10), 11 to 15 years old (11–15), and 16 to 17 years old (16, 17).

A summary of patient body masses is presented in Table 2.

Table 2 Patient body mass

All PET-CT examinations were performed with a GE Discovery 690 PET-CT, the CT portion comprised of a GE Lightspeed 16 CT unit.

The PET scan technique for all patients was a whole-body 3D PET protocol. The CT scan technique for all patients was an attenuation correction/localization (ACL) scan using a tube voltage and current selected based on patient body mass. Pitch factor was 0.98 or 1.38, rotation time 0.5 or 0.8 s, and tube potential 100 or 120 kVp. The tube current was specified according to body mass: less than 40 kg, 40 mA; 41–60 kg, 60 mA; 61–80 kg, 70 mA; 80–100 kg, 85 mA; and greater than 100 kg, 100 mA. A “scout” scan was performed at 10 mA prior to the ACL scan for gross anatomical visualization.

OLINDA/EXM Version 2.0 (Vanderbilt University) was used to calculate PET organ radiation absorbed doses and ED. The program requires specification of the radionuclide, organ residence times, and anatomic phantom. The program offers the choice of twenty-five human and ten animal (rodent) phantoms. The phantoms chosen for the current study include male or female newborn, 1-year-old, 5-year-old, 10-year-old, 15-year-old and adult. 18F-FDG residence times defined in ICRP 128 were used as input to the software [31]. Phantom was chosen by matching patient mass to the closest phantom mass, and phantom organ masses were scaled in the program by the ratio of the patient mass to the phantom mass. The program then produced dose factors for each organ, in terms of equivalent dose and E per unit injected activity (mSv/MBq). The dose factors were multiplied by the injected activity to obtain the total equivalent dose for each defined organ and the total E.

While the program produced factors of equivalent dose as mSv, due to the fact that 1 mSv is equal to 1 mGy for the radiations of concern, organ radiation absorbed dose is reported in Table 3 as mGy. Total colon dose was calculated by averaging the reported dose to the left colon, right colon and rectum.

Table 3 PET Organ Absorbed Dose (mGy)

VirtualDose CT (Virtual Phantoms, Inc.) was used to calculate CT organ absorbed doses and E. VirtualDose CT offers 23 phantoms and the phantoms used in this study were male and female newborn, 1-year-old, 5-year-old, 10-year-old, 15-year-old and adult. The phantom was chosen by matching patient mass to the closest phantom mass. CT absorbed dose (mGy) was reported by VirtualDose CT for the organs and tissues in Table 4. Breast dose is only reported in phantom age 15-year-old and older, breast dose reported in the table is gender averaged. Total colon dose was calculated by averaging the reported dose to the colon and rectosigmoid colon. The software also reported total E utilizing tissue weighting factors in Report 103 of the International Commission of Radiological Protection. Eye lens dose was among those reported by this software. Scan range was selected within the software to indicate the head-to-toe scan range used for all pediatric PET-CT protocols.

Table 4 CT Organ Absorbed Dose (mGy)

The body masses of the phantoms used in VirtualDose CT and OLINDA are shown in Table 5.

Table 5 Phantom Masses, kg

For both PET and CT dose, genitourinary organ dose is reported as prostate for male and uterus for female. Gonad dose is estimated as testes for male and ovaries for female, and the gender average gonad dose is reported in the tables. Total organ radiation absorbed dose to a given organ was calculated as the sum of the doses from PET and from CT for that organ, as shown in Table 6.

Table 6 PET + CT Total Organ Absorbed Dose (mGy)

Result

Table 6 presents the total (PET + CT) organ radiation absorbed dose for each age group, Table 3 presents PET organ radiation absorbed dose for each age group, and Table 4 presents CT organ radiation absorbed dose for each age group. A summary of calculated effective doses is presented in Table 7.

Table 7 Effective Dose (mSv)

The five organs with highest total dose from PET and CT combined, as well as for PET alone were: Urinary bladder, heart, liver, lungs, brain.

The five organs with highest CT dose were: Thymus, thyroid, kidneys, eye lens, gonads (testes, male; ovaries, female).

For all patients, the mean difference between actual patient body mass and the mass of the phantom chosen to represent the patient, was 17%.

Forty five percent of all patients received more than one scan over the time period of the study; 50% of all patients aged 15 years old and younger received more than one scan, and 25% of patients aged 16 and 17 received more than one scan.

One patient who underwent 10 examinations during the study period received a cumulative eye lens absorbed dose of 81.9 mGy, and the five organs with the highest total dose were the heart, urinary bladder, thymus, liver and brain.

Discussion

An important first step to managing patient dose in PET-CT is finding suitable methods to quantify dose from both the CT and the PET portions of the examination. Methods which incorporate examination-specific and patient-adjusted parameters require considerable effort to collect and appropriately analyze data but provide results that more accurately represent the individual patient and irradiation conditions than generalized methods. A more accurate result is important for patients who are likely to receive multiple scans over the course of their disease management. As a retrospective investigation, this study entailed extraction of data from electronic records but a future evaluation could reduce time spent locating data in records by manually prospectively recording data such as injected activity, patient data and CT technique at the time of the examination. Our reported results represent pediatric patients in our institution and should be compared to other patient populations carefully. While the dosimetry tools employed in this study utilize phantoms of both genders, the reported results are gender-averaged. It should be noted that because we defined pediatric as less than 18 years old, only patients who were less than 18 years old at the time of exam were included in this study. The limited number of patients aged less than 1 year old in this study does not provide definitive findings for patients in this age group. The 429 examinations for which dosimetry was performed represent 133 unique patients, indicating that patients often underwent multiple scans. About half of the patients in this study had more than one PET-CT scan and 7% had 5 or more scans, supporting the importance of ongoing monitoring of individual radiation dose. One notable patient had 10 scans during the study period and received a cumulative eye lens absorbed dose of 81.9 mGy. While CT doses below 2 mSv are achievable for PET-CT, the average CT dose of 6.4 mSv for the patients in our study reflects the objective of pediatric PET-CT exams at our institution to provide localization information along with attenuation correction from the x-rays.

OLINDA 2.0 represents many improvements over the previous version, which serve to increase the accuracy of individual patient dosimetry. The software employs the latest phantoms of both genders, which are neither voxelized nor stylized, but are anatomically realistic and can easily be modified. Dose coefficients based on older stylized computational phantoms have been found to be different from those based on newer hybrid phantoms, especially for smaller body sizes. As shown in Table 8, dose coefficients provided by OLINDA 2.0 are lower than those provided by ICRP 128. The exceptions are the heart, stomach, esophagus, and thymus for which OLINDA 2.0 estimated a higher absorbed dose per unit injected activity than ICRP 128. Dose coefficients for urinary bladder, kidneys, heart, red bone marrow and lungs were estimated by OLINDA 2.0 to be lower than ICRP 128. Relative differences between ICRP 128 coefficients and those reported in our study are consistent with those demonstrated by Khamwan et al., in which lower lung and urinary bladder dose coefficients were attributed to improved approximation of adjacent organ boundaries as modeled by newer phantoms, compared to older stylized phantoms [32]. As a result of the organ dose differences between the two methods, the ED coefficients also differ, with those estimated by OLINDA 2.0 being approximately 34% less than those provided by ICRP 128. In accordance with ICRP 103 methodology, effective doses are calculated in the softwares by averaging gender-specific dose. Table 7 includes adult organ dose and ED coefficients for reference, with differences in the coefficients being consistent with those in pediatric phantoms. OLINDA 2.0 reported dose factors for left colon, right colon and rectum and we report total colon PET dose as the average of the three. The adjustment in OLINDA 2.0 of phantom organ mass made phantoms more representative of individual patient body size than the default phantom, but still not as specific to the patient as would be from segmentation of an actual patient image. Additionally, modification of all organs by the same ratio does not accurately reflect a non-linear change in organ mass with body mass.

Table 8 Comparison of Organ Dose Coefficients, OLINDA v2.0 and ICRP 128

VirtualDose CT software also utilizes the current generation of computational phantoms while offering the ability to incorporate exam-specific parameters. Compared to doses estimated using MIRD-style phantoms, the doses estimated by VirtualDose CT can be higher or lower depending on the location of the organ, but more accurately represent the patient, so are understood to be more accurate [33]. The improved approximation of human anatomy of phantoms in both VirtualDose and OLINDA 2.0 also means the organs represented are not exactly consistent across all ages, so doses from different age phantoms must be aggregated with care. For example, breast dose is only reported for 15-year-old and adult female phantoms, and not reported for 1-year, 5-year, 10-year phantoms of either gender. While VirtualDose reports eye lens dose and OLINDA 2.0 does not, eye lens dose results are included in this study for reference. Due to the accumulation of FDG in the brain, some dose to the eye lens is expected from PET.

Because phantom selection was based on a comparison of phantom mass with patient mass, some pediatric patients were best modeled by phantoms, which did not necessarily correspond to patient age in both PET and CT dosimetry software. For example, several patients were best approximated by adult phantoms. While PET organ dose could be more accurately represented by modification of phantom organ mass by the ratio of phantom mass to patient mass in PET software, it should be noted that CT organ mass was fixed to the chosen phantom. Although all of our pediatric PET-CT exams are conducted without tube current modulation, (TCM) the influence of this technique on patient dose should be considered where it might be implemented, such as a PET-CT examination that includes a diagnostic-quality CT. Failing to account for TCM can result in an over- or under-estimation of dose depending on the body region imaged. When the tube current is modulated, an organ dose estimation method based on a single CT dose metric such as dose length product (DLP) does not accurately represent patient dose, indicating the need for comprehensive dose estimation using appropriate methodology. Anatomy selection and accurate representation of patient size and composition are important considerations for pediatric CT patients, because organ dose changes are relatively greater in smaller patients depending on anatomy selection. A recent study demonstrated organ dose change resulting from inclusion or exclusion of an organ in scan range is more drastic in small patients [34]. In light of the wide range of considerations for accurate dosimetry, including patient size, age and imaging technique, a variety of dosimetry methodologies including those examined in the current study are beneficial to have on hand.

Conclusions

Radiopharmaceutical and x-ray internal radiation dose adjusted to individual pediatric patients can be estimated with available methods, which utilize appropriate anatomically-realistic models with patient-adjusted inputs. The ability to routinely evaluate dose representative of individual patients is especially important for radiosensitive populations such as children and radiosensitive organs subject to deterministic effects such as the lens of the eye. Dose estimates, whether organ or effective dose, are central to understanding how radiation dose relates to patient detriment and are important groundwork for a rigorous benefit analysis applicable to any medical imaging modality. Organ doses estimated using methodology employing anatomically realistic phantoms can be considerably different from those organ doses based on older generalized phantoms, but are understood to be more accurate because of the anatomical realism. Along with long-term monitoring of disease management outcomes, routine evaluation of individual patient dose is a key component in improving the understanding of the relationship between radiation exposure and biological effect. Whether for justification of examinations, long term tracking of patient doses or optimization of protocols, dose estimates are achievable, which are expediently formulated using appropriate methodology that closely represents the patient. As truly patient-specific dosimetry is becoming more and more achievable, patient-adjusted methods such as those in the current study facilitate a meaningful understanding of patient radiation dose by accounting for dosimetry factors representative of the patient and exposure scenario.

Availability of data and materials

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Abbreviations

18F-FDG-2:

18-Fluoro-2-deoxy-D-glucose

AAPM:

American Association of Physicists in Medicine

ACR:

American College of Radiology

BSA:

Body Surface Area; CT-Computed Tomography

CTAC:

CT Attenuation Correction

CTDIvol:

Volumetric Computed Tomography Dose Index

DLP:

Dose Length Product

EANM:

European Association of Nuclear Medicine

ED:

Effective Dose

ICRP:

International Council on Radiation Protection

MIRD:

Medical Internal Radiation Dose Committee

PET:

Positron Emission Tomography

TCM:

Tube Current Modulation;

References

  1. 1.

    NCRP. NCRP report 160: ionizing radiation exposure of the population of the United States. Bethesda: National Council on Radiation Protection and Measurements; 2006.

    Google Scholar 

  2. 2.

    Quinn B, Dauer Z, Pandit-Raskar N, Schoder H, Dauer LT. Radiation Dosimetry of 18F-FDG PET/CT: incorporating exam-specific parameters in dose estimates. BMC Med Imaging. 2016;16(1):41.

    Article  Google Scholar 

  3. 3.

    Chawla SC, Federman N, Zhang D, Nagata K, et al. Estimated cumulative Radiation dose from PET/CT in children with Malifnancies: a 5-year retrospective review. Pediatr Radiol. 2010;40(5):681–6.

    Article  Google Scholar 

  4. 4.

    Alessio AM, Kinahan PE, Manchanda V, Ghioni V, Aldape L, Parisi M. Weight-based, low-dose pediatric whole-body PET/CT protocols. J Nucl Med. 2009;50(10):1570–8.

    Article  Google Scholar 

  5. 5.

    Kim YY, Shin HJ, Kim MJ, Lee MJ. Comparison of Effective Radiation Doses from X-ray, CT, and PET/CT in Pediatric Patients with Neuroblastoma Using a Dose Monitoring Program. Diagn Interv Radiol. 2009;22(4):390–4 2016.

    Article  Google Scholar 

  6. 6.

    Huang B, Law MWM, Khong PL. Whole-body PET/CT scanning: estimation of Radiation dose and Cancer risk. Radiology. 2009;251(1):166–74.

    Article  Google Scholar 

  7. 7.

    UNSCEAR. Report of the United Nations Scientific Committee on the Effects of Atomic Radiation. Seventy-second Session. General Assembly Records Sixty Seventh Session, Supplemental No. 46. United Nations: Annex A (A/72/46); 2018.

    Google Scholar 

  8. 8.

    ICRP. The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann ICRP. 2007;37(2–4):129.

  9. 9.

    Fisher DR, Fahey FH. Appropriate Use of Effective Dose in Radiation Protection and Risk Assessment. Health Phys. 2017;113(2):102–9.

    CAS  Article  Google Scholar 

  10. 10.

    NCRP. Commentary No. 27 – Implications of Recent Epidemiologic Studies for the Linear-Nonthreshold Model and Radiation Protection. Bethesda: National Council on Radiation Protection and Measurements; 2018.

    Google Scholar 

  11. 11.

    Shore RE, Beck HL, Boice JD Jr, et al. Recent Epidemiologic Studies and the Linear No-Threshold Model For Radiation Protection Consideration Regarding NCRP Commentary 27. Health Phys. 2019;116(2):235–46.

    CAS  Article  Google Scholar 

  12. 12.

    Shore RE, Beck HL, Boice JD, et al. Implications of Recent Epidemiologic Studies for the Linear Nonthreshold Model and Radiation Protection. J Radiol Prot. 2018;38(3):1217–33.

    CAS  Article  Google Scholar 

  13. 13.

    National Research Council. Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2. Washington: The National Academies Press; 2006.

    Google Scholar 

  14. 14.

    Siegel J, Pennington C, Sacks B. Subjecting Radiologic Imaging to the Linear No-Threshold Hypothesis: A non-sequitur of Non-Trivial Proportion. J Nucl Med. 2017;58:1–6.

    Article  Google Scholar 

  15. 15.

    Weber W, Zanzonico P. The Controversial Linear-no Threshold Model. J Nucl Med. 2017;58(1):7–8.

    Article  Google Scholar 

  16. 16.

    Goske MJ, Applegate KE, Boylan J, Butler PF, Callahan MJ, Coley BD, Farley S, Frush DP, Hernanz-Schulman M, Jaramillo D, et al. The image Gently campaign: working together to change practice. AJR Am J Roentgenol. 2008;190(2):273–4.

    Article  Google Scholar 

  17. 17.

    Image Gently. IG CT Protocols. https://www.imagegently.org/portals/6/procedures/IG%20CT%20Protocols%20111717.pdf. Accessed 22 July 2019.

  18. 18.

    AAPM. The Alliance for Quality Computed Tomography. https://www.aapm.org/pubs/CTProtocols/?tab=5#CTabbedPanels. Accessed 22 July 2019.

  19. 19.

    ACR. DIR User Guide. American College of Radiology. https://www.acr.org/Practice-Management-Quality-Informatics/Registries/Dose-Index-Registry. Accessed 25 May 2018.

  20. 20.

    Treves ST, Davis RT, Fahey FH. Administered radiopharmaceutical doses in children: a survey of 13 pediatric hospitals in North America. J Nucl Med. 2008;49:1024–7.

    Article  Google Scholar 

  21. 21.

    Parisi MT, Bermo MS, Alessio AM, Sharp SE, Gelfand MJ, Shulkin BL. Optimization of pediatric PET/CT. Semin Nucl Med. 2017 May;47(2):258–74.

    Article  Google Scholar 

  22. 22.

    Kaste SC. Issues specific to implementing PET-CT for pediatric oncology: what we have learned along the way. Pediatr Radiol. 2004;34:205–13.

    Article  Google Scholar 

  23. 23.

    McQuattie S. Pediatric PET/CT imaging: tips and techniques. J Nucl Med Technol. 2006;36:171–8.

    Article  Google Scholar 

  24. 24.

    Fahey FH, Goodkind A, MacDougal RD, Oberg L, Ziniel SI, Cappock R, Callahan MJ, Kwatra N, Treves ST, Voss SD. Operational and Dosimetric Aspects of Pediatric PET/CT. J Nucl Med. 2017;58(9):1360–6.

    Article  Google Scholar 

  25. 25.

    Brix G, Nosske D, Lechel U. Radiation exposure of patients undergoing whole-body FDG-PET/CT examinations: an update pursuant to the new ICRP recommendations. Nuklearmedizin. 2014;53(5):217–20.

    CAS  Article  Google Scholar 

  26. 26.

    Shrimpton PC, Wall BF. Reference doses for Paediatric computed tomography. Radiat Prot Dosim. 2000;90(1–2):249–52.

    Article  Google Scholar 

  27. 27.

    ICRP. Radiological Protection in Medicine. International Commission on Radiological Protection. ICRP Publication 105. Ann ICRP. 2007;37(6):25–33.

  28. 28.

    Stabin M, Sparks R, Crowe E. OLINDA/EXM: the second-generation personal computer software for internal dose assessment in nuclear medicine. J Nucl Med. 2005;46(6):1023–7.

    PubMed  Google Scholar 

  29. 29.

    Ding A, Gao Y, Liu H, Caracappa PF, Long DJ, Bolch WE, Liu B, Xu XG. VirtualDose: a software for reporting organ doses from CT for adult and pediatric patients. Phys Med Biol. 2015;60(14):5601–25.

    Article  Google Scholar 

  30. 30.

    Shore RM, Hendee WR. Radiopharmaceutical dosage selection for pediatric nuclear medicine. J Nucl Med. 1986;27(2):287–98.

    CAS  PubMed  Google Scholar 

  31. 31.

    ICRP. Radiation Dose to Patients from Radiopharmaceuticals: A Compendium of Current Information Related to Frequently Used Substances. ICRP Publication 128. Ann ICRP. 2015;44(2S):108.

  32. 32.

    Khamwan K, OReilly S, Plyku D, Goodkind A, Josefsson A, Cao X, Fahey F, Treves T, Bolch W, Sgouros G. Re-evaluation of pediatric 18F-FDG Dosimetry: Cristy-Eckerman versus UF/NCI hybrid computational phantoms. Phys Med Biol. 2018;63(16):165012.

    Article  Google Scholar 

  33. 33.

    Ding A, Gu J, Mille M, Xu XG, Liu B. VirtualDose: A CT Dose Reporting Software Based on Anatomically Realistic Phantoms. J Nucl Med. 2010;51:S2 520.

    Google Scholar 

  34. 34.

    Gao Y, Quinn B, Mahmood U, Long D, Erdi Y, St Germain J, Pandit-Taskar N, Xu XG, Bolch W, Dauer L. A comparison of pediatric and adult CT organ dose estimation methods. BMC Med Im. 2017;17:28.

    Article  Google Scholar 

Download references

Acknowledgements

Not applicable.

Funding

This research was funded in part through the NIH/NCI Cancer Center Support Grant P30 CA008748.

Author information

Affiliations

Authors

Contributions

BMQ collected, analysed and interpreted data, managed the database, drafted the manuscript, and designed the study. YG collected and interpreted data, designed the study, helped draft the manuscript, provided expertise on internal CT dosimetry and provided expertise utilizing VirtualDose CT software. UM provided technical expertise on GE DoseWatch software, CT technique and helped draft manuscript relevant to CT technique. NP-T provided medical and molecular imaging input and helped draft the manuscript relevant to medical and practical clinical aspects. GB provided pediatric radiology expertise and helped draft the manuscript relevant to clinical pediatric radiology. PZ provided expertise on internal dosimetry and radiation protection, edited and drafted the manuscript relevant to internal radiopharmaceutical dosimetry and radiation protection. LD conceived of and helped design the study, provided technical oversight of dose calculation methods, provided radiation protection expertise and drafted the manuscript relevant to radiation protection. All authors read and approved final manuscript.

Corresponding author

Correspondence to Brian M. Quinn.

Ethics declarations

Ethics approval and consent to participate

A waiver of informed consent was obtained for usage of the data in this study.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Quinn, B.M., Gao, Y., Mahmood, U. et al. Patient-adapted organ absorbed dose and effective dose estimates in pediatric 18F-FDG positron emission tomography/computed tomography studies. BMC Med Imaging 20, 9 (2020). https://doi.org/10.1186/s12880-020-0415-4

Download citation

Keywords

  • PET/CT dosimetry
  • CT dosimetry
  • PET dosimetry
  • Effective dose
  • Pediatric