Related Experiment Video
Updated: Oct 18, 2025
06:20
Irradiator Commissioning and Dosimetry for Assessment of LQ α and β Parameters, Radiation Dosing Schema, and in vivo Dose Deposition
Published on: March 11, 2021
7.4K
A SIMPLE AND NOVEL APPROACH TO STUDY KINETICS AND ESTIMATE RADIATION DOSES FROM INTERNALLY ADMINISTERED
Amit Nautiyal1,2, Tanmoy Mondal3, Deepanjan Mitra1
1Institute of Nuclear Medicine & Molecular Imaging, AMRI Hospitals, Dhakuria, Kolkata, India.
Radiation Protection Dosimetry
|September 29, 2021
Summary
A novel external dose measurement system accurately quantifies radiotracer uptake and organ doses in patients undergoing 18F-FDG PET/CT scans. This convenient and reliable technique aids internal dosimetry in nuclear medicine practice.
Area of Science:
- Nuclear Medicine
- Medical Physics
- Radiopharmacology
Background:
- Radiotracer kinetics and internal dosimetry are crucial for clinical nuclear medicine.
- Existing methods for dosimetry can be complex and less feasible for routine practice.
Purpose of the Study:
- To quantify cumulative activity and organ doses using a novel indigenously designed external dose measurement system.
- To assess the reliability and convenience of this system for routine clinical application.
Main Methods:
- Demonstration on patients undergoing whole-body 18F-FDG PET/CT.
- Utilized an ionization chamber-survey meter with a movable focusing collimator to quantify 18F-FDG uptake in liver and brain.
- Calculated cumulative and normalized cumulative activity.
- Validated results using a uniformly filled 18F-FDG phantom.
Main Results:
- The external dose measurement system successfully quantified 18F-FDG uptake in target organs.
- A statistically significant difference (p < 0.05) was observed in absorbed dose estimations with and without the collimator.
- Phantom validation confirmed the system's accuracy.
Conclusions:
- The developed external dose measurement technique is a novel, convenient, and reliable method for assessing internal absorbed organ doses.
- This system holds promise for routine clinical nuclear medicine practice, enhancing internal dosimetry capabilities.
More Related Videos
Related Concept Videos
02:59Biological Effects of Radiation
16.3K
All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break chemical bonds, or ionize molecules. The most serious biological damage results when these radioactive emissions fragment or ionize molecules. For example, α and β particles emitted from nuclear decay reactions possess much higher energies than ordinary chemical bond energies. When these particles strike and penetrate matter, they...
16.3K
01:30Measurement of Bioavailability: Pharmacokinetic Methods
37
Pharmacokinetics is a vital branch of pharmacology that examines how drugs are absorbed, distributed, metabolized, and excreted by the body. Two key methodologies in pharmacokinetics are plasma drug concentration studies and urinary drug excretion analyses, both of which provide critical insights into a drug's therapeutic efficacy and bioavailability.Plasma Drug Concentration-Time StudiesPlasma drug concentration-time studies involve analyzing blood samples at specific intervals to quantify...
37
01:25Imaging Studies II: Positron Emission Tomography and Scintigraphy
270
Positron Emission Tomography (PET) is a medical imaging technique that provides crucial insights into the body's physiological functions at a molecular level. It is an indispensable resource for diagnosing, staging, and monitoring various illnesses, notably cancer, neurological disorders, and cardiovascular conditions.
Fundamental Principles of PET
Fundamental Principles of PET
270
01:24One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for ka Estimation
805
This lesson introduces two critical methods in pharmacokinetics, the Wagner-Nelson and Loo-Riegelman methods, used for estimating the absorption rate constant (ka) for drugs administered via non-intravenous routes. The Wagner-Nelson method relates ka to the plasma concentration derived from the slope of a semilog percent unabsorbed time plot. However, it is limited to drugs with one-compartment kinetics and can be impacted by factors like gastrointestinal motility or enzymatic degradation.
On...
On...
805
01:01Dosage Regimens: Partial Pharmacokinetic Parameters
26
It is not uncommon for complete drug pharmacokinetic profiles to remain elusive in pharmacokinetics. This necessitates certain educated assumptions by pharmacokineticists to determine appropriate dosage regimens without comprehensive pharmacokinetic data from animal or human studies. One prevalent assumption is setting the bioavailability factor, denoted as F, to 1 or 100%. This assumption caters to the scenario where a drug doesn't achieve full systemic absorption, resulting in the patient...
26
01:20Measurement of Bioavailability: Pharmacodynamic Methods
21
Pharmacodynamic methods provide insights into a drug's effects on physiological processes over time and play a crucial role in understanding bioavailability and therapeutic efficacy. These methods can be broadly classified into acute pharmacological and therapeutic response approaches, each with distinct mechanisms and applications.The acute pharmacological response method directly correlates a drug's physiological effects, such as ECG or pupil diameter changes, to its time course in the body.
21