scholarly journals Cancer Risk Assessment of Patients Undergoing Computed Tomography Examination at the Korle-Bu Teaching Hospital

2018 ◽  
pp. 861-868
Author(s):  
T. A. Sackey ◽  
C. Schandorf ◽  
J. J. Fletcher ◽  
Y. B. Mensah ◽  
I. Shirazu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cancer Risk ◽  
Effective Dose ◽  
Teaching Hospital ◽  
Cancer Incidence ◽  
Attributable Risk ◽  
Cancer Risk Assessment ◽  
Dose Length Product ◽  
Effective Doses ◽  
Risk Of Cancer

The aim of this study is to estimate the effective dose and assess the lifetime attributable risk of cancer incidence of patients undergoing computed tomography scan at the Korle-Bu Teaching Hospital in the Greater Accra Region of Ghana. Data on Volume CT Dose Index ( ) and Dose Length Product ( ) displayed on the scanner control console was recorded after confirmation of the results by performing independent checks on a phantom. The effective doses were estimated using the  displayed and the anatomic region specific conversion factors ( ). The average effective dose for the head, abdomen, chest, neck, and pelvis were 3.63± 2.39mSv, 15.37±8.49 mSv, 12.72 ± 13.97 mSv, 4.04 ± 1.47 mSv and 15.8 ± 3.59 mSv respectively. Effective doses for the head and neck were within the typical range of (1-10mSv) for CT examinations whilst abdomen, chest and pelvis were above 10mSv. The average life attributable risk of cancer incidence for each region of examination were determined from the effective dose, sex and age using  the model proposed in BEIR VII Report . The average cancer risk incidence for head, neck, chest, abdomen and pelvis examinations were low in the range 1 in 10,000 to 1 in 1,000. There were wide variations in the effective dose values obtained for the same region under examination. This trend calls for the optimization of CT examination protocols to be established to ensure that patient doses are as low as reasonably achievable, economic and social factors being taken into account especially for chest examinations.

ORGAN EQUIVALENT DOSE AND LIFETIME ATTRIBUTABLE RISK OF CANCER INCIDENCE AND MORTALITY ASSOCIATED WITH CARDIAC CT ANGIOGRAPHY

2020 ◽  
Vol 189 (2) ◽  
pp. 213-223
Author(s):  
Seyed Mohammad Bagher Hosseini Nasab ◽  
Mohammad Reza Deevband ◽  
Ali Shabestani-Monfared ◽  
Seyed Ali Hoseini Amoli ◽  
Seyed Hasan Fatehi Feyzabad
Keyword(s):  
Lung Cancer ◽  
Cancer Risk ◽  
Ct Angiography ◽  
Cancer Incidence ◽  
Organ Dose ◽  
Attributable Risk ◽  
Lifetime Attributable Risk ◽  
Incidence And Mortality ◽  
Males And Females ◽  
Risk Of Cancer

Abstract The aim of this study is the calculation of equivalent organ dose and estimation of lifetime attributable risk (LAR) of cancer incidence and mortality related to cardiac computed tomography angiography (CCTA) because the use of CT angiography as a noninvasive diagnostic method has increased. The organ dose has been calculated by ImPACT software based on the volumetric CT dose index (CTDIvol), and LAR of cancer risk incidence and mortality from CCTA has estimated according to the BEIR VII report. The median value of the effective dose was 13.78 ± 6.88 mSv for both genders. In all scanners, the highest median value for LAR of cancer incidence in males and females for lung cancer was 44.20 and 109.17 per 100 000, respectively. And in infants was 5.89 and 12 for lung cancer in males and breast cancer in females, respectively. Also, the median value of LAR of all cancer incidence from single CCTA in adult patients for males and females was 122 and 238 cases, respectively. Maximum LAR of cancer mortality in adults for lung cancer was 40.28 and 91.84 and in pediatrics was 5.69 and 8.50 in males and females, respectively. Despite many benefits of CTA in the heart disease evaluation, according to a high radiation dose in CCTA, to reduce the cancer risk: CCTA should be used cautiously, especially for pediatric and females.

scholarly journals Estimating the current and future cancer burden in Canada: methodological framework of the Canadian population attributable risk of cancer (ComPARe) study

BMJ Open ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. e022378 ◽  
Author(s):  
Darren R Brenner ◽  
Abbey E Poirier ◽  
Stephen D Walter ◽  
Will D King ◽  
Eduardo L Franco ◽  
...  
Keyword(s):  
Risk Factor ◽  
Cancer Risk ◽  
Cancer Incidence ◽  
Population Attributable Risk ◽  
Attributable Risk ◽  
Population Exposure ◽  
Cancer Society ◽  
National Network ◽  
Canadian Population ◽  
Risk Of Cancer

IntroductionThe Canadian Population Attributable Risk of Cancer project aims to quantify the number and proportion of cancer cases incident in Canada, now and projected to 2042, that could be prevented through changes in the prevalence of modifiable exposures associated with cancer. The broad risk factor categories of interest include tobacco, diet, energy imbalance, infectious diseases, hormonal therapies and environmental factors such as air pollution and residential radon.Methods and analysisUsing a national network, we will use population-attributable risks (PAR) and potential impact fractions (PIF) to model both attributable (current) and avoidable (future) cancers. The latency periods and the temporal relationships between exposures and cancer diagnoses will be accounted for in the analyses. For PAR estimates, historical exposure prevalence data and the most recent provincial and national cancer incidence data will be used. For PIF estimates, we will model alternative or ‘counterfactual’ distributions of cancer risk factor exposures to assess how cancer incidence could be reduced under different scenarios of population exposure, projecting incidence to 2042.DisseminationThe framework provided can be readily extended and applied to other populations or jurisdictions outside of Canada. An embedded knowledge translation and exchange component of this study with our Canadian Cancer Society partners will ensure that these findings are translated to cancer programmes and policies aimed at population-based cancer risk reduction strategies.

scholarly journals Identification of Candidates for Longer Lung Cancer Screening Intervals Following a Negative Low-Dose Computed Tomography Result

2019 ◽  
Vol 111 (9) ◽  
pp. 996-999 ◽  
Author(s):  
Hilary A Robbins ◽  
Christine D Berg ◽  
Li C Cheung ◽  
Anil K Chaturvedi ◽  
Hormuzd A Katki
Keyword(s):  
Computed Tomography ◽  
Lung Cancer ◽  
Cancer Risk ◽  
Low Dose ◽  
Lung Cancer Risk ◽  
Cancer Risk Assessment ◽  
Ct Screening ◽  
Screening Interval ◽  
Low Dose Computed Tomography ◽  
Risk Of Cancer

Abstract Lengthening the annual low-dose computed tomography (CT) screening interval for individuals at lowest risk of lung cancer could reduce harms and improve efficiency. We analyzed 23 328 participants in the National Lung Screening Trial who had a negative CT screen (no ≥4-mm nodules) to develop an individualized model for lung cancer risk after a negative CT. The Lung Cancer Risk Assessment Tool + CT (LCRAT+CT) updates “prescreening risk” (calculated using traditional risk factors) with selected CT features. At the next annual screen following a negative CT, risk of cancer detection was reduced among the 70% of participants with neither CT-detected emphysema nor consolidation (median risk = 0.2%, interquartile range [IQR] = 0.1%–0.3%). However, risk increased for the 30% with CT emphysema (median risk = 0.5%, IQR = 0.3%–0.8%) and the 0.6% with consolidation (median = 1.6%, IQR = 1.0%–2.5%). As one example, a threshold of next-screen risk lower than 0.3% would lengthen the interval for 57.8% of screen-negatives, thus averting 49.8% of next-screen false-positives among screen-negatives but delaying diagnosis for 23.9% of cancers. Our results support that many, but not all, screen-negatives might reasonably lengthen their CT screening interval.

Evaluation of Radiation Doses from Computed Tomography Conducted in Al Jouf Region (Saudi Arabia)

2021 ◽  
Vol 11 (8) ◽  
pp. 2130-2136
Author(s):  
Ziyad Awadh Alrowaili ◽  
M. Ashari
Keyword(s):  
Computed Tomography ◽  
Saudi Arabia ◽  
Effective Dose ◽  
Computer Software ◽  
Northern Region ◽  
The Body ◽  
Adult Patients ◽  
Dose Length Product ◽  
Comparison Of The Results ◽  
Dose Index

A safe radiation dose from computed tomography (CT) is normally specified through the Computed Tomography Dose Index (CTDI) as an “effective dose.” Radiation exposure from CT is relatively high in comparison with other radiological tests. In this paper, we evaluate doses used on adult patients during typical CT scans, in Al Jouf, the northern region of Saudi Arabia. Scanning processes were taken place in different parts of the body; including the pelvis, head, abdomen, and chest. The dose indices were calculated using the CT-expo v2.5 computer software. A comparison of the results with similar investigations, regionally and globally, was made. Other comparisons between displayed and calculated dose indices were also performed. The main values of CT volume are the dose index (CTDIvol) and dose-length product (DLP). The effectiveness results for head CTs were 45.0 mGy, 488 mGy.cm, and 5.2 mSv; while for pelvic CTs they were 16.4 mGy, 391 mGy.cm, and 4.0 mSv; whereas for abdominal CTs they were 22.2 mGy, 613 mGy.cm, and 6.5 mSv; finally they were 17.5 mGy, 380 mGy.cm, and 3.9 mSv for chest CTs. It is confirmed that the values obtained are within the internationally accepted values, except for the values of the head examination, in which the effective dose value of 5.2 mSv was higher than the recommended value. This work gives an overview of the doses received by adult patients during regular CT examination. It is the first regional CT dose survey and provides a baseline for improvement and quality control in the region of Al Jouf.

Conversion from dose-length product to effective dose in computed tomography venography of the lower extremities

2022 ◽  
Author(s):  
Yusuke Inoue ◽  
Yuka Yonekura ◽  
Kazunori Nagahara ◽  
Ayuka Uehara ◽  
Hideki Ikuma
Keyword(s):  
Computed Tomography ◽  
Effective Dose ◽  
Conversion Factor ◽  
Lower Extremities ◽  
Pulmonary Angiography ◽  
Ct Scanner ◽  
Dose Length Product ◽  
Ct Venography ◽  
Simplified Method ◽  
Imaging Conditions

Abstract For radiation dose assessement of computed tomography (CT), effective dose (ED) is often estimated by multiplying the dose-length product (DLP), provided automatically by the CT scanner, by a conversion factor. We investigated such conversion in CT venography of the lower extremities performed in conjunction with CT pulmonary angiography. The study subjects consisted of eight groups imaged using different scanners and different imaging conditions (five and three groups for the GE and Siemens scanners, respectively). Each group included 10 men and 10 women. The scan range was divided into four anatomical regions (trunk, proximal thigh, knee and distal leg), and DLP was calculated for each region (regional DLP). Regional DLP was multiplied by a conversion factor for the respective region, to convert it to ED. The sum of the ED values for the four regions was obtained as standard ED. Additionally, the sum of the four regional DLP values, an approximate of the scanner-derived DLP, was multiplied by the conversion factor for the trunk (0.015 mSv/mGy/cm), as a simplified method to obtain ED. When using the simplified method, ED was overestimated by 32.3%−70.2% and 56.5%−66.2% for the GE and Siemens scanners, respectively. The degree of overestimation was positively and closely correlated with the contribution of the middle and distal portions of the lower extremities to total radiation exposure. ED/DLP averaged within each group, corresponding to the conversion factor, was 0.0089−0.0114 and 0.0091−0.0096 mSv/mGy/cm for the GE and Siemens scanners, respectively. In CT venography of the lower extremities, ED is greatly overestimated by multiplying the scanner-derived DLP by the conversion factor for the trunk. The degree of overestimation varies widely depending on the imaging conditions. It is recommended to divide the scan range and calculate ED as a sum of regional ED values.

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