RPS 714 - Hot topics in computed tomography and radiotherapy practice

Purpose:

Given the extensive use of CT in radiation-sensitive patient groups, such as pregnant and paediatric patients, and the importance of the CT-protocol tailoring for both radiation dose and image quality, the purpose of this study was to determine the extent to which individualisation of CT-protocols is practised across the country.

Methods and materials:

The cross-sectional study involved collecting CT-protocols along with a mini-questionnaire in order to obtain additional information about how the CT-examination is individualised. All public hospitals performing CTs for detecting pulmonary embolisms were invited and 41% participated.

Results:

Tailoring a standard protocol to different patient groups was more common than using dedicated protocols. Most of the available radiation dose reduction approaches were used. However, the implementation of these strategies was not systematic. Children and pregnant patients were examined without using dedicated CT-protocols or protocol adjustments focusing on a radiation dose reduction in 30% and 39% of the hospitals, respectively.

Conclusion:

There is a need for practice optimisation, especially for developing dedicated CT-protocols or guidelines for tailoring the existing protocol to paediatric and pregnant patients.

Limitations:

The senior CT-radiographer of the department who answered the questions might not always have extensive knowledge of all the adhoc protocol adjustments made by other radiographers. The extent of adjusting CT-protocols when examining children or pregnant patients might be higher than reported.

Ethics committee approval

The need for approval from The Regional Committee for Medical and Health Research Ethics and the Norwegian Centre for Research Data was waived as the project did not involve any health related or personal information. Participants were informed about the study's aim and that an e-mail reply containing attached CT-protocols would be regarded as implied consent to participation.

Funding:

No funding was received for this work.

Purpose:

To investigate occupational burnout levels among radiation therapists (RTT) in Italy and the possible associations with socio-demographic factors.

Methods and materials:

The Italian Association of Radiation Therapists (AITRO) and the Italian Federation of Scientific Radiographers Societies (FASTeR) proposed a national online survey including the Maslach Burnout Inventory to RTTs. Italian RTTs count around 2,000 individuals. Mann-Whitney U and c2 tests were used.

Results:

We obtained 246 answers, 106 (43%) respondents were men, RTT age was <30yo for 44 respondents (18%), 31-40yo for 73 (30%), 41-50yo for 63 (25%), and >50yo for 66 (27%), and 235 (95%) RTTs worked full-time. RTTs had an overall high median emotional exhaustion (EE) score (37, IQR 31-46), and high depersonalisation (16, IQR 13-21) compared to occupational burnout references (≥27 and ≥13, respectively). The median score of personal achievement (PA) (31, IQR 28-34) was comparable to the reference (≤31). Using a subgroup analysis, females had significantly higher levels of EE (p=0.003). Having sons and working with paediatric patients did not show an impact on occupational burnout (p>0.086). A total of 67 (27%) RTTs stated that a specific stress management course was available at their workplace and it appeared related to a reduced EE score (p=0.005), while 60 (24%) respondents declared that they relied on psychological support relating to a reduced EE (p=0.035). High levels of EE, depersonalisation, and low levels of PA were present in 235 (96%), 193 (78%), and 130 (53%) participants, respectively.

Conclusion:

Italian RTTs’ levels of burnout exceed the reference value, especially for EE and depersonalisation. Future interventions aimed at preventing burnout stressors should be implemented in the radiation therapy work environment

Limitations:

An Italian survey.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

Cone-beam computed tomography (CBCT) is an important tool in patient position verification before radiotherapy treatment delivery. The purpose of this study was the development of a training program directed to therapeutic radiographers based on a 3D CBCT treatment verification in prostate cancer.

Methods and materials:

An initial sample of 51 therapeutic radiographers answered a survey and performed the image verification of 10 clinical cases before integration into the training program. Participants performed the analysis of the same CBCT images and answered a survey of 4 closed questions and an open one related to their perception about the training program. To evaluate the shifts resulting from the image analysis, the t-test was used for paired samples, comparing the mean absolute deviation (MAD) in the 4 directions of the couch mechanical movements.

Results:

A sample of 41 therapeutic radiographers completed all phases. No statistically significant differences were found in general and in subgroups of <2 years and >2 years’ experience with CBCT (p>0.05). Professionals with more than 10 years of experience revealed an improvement in image analysis after the training program, with differences in the vertical shift before and after (p=0.001). No relation was observed between years of experience and the level of confidence.

Conclusion:

This training program structure shows a level of effectiveness considered satisfactory for its implementation, as there is an educational need to update the programmatical contents related to the cross-sectional pelvic anatomy. Since decision-making is vital for treatment delivery, critical analysis of CBCT, and improving patient outcomes, it is important to include these contents in clinical practice.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

The significant advances in science, particularly in the radiation therapy (RT) field, have an important role in promoting and improving patient care and cancer treatments. During this, the patient is exposed to radiation related to the RT treatment but also to other examinations that must be quantified. The aim of this study is to characterise RT planning and verification of radiation exposure, excluding the dose values directly related to the treatment.

Methods and materials:

The dose files related to computed tomography (CT) (Siemens®) and cone-beam computed tomography (CBCT) integrated on the linear accelerator TrueBeam (Varian Medical Systems®) of 60 patients with prostate cancer were analysed.

Results:

A total of 1,252 exams were analysed and the mean values of DLP were 351.95 mGy for CBCT, 791.22 mGy for CT without current modulation, and 491.43 mGy for CT with current modulation.

Conclusion:

The effective dose during the planning and verification of radiation therapy treatment is relevant. Optimisation of this imaging modality must be taken into account in order to reduce the patient risk.

Limitations:

The results of this study are directly related to the radiotherapy equipment technology.

Ethics committee approval

Institution ethical approval obtained.

Funding:

No funding was received for this work.

Purpose:

To evaluate the reproducibility over time of abdominal compression with a thermoplastic mask, identifying the position of the diaphragm on computed tomography (CT), and comparing the image dataset acquired in the simulation phase with those related to intra-treatment revaluations in the same respiratory phase.

Methods and materials:

A group of 5 patients treated with carbon ions and respiratory gating was considered. The breathing signal was acquired through a pressure sensor placed between the patient and the thermoplastic mask. The 4D image datasets were reconstructed in at least 4 respiratory phases: (0% ex), 30% inspiration (30% in), 30% expiration (30% ex), and end-inspiration (100% in). The diaphragm was contoured on the dataset correspond to the maximum expirio phase. On a weekly basis, an intra-treatment CT revaluation was acquired for checking the consistency of the patient’s anatomy and setup, acquired in the same way as the CT baseline. The difference between the positions of the mass centre of the diaphragm between CT planning and CT revaluation at the maximum expirio phase (Pdiaframma = √(x_diafr^2+y_diafr^2+z_diafr^2)) was used to evaluate the reproducibility of abdominal compression.

Results:

A different position of the centre of mass was observed (1.3 ± 0.3 cm). During CT revaluation, there was a greater abdominal compression which cranially moves the diaphragm as happens during treatment.

Conclusion:

Increase the time to be allowed to elapse (e.g. half/full day) between the mask packaging and CT acquisition.

Limitations:

Patients who struggle to keep a constant breath for at least 20 minutes.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To compare the patient dose and image quality of state-of-the-art intraoperative cone-beam CT (CBCT; Artis Pheno, SiemensHealthineers, Germany) and preoperative multi-slice CT (MSCT; Lightspeed VCT, GE, USA) for spine surgery navigation.

Methods and materials:

Radiation dose measurements were performed using a torso anthropomorphic phantom (RAN-100; Phantom Laboratory, USA) with optically stimulated luminescence dosimeters (GD-352M; Chiyoda Technol, Japan). The dosimeters were attached to various landmarks on the phantom surface, in the centre-plane, in the breasts regions, and in other organs at risk. Dosimeter measurements were repeated 3 times each for CBCT and MSCT, and for each clinical protocol at our institution. Image quality was evaluated with modulation transfer function (MTF), noise power spectrum (NPS), and contrast-to-noise ratio (CNR) using a Catphan 700 phantom (Phantom Laboratory).

Results:

The measured average dose for CBCT and MSCT was 42.4mGy and 46.4mGy, respectively. The spatial frequency at 10% MTF for CBCT and MSCT was 1.22cycle/mm and 1.09cycle/mm. NPS value at 0.5cycle/mm for CBCT and MSCT was 368 and 196, respectively. CNR for CBCT and MSCT was 16.9 and 29.0, respectively.

Conclusion:

In our clinical protocols, CBCT was found to have a 9% lower radiation dose than MSCT, without significant degradation in image quality. Therefore, the CBCT protocol is recommended for use in spine surgery navigation when it is available.

Limitations:

One paired equipment study of CBCT and MSCT. A one institutional, phantom study.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To understand the proper guidelines regarding administration of iodinated and gadolinium-based contrast agents, particularly in patients with renal compromise, in pregnancy, and lactation, and to clarify misconceptions regarding the diagnostic usage of contrast media.

There is a lack of proper understanding among clinicians and radiologists about the guidelines and approach to contrast administration in various clinical scenarios, which can lead to unnecessary delay or avoidance of useful diagnostic studies. Contrast-induced nephropathy is grossly overestimated by both radiologists and clinicians. The risk of undergoing a non-diagnostic non-contrast CT is probably higher than the potential risk of developing CIN even in patients with eGFR <30 ml/min.

Methods and materials:

We conducted an audit among the radiology departmental staff and clinicians regarding the basic principles of contrast administration with a questionnaire with 10 questions (1st audit). The response was assessed on the same day and results regarding awareness were analysed. Lectures were conducted for radiologists, technicians, and clinicians regarding recent guidelines related to contrast administration following which a 2nd audit was conducted after 6 months. The response was assessed and the improvement in awareness and implementation in routine practice was reviewed.

Results:

Significant improvement in awareness was observed in second audit results among radiologists (80% vs 100%), residents (70% vs 100%), technicians (50% vs 90%), and clinicians (30% vs 80%).

Conclusion:

It is of utmost importance that radiology residents and radiologists have a good understanding of the basic principles of contrast administration.

It is essential to adequately educate and train the radiographers for the judicious utilisation and optimisation of radiological studies and to ensure smooth workflow.

Limitations:

The attrition among the responders.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To identify risk factors for contrast medium extravasation at the injection site and interventions to prevent or reduce damages.

Methods and materials:

To find studies that included patients undergoing computed tomography performed with intravenous contrast, 9 databases were searched, including PubMed, CINAHL, and Embase. This review evaluated risk factors (patient demographics, comorbidities, and medication history) and interventions (e.g. contrast agent, injection per se, the material used for injection, and the healthcare professionals involved). Articles were assessed by two independent groups of reviewers for methodological validity using the Joanna Briggs institute system for the unified management (JBI SUMARI). In one case, quantitative data from two cohort studies was pooled in a statistical meta-analysis.

Results:

15/2,151 articles were selected. 2 were randomised controlled trials and 13 were quasi-experimental and observational studies. The quality of these studies was considered moderate to low. Being of female sex and inpatient status appeared to be risk factors for extravasation. Furthermore, the volume extravasated could be affected by the injection rate, venous access site, and catheter dwelling time. Preliminary studies seemed to indicate the potential of extravasation detection accessories to identify extravasation and reduce the volume extravasated. The other interventions either did not result in a significant reduction in the frequency/volume of extravasation or the results were mixed across the studies.

Conclusion:

Potential risks were identified and areas for possible interventions such as the use of new catheters for injection. Further studies, however, should be conducted with solid methodological designs to allow the development of high-quality strategies to reduce the risks associated with extravasation.

Limitations:

Statistical pooling was not always possible due to the heterogeneity of the studies.

Ethics committee approval

n/a

Funding:

HES-SO.

Purpose:

To create a standardised study protocol that can be applied to all CT scanners in a hub-and-spoke hospital organisation design to diagnose ictus cerebri and to promote training events for radiographers who work in the radiology department.

Methods and materials:

A multi-professional working group has been created involving radiographers and radiologists with great experience in a hub centre and in 4 spoke hospitals in the same geographic area.

Data are from a 4-month long study and have been compared to literature of the same hospital design.

The technology available (6 CT scanners from 16-256 slice) has been analysed to define standard scanning techniques, reconstruction algorithms, window settings, and necessary reformations in order to produce comparable diagnostic images of the brain in all hospitals of the radiology department.

The multi-professional group planned a specific training for 60 radiographers working in CT imaging in order to share technical features of the new operating model.

Results:

The new multiphase CT angiography protocol was defined.

2 major training events were realised with a 90% commitment to the project.

After that the new protocol has been adopted in the hub and in 3 out of 4 spoke hospitals, according to the technology available (with 16 slice-CT scanners, not all angiographic phases can be taken appropriately).

Reliability and reproducibility of diagnostic images produced in spoke hospitals increased and the repetition of unnecessary CT examinations, when patients with acute ischaemic stroke arrived at the hub hospital for treatment, has been largely avoided.

Conclusion:

Multiphase CT angiography represents the gold standard when studying ictus cerebri in hub and spoke organisations. The use of standard protocol allows for a time-saving and widely available technique.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

The importance of patient centring when performing a CT is essential to provide good image quality and to ensure radioprotection. Because of time constraints, CT scans performed in the emergency department may have poor patient installation and centring, and thus lower quality.

Methods and materials:

This retrospective study analysed brain-CT scans during a three-month period performed on various CT scanners in our institution. Centring was evaluated using DoseWatch. Straightness was assessed using SSDE view scout in the same software in order to identify the use of a head support (foam cushion or CT-head holder). The inclusion criteria was a brain-CT with at least native acquisition.

200 cases were randomly selected and subsequently divided into emergency-CT scans (100 cases) and routine/elective CT scans (50 cases each, performed during working hours). The same analysis was carried out after a workshop discussion with the CT radiographer’s team concerning the preliminary results.

Results:

After the workshop, we observed a change in practice. Radiographers adopted the use of the head support to improve centring. The preliminary results showed that centring was overall good, but still with outliers demonstrating a misuse of the chosen head support. Initially, 1% of cases were performed with a CT-head holder in the emergency-CT compared to 25% for the routine/elective CT. After the workshop, it increased to 5% and 35%, respectively. Straightness improved by 15% for the foam head cushion and a significant decrease in the number of outliers was observed after the workshop.

Conclusion:

Radiographers performed CTs with better quality after the initial evaluation followed by a workshop, which is an effective and low-cost solution to improve CT image quality.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

A recent body of evidence from the literature around the world has shown that the human sinuses are sexually dimorphic, which may be very useful both in forensic and archaeological contexts. The main goal of the present study is to ascertain if this sexual dimorphism is also present in Portuguese individuals.

Methods and materials:

The present study included 30 crania ([15 females, 15 males]; age-at-death ranges from 19-87 years old; x̅=44.57, SD=16.85 [males x̅=41.47, SD=15.51 and females x̅=47.67, SD=18.09]) from the International Exchange Skull collection stored at the University of Coimbra (Portugal). CT scans were performed using a Siemens Somatom Emotion 16-CT scanner with a study protocol for imaging the paranasal sinuses. 6 linear measurements were taken in both right and left frontal sinuses (RF and LF weight; RF and LF height; RF and LF anteroposterior length) using RadiAnt DICOM Viewer 4.0.1 (64-bit). 3 volumetric measurements, the nasofrontal angle (NFA), and 3Dmeshes were obtained with ITK-SNAP software.

Results:

5 measurements resulted in higher means in males (one is equal in both sexes), although, no significant differences were found in all the linear measures and volumes taken in the frontal sinuses. Nevertheless, females had a significantly higher mean (Student's t=-2,453; d.f.=27; p=0.021) for NFA. Age at death does not seem to play a role in the present results (Student’s t=-1.008; d.f.=28; p=0.322).

Conclusion:

The present results question if dimorphic differences between sinuses may be specific to certain populations and show that NFA may be useful for sexual discrimination. In the future, the maxillary sinuses, as well as their morphology/shape, should also be considered as parameters of analysis for sexual discrimination. Also, a large sample size should be considered.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

FCTFellowship SFRH/BD/102980/2014.