Added Radiation Exposure Research Articles

The effectiveness of the pregnancy adapted YEARS algorithm to safely identify patients for CT pulmonary angiogram in pregnant and puerperal patients suspected of having pulmonary embolism.

BackgroundPulmonary thromboembolism is one of the leading causes of maternal death worldwide. Globally there has been increasing physician reliance on CT pulmonary angiogram for definitive diagnoses and exclusion of pulmonary thromboembolism. The problem, however, arises when considering the high radiation penalty from performing these investigations, highlighted by the low diagnostic yield. Of recent, the pregnancy-adapted YEARS algorithm has shown promise in international studies as a possible alternative for stratifying risk of pulmonary thromboembolism during the pregnancy and puerperal period.ObjectivesTo determine the effectiveness of the pregnancy adapted YEARS algorithm to safely minimise the number of true negative CT pulmonary angiograms for patients suspected of having pulmonary embolism in our clinical setting.MethodA cross-sectional study was performed in a tertiary hospital in Gauteng on puerperal and pregnant patients suspected of having pulmonary embolism. We retrospectively applied the pregnancy adapted YEARS algorithm and reviewed the various outcomes.ResultsThe pregnancy adapted YEARS algorithm proved effective in safely identifying patients for CT pulmonary angiography. By retrospectively applying the algorithm, there could have been a 25.7% scan reduction, whilst maintaining a negative predictive value of 100.0%.ConclusionAs physician reliance on radiological investigations increases, we must remain cognisant of the added radiation exposure and the long-term adverse effects of ionising radiation. The pregnancy-adapted YEARS algorithm provides a safe, reproducible alternative to aid our bid going forward.

Trends in Intraoperative Assessment of Spinal Alignment: A Survey of Spine Surgeons in the United States.

Study Design:Survey.Objectives:To characterize national practices of and shortcomings surrounding intraoperative assessments of spinal alignment.Methods:Spine surgeons in the US were surveyed to analyze their experience with assessing spinal alignment intraoperatively.Results:108 US spine surgeons from 77 surgical centers with an average of 19.2 + 8.8 years of surgical experience completed the survey. To assess alignment intraoperatively, 84% (91/108) use C-arm or spot radiographs, 40% (43/108) use full-length radiographs, and 20% utilize the T-bar (22/108). 88% of respondents’ surgical centers (93/106) possessed a navigation camera and 63% of respondents (68/108) report using surgical navigation for 40% of their deformity cases on average. Reported deterrents for using current technology to assess alignment were workflow interruption (54%, 58/108), expense (33%, 36/108), and added radiation exposure (26%, 28/108). 87% of respondents (82/94) reported a need for improvement in current capabilities of making intraoperative assessments of spinal alignment.Conclusions:Corrective surgery for spinal deformity is a complex procedure that requires a high level of expertise to perform safely. The majority of surveyed surgeons primarily rely on radiographs for intraoperative assessments of alignment. Despite the majority of surveyed surgical practices possessing navigation cameras, they are utilized only for a minority of spinal deformity cases. With the majority of surveyed surgeons reporting a need for improvement in technology to assess spinal alignment intraoperatively, 3 of the top design considerations should include workflow interruption, expense, and radiation exposure.

Intracranial venous sinus stenosis: hemodynamic assessment with two-dimensional parametric parenchymal blood flow software on digital subtraction angiography

ObjectiveIntracranial venous sinus stenosis (IVSS) is the most common finding associated with idiopathic intracranial hypertension. A pressure gradient >8–10 mm Hg across the stenosis is considered hemodynamically significant, and typically...

Abstract P3-03-40: A prospective two arm comparative study of indo-cyanine green (ICG) enhanced fluorescence imaging vs conventional methods (blue dye and radiocolloid/hand held gamma probe) for sentinel lymph node detection in breast cancer - Going beyond the horizon

Abstract Background: The dual technique with radio colloid and blue dye is the gold standard in sentinel lymph node biopsy (SLNB) to stage axilla in breast cancer. However due to cost & infrastructural demands of nuclear medicine department most of the oncology centers are not doing slnb or are doing SLNB with blue dye which is not a standard of care. Indocyanine green (ICG) has recently been used as a method of identifying sentinel lymph nodes. Studies have shown that ICG fluorescence imaging alone or in combination with the blue dye method or the radionuclide method is a safe and easy technique. The objective of the present study was to assess the diagnostic performance of sentinel lymph node (SLN) biopsy using the indocyanine green (ICG) fluorescence method compared with that using the conventional method in detection of sentinel lymph nodes. Material & Methods: 60 patients diagnosed with early breast cancer underwent the SLNB procedure using technetium-99m radio colloid (R), methylene blue dye (MB), and ICG. Fluorescence imaging was done using an indigenously designed , very economical fluorescence imaging system, Irilic.nm fluorescence imaging along with Indocyanine green. All SLNs that were removed during surgery were labelled as hot, blue or/and fluorescent and sent for pathological examination. The detection rate of SLNs and positive SLNs, and the number of SLNs of ICG, MB+ R, ICG + MB, ICG + R were compared. Injection safety of ICG and MB was evaluated. Results: Sentinel Lymph Node was identified in all 60 cases. Total Sentinel lymph nodes removed was 145 (Mean=2, Range 2-5), ICG was able to identify more nodes than the dual dye technique. The identification rate with the dual dye technique was 95%, with blue dye alone 93.6% and with radioisotope alone 96.8% whereas with ICG alone was 100%, with ICG + MB was 96.6% & ICG + R was 96.6 %. 28(46.6%) out of 60 patients had positive nodes which was identified by both dual dye & ICG. None of the patients had any local or systemic reaction with ICG, 3 patients with blue dye had tattooing & staining of skin. Conclusion: ICG is as effective as the dual dye for SLNB. ICG is safe & reliable. In addition, as a near-infrared dye, it has the advantages of real-time visualization, lower cost, and wider availability. It can be a boon for developing countries & second tier referral centers of developed country where there is limited access to nuclear medicine department & radiocolloid and even if its accesible the cost involved is too high which comes with added radiation exposure to medical personnel handling them. A combination of blue dye and ICG is useful dual approach when radioisotope is unavailable. ICG verus Conventional Dye Clinical Profile ICGRadio-colloid+ B;ue DyeDetection Rate100%95%Sensitivity100% (CI 83.16% to 100.00%)100% (CI 83.16% to 100.00%)Positive Predictive Value100%100%Accuracy100%100% Citation Format: Somashekhar S, Rohit Kumar C, Zaveri S, Rajgopal A, Rakshit S, Ali SH. A prospective two arm comparative study of indo-cyanine green (ICG) enhanced fluorescence imaging vs conventional methods (blue dye and radiocolloid/hand held gamma probe) for sentinel lymph node detection in breast cancer - Going beyond the horizon [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-40.

Magnetic Resonance Image-Guided Radiotherapy (MRIgRT): A 4.5-Year Clinical Experience

AimsMagnetic resonance image-guided radiotherapy (MRIgRT) has been clinically implemented since 2014. This technology offers improved soft-tissue visualisation, daily imaging, and intra-fraction real-time imaging without added radiation exposure, and the opportunity for adaptive radiotherapy (ART) to adjust for anatomical changes. Here we share the longest single-institution experience with MRIgRT, focusing on trends and changes in use over the past 4.5 years. Materials and methodsWe analysed clinical information, including patient demographics, treatment dates, disease sites, dose/fractionation, and clinical trial enrolment for all patients treated at our institution using MRIgRT on a commercially available, integrated 0.35 T MRI, tri-cobalt-60 device from 2014 to 2018. For each patient, factors including disease site, clinical rationale for MRIgRT use, use of ART, and proportion of fractions adapted were summated and compared between individual years of use (2014–2018) to identify shifts in institutional practice patterns. ResultsSix hundred and forty-two patients were treated with 666 unique treatment courses using MRIgRT at our institution between 2014 and 2018. Breast cancer was the most common disease, with use of cine MRI gating being a particularly important indication, followed by abdominal sites, where the need for cine gating and use of ART drove MRIgRT use. One hundred and ninety patients were treated using ART in 1550 fractions, 67.6% (1050) of which were adapted. ART was primarily used in cancers of the abdomen. Over time, breast and gastrointestinal cancers became increasingly dominant for MRIgRT use, hypofractionated treatment courses became more popular, and gastrointestinal cancers became the principal focus of ART. DiscussionMRIgRT is widely applicable within the field of radiation oncology and new clinical uses continue to emerge. At our institution to date, applications such as ART for gastrointestinal cancers and accelerated partial breast irradiation (APBI) for breast cancer have become dominant indications, although this is likely to continue to evolve.

The role of computed tomography in following up pediatric skull fractures

BackgroundDespite the added radiation exposure and costs, the role of computed tomography (CT) in following pediatric skull fractures has not been fully evaluated. MethodsWe reviewed the radiology reports and images of the initial and follow-up head CT examinations of children with skull fractures to determine whether any interval changes in the fracture morphology and associated complications necessitate a change in clinical management. ResultsA total of 316 pediatric cases of skull fractures were identified, including 172 patients with and 144 without follow-up scans. At follow-up, 7% of skull fractures were unchanged, 65% healing, and 28% healed. No patient showed findings to cause a change in clinical management or a need for further medical or surgical intervention regardless of the number and patterns of the fractures or the initial intracranial complications such as intracranial hemorrhage, pneumocephalus, and traumatic brain injuries. ConclusionsHead CT may be unnecessary in following pediatric skull fractures in asymptomatic patients to avoid added radiation exposure and cost.

The right atrium: gateway to the heart--anatomic and pathologic imaging findings.

Knowledge of right atrial anatomic and pathologic imaging findings and associated clinical symptoms is important to avoid false-positive diagnoses and missed findings. Complete evaluation of the heart often requires a multimodality approach that includes radiography, echocardiography, computed tomography (CT), magnetic resonance (MR) imaging, and invasive angiography. In general, CT provides the highest spatial resolution of these modalities at the cost of radiation exposure to the patient. Echocardiography and MR imaging offer complementary and detailed information for functional evaluation without added radiation exposure. The advantages and disadvantages of each modality for the evaluation of right atrial anatomic structure, size, and pathologic findings are discussed. Cardiac MR imaging is the reference standard for evaluation of right atrial size and volume but often is too time consuming and resource intensive to perform in routine clinical practice. Therefore, established reference ranges for two-dimensional transthoracic echocardiography are often used. Right atrial pathologic findings can be broadly categorized into (a) congenital anomalies (cor triatriatum dexter, Ebstein anomaly, and aneurysm), (b) disorders of volume (tricuspid regurgitation, pathologic mimics such as a pseudoaneurysm, and atrial septal defect), (c) disorders of pressure (tricuspid stenosis, restrictive cardiomyopathy, and constrictive pericarditis), and (d) masses (pseudomasses, thrombus, lipomatous hypertrophy of the interatrial septum, lipoma, myxoma, sarcoma, and metastatic disease). Familiarity with each pathologic entity and its treatment options is essential to ensure that appropriate imaging modalities are selected. Online supplemental material is available for this article.

Intramedullary nailing of femoral diaphyseal metastases: is it necessary to protect the femoral neck?

Intramedullary nailing is the accepted form of treatment for impending or pathologic fractures of the femoral diaphysis. Traditional teaching promotes the use of a cephalomedullary nail so that stabilization is provided for the femoral neck in the event that a future femoral neck metastasis develops. However, that approach may add cost, surgical time, blood loss, and added radiation exposure to staff members, and there is limited evidence in the literature that supports this practice. The purpose of our study was to evaluate the incidence of femoral neck metastases in patients who underwent femoral nailing of diaphyseal metastases. Retrospective analysis of our Musculoskeletal Oncology database identified 145 femoral nailings performed for metastatic disease, myeloma, or lymphoma of the femoral diaphysis between 2001 and 2011. Average patient age was 59 years. One hundred forty-one patients underwent 145 femoral nailings (four were bilateral). One hundred forty-four of the nails used were cephalomedullary implants and one was a flexible nail. Thirty-six (25%) femurs had sustained a pathologic fracture and 109 (75%) femurs were treated as impending fractures. Eighty-four patients received either preoperative or postoperative radiation therapy. Average radiographic followup was 13 months and average postoperative survival was 16 months. Of the 141 patients in this series, 121 (86%) are known to have died at a median of 9 months (range, 0.1-133 months) after surgery. The latest followup radiographs were obtained at a median of 5 months after the femoral nailing (range, 0-119 months). Of the 90 patients with documented dates of death and radiographic followup greater than zero months, 76 (84%) had radiographs available within a year of death. Thirty-one patients had zero months radiographic followup. The median survival for this group of patients was only 0.9 months (range, 0.1-12 months). No patients (0%) in this series had femoral neck metastases develop postoperatively. Despite traditional teaching that supports the use of cephalomedullary implants when treating metastatic disease of the femur, we were unable to identify a single patient who had femoral neck metastasis after surgery on the femur. Our findings do not support the use of cephalomedullary implants in this patient population for the sole purpose of prophylactic femoral neck stabilization; however, this series was relatively small, and the experiences of other centers will be needed to come to a more-complete sense of the frequency of what in all likelihood is a rare event.

4:15 PM; Abstract No. 141 - The utility of cone-beam computed tomography (CBCT) for the assessment of adequate uterine fibroid embolization (UFE)

4:15 PM; Abstract No. 141 - The utility of cone-beam computed tomography (CBCT) for the assessment of adequate uterine fibroid embolization (UFE)

The value of flat-detector computed tomography during catheterisation of congenital heart disease

To analyse the diagnostic utility of flat-detector computed tomography imaging (FD-CT) in patients with congenital heart disease, including the value of image fusion to overlay three-dimensional (3D) reconstructions on fluoroscopic images during catheter-based interventions. We retrospectively analysed 62 consecutive paediatric patients in whom FD-CT was used during catheterisation of congenital heart disease. Expert operators rated the clinical value of FD-CT over conventional fluoroscopic imaging. Added radiation exposure and contrast medium volume were evaluated. During a 12-month period, FD-CT was performed in 62 out of 303 cardiac catheterisations. Median patient age was 3.5 years. In 32/62 cases, FD-CT was used for diagnostic purposes, in 30/62 cases it was used in the context of interventions. Diagnostic utility was never rated as "misleading". It was classified as "not useful" in six cases (9.7%), "useful" in 18 cases (29.0%), "very useful" in 37 cases (59.7%) and "essential" in one case (1.6%). The median added dose-area product was 111.0 μGym(2), the required additional quantity of contrast medium was 1.6 ml/kg. FD-CT provides useful diagnostic information in most of the patients investigated for congenital heart disease. The added radiation exposure and contrast medium volume are reasonable.

Editorial Comment

In this study, the authors nicely illustrate the problem of overuse in the diagnosis and treatment of low-risk prostate cancer on two fronts. First, even using the most conservative classification criteria, the authors observed that 48% of low-risk patients underwent diagnostic imaging, including more than 200 who had multiple tests. Second, all the patients underwent pelvic lymphadenectomy, which has only modest, if any, value in this patient population. 1 Weight C.J. Reuther A.M. Gunn P.W. Zippe C.R. Dhar N.B. Klein E.A. Limited pelvic lymph node dissection does not improve biochemical relapse-free survival at 10 years after radical prostatectomy in patients with low-risk prostate cancer. Urology. 2008; 71: 141-145 Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar Indeed, the costs of unnecessary imaging approximated those of surgical treatment. Most importantly, all of these patients incurred a variety of unnecessary risks, including injury to pelvic vessels and nerves, lymphatic leak, added radiation exposure, need for subsequent testing, and possible complications related to these tests. Although serious adverse events are relatively rare, the absolute implications on a population level are significant. Why are the guidelines not being followed? Is it because physicians are comfortable practicing individualized, dogmatic, or defensive medicine? Or, are there factors other than patient need fueling the overuse? Unnecessary Imaging for the Staging of Low-risk Prostate Cancer Is CommonUrologyVol. 77Issue 2PreviewTo quantify the rate of overuse of preoperative imaging procedures in a referral cohort of low-risk patients. International evidence-based best practice guidelines discourage routine imaging for staging purposes in low-risk patients with newly diagnosed prostate cancer. Full-Text PDF

Female breast surface radiation exposure during FDG PET/CT examinations

The combined positron emission tomography (PET) and computed tomography (CT) scanners have been developed in which CT data can be used for both anatomical landmarks and attenuation correction of PET images. However, this modality potentially introduces more radiation burden to patients compared to conventional PET scanning as a result of the added radiation exposure received from CT examination. The purpose of our study was to determine the breast radiation doses of combined PET/CT examination. Patients' superficial breast doses were calculated using thermoluminescence dosimeters (TLDs) placed onto the surface of the breasts. TLDs were positioned before FDG injection and removed after 24 h. We also determined the average superficial and glandular breast radiation doses from the anthropomorphic dosimetric phantom imaged using similar CT protocol (low dose) to the patients' study. The mean superficial breast dose of the breast skin measured from the PET/CT studies was 14.42+/-2.41 mGy. The average superficial and glandular breast doses of the anthropomorphic phantom measured from the low-dose CT was 9.50 mGy and 5.94 mGy, respectively. This study showed that radiation exposure to the breasts during PET/CT was higher than the recommended doses. Therefore, combined PET/CT scanning must be used for essential indications, particularly in women of reproductive age and preferentially a low-dose CT protocol should be implemented to avoid overexposure in such patients.

The efficacy of x-rays after chest tube removal

Scott R. Peterson, MD (Phoenix, Arizona): Dr. Palesty and his colleagues have presented a retrospective review of 72 patients over a 5-year period who had closed tube thoracostomies, to determine the efficacy of post tube removal chest x-rays. Their hypothesis is that chest radiographs obtained following tube removal are of no benefit, and that the added radiation exposure and the expense to the patients are not justified, challenges the conventional wisdom, and brings tears to the eyes of managed health-care plan directors. Unfortunately, their review provides few data to support their biases.

Tuberculosis: When Not to Order Roentgenograms

IN 1979, the National Center for Devices and Radiological Health of the Food and Drug Administration sponsored the formation of a Chest X-ray Panel to review the selection of patients for chest x-ray screening examinations. The panel's recommendations have recently been published. 1 The panel's statements regarding pulmonary tuberculosis are of particular interest and should be emphasized. Essentially, the panel concluded that (1) the yield of tuberculosis cases found by screening or repeated chest x-ray examinations was not sufficient to justify the monetary cost or added radiation exposure, (2) mandated chest x-ray examinations as a condition of initial or continued employment were not productive for tuberculosis detection, (3) repeated chest x-ray examinations of persons with significant tuberculin reactions (without current disease), including those not treated with isoniazid, were not of value, (4) repeated chest x-ray examinations of asymptomatic patients with tuberculosis who had completed treatment were of insufficient clinical value,

ROENTGENOLOGIC DIAGNOSIS IN SOFT TISSUE DYSTOCIA

It has been said that birth is the interruption of a "nice quiet life." As a part of the effort to make this transition as smooth and as free of hazards as possible, it seems appropriate to discuss the roentgenologic diagnosis of some of the less obvious soft tissue abnormalities which, in the most insidious manner, seem to contrive to make this short transition longer and more difficult for all concerned. SUMMARY The foregoing are a few of the conditions whose presence is to be suspected in cases in which there is persistent failure of the presenting part to engage, after bony disproportion has been excluded, and when adequate expulsion force of the uterus is present. The roentgenologist is obligated to supplement negative pelvimetry studies with soft tissue studies which can be made with minimal added radiation exposure to mother and child. Close cooperation between obstetrician and roentgenologist is essential in every case to properly evaluate slight variations from the normal. Neither should be content with the information revealed by pelvic measurements alone. A roentgenologic examination must be a consultation in the true sense of the word if the patient is to receive maximum benefit. Mere compliance with a request for a technical procedure, pelvic measurement, is not enough.