Para-[123I]iodo-L-phenylalanine in patients with pancreatic adenocarcinoma

2008 ◽  
Vol 47 (05) ◽  
pp. 220-224 ◽  
Author(s):  
E. Gouverneur ◽  
A. Schaefer ◽  
J. Raedle ◽  
M. Menges ◽  
C.-M. Kirsch ◽  
...  
Keyword(s):  
Effective Dose ◽  
Brain Tumour ◽  
Pancreatic Adenocarcinoma ◽  
Bladder Wall ◽  
Whole Body ◽  
Residence Times ◽  
Tumour Imaging ◽  
Time Activity ◽  
Tumour Uptake ◽  
Absorbed Doses

SummaryRecently, p-[123I]iodo-L-phenylalanine (IPA) was clinically validated for brain tumour imaging. Preclinical studies demonstrated uptake of IPA into pancreatic adenocarcinoma suggesting its diagnostic application in patients with pancreatic tumours. The aim was to study the tumour uptake of IPA in patients with pancreatic adenocarcinoma and to analyse its biodistribution and dosimetry to assess the radiation dose resulting from its diagnostic use. Patients, methods: Seven patients with pancreatic adenocarcinoma underwent whole-body scintigraphies and SPECT up to 24 h after administration of 250 MBq of IPA. Tumour uptake of IPA was assessed visually. Time activity curves and the corresponding residence times were determined for whole-body, kidneys, liver, spleen, lung, heart content, brain, and testes. Mean absorbed doses for various organs and the effective dose were assessed based on the MIRD formalism using OLINDA/EXM. Results: IPA exhibited no accumulation in proven manifestations of pancreatic adenocarcinomas. IPA was exclusively eliminated by the urine and showed a delayed clearance from blood. Residence times were 0.26 ± 0.09 h for kidneys, 0.38 ± 0.19 h for liver, 0.15 ± 0.07 h for spleen, 0.51 ± 0.20 h for lungs, 0.22 ± 0.07 h for heart content, 0.11 ± 0.05 h for brain, 0.014 ± 0.005 h for testes and 6.4 ± 2.2 h for the remainder. The highest absorbed doses were determined in the urinary bladder wall and in the kidneys. According to the ICRP 60 the effective dose resulting from 250 MBq IPA was 3.6 ± 0.7 mSv. Conclusion: Para-[123I]iodo-L-phenylalanine can be used in diagnostic nuclear medicine with acceptable radiation doses. Besides its proven validity for brain tumour imaging, IPA does not appear to be suitable as tracer for pancreatic cancer.

scholarly journals Whole-body biodistribution and radiation dosimetry of [18F]PR04.MZ: a new PET radiotracer for clinical management of patients with movement disorders

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Wencke Lehnert ◽  
Patrick J. Riss ◽  
Ana Hurtado de Mendoza ◽  
Sandra Lopez ◽  
Gonzalo Fernandez ◽  
...  
Keyword(s):  
Gall Bladder ◽  
Effective Dose ◽  
Cortical Bone ◽  
Pet Imaging ◽  
Movement Disorders ◽  
Radiation Dosimetry ◽  
Bladder Wall ◽  
Whole Body ◽  
Absorbed Doses ◽  
Red Marrow

Abstract Purpose [18F]PR04.MZ is a new PET imaging agent for dopamine transporters, providing excellent image quality and allowing for the evaluation of patients with movement disorders such as Parkinson’s disease. The objective of this study was to evaluate the biodistribution and radiation dosimetry of [18F]PR04.MZ by serial PET imaging. Methods Six healthy subjects (n = 3 males, n = 3 females) were enrolled in this study. A series of 14 whole-body PET/CT scans were acquired until 5.5 h post-injection of 200 ± 11 MBq of [18F]PR04.MZ. After rigid co-registration, volumes of interest were outlined either on CT or PET images. Time-integrated activity coefficients were calculated for selected source organs. Organ absorbed doses, and the effective dose were calculated using IDAC-Dose 2.1. Results Physiological uptake of [18F]PR04.MZ was mainly observed in the striatum, brain, liver, gall bladder, intestine, red marrow and cortical bone. [18F]PR04.MZ was primarily excreted via hepatobiliary clearance and, to a lower extent, via renal clearance. The normalized absorbed doses were highest in gall bladder wall (32.2 ± 6.4 µGy/MBq), urinary bladder wall (27.2 ± 4.5 µGy/MBq), red marrow (26.5 ± 1.4 µGy/MBq), cortical bone surface (26.3 ± 2.5 µGy/MBq), liver (22.5 ± 1.8 µGy/MBq) and kidneys (21.8 ± 1.1 µGy/MBq). The effective dose according to ICRP 60 and 103 was 16.3 ± 1.1 and 16.6 ± 1.5 µSv/MBq, respectively. Conclusion [18F]PR04.MZ has a favourable dosimetry profile, comparable to those of other 18F-labelled PET tracers, and is suitable for larger clinical applications. Trial registration CEC SSM Oriente, Santiago, Chile, permit 20140520.

scholarly journals Human biodistribution and dosimetry of [11C]-UCB-J, a PET radiotracer for imaging synaptic density

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Christopher Cawthorne ◽  
Paul Maguire ◽  
Joel Mercier ◽  
David Sciberras ◽  
Kim Serdons ◽  
...  
Keyword(s):  
Effective Dose ◽  
Phase 1 ◽  
Bladder Wall ◽  
Absorbed Dose ◽  
Whole Body ◽  
Time Activity ◽  
Urinary Bladder Wall ◽  
Dose Coefficients ◽  
Pet Scans

Abstract Rationale [11C]-UCB-J is an emerging tool for the noninvasive measurement of synaptic vesicle density in vivo. Here, we report human biodistribution and dosimetry estimates derived from sequential whole-body PET using two versions of the OLINDA dosimetry program. Methods Sequential whole-body PET scans were performed in 3 healthy subjects for 2 h after injection of 254 ± 77 MBq [11C]-UCB-J. Volumes of interest were drawn over relevant source organs to generate time-activity curves and calculate time-integrated activity coefficients, with effective dose coefficients calculated using OLINDA 2.1 and compared to values derived from OLINDA 1.1 and those recently reported in the literature. Results [11C]-UCB-J administration was safe and showed mixed renal and hepatobiliary clearance, with largest organ absorbed dose coefficients for the urinary bladder wall and small intestine (21.7 and 23.5 μGy/MBq, respectively). The average (±SD) effective dose coefficient was 5.4 ± 0.7 and 5.1 ± 0.8 μSv/MBq for OLINDA versions 1.1 and 2.1 respectively. Doses were lower than previously reported in the literature using either software version. Conclusions A single IV administration of 370 MBq [11C]-UCB-J corresponds to an effective dose of less than 2.0 mSv, enabling multiple PET examinations to be carried out in the same subject. Trial registration EudraCT number: 2016-001190-32. Registered 16 March 2016, no URL available for phase 1 trials.

scholarly journals Internal dosimetry in F-18 FDG PET examinations based on long-time-measured organ activities using total-body PET/CT: does it make any difference from a short-time measurement?

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Pengcheng Hu ◽  
Xin Lin ◽  
Weihai Zhuo ◽  
Hui Tan ◽  
Tianwu Xie ◽  
...  
Keyword(s):  
Effective Dose ◽  
Dynamic Model ◽  
Bladder Wall ◽  
Time Measurement ◽  
Post Injection ◽  
Time Activity ◽  
Pet Ct ◽  
Long Time ◽  
Total Body ◽  
Short Time

Abstract Purpose A 2-m axial field-of-view, total-body PET/CT scanner (uEXPLORER) has been recently developed to provide total-body coverage and ultra-high sensitivity, which together, enables opportunities for in vivo time-activity curve (TAC) measurement of all investigated organs simultaneously with high temporal resolution. This study aims at quantifying the cumulated activity and patient dose of 2-[F-18]fluoro-2-deoxy-D-glucose (F-18 FDG ) imaging by using delayed time-activity curves (TACs), measured out to 8-h post-injection, for different organs so that the comparison between quantifying approaches using short-time method (up to 75 min post-injection) or long-time method (up to 8 h post-injection) could be performed. Methods Organ TACs of 10 healthy volunteers were collected using total-body PET/CT in 4 periods after the intravenous injection of F-18 FDG. The 8-h post-injection TACs of 6 source organs were fitted using a spline method (based on Origin (version 8.1)). To compare with cumulated activity estimated from spline-fitted curves, the cumulated activity estimated from multi-exponential curve was also calculated. Exponential curve was fitted with shorter series of data consistent with clinical procedure and previous dosimetry works. An 8-h dynamic bladder wall dose model considering 2 voiding were employed to illustrate the differences in bladder wall dose caused by the different measurement durations. Organ absorbed doses were further estimated using Medical Internal Radiation Dose (MIRD) method and voxel phantoms. Results A short-time measurement could lead to significant bias in estimated cumulated activity for liver compared with long-time-measured spline fitted method, and the differences of cumulated activity were 18.38% on average. For the myocardium, the estimated cumulated activity difference was not statistically significant due to large variation in metabolism among individuals. The average residence time differences of brain, heart, kidney, liver, and lungs were 8.38%, 15.13%, 25.02%, 23.94%, and 16.50% between short-time and long-time methods. Regarding effective dose, the maximum differences of residence time between long-time-measured spline fitted curve and short-time-measured multi-exponential fitted curve was 9.93%. When using spline method, the bladder revealed the most difference in the effective dose among all the investigated organs with a bias up to 21.18%. The bladder wall dose calculated using a long-time dynamic model was 13.79% larger than the two-voiding dynamic model, and at least 50.17% lower than previous studies based on fixed bladder content volume. Conclusions Long-time measurement of multi-organ TACs with high temporal resolution enabled by a total-body PET/CT demonstrated that the clinical procedure with 20 min PET scan at 1 h after injection could be used for retrospective dosimetry analysis in most organs. As the bladder content contributed the most to the effective dose, a long-time dynamic model was recommended for the bladder wall dose estimation.

scholarly journals Clinical translation of 18F-fluoropivalate – a PET tracer for imaging short-chain fatty acid metabolism: safety, biodistribution, and dosimetry in fed and fasted healthy volunteers

2020 ◽  
Vol 47 (11) ◽  
pp. 2549-2561 ◽  
Author(s):  
Suraiya R. Dubash ◽  
Nicholas Keat ◽  
Kasia Kozlowski ◽  
Chris Barnes ◽  
Louis Allott ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Healthy Volunteers ◽  
Effective Dose ◽  
Short Chain Fatty Acid ◽  
Safety Data ◽  
Chain Fatty Acid ◽  
Short Chain ◽  
Whole Body ◽  
Residence Times

Abstract Background Fatty acids derived de novo or taken up from the extracellular space are an essential source of nutrient for cell growth and proliferation. Radiopharmaceuticals including 11C-acetate, and 18F-FAC (2-18F-fluoroacetate), have previously been used to study short-chain fatty acid (SCFA) metabolism. We developed 18F-fluoropivalate (18F-FPIA; 3-18F-fluoro-2,2-dimethylpropionic acid) bearing a gem-dimethyl substituent to assert metabolic stability for studying SCFA metabolism. We report the safety, biodistribution, and internal radiation dosimetry profile of 18F-FPIA in 24 healthy volunteers and the effect of dietary conditions. Materials and methods Healthy volunteer male and female subjects were enrolled (n = 24), and grouped into 12 fed and 12 fasted. Non-esterified fatty acids (NEFA) and carnitine blood measurements were assessed. Subjects received 159.48 MBq (range, 47.31–164.66 MBq) of 18F-FPIA. Radiochemical purity was > 99%. Safety data were obtained during and 24 h after radiotracer administration. Subjects underwent detailed multiple whole-body PET/CT scanning with sampling of venous bloods for radioactivity and radioactive metabolite quantification. Regions of interest were defined to derive individual and mean organ residence times; effective dose was calculated using OLINDA 1.1. Results All subjects tolerated 18F-FPIA with no adverse events. Over 90% of radiotracer was present in plasma at 60 min post-injection. The organs receiving highest absorbed dose (in mGy/MBq) were the liver (0.070 ± 0.023), kidneys (0.043 ± 0.013), gallbladder wall (0.026 ± 0.003), and urinary bladder (0.021 ± 0.004); otherwise there was low tissue uptake. The calculated effective dose using mean organ residence times over all 24 subjects was 0.0154 mSv/MBq (SD ± 0.0010). No differences in biodistribution or dosimetry were seen in fed and fasted subjects, though systemic NEFA and carnitine levels reflected fasted and fed states. Conclusion The favourable safety, imaging, and dosimetric profile makes 18F-FPIA a promising candidate radiotracer for tracing SCFA metabolism.

scholarly journals Internal dosimetry in F-18 FDG PET examinations based on long time measured organ activities using total-body PET/CT: dose it makes any difference from a short-time measurement?

2020 ◽  
Author(s):  
Pengcheng Hu ◽  
Xin Lin ◽  
Weihai Zhuo ◽  
Hui Tan ◽  
Tianwu Xie ◽  
...  
Keyword(s):  
Effective Dose ◽  
Dynamic Model ◽  
Bladder Wall ◽  
Time Measurement ◽  
High Temporal Resolution ◽  
Time Activity ◽  
Pet Ct ◽  
Long Time ◽  
Total Body ◽  
Short Time

Abstract Purpose The 2-meter long total-body PET/CT scanner (uEXPLORER) has been developed recently while its total-body coverage and ultra-high sensitivity provide opportunities for in vivo time-activity curve (TAC) measurement of all investigated organs with high temporal resolution simultaneously. This study aims at quantifying the cumulated activity and patient dose with long-time measured time-activity curves (TACs) of different organs, so that the comparison between estimation of quantifying methods using short-time or long-time TACs could be performed.Methods Organ TACs of 10 healthy volunteers were collected by the newly developed dynamic total-body PET/CT system in 4 periods after the intravenous injection of 2-[F-18]Fluoro-2-deoxy-D-glucose (18F-FDG). The 8-hour TACs of 6 source organs were fitted by using a spline method. Comparing cumulated activity estimated from spline fitted curves, the cumulated activity estimated from multi-exponential curve was also calculated. Exponential curve was fitted with shorter series of data consisting with clinical procedure and previous dosimetry works. An 8-hours dynamic bladder wall dose model considering 2 voiding were demonstrated to illustrate the differences in bladder dose caused by the different measurement durations. Organ absorbed doses were further estimated by using MIRD method and voxel phantoms for effective dose estimations.Results Short-time measurement could bring significant differences in estimated cumulated activity for liver compared with long-time measured spline fitted method while the differences of cumulated activity were 18.38% on average. For myocardium, the estimated cumulated activity difference was statistically neglectable due to the individual variation in metabolism. The average residence time differences of brain, heart, kidney, liver and lungs are 8.38%, 15.13%, 25.02%, 23.94% and 16.50% between spline fitted curve and multi-exponential fitted curve (fitted using the data from 57 minutes to 75 minutes after injection). When considering effective dose, the maximum differences of residence time between long-time measured spline fitted curve and multi-exponential fitted curve (fitted with shorter series of data) was 9.93%. The bladder contributed the most to the effective dose among all the investigated organs with the value of 21.18%. The bladder wall dose calculated using a long-time dynamic model was 13.79% larger than the two-voiding dynamic model, while at least 50.17% smaller than previous study using fixed bladder content volume.Conclusions Multi-organ TACs in-vivo long-time measurement with high temporal resolution by using total-body PET/CT proved that the data of clinical procedure with 20 minutes PET scan at 1 hour after injection could be used for retrospective dosimetry analysis. As the bladder content contributed the most to the effective dose, a long-time dynamic model was recommended for the bladder wall dose estimation.

Bio-Distribution and Dosimetry of a Renal Agent in Normal Bangladeshi Subjects

2013 ◽  
Vol 4 (1) ◽  
pp. 21-26
Author(s):  
MN Islam ◽  
F Alam ◽  
MF Kabir ◽  
AS Mollah ◽  
MA Zaman
Keyword(s):  
Effective Dose ◽  
Large Intestine ◽  
Medical Physics ◽  
Absorbed Dose ◽  
Region Of Interest ◽  
The Body ◽  
Published Data ◽  
Residence Times ◽  
Time Activity ◽  
Blood Plasma Sample

Radiation absorbed dose estimation was performed on eleven normal patients who were in a process of routine diagnostic investigation of the renal function. Bio-kinetics and bio-distribution of 99mTc-DTPA in patients was evaluated by dual-head gamma camera imaging and blood-plasma sample counting method. Radiation dose estimations were performed using standard MIRD techniques and biodistribution of different organ was estimated by drawing region of interest (ROI) according to MIRD phantom model [1]. From the time-activity curves, cumulative activities and residence times of 99mTc- DTPA in the kidneys, brain, upper large intestine (ULI), small intestine (SI), lower large intestine (LLI), stomach, heart, liver, lung and remainder of the body was calculated. Using the information of residence times of the total body and urinary bladder voiding at 2.4 hours on MIRD 12 absorbed dose for the 99mTc-DTPA in different target organs of the body was measured [2]. The estimated average absorbed dose to the kidneys as a target organ in normal Bangladeshis are 5.71E-03 mGy/MBq of 99mTc-DTPA which is closer to the ICRP 53 and other recent published data. The calculated effective dose equivalent and effective dose was found 5.72E-03 mSv/MBq and 4.89E-03 mSv/MBq respectively. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14674 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 21-26

scholarly journals Estimating the Absorbed Dose of Organs in Pediatric Imaging of 99mTc-DTPA Radiopharmaceutical using MIRDOSE Software

2019 ◽  
Author(s):  
K Ebrahimnejad Gorji ◽  
R Abedi Firouzjah ◽  
F Khanzadeh ◽  
N Abdi-Goushbolagh ◽  
A Banaei ◽  
...  
Keyword(s):  
Effective Dose ◽  
Bladder Wall ◽  
Absorbed Dose ◽  
Region Of Interest ◽  
Time Activity ◽  
Significant Difference ◽  
Urinary Bladder Wall ◽  
The Mean ◽  
Absorbed Radiation Dose ◽  
Renal Agent

Introduction: In this study, organ radiation doses were calculated for the renal agent 99mTc-DTPA in children. Bio-kinetic energy of 99mTc-DTPA was evaluated by scintigraphy and estimates for absorbed radiation dose were provided using standard medical internal radiation dosimetry (MIRD) techniques.Materials and Methods: In this applied research, fourteen children patients (6 males and 8 females) were imaged using a series of planar and SPECT images after injecting with technetium-99m diethylenetriaminepentaacetic acid (99mTc-DTPA). A hybrid planar/SPECT method was used to plot time-activity curves to obtain the residence time of the source organs and also MIRDOSE software was used to calculate the absorbed dose of every organ. P-values were calculated using t-tests in order to make a comparison between the adsorbed doses of male and female groups.Results: Mean absorbed doses (µGy/MBq) for urinary bladder wall, kidneys, gonads, liver and adrenals were 213.5±47.8, 12.97±6.23, 12.0±2.5, 4.29±1.47, and 3.31±0.96, respectively. Furthermore, the mean effective dose was 17.5±3.7 µSv/MBq. There was not any significant difference in the mean absorbed dose of the two groups.Conclusion: Bladder cumulated activity was the most contribution in the effective dose of patients scanned with 99mTc-DTPA. Using a hybrid planar/SPECT method can cause an increase in accumulated activity accuracy for the region of interest. Moreover, patient-specified internal dosimetry is recommended.

scholarly journals Biodistribution and post-therapy dosimetric analysis of [177Lu]Lu-DOTAZOL in patients with osteoblastic metastases: first results

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ambreen Khawar ◽  
Elisabeth Eppard ◽  
Frank Roesch ◽  
Hojjat Ahmadzadehfar ◽  
Stefan Kürpig ◽  
...  
Keyword(s):  
Urinary Bladder ◽  
Radionuclide Therapy ◽  
Bladder Wall ◽  
Absorbed Dose ◽  
Whole Body ◽  
Normal Organ ◽  
Skeletal Disease ◽  
Absorbed Doses ◽  
Urinary Bladder Wall ◽  
Dosimetric Analysis

Abstract Background Preclinical biodistribution and dosimetric analysis of [177Lu]Lu-DOTAZOL suggest the bisphosphonate zoledronate as a promising new radiopharmaceutical for therapy of bone metastases. We evaluated biodistribution and normal organ absorbed doses resulting from therapeutic doses of [177Lu]Lu-DOTAZOL in patients with metastatic skeletal disease. Method Four patients with metastatic skeletal disease (age range, 64–83 years) secondary to metastatic castration-resistant prostate carcinoma or bronchial carcinoma were treated with a mean dose of 5968 ± 64 MBq (161.3 mCi) of [177Lu]Lu-DOTAZOL. Biodistribution was assessed with serial planar whole body scintigraphy at 20 min and 3, 24, and 167 h post injection (p.i.) and blood samples at 20 min and 3, 8, 24, and 167 h p.i. Percent of injected activity in the blood, kidneys, urinary bladder, skeleton, and whole body was determined. Bone marrow self-dose was determined by an indirect blood-based method. Urinary bladder wall residence time was calculated using Cloutier’s dynamic urinary bladder model with a 4-h voiding interval. OLINDA/EXM version 2.0 (Hermes Medical Solutions, Stockholm, Sweden) software was used to determine residence times in source organs by applying biexponential curve fitting and to calculate organ absorbed dose. Results Qualitative biodistribution analysis revealed early and high uptake of [177Lu]Lu-DOTAZOL in the kidneys with fast clearance showing minimal activity by 24 h p.i. Activity in the skeleton increased gradually over time. Mean residence times were found to be highest in the skeleton followed by the kidneys. Highest mean organ absorbed dose was 3.33 mSv/MBq for osteogenic cells followed by kidneys (0.490 mSv/MBq), red marrow (0.461 mSv/MBq), and urinary bladder wall (0.322 mSv/MBq). The biodistribution and normal organ absorbed doses of [177Lu]Lu-DOTAZOL are consistent with preclinical data. Conclusion [177Lu]Lu-DOTAZOL shows maximum absorbed doses in bone and low kidney doses, making it a promising agent for radionuclide therapy of bone metastasis. Further studies are warranted to evaluate the efficacy and safety of radionuclide therapy with [177Lu]Lu-DOTAZOL in the clinical setting.

scholarly journals Human biodistribution and internal dosimetry of 4-[ 18F]fluorobenzyl-dexetimide: a PET radiopharmaceutical for imaging muscarinic acetylcholine receptors in the brain and heart

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Cameron D. Pain ◽  
Graeme J. O’Keefe ◽  
Uwe Ackermann ◽  
Vincent Dore ◽  
Victor L. Villemagne ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Effective Dose ◽  
Muscarinic Receptors ◽  
Left Ventricular ◽  
Whole Body ◽  
Myocardial Uptake ◽  
Parasympathetic Innervation ◽  
Time Activity ◽  
The Brain

Abstract Background 4-[18F] fluorobenzyl dexetimide (F-DEX) is the first non-subtype selective fluorine-18 labelled tracer for muscarinic receptors (mAChR) used in humans. A recent first-in-human study found high regional brain uptake with low variation in normal subjects. Disturbance of mAChR has been reported in Alzheimer’s and Parkinson’s disease, schizophrenia and depression and various cardiac diseases. The following work assesses the biodistribution, organ tracer kinetics and radiation dose associated with F-DEX. Method Dose calculations were based on activity uptake derived from multiple time point whole body PET CT imaging and the organ-specific dosimetric S-factors derived from the ICRP 133 standard man and woman mathematical phantoms. Effective doses were calculated using the latest ICRP tissue weighting factors. Results Serial images and time activity curves demonstrate high brain and left ventricular myocardial uptake (5% and 0.65% of injected activity, respectively) with greater retention in brain than myocardium. The mean effective dose was in concordance with other 18F labelled tracers at 19.70 ± 2.27 μSv/MBq. The largest absorbed doses were in the liver (52.91 ± 1.46 μGy/MBq) and heart wall (43.94 ± 12.88 μGy/MBq) for standard man and the liver (61.66 ± 13.61 μGy/MBq) and lungs (40.93 ± 3.11 μGy/MBq) for standard woman. The absorbed dose to all organs, most notably, the red bone marrow (20.03 ± 2.89 μGy/MBq) was sufficiently low to ensure no toxicity after numerous follow-up procedures. Conclusions The radiation dose associated with an administration of F-DEX is comparable to that of other 18F labelled tracers such as FDG (19.0 μSv/MBq) and lower than tracers used for SPECT imaging of muscarinic receptors (I-DEX 28.5 μSv/MBq). Clinical use would likely result in an effective dose less than 4 mSv for the ICRP 133 standard phantoms after dose optimisation allowing justification for numerous follow-up procedures. Recent results from first in-human studies and a comparatively low radiation dose make F-DEX an attractive option for future applications of imaging muscarinic receptors in the brain. Further investigation of the potential of F-DEX for imaging parasympathetic innervation of the heart may be warranted.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

Sign in / Sign up

Export Citation Format

Share Document