Running head: RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 1

Radiation Safety for Adults in Medical Imaging

Craig S. Peters

Boise State University

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 2

Radiation Safety for Adults in Medical Imaging

Craig S. Peters

This paper examines the topic, “Radiation Safety for Adults in Medical Imaging”, by

discussing different findings from several studies. Different people have varying sensitivity to

radiation than others. At present, there is no definitive way to determine one’s sensitivity to

radiation. Doudenkova & Bélisle (2016) researched that as much as 50% of radiological

examinations potentially were unnecessary and surmised that regulation of radiological practices

would be highly impacted by information and patient consent. Consensus regarding the nature

and need of patient consent prior to ionizing radiation exposure is absent.

This paper will first provide a brief background on how radiation is an essential part of

our lives. Next, a “General Conclusions from Research” section will highlight what causes

overutilization of imaging, what happens within the health delivery system that leads to this

overutilization of imaging, and the efficacy of programs aimed at reducing unnecessary imaging.

Finally, this paper proposes a study to compare the benefits of, versus the hazards of, radiation

exposure to older adults in medical imaging. Radiation exposure is unavoidable in medical

imaging for diagnostic purposes. A significant gap exists regarding agreement on what is, and is

not, an acceptable level of radiation exposure to patients in this environment.

Background on Research on Topic

The study designs and study methods referenced in this paper include a Phase-I trial, a

prospective cohort study, an epidemiologic study data review, an aggregated billing data review,

and a prospective, interdisciplinary study. Radiation is all around us. Gamma radiation is a

naturally occurring source of radiation produced by the Sun, known as sunlight. Sunlight is

composed of electromagnetic waves ranging from infrared (IR) to ultraviolet rays (UV), and

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 3

includes visible light waves, which are between IR and UV in the electromagnetic spectrum.

The Sun produces other forms of radiation.

As a comparison, an accumulation dose level of 0.2 Gy takes approximately two

centuries of exposure to naturally occurring gamma radiation. Numerous studies have been

conducted on patients in the 65-years-old and older age group. Several studies have been

conducted on pediatric patients. As this research was conducted, an overwhelming gap between

the pediatric age group and the geriatric age group was evident.

Accumulated radiation dose levels found in the human body received during diagnostic

medical imaging has been studied in populations of adults, generally aged 65 years and older.

On the opposite end of that scale, accumulated radiation dose levels found in the human body

received during diagnostic medical imaging has been studied in pediatrics. Studies of radiation

dose levels in “Middle-aged” adults, (45 – 64 years of age), are lacking. Radiation safety

concerns gained popularity in recent years due to an increase in cancer-related cases among

adults and children. These concerns fall into categories related to General Radiation Safety,

Computed Tomography (CT), Nuclear Medicine, and Fluoroscopy (Imaging Modalities, 2016).

According to Schauer and Linton (2009), a large source of radiation exposure to

American patients, which almost equals the radiation amount received from background

radiation sources, is radiation from medical imaging procedures. Computed tomography is the

largest source of medical radiation exposure (Schauer and Linton, 2009). Computed tomography

benefits are many and far exceed the risks when appropriately ordered with the lowest radiation

dosage utilized to obtain the best image quality (Schauer and Linton, 2009).

The top three sources of medical radiation exposure are, computed tomography, nuclear

medicine and fluoroscopy. Computed tomography is the largest source of medical radiation

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 4

exposure (Computed Tomography, 2016). Nuclear medicine is the second largest source of

medical radiation exposure after computed tomography (Nuclear Medicine, 2016). Fluoroscopy

is the third largest source of medical radiation exposure behind computed tomography and

nuclear medicine (Fluoroscopy, 2016).

Computed tomography (CT) is used, in part, when cranial images are needed. Nuclear

medicine is used in targeting specific areas, or groups, of tissues (Imaging Modalities, 2016).

For example, radioactive “seeds” can be implanted in patients for targeting prostatic cancer

tissue. Peters (2013) observed approximately 20 fluoroscopy procedures. Peters (2013)

surmised fluoroscopy was used in “active” examinations where the patient swallows a contrast

material while the fluoroscope monitors, in real time, the patient’s ability to move the contrast

material from the mouth to the stomach. The entire path is visible and the muscles used to

swallow the contrast material are monitored for proper function, possible herniation, and other

damage that would cause the patient difficulty during swallowing (C. Peters, personal

communication, 2013).

General Conclusions from Research

Numerous studies confirm lower tube current settings reduce the radiation dose level a

patient receives during a diagnostic medical imaging encounter. According to Linet, et al.,

(2012), technological improvements, including automatic tube current modulation (which

modifies the dose depending on the thickness of the anatomic site to be examined) and noise

reduction filters, further reduces the radiation doses from CT. Generally, this does not affect the

quality and clarity of the diagnostic image.

Variables that do affect the use of a reduced tube setting, and that are outside the control

of radiologists and radiology technicians, have been previously identified in numerous studies,

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 5

include a patient’s age, pregnancy status in females, and a patient’s physical size or anatomical

part thickness (Linet, et al., 2012). The further the emitted diagnostic medical imaging radiation,

or incident photons, needs to travel, the greater the intensity of radiation is required to penetrate

the additional tissue in order for one photon to reach the image intensifier (Duncan and

Panahipour, 2014).

Synthesized Finding #1: Reducing Tube Current Reduces Radiation Dose

Reducing the tube current setting is a primary method to reducing the accumulated

radiation dose level received by a patient during a diagnostic medical imaging encounter.

Manssor, et al., (2015) determined reducing the tube current value setting is the best method for

reducing radiation dose levels received by the patient. For example, changing the tube current

setting from 140 kVp to 120 kVp equates to, for a majority of abdominal CT scan patients, a

reduction of 20% – 40% in radiation dose levels.

Linet, et al., (2012), identified referring medical practitioners needed guidance to

determine whether an imaging study was needed. If an imaging study was required, determining

which imaging study type, in order to obtain the necessary clinical information at the lowest

achievable radiation dose, was paramount. An inappropriate imaging study, conducted at too

high a setting, produces useless diagnostic images, while increasing the accumulated radiation

dose level in the patient. Moloney, et al., (2016) identified one strategy available for radiation

dose optimization included reducing the amount of phases acquired. Another strategy identified

used automated exposure control processes rather than fixed tube current processes. Poor patient

centering, which significantly increases radiation dose levels, was also noted. As such, centering

the patient accurately reduces the overall radiation dose level received during the diagnostic

medical imaging process.

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 6

Linet, et al., (2012) recommended using as few phases as possible, with one phase being

preferred, during each medical imaging run, whether or not contrast was used, as well as

including some technological improvements now available. Two of the available technological

improvements include: 1) noise reduction filters, and 2) automatic tube current modulation. This

automatically modifies the tube current setting according to the thickness of the anatomic site

examined.

Synthesized Finding # 2: Patient Thickness Impacts Patient Radiation Dose

As patient thickness increases, higher radiation energies are needed for one photon to

reach the image detector (Duncan and Panahipour, 2014). This seems counter-intuitive to the

previous finding; however, it is a necessary compromise in order to obtain a viable image for

diagnostic purposes. Accumulated radiation dose levels increase with each medical imaging

event. Multiple images at lower tube current settings increase a patient’s accumulated radiation

dose level faster than a single image taken at a slightly higher tube current setting. Huang and

Jones, (2012) noted that with a tube current setting of 60 kV, a 3.5 cm increase in patient

thickness effectively doubles the number of X-rays required to penetrate the patient and reach the

image intensifier.

Linet, et al., (2012) noted that some technological improvements, including automatic

tube current modulation and noise reduction filters, improves images and further reduces the

doses from CT. Duncan and Panahipour (2014) formulated a tissue thickness of five centimeters

required three incident photons to ensure one photon reached the image detector; 66% of these

incident photons were absorbed or scattered by the patient’s tissue. Five centimeters in thickness

is comparable to the diameter of a participant’s wrist. In comparison, Duncan and Panahipour

(2014) formulated a tissue thickness of 30 centimeters required 1,000 incident photons to ensure

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 7

one photon reached the image detector; 99.9% of these incident photons were absorbed or

scattered by the patient’s tissue. Thirty centimeters in thickness is comparable to the diameter of

an obese participant’s waist.

Synthesized Finding # 3: Cardiac CTA use Dramatically Increased

During the previous ten years or more, cardiac computed tomographic angiography

(CTA) use has increased dramatically and is used to manage numerous cardiac conditions.

Nguyen, et al., (2015) determined that, in this procedure and due to cardiac motion, gating was

required to compensate for this motion, and the procedure’s resultant radiation exposure from

cardiac CTA was significant. A single cardiac CTA exposed patients to radiation dose levels

equivalent to receiving 150 or more chest x-rays (Nguyen, et al., 2015).

Aparicio, et al., (2014) observed that patients with biopsy-proven, unresectable pancreatic

adenocarcinoma, (based on vascular invasion detected by computed tomography), were treated

with gemcitabine, (300 mg/m2 i.v. weekly x5 weeks), concurrently with radiation therapy, (45

Gy in 25 fractions), and sorafenib, (escalated doses in a 3+3 design, from 200 to 800 mg/day).

At this stage of the study, patient thickness was not a primary consideration. Following

standard protocols and procedures for radiation therapy currently in use today, tube current levels

would require proper adjustments due to patient thickness in order to properly acquire medical

images for diagnostic and study-related evaluation purposes. Treatments were palliative due to

the twelve patients included in this study, all greater than 18 years of age, having a diagnosis of

pancreatic adenocarcinoma (Aparicio, et al., 2014).

Arasu, et al., (2015) identified that, in the emergency department, imaging usage had

increased significantly as the primary method for acute illness and trauma diagnosis. Helical

multidetector computed tomography is the preferred technology for imaging in emergency

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 8

departments today due to its speed, image resolution, and prevalence in emergency departments.

Arasu, et al., (2015) found the increase in emergency department radiology usage was criticized

as a replacement for the physical and other, less costly diagnostic examinations. Another

criticism was due to increased radiation exposure, and enabling defensive medicine practices,

despite the data supporting the improved diagnostic accuracy of these imaging procedures

(Arasu, et al., 2015). To help curb overutilization, evidenced-based practice guidelines and

increased awareness of radiation risk was introduced through the Image Wisely campaign

(Arasu, et al., 2015).

Need for Further Research

Nguyen, et al., (2015) determined that, to date, no human studies conducted have

measured the radiation exposure effects from medical imaging on changes in in vivo gene

expression. This gene expression change is significantly up-regulated after radiation therapy

(Nguyen, et al., 2015). A single cardiac CTA exposes patients to radiation levels equal to 150 or

more chest x-rays (Nguyen, et al., 2015). Expansive utilization of this procedure raises

significant concern between physicians and patients regarding the harmful effects related to

cardiac CTA radiation exposure (Nguyen, et al., 2015).

One can infer healthcare professionals and researchers agree, to some extent, that

research data and information is severely lacking on the subject of an acceptable, safe radiation

dose level for adults in diagnostic medical imaging. By measuring, as accurately as possible

with current and developing technologies, and monitoring radiation dose levels earlier in life, as

one ages, a reduction in accumulated radiation dose level-induced cancers could be seen. Rather

than waiting until age 65 to become concerned with an individuals accumulated radiation dose

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 9

level from diagnostic medical imaging, closely monitoring those same individuals’ radiation

dose levels prior to middle-age could lead to a better quality of life.

This study is feasible and realistic due to the current age range of patients currently

involved in similar studies. To identify possible participants, a request for volunteers could be

made at the time a diagnostic medical imaging procedure is conducted. A prospective cohort

study of these middle-aged patients who received diagnostic medical imaging procedures in

medical centers in the United States would close the gap that currently exists. The estimated

median blood radiation exposure is determined by using the ImPACT Computed Tomography

Patient Dosimetry Calculator spreadsheet currently available and used in London, England.

Biomarkers of deoxynucleic acid damage and apoptosis would be measured by flow

cytometry, whole genome sequencing, and single cell polymerase chain reaction from whole-

blood samples taken from participants to establish their baseline values. Additional whole-blood

samples would be taken multiple times throughout the study period. These participants would

then be asked to provide additional data at the time the blood sample was given. Medical

professionals would obtain biometrics from the participants to include weight, height, age, race,

procedure performed, body mass index (BMI), and blood type using standard protocols. Privacy

concerns of the participants would be addressed by fully complying with all HIPAA privacy

rules and guidelines in place at the time of the study commencement.

I propose a longitudinal study of 15 to 20 years on accumulated radiation dose level study

be conducted on 500,000 middle-aged adult males and 500,000 middle-aged adult females in the

United States. This study of middle-aged, (45-years-old to 64-years-old), females and males,

would close the gap between pediatric and geriatric studies currently in existence. This study

would establish a currently unknown baseline radiation dose level currently experienced by, but

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 10

unknown to, residents of all U.S. states. The total number of participants from each State could

be based upon a percentage of the current State population, as determined by the most recent

U.S. Census data on file.

This study would include several limitations. First, the technology available at this time

is not advanced enough to accurately measure and monitor the continual accumulation of

radiation dose levels associated with diagnostic medical imaging when future imaging

procedures are received. Second, current technologies can only measure and monitor the

additional damage to blood cells and DNA. Third, the rate of DNA decay and damage is not

measurable on a microcellular level. Fourth, use of an electron microscope could potentially

allow measurement and monitoring of DNA decay and damage, but the cost per patient per use

would be astronomical and is not fiscally feasible at this stage of the study. Fifth, x-ray image

intensifiers convert transmitted x-rays into an image. This occurs within the input phosphor of

the image intensifier by converting the x-ray photons to light photons. Once these light photons

reach the photocathode, they are converted to photoelectrons. Image intensifiers currently

available cannot be modified to use less radiation. Research into a new technology device that

can accept lower emissions from reduced tube settings is needed. This new technology device

would replace, or possibly augment, the image intensifiers currently available.

In closing, healthcare professionals and researchers agree a reduction in accumulated

radiation dose levels from diagnostic medical imaging is necessary. Conducting studies of

patients exposed to diagnostic medical imaging helps monitor their accumulated radiation dose

levels. The majority of studies of this type currently available do not occur until an individual

reaches a minimum of 65 years of age.

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 11

References

Aparicio, J., García-Mora, C., Martín, M., Petriz, M., Feliu, J., Sánchez-Santos, M., … Maurel, J.

(2014). A Phase I, Dose-Finding Study of Sorafenib in Combination with Gemcitabine

and Radiation Therapy in Patients with Unresectable Pancreatic Adenocarcinoma: A

Grupo Español Multidisciplinario en Cáncer Digestivo (GEMCAD) Study. PLoS ONE,

9(1), e82209. http://doi.org/10.1371/journal.pone.0082209

Armao, D., Semelka, R., & Elias, J. (2012). Radiology's ethical responsibility for healthcare

reform: tempering the overutilization of medical imaging and trimming down a

heavyweight. Journal Of Magnetic Resonance Imaging: JMRI, 35(3), 512-517.

doi:10.1002/jmri.23530

Arasu, V., Abujudeh, H., Biddinger, P., Noble, V., Halpern, E., Thrall, J., & Novelline, R.

(2015). Diagnostic Emergency Imaging Utilization at an Academic Trauma Center From

1996 to 2012. Journal of the American College of Radiology, 12, 5, 467-474.

Bettman, M. (2010). Selecting the Right Test and Relative Radiation Dose as They Relate to

Appropriateness Criteria. Retrieved November 27, 2016, from

http://www.imagewisely.org/Imaging-Modalities/Computed-Tomography/Imaging-

Physicians/Articles/Selecting-the-Right-Test-and-Relative-Radiation-Dose

Computed Tomography. (2016). Retrieved October 09, 2016, from

http://www.imagewisely.org/Imaging-Modalities/Computed-Tomography

Doudenkova, V., & Bélisle, P. J. C. (2016). Duty to Inform and Informed Consent in Diagnostic

Radiology: How Ethics and Law can Better Guide Practice. Healthcare Ethics

Committee Forum, 28, 1, 75-94. DOI: 10.1007/s10730-015-9275-7

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 12

Duncan, J., & Panahipour, S. (2014). Tissue Attenuation of X-Rays. Retrieved October 09, 2016,

from http://www.imagewisely.org/Imaging-Modalities/Fluoroscopy/Articles/Duncan-

Panahipour-Tissue-Attenuation-of-X-Rays

Fluoroscopy. (2016). Retrieved December 10, 2016, from http://www.imagewisely.org/Imaging-

Modalities/Fluoroscopy

Hauptmann, M., Haghdoost, S., Gomolka, M., Sarioglu, H., Ueffing, M., Dietz, A., ... Hornhardt,

S. (2016). Differential Response and Priming Dose Effect on the Proteome of Human

Fibroblast and Stem Cells Induced by Exposure to Low Doses of Ionizing Radiation.

Radiation Research, 185(3), 299-312. doi:10.1667/RR14226.1

Hendee, W., Becker, G., Borgstede, J., Bosma, J., Casarella, W., Erickson, B., … Wallner, P.

(2010). "Addressing overutilization in medical imaging.". Radiology (0033-8419), 257

(1), 240-245. DOI: http://dx.doi.org/10.1148/radiol.10100063

Huang, S., & Jones, A. (2014). Procedure- and Patient-Specific Factors Affecting Radiation

Exposure. Retrieved October 19, 2016, from http://www.imagewisely.org/Imaging-

Modalities/Fluoroscopy/Articles/Huang-Patient-Specific-Factors

Imaging Modalities. (2016). Imaging Modalities. Retrieved November 12, 2016, from

http://www.imagewisely.org/Imaging-Modalities

Image Wisely. (2016). Retrieved November 27, 2016, from http://www.imagewisely.org/

Lewiss, R., Chan, W., Sheng, A., Soto, J., Castro, A., Meltzer, A., ... Chen, E. (2015). Research

Priorities in the Utilization and Interpretation of Diagnostic Imaging: Education,

Assessment, and Competency. Academic Emergency Medicine: Official Journal Of The

Society For Academic Emergency Medicine, 22(12), 1447-1454. doi:10.1111/acem.12833

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 13

Linet, M., Slovis, T., Miller, D., Kleinerman, R., Lee, C., Rajaraman, P., & Berrington de

Gonzalez, A. (2012). Cancer risks associated with external radiation from diagnostic

imaging procedures. CA: A Cancer Journal for Clinicians, 62(2), 75-100.

doi:10.3322/caac.21132

Manssor, E., Abuderman, A., Osman, S., Alenezi, S., Almehemeid, S., Babikir, E., ... Sulieman,

A. (2015). Radiation doses in chest, abdomen and pelvis CT procedures. Radiation

Protection Dosimetry, 165(1-4), 194-198. doi:10.1093/rpd/ncv107

McCollough, C. (2010). Diagnostic Reference Levels. Retrieved November 27, 2016, from

http://www.imagewisely.org/Imaging-Modalities/Computed-Tomography/Medical-

Physicists/Articles/Diagnostic-Reference-Levels

Moloney, F., Fama, D., Twomey, M., O’Leary, R., Houlihane, C., Murphy, K., … Maher, M.

(2016). Cumulative radiation exposure from diagnostic imaging in intensive care unit

patients. World Journal of Radiology, 8(4), 419–427. http://doi.org/10.4329/wjr.v8.i4.419

Moore, C., Broder, J., Gunn, M., Bhargavan-Chatfield, M., Cody, D., Cullison, K., …

Sodickson, A. D. (2015). Comparative Effectiveness Research: Alternatives to

"Traditional" Computed Tomography Use in the Acute Care Setting. Academic

Emergency Medicine: Official Journal Of The Society For Academic Emergency

Medicine, 22(12), 1465-1473. doi:10.1111/acem.12831

Nguyen, P., Lee, W., Li, Y., Hong, W., Hu, S., Chan, C., … Wu, J. (2015). Assessment of the

Radiation Effects of Cardiac CT Angiography Using Protein and Genetic Biomarkers.

JACC. Cardiovascular Imaging, 8(8), 873-884. doi:10.1016/j.jcmg.2015.04.016

Nuclear Medicine. (2016). Retrieved December 10, 2016, from

http://www.imagewisely.org/Imaging-Modalities/Nuclear-Medicine

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 14

Peck, D., & Samei, E. (2010). How to Understand and Communicate Radiation Risk. Retrieved

November 27, 2016, from http://www.imagewisely.org/Imaging-Modalities/Computed-

Tomography/Medical-Physicists/Articles/How-to-Understand-and-Communicate-

Radiation-Risk

Schauer, D. & Linton, O. (2009). NCRP Report No. 160, Ionizing Radiation Exposure of the

Population of the United States, medical exposure--are we doing less with more, and is

there a role for health physicists?. Health Physics, 97(1), 1-5.

doi:10.1097/01.HP.0000356672.44380.b7

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 15

Appendix A – Study Analysis Table

Citation Information

Aparicio, J., García-Mora, C., Martín, M., Petriz, M., Feliu, J., Sánchez-Santos, M., … Maurel, J. (2014). A Phase I, Dose-Finding Study of Sorafenib in Combination with Gemcitabine and Radiation Therapy in Patients with Unresectable Pancreatic Adenocarcinoma: A Grupo Español Multidisciplinario en Cáncer Digestivo (GEMCAD) Study. PLoS ONE, 9(1), e82209. http://doi.org/10.1371/journal.pone.0082209

Arasu, V., Abujudeh, H., Biddinger, P., Noble, V., Halpern, E., Thrall, J., & Novelline, R. (2015). Diagnostic Emergency Imaging Utilization at an Academic Trauma Center From 1996 to 2012. Journal of the American College of Radiology, 12, 5, 467-474.

Linet, M., Slovis, T., Miller, D., Kleinerman, R., Lee, C., Rajaraman, P., & Berrington de Gonzalez, A. (2012). Cancer risks associated with external radiation from diagnostic imaging procedures. CA: A Cancer Journal for Clinicians, 62(2), 75.

Permalink https://www-ncbi-nlm-nih-gov.libproxy.boisestate.edu/pmc/articles/PMC3886976/

http://www.sciencedirect.com.libproxy.boisestate.edu/science/article/pii/S1546144014007881

http://onlinelibrary.wiley.com.libproxy.boisestate.edu/doi/10.3322/caac.21132/full

Purpose Evaluate the safety profile and recommended dose of these medications used with concomitant radiation therapy.

Review emergency radiology volume growth rate at an urban academic trauma center, 1996 to 2012.

Reduce future projected cancers from diagnostic procedures and develop electronic lifetime records of imaging procedures.

Study Design

A phase I–II multicenter, non-randomized clinical trial.

Aggregated billing data collected from 1996 to 2012 were reviewed.

An analysis of patient records from multiple studies were reviewed.

Participants Patients’ proven diagnosis of pancreatic adenocarcinoma were included in the study if they presented a locally advanced disease, or metastatic disease, or unresectable local relapse. Other inclusion criteria were age >18 years, written informed consent, measurable disease.

Human subjects research. Aggregated billing data from 1,458,230 diagnostic radiologic examinations were reviewed in this study.

Patient records from epidemiologic studies of medical and other radiation sources and cancer risks, and dose trends from diagnostic procedures. Experimental studies records were reviewed to project risks from current imaging procedures.

Data Collection

Pretreatment evaluation comprised symptom assessment, physical examination, hematology, serum biochemistry, CA 19.9 levels, coagulation tests, EKG, tumor measurements by means of multidetector or spiral computed tomography (CT) scans, endoscopic ultrasound (EUS), and other symptom-guided explorations when needed.

Aggregated billing data from diagnostic radiologic examinations ordered in a tertiary care, academic teaching hospital with approximately 900 beds in an urban setting at a Level I adult, pediatric, and burn trauma center emergency department (ED) were reviewed.

Records review of approximately 2500 atomic bomb survivors whowere in utero at the time of the bombings. More than 105,000 records from The Life Span Study of atomic bomb survivors (including 30,000 children), were reviewed.

Results Twelve patients with unresectable, locally advanced or metastatic pancreatic adenocarcinoma were included between 12/07 and 09/09, median patient age was 59 years, with the age range of 39 – 69 years, seven female patients. All patients were evaluable for response.

ED patient visits grew annually. ED visit imaging increased from 1996 to 2003. ED physician ultrasound data showed growth from 2002 to 2011. CT and MRI decreased from 2004 to 2012. No change in ultrasound and x-ray use during the study period.

Total solid cancer risk shows linear dose response. Significant radiation–associated excesses seen for most solid tumors. Dose-response excess persisted for several decades for ALL and CML, but peaked at 10 years after the bombings for AML.

Weaknesses There are no previous published clinical data of the combination of sorafenib, radiotherapy and

Individual patient cumulative radiation dosages were not calculated during this study.

ACR Appropriateness Criteria have been criticized for not utilizing the rigorous

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 16

gemcitabine in pancreatic ductal adenocarcinoma (PDAC).

methodology of the evidence-based medicine approach for radiology.

Strengths Preliminary clinical data shows response rate activity by RECIST criteria (16%), by PERCIST criteria (100%), and local control (75%).

The amount of patient data analyzed during this study is huge when compared to other studies of this type.

Patient data analyzed in this study exceeded 105,000 records. Data from multiple studies were reviewed and analyzed during this study.

Relevance to Topic

Radiation therapy and drug therapy were combined to treat patients with pancreatic cancer.

ED patient visit data was analyzed showing how prevalent medical imaging use is in an emergent situation and environment.

Radiation exposure amounts and dosing levels in adults and children were identified, tracked, and documented during this study.

Citation Information

Moloney, F., Fama, D., Twomey, M., O’Leary, R., Houlihane, C., Murphy, K., … Maher, M. (2016). Cumulative radiation exposure from diagnostic imaging in intensive care unit patients. World Journal of Radiology, 8(4), 419–427. http://doi.org/10.4329/wjr.v8.i4.419

Nguyen, P., Lee, W., Li, Y., Hong, W., Hu, S., Chan, C., & ... Wu, J. (2015). Assessment of the Radiation Effects of Cardiac CT Angiography Using Protein and Genetic Biomarkers. JACC. Cardiovascular Imaging, 8(8), 873-884. doi:10.1016/j.jcmg.2015.04.016

Manssor, E., Abuderman, A., Osman, S., Alenezi, S., Almehemeid, S., Babikir, E., & ... Sulieman, A. (2015). Radiation doses in chest, abdomen and pelvis CT procedures. Radiation Protection Dosimetry, 165(1-4), 194-198. doi:10.1093/rpd/ncv107

Permalink https://www-ncbi-nlm-nih-gov.libproxy.boisestate.edu/pmc/articles/PMC4840200/

http://www.sciencedirect.com.libproxy.boisestate.edu/science/article/pii/S1936878X15003770?np=y

https://rpd-oxfordjournals-org.libproxy.boisestate.edu/content/165/1-4/194

Purpose To quantify cumulative effective dose of intensive care unit (ICU) patients attributable to diagnostic imaging.

Evaluate whether radiation exposure from cardiac computed tomographic angiography (CTA) damages deoxyribonucleic acid (DNA).

Determine patient optimal doses required to reduce radiation risk due to unnecessary radiation exposure.

Study Design

A prospective, interdisciplinarystudy.

Prospective cohort study in patients undergoing cardiac computed tomographic angiography.

A retrospective analysis was done on the CT dose reports.

Participants Human subjects research.Of patients admitted to a general Intensive Care Unit over a one-year period, a total of 2737 studies were performed on 421 adult patients and a total of 23 pediatric patients were selected for subgroup analysis.

Sixty-seven adult patients, aged 18 years and older, who underwent a clinically indicated cardiac CTA between January 2012 and December 2013 were recruited from Stanford Hospital (Stanford, California) and the Veterans Affairs Palo Alto Health Care System (Palo Alto, California).

Fifty-one patients (24 men, 47 % and 27 women, 53 %), aged 16-85, had CT scans of the chest, abdomen and pelvis (trunk) with contrast media in one exam to rule out metastasis after confirmed primary tumor.

Data Collection

Age, gender, date of ICU admission, primary reason for ICU admission, APACHE II score, length of stay, number of days intubated, date of death or discharge, and re-admission data was collected on all patients admitted over a 1-year period.

Methods utilized in this study include: Patients and Diagnostic Imaging Studies, Estimation of Radiation Dose, Sample Collection for in Vivo Studies, Proteomic Biomarker Assays, Genomic Biomarker Assays, and Statistical Analysis during the two-year study period.

Patients’ weight, height and body mass index (BMI) were analyzed. Exposure parameters were collected using a patient dose survey form prepared for collecting kVp, mAs, CTDIvol, DLP, scan pitch, slice thickness, number of slices and field of view (FOV) values.

Results Cumulative effective radiation dose (CED) was 1704 millisieverts (mSv) with a median

Of the 82 eligible patients, 67 underwent biomarker analysis before and after exposure to

The mean and standard deviation of patients’ age, weight, height and BMI were 48.0+18.6 y,

RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 17

CED of 1.5 mSv (IQR 0.04-6.6 mSv). Total CED in pediatric patients was 74.6 mSv with a median CED of 0.07 mSv (IQR 0.01-4.7 mSv) IQR=Interquartile range.

cardiac CTA. Seventy-percent of patients (36 of 57) had ≥ 2% increase in phosphorylation of at least 1 DNA damage marker post-radiation exposure.

73.8+16.1 kg, 162.5+10.7 cm, 28.1+6.2 kg m-2, respectively. The mean effective dose was 21.2+5.7 mSv per procedure.

Weaknesses The study only measured ionizing radiation exposure while patients were in the ICU. Patients were studied in a single center.

DNA damage was not directly measured during the study. The risk of cancer from radiation exposure from cardiac CTA measured.

Study consisted of a small number of patients for data comparison. Data collected from one location, (Siemens healthcare, Forchheim, Germany).

Strengths A large sample size compared to previous studies assessing radiation dose. Requesting physicians were unaware of the study.

Exposure to CTA radiation activates biological pathways and genes, increases transcription factors in cell repair, cell cycle progression, and apoptosis.

Each category included wide ranges in which values were collected. The data is more relevant for wider ranges of individuals.

Relevance to Topic

This study included 421 adult patients and 23 pediatric patients in a general Intensive Care Unit.

This study analyzed the amount of damage to human cells at the lowest level possible with the techniques available today.

Cumulative radiation exposure dosage values were calculated for individual patients with wide ranges in age, weight, height, and BMI.