Emerg Radiol DOI 10.1007/s10140-016-1449-3

ORIGINAL ARTICLE

Role of computed tomography at a cancer center emergency department Jessyca Couto Otoni 1 & Julia Noschang 1 & Thábata Yaedu Okamoto 1 & Diego Rosseman Vieira 1 & Michel Souto Mayor Petry 1 & Lucas de Araujo Ramos 1 & Paula Nicole Vieira Pinto Barbosa 1 & Almir Galvão Vieira Bitencourt 1 & Rubens Chojniak 1

Received: 4 August 2016 / Accepted: 29 September 2016 # American Society of Emergency Radiology 2016

Abstract To evaluate the imaging methods used at the emergency department (ED) of a cancer center, with emphasis on computed tomography (CT). A descriptive, retrospective, single-center study was conducted by reviewing imaging exams and medical records, after approval of the institution’s Ethics Review Board. The demographic data, cancer history, and imaging exam requested were evaluated for all patients and the indications and results of head, chest, and abdominopelvic CT scans were also evaluated. During the study period, there were 8710 visits to the ED, and 5999 imaging studies were requested in 3788 patients (43.5 % of total of visits). One thousand eight hundred twenty-nine CT exams were used in 1121 visits (12.9 % of total of visits). The mean age of patients was 57.7 years and most patients (93.2 %) had a known primary tumor. The most common indications for abdominopelvic CT were non-oncologic emergencies (26.7 %) and postoperative complications (19.2 %), and the results were negative in 36.6 %, positive for clinical suspicion in 49.0 %, and incidental positive in 14.5 %. The most frequent indication for chest CT was suspected pulmonary embolism (34.4 %); however, only 11.1 % confirmed the diagnosis. The results of head TC were negative in 72.9 % and the indications that had more positive findings were suspected metastasis (32.1 %) and focal neurological sign/altered level of consciousness (24.5 %). CT plays an important role in driving the cancer patients visiting the ED. However, the high rate of negative or discordant results causes a concern for the inadvertent and excessive use of this imaging modality.

* Almir Galvão Vieira Bitencourt [email protected]

1

Department of Imaging, AC Camargo Cancer Center, R. Prof. Antonio Prudente, 211, São Paulo, SP 09015-010, Brazil

Keywords Computed tomography . Emergency department . Diagnostic imaging . Cancer

Introduction The incidence of cancer has increased worldwide due to the growth and aging population, lifestyle changes, and dissemination of screening programs [1]. According to estimates of GLOBOCAN, there were about 14.1 million new cancer cases and 8.2 million cancer deaths in 2012 in worldwide [2]. On the other hand, early detection and the development of new, more effective treatments in fighting cancer have increased survival and, consequently, a higher number of cancer patients seek emergency care [1, 3]. These patients go to the emergency department for several reasons: symptoms caused by cancer, complications caused by the current or previous cancer treatment (surgery, radiotherapy, chemotherapy), or symptoms not directly related to cancer or its treatment [4]. Imaging exams have a key role in the assessment of cancer and its complications. Radiographs and ultrasound examinations are commonly requested in the initial evaluation because of its wide availability, low cost, and minimal or no exposure to radiation [5]. Computed tomography (CT) is the imaging method of choice in the investigation of most thoracic and abdominal emergencies, because it is fast, non-invasive, and readily available in most hospitals [6]. Magnetic resonance imaging (MRI) is less frequently used in this context, and it is mainly indicated in the evaluation of central nervous system disorders including cerebral herniation, meningeal carcinomatosis, and spinal cord compression [6]. Thus, it is observed that there are many imaging methods available and it is essential that the emergency physician request the proper examination based on clinical history and physical examination, and the radiologist should be prepared

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to identify these imaging findings, most peculiar in cancer patients, so that the correct diagnosis and treatment be promptly instituted. The objective of this study was to evaluate the imaging methods used at an emergency department of a cancer center, with emphasis on the analysis of CT scan indications.

Table 1 Types of imaging methods used at the emergency department of a cancer center (n = 5999) Exam type

A descriptive, retrospective, single-center study was conducted by reviewing imaging exams and medical records, after approval of the institution’s Ethics Review Board. Patients attended at the emergency department of an academic, large health system, urban cancer center from January to April 2015 were included and imaging methods requested for all patients were reviewed. Exclusion criteria were duplicated requests or exams that were not performed for some reason, such as patient refusal or medical contraindication. The demographic data (gender and age), cancer history, and imaging exam requested were evaluated for all patients submitted to CT. The indication and results of CT scans of the head, chest, abdomen, and/or pelvis were also evaluated. The exam results were classified as negative, when there were no significant changes related to the current clinical story; positive for suspicion, when the result of CT confirmed the clinical suspicion or was compatible with the complaint; and incidental positive, when other significant findings were observed, different from initial clinical suspicion. Statistical analyses were performed using SPSS for Windows, version 20.0 (SPSS Inc. Chicago, Illinois). Frequency analysis was performed to characterize the sample. Continuous variables were described as mean value and standard deviation (SD). The following tests were used to compare variables: chi-square test when both variables were categorical, and Student’s t test or Mann-Whitney test when one of the variables was continuous with and without normal distribution, respectively. p value was considered statistically significant when equal to or less than 0.05.

Results During the study period, there were 8710 visits to the emergency department, and 5999 imaging studies were requested in 3788 patients (43.5 % of total of visits). The number of imaging tests requested per patient ranged from 1 to 10, with a mean of 1.58 (SD 0.95). Table 1 shows the types of imaging methods used. One thousand eight hundred twenty-nine CT exams were used in 1121 visits (12.9 % of total of visits), ranging from 1 to 6 scans per patient, with a mean of 1.63 (SD 0.76). The mean age of patients was 57.7 years (SD 16.7 years), ranging from 0 to 96 years. Most patients

Percent

Radiographs

3028

50.5

Computed tomography

1829

30.5

965 80

16.1 1.3

Interventional procedures

40

0.7

Nuclear medicine Endoscopic exams

27 20

0.5 0.3

10 5999

0.2 100.0

Ultrasound Echocardiography

Material and methods

Number

Magnetic resonance imaging Total

(93.2 %) had a known primary tumor, being the most common: breast (13.5 %), head and neck (9.9 %), colon (9.1 %), lung (8.5 %), prostate (5.1 %), and lymphoma (4.5 %). The types of CT scans performed are shown in Table 2. Abdominopelvic CT The indications and results of 525 CT scans of the abdomen and/or pelvis were analyzed. The mean age of patients was 56.4 years (SD 16.1 years), ranging from 5 to 90 years, and 300 (57.1 %) were female. The majority of patients had a known cancer (91.2 %), being the most common primary sites: colorectal (15.0 %), breast (9.3 %), and prostate (7.0 %). The most common indications were non-oncologic emergencies (26.7 %), postoperative complications (19.2 %), oncological complications (14.3 %), intestinal obstruction (12.2 %), and restaging (6.7 %). The most common causes of non-oncologic emergencies were urolithiasis (33.6 %), inflammatory/infectious diseases (26.6 %), which included appendicitis, diverticulitis, pancreatitis, cholecystitis and other less frequent conditions, and acute nonspecific abdominal pain (19.6 %). Regarding the results of CT, 192 patients (36.6 %) were negative, 257 (49.0 %) were positive for clinical suspicion, Table 2 Types of CT scans performed at the emergency department of a cancer center (n = 1829) Exam type

Number

Percent

Abdomen and/or pelvis Chest Head Neck Face Spine Extremities Total

1035 368 276 57 39 34 20 1829

56.6 20.1 15.1 3.1 2.1 1.9 1.1 100

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and 76 (14.5 %) had an incidental positive result, unrelated to initial clinical suspicion. Among patients who underwent CT of the abdomen and/or pelvis, 155 (29.5 %) were admitted to the hospital. Hospitalization was more common in patients who had positive CT (n = 109, 32.7 %), than those who what were negative (n = 46, 24.0 %), with statistical significance (p = 0.034). Chest CT The indications and results of 343 chest CT scans were analyzed. The mean age of patients was 59.4 years (SD 16.4 years), ranging from 10 to 96 years, and 191 (55.7 %) were female. The majority of patients had a known cancer (95.9 %), being the most common primary sites: lung (19.2 %), breast (12.5 %), head and neck (7.0 %), and lymphoma (6.7 %). The most frequent indication was CT angiography for pulmonary embolism (PE) in 118 cases (34.4 %). Other common indications were non-oncologic emergency (n = 64, 18.7 %), restaging (n = 43, 12.5 %), and oncological complications (n = 37, 10.8 %). The most common causes of nononcologic emergencies were inflammatory and infectious diseases. Regarding chest CT results, 134 (39.1 %) were negative, 152 (44.3 %) were positive for clinical suspicion, and 57 (16.6 %) were incidental positive, unrelated to initial clinical suspicion. Considering only the 118 patients with suspected PE, only 13 (11.1 %) confirmed the diagnosis, 72 (61.0 %) were negative, and 33 (28.0 %) had other positive findings. Among patients who performed chest CT, 142 (41.4 %) were admitted to the hospital. Hospitalization was more common in patients who had positive CT (n = 94, 45.0 %), than those who were negative (n = 48, 35.8 %); however, there was no statistical significance (p = 0.093). Considering only the cases with suspected PE, hospitalization was more common in patients who had a positive result on CT (n = 25, 54.3 %), than those who were negative (n = 21, 29.2 %), with statistical significance (p = 0.006). Head CT The indications and results of 251 head CT scans were analyzed. The mean age of patients was 57.9 years (SD 17.8 years), ranging from 0 to 94 years, and 141 (56.2 %) were female. The majority of patients had a known cancer (95.9 %), being the most common primary sites: breast (22.7 %), head and neck (17.2 %), and lung (7.6 %). The most frequent indications were focal neurological sign/altered level of consciousness (n = 40, 15.9 %), traumatic brain injury (n = 35, 13.9 %), headache (n = 34, 12.4 %), suspected metastasis (n = 28, 11.2 %), stroke (n = 20, 8.0 %), and intracranial hemorrhage (n = 17, 6.8 %).

Regarding the results of TC, 183 (72.9 %) were negative, 59 (22.6 %) were positive for clinical suspicion, and 9 (3.6 %) had positive incidental, unrelated to suspicion initial clinical. As noted in Fig. 1, the indications that had more positive findings on CT were suspected metastasis (32.1 %) and focal neurological sign/altered level of consciousness (24.5 %), while those with lower frequency positive results were headache (12.8 %) and traumatic brain injury (14.2 %). Among patients who performed head CT, 73 (28.4 %) were admitted to the hospital. Hospitalization was more common in patients who had positive CT (n = 34, 38.2 %), than those who were negative (n = 39, 23.2 %), with statistical significance (p = 0.011).

Discussion The role of CT in emergency patients has increased significantly, representing the second imaging modality most commonly used in our institution. CT exams were requested in about 13 % of patients visited, which was similar to other studies, ranging from 11 to 14 % [7, 8]. This finding can be explained by the fact that our population is composed predominantly of cancer patients (91 %), which have more complex clinical management due to health problems related to their illness, the effects of treatment, infectious, and vascular complications. CT has many advantages as it is widely available in health services, not operator dependent such as ultrasound, has short scan time, higher spatial and contrast resolution, and can be performed even in severely ill patients. Multidetector CT produces high-quality anatomical images that allow multiplanar reformatting, vascular studies, 3D endoluminal, and volumetric reconstructions. These factors, combined with patient’s expectations and physicians’ fear of medicolegal repercussions, helped promote a disproportionate and perhaps exaggerated increase in the use of CT in the emergency departments [9]. Despite CT use appears to be related to the decline in the number of hospital admissions, as patients with negative results are more likely to be discharged, indiscriminate use also brings risks and concerns such as exposure to ionizing radiation [10, 11]. This is a special concern in cancer patients, who are submitted to numerous imaging exams at all stages of the natural history of the disease, especially in pediatric patients. Another concern is the use of intravenous contrast, which may be related to increased risk of nephropathy, especially in the elderly, and allergic reactions [12]. In addition, findings incidental and often harmless can lead to unnecessary procedures, causing stress and risk to the patient, which has become a public health problem known as overdiagnosis [13]. The most requested CT scans were abdomen and/or pelvis, followed by chest and head. When we evaluated the abdomen

Emerg Radiol Fig. 1 Percentage of positive results on head CT, according to clinical indication. TBI traumatic brain injury, FNS/ALC focal neurological sign/altered level of consciousness

POSITIVE 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

NEGATIVE

13.0%

14.2%

20.0%

23.4%

25.0%

Headache

TBI

Seizure

Hemorrhage

Stroke

27.5%

32.1%

FNS / ALC Metastasis

TBI: Traumatic Brain Injury FNS / ALC: Focal Neurological Sign / Altered Level of consciousness

and/or pelvis CT scans, we observed a wide variety of clinical indications, oncological or not, and positive results were observed in almost 2/3 of the cases, suggesting that CT is fundamental for the management of most of these patients. Abdominal cancer surgeries are complex procedures, and its complications were the second most common indication for abdominal CT. The most common clinical indication for chest CT in our study was suspected PE; however, only a small number of patients (11 %) confirmed the diagnosis. This finding was similar to those found in the literature demonstrating the overuse of this method and the importance of stricter adoption of pretest probability criteria for PE [14, 15]. Despite the higher incidence of PE in cancer patients, when compared to the general population, its frequency is relatively low. A significant percentage of chest (28 %) and abdominopelvic (14.5 %) CT found a discordant result with the initial clinical suspicion, incurring a change in management and decision-making by the emergency medical staff. This finding agrees with the study of Pandharipande et al. (2015), which showed that physicians’ diagnoses and admission decisions change frequently after CT [16]. We also observed that a considerable frequency of exams (6.7 % of abdominopelvic CT and 12.5 % of chest CT) were performed for restaging purposes, which reveals the inappropriate use in the emergency department, since reassessment of tumor burden can and should be performed in elective outpatients. Most head CT scans performed in our emergency department were normal, especially for patients with headache and traumatic brain injury. This finding agrees with the study of Wang et al. (2013), which proposes a reduction in the use of cranial CT in the emergency department, establishing clinical predictors of abnormal findings [17]. In that study, the following six clinical variables were considered independent predictors of abnormal head CT findings among patients in the emergency department who were referred for nontraumarelated indications: age over 70 years, focal neurologic deficit,

altered mental status, history of malignancy, nausea and/or vomiting, and derangements in coagulation profile [17]. In our study, patients referred for head CT who presented suspected metastasis, focal neurological sign, and altered level of consciousness had a higher rate of positive findings. Currently, there is a concern that the increasing number of CT scans ordered is unnecessary, which led to an increasing debate about how to address this issue. The implementation of specific protocols based on appropriateness criteria at the emergency room, as well as the availability of radiologist consultation, can help the emergency physician to provide the best management for each patient. The use of evidencebased clinical decision support modules may help to decrease the number of inappropriate exams on specific conditions [18]. Another important issue is the need to provide detailed history to improve clinical interpretation by the radiologist. Often indications are generic or resumed on the exam request. At our institution, we have access to the patient’s electronic health record, including medical history and prior studies. However, in many institutions, the radiologist does not have access to prior history, including primary tumor, stage, treatment, or prior imaging. This study has limitations intrinsic to its retrospective design, such as loss of data in electronic medical records and some images in the PACS system, no standardization of the terms used in medical forms and exam request without clinical indication. Besides that, the study was conducted in only one institution and in a specific time period, which hinders the extrapolation of the results to other populations. Nevertheless, this study demonstrated a panorama of the use of imaging tests in the emergency department of a cancer center, with particular focus of interest in CT scans, helping to direct future studies to enable an improved use of this tool. We conclude that CT plays an important role in the management of cancer patients visiting the emergency department. However, the high rate of negative or discordant results causes a concern for the inadvertent and excessive use of this imaging

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modality. The recognition of the profile of emergency department visits at a cancer center and the use of clinical decision support modules or radiologist consultation might contribute to a better use of available diagnostic exams in the future. Compliance with ethical standards All procedures performed in this study were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments. The manuscript does not contain clinical studies or patient data.

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9.

10.

Conflict of interest The authors declare that they have no conflict of interest. 11.

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