Diagnostic Yield and False-Referral Rate of Staging Chest CT in Patients with Colon Cancer

Conceptual review of outcome metrics and measures used in clinical evaluation of artificial intelligence in radiology

Artificial intelligence (AI) has numerous applications in radiology. Clinical research studies to evaluate the AI models are also diverse. Consequently, diverse outcome metrics and measures are employed in the clinical evaluation of AI, presenting a challenge for clinical radiologists. This review aims to provide conceptually intuitive explanations of the outcome metrics and measures that are most frequently used in clinical research, specifically tailored for clinicians. While we briefly discuss performance metrics for AI models in binary classification, detection, or segmentation tasks, our primary focus is on less frequently addressed topics in published literature. These include metrics and measures for evaluating multiclass classification; those for evaluating generative AI models, such as models used in image generation or modification and large language models; and outcome measures beyond performance metrics, including patient-centered outcome measures. Our explanations aim to guide clinicians in the appropriate use of these metrics and measures.

Clinical study on simultaneous resection of liver metastases combined with hyperthermic intraperitoneal chemotherapy for synchronous colorectal cancer liver metastasis

PURPOSE

This study aimed to analyze the clinical effect of simultaneous resection of liver metastases combined with hyperthermic intraperitoneal chemotherapy (HIPEC) on synchronous colorectal cancer liver metastasis.

METHODS

A total of 144 patients with synchronous colorectal cancer liver metastasis who were admitted to our hospital between January 2018 and January 2019 were randomly assigned into a control group and an intervention group. The patients in the control group received simultaneous resection of liver metastases. The patients in the intervention group obtained simultaneous resection of liver metastases combined with HIPEC. The recent total effective rate of the 2 groups was compared, and the disease control rate of the 2 groups was calculated at 3 months after treatment. The patients were followed up for 3 years. The survival time of the 2 groups was observed and compared. Fasting venous blood was collected from patients in the 2 groups, and the carcinoembryonic antigen (CEA) level was compared. The level of quality of life scale (Short Form 36-item Health Survey) and the occurrence of adverse reactions were compared between the 2 groups.

RESULTS

The R0 complete resection rate in the intervention group was significantly higher than that in the control group (P < .05). The recent total effective rate in the intervention group (87.50%) was significantly higher than that in the control group (59.72%) (P < .05). The negative change of CEA in the intervention group was 72.22%, which was prominently higher than that in the control group of 43.06% (χ2 = 12.542, P < .001). After a 36-month follow-up, the overall survival rate of the observation group was significantly higher than that of the control group (hazard ratio, 2.54; 95% CI, 1.05-5.48; P < .001). The patients in the intervention group had significantly higher life quality scores of health status, social function, emotional function, physical function, and mental health than in the control group (P < .05). There was no significant difference in the incidence of complications between the 2 groups (P > .05). Age > 60 years, preoperative comorbidities, moderate and high differentiation of tumors, intraoperative blood loss > 150 mL, and less experienced surgeons were risk factors affecting the occurrence of complications after treatment and were closely correlated with the prognosis and survival of patients (P < .05). Patients with age ≤ 60 years, no preoperative comorbidities, low tumor differentiation, intraoperative blood loss ≤ 150 mL, more experienced surgeons, and complete R0 resection had a longer survival time. Age > 60 years, preoperative comorbidities, moderate and high differentiation of tumors, intraoperative blood loss > 150 mL, and less experienced surgeons were independent risk factors affecting the prognosis of patients with colorectal cancer liver metastases (P < .05), whereas R0 surgery was an independent protective factor for the prognosis (P < .05).

CONCLUSION

In the treatment of synchronous colorectal cancer liver metastases, simultaneous resection of liver metastases in conjunction with HIPEC demonstrated superior efficacy. This approach may potentially extend patient survival and enhance quality of life and deserve to be extensively used in clinical practice.

Staging Chest CT in Patients With Early-Stage Colon Cancer: Analysis of Impact on Survival Using Inverse Probability Weighting and Causal Diagram

BACKGROUND. Staging chest CT has been shown to have negligible diagnostic yield for detecting lung metastases in patients with early-stage colon cancer. Nonetheless, staging chest CT may have potential survival benefits, including opportunistic screening of comorbidity and provision of a baseline examination for future comparisons. Evidence is lacking regarding the impact of staging chest CT on survival in patients with early-stage colon cancer. OBJECTIVE. The purpose of this study was to determine whether the performance of staging chest CT affects survival in patients with early-stage colon cancer. METHODS. This retrospective study included patients with early-stage colon cancer (defined as clinical stage 0 or I on staging abdominal CT) at a single tertiary hospital between January 2009 and December 2015. Patients were divided into two groups according to the presence of a staging chest CT examination. To ensure comparability between the two groups, inverse probability weighting was applied to adjust for the confounders derived from a causal diagram. The between-group differences in adjusted restricted mean survival time at 5 years were measured for overall survival, relapse-free survival, and thoracic metastasis-free survival. Sensitivity analyses were performed. RESULTS. A total of 991 patients (618 men and 373 women; median age, 64 years [IQR, 55-71 years]) were included: 606 patients (61.2%) had staging chest CT. For overall survival, the difference between groups in restricted mean survival time at 5 years was not significant (0.4 months [95% CI, -0.8 to 2.1 months]). The differences between groups in restricted mean survival at 5 years were also not significant for relapse-free survival (0.4 months [95% CI, -1.1 to 2.3 months]) and for thoracic metastasis-free survival (0.6 months [95% CI, -0.8 to 2.4 months]). Similar results were observed in sensitivity analyses that tested 3- and 10-year RMST differences, excluded patients who underwent FDG PET/CT during staging workup, and added treatment decision (surgery vs no surgery) to the causal diagram. CONCLUSION. The use of staging chest CT did not affect survival in patients with early-stage colon cancer. CLINICAL IMPACT. Staging chest CT may be omitted from the staging workup for patients with colon cancer of clinical stage 0 or I.

Use of "Diagnostic Yield" in Imaging Research Reports: Results from Articles Published in Two General Radiology Journals

OBJECTIVE

"Diagnostic yield," also referred to as the detection rate, is a parameter positioned between diagnostic accuracy and diagnosis-related patient outcomes in research studies that assess diagnostic tests. Unfamiliarity with the term may lead to incorrect usage and delivery of information. Herein, we evaluate the level of proper use of the term "diagnostic yield" and its related parameters in articles published in Radiology and Korean Journal of Radiology (KJR).

MATERIALS AND METHODS

Potentially relevant articles published since 2012 in these journals were identified using MEDLINE and PubMed Central databases. The initial search yielded 239 articles. We evaluated whether the correct definition and study setting of "diagnostic yield" or "detection rate" were used and whether the articles also reported companion parameters for false-positive results. We calculated the proportion of articles that correctly used these parameters and evaluated whether the proportion increased with time (2012-2016 vs. 2017-2022).

RESULTS

Among 39 eligible articles (19 from Radiology and 20 from KJR), 17 (43.6%; 11 from Radiology and 6 from KJR) correctly defined "diagnostic yield" or "detection rate." The remaining 22 articles used "diagnostic yield" or "detection rate" with incorrect meanings such as "diagnostic performance" or "sensitivity." The proportion of correctly used diagnostic terms was higher in the studies published in Radiology than in those published in KJR (57.9% vs. 30.0%). The proportion improved with time in Radiology (33.3% vs. 80.0%), whereas no improvement was observed in KJR over time (33.3% vs. 27.3%). The proportion of studies reporting companion parameters was similar between journals (72.7% vs. 66.7%), and no considerable improvement was observed over time.

CONCLUSION

Overall, a minority of articles accurately used "diagnostic yield" or "detection rate." Incorrect usage of the terms was more frequent without improvement over time in KJR than in Radiology. Therefore, improvements are required in the use and reporting of these parameters.

The novel antitumor compound clinopodiside A induces cytotoxicity via autophagy mediated by the signaling of BLK and RasGRP2 in T24 bladder cancer cells

In the study, we investigated the anti-cancer effect of clinopodiside A and the underlying mechanisms using T24 bladder cancer cells as an experimental model. We found that the compound inhibited the growth of the bladder cancer cells in vitro and in vivo in a in a concentration- and dose-dependent manner, respectively, which showed a combinational effect when used together with cisplatin. In the bladder cancer cells, clinopodiside A caused autophagy, which was mediated by the signaling of BLK and RasGRP2, independently. Inhibition of the autophagy by chemical inhibitor 3-methyladenine or by the inhibition of the signaling molecules attenuated the cytotoxicity of clinopodiside A. Further analyses showed that clinopodiside A acted in synergism with cisplatin which itself could trigger both autophagy and apoptosis, which occurred with concomitant enhancements in autophagy and the cisplatin-evoked apoptosis. In conclusion, our results suggest that clinopodiside A inhibits the growth of the bladder cancer cells via BLK- and RasGRP2-mediated autophagy. The synergistic effect between clinopodiside A and cisplatin is attributed to the increases in autophagy and autophagy-promoted apoptosis. Clinopodiside A is a promising investigational drug for the treatment of cancer, at least blabber, which can be used alone or in combination with clinical drug(s).

Outcome of staging chest CT and identification of factors associated with lung metastasis in children with hepatoblastoma

OBJECTIVES

To evaluate the outcome of staging chest CT and to identify clinicoradiological factors predictive of lung metastasis in patients with hepatoblastoma based on the 2017 PRE-Treatment EXTent of tumor (PRETEXT) system.

METHODS

This bi-center study retrospectively identified patients diagnosed with hepatoblastoma between January 1998 and September 2019 in two tertiary hospitals. The primary outcome was the proportion of the patients who had lung metastasis at staging chest CT. The diagnostic accuracy of staging chest CT was calculated based on the 2017 PRETEXT criteria. The secondary outcome was the identification of factors predictive of lung metastasis using multivariable logistic regression.

RESULTS

In total, 123 patients (median age, 1 year; interquartile range, 0-4 years; 59 female) were included. Among those, 28% (35/123; 95% confidence interval [CI], 21-37%) had lung metastasis at staging chest CT. The overall accuracy of staging chest CT was 96.8%. The proportion of lung metastasis in patients with stage I, II, III, and IV was 0%, 24% (12 of 49; 95% CI, 14-38%), 23% (9 of 40; 95% CI, 12-38%), and 56% (14 of 25; 95% CI, 37-73%), respectively. Multifocality (adjusted odds ratio, 6.7; 95% CI, 2.7-17.5; p < .001) and male sex (adjusted odds ratio, 3.1; 95% CI, 1.2-8.6; p = .02) were associated with the presence of lung metastasis.

CONCLUSIONS

Twenty-eight percent of the patients with hepatoblastoma had lung metastasis at staging chest CT. Multifocality and male sex were predictive factors for lung metastasis on staging chest CT.

KEY POINTS

• The proportion of lung metastasis in patients with hepatoblastoma was 28%. • The overall accuracy of staging chest CT was 97% based on the 2017 PRETEXT system. • Hepatic tumor multifocality and male sex were predictors of lung metastasis.

Lung Nodules in Melanoma Patients: Morphologic Criteria to Differentiate Non-Metastatic and Metastatic Lesions

Lung nodules are frequent findings in chest computed tomography (CT) in patients with metastatic melanoma. In this study, we assessed the frequency and compared morphologic differences of metastases and benign nodules. We retrospectively evaluated 85 patients with melanoma (AJCC stage III or IV). Inclusion criteria were ≤20 lung nodules and follow-up using CT ≥183 days after baseline. Lung nodules were evaluated for size and morphology. Nodules with significant growth, nodule regression in line with RECIST assessment or histologic confirmation were judged to be metastases. A total of 438 lung nodules were evaluated, of which 68% were metastases. At least one metastasis was found in 78% of patients. A 10 mm diameter cut-off (used for RECIST) showed a specificity of 95% and a sensitivity of 20% for diagnosing metastases. Central location (n = 122) was more common in metastatic nodules (p = 0.009). Subsolid morphology (n = 53) was more frequent (p < 0.001), and calcifications (n = 13) were solely found in non-metastatic lung nodules (p < 0.001). Our data show that lung nodules are prevalent in about two-thirds of melanoma patients (AJCC stage III/IV) and the majority are metastases. Even though we found a few morphologic indicators for metastatic or non-metastatic lung nodules, morphology has limited value to predict the presence of lung metastases.

Usefulness of Staging Chest CT in Breast Cancer: Evaluating Diagnostic Yield of Chest CT According to the Molecular Subtype and Clinical Stage

The aim of this study is to investigate the clinical utility of staging chest CT in breast cancer by evaluating diagnostic yield (DY) of chest CT in detection of metastasis, according to the molecular subtype and clinical stage. This retrospective study included 840 patients with 855 breast cancers from January 2017 to December 2018. The number of patients in clinical stage 0/I, II, III and IV were 457 (53.5%), 298 (34.9%), 92 (10.8%) and 8 (0.9%), respectively. Molecular subtype was identified in 841 cancers and there were 709 (84.3%) luminal type, 55 (6.5%) human epidermal growth factor receptor 2 (HER2)-enriched type and 77 (9.2%) triple-negative (TN) type. The DYs in clinical stage 0/I, cII, cIII and cIV were 0.2% (1/457), 1.7% (5/298), 4.3% (4/92) and 100.0% (8/8), respectively. The DYs in luminal type, HER2-enriched type and TN type were 1.7% (12/709), 3.6% (2/55) and 2.6% (2/77), respectively. Clinical stage was associated with the DY (p = 0.000). However, molecular subtype was not related to the DY (p = 0.343). Molecular subtype could not provide useful information to determine whether staging chest CT should be performed in early-stage breast cancer. However, chest CT should be considered in advanced breast cancer.

Usefulness of staging chest-CT in patients with operable breast cancer

Objective

The aim of this study was to investigate the usefulness of staging chest-CT in terms of diagnostic yield and false-referral rate in patients with operable breast cancer.

Materials and methods

This study was approved by the institutional review border. In this retrospective study, we reviewed patients who underwent staging chest-CT between January 2014 and June 2016. Reference standard was defined as a combination of pathology and radiologic tumor changes in accordance with primary tumor or metastatic lesions and stability during the 12-month follow-up period. We calculated diagnostic yield and false-referral rates stratified by pathologic stage. The important ancillary findings of staging chest-CT were also recorded.

Results

A total of 1,342 patients were included in this study. Of these, four patients (0.3%; 4/1342) had true pulmonary metastasis. Diagnostic yields of stage I, II, III disease were 0.0% (0/521), 0.3% (2/693), and 1.6% (2/128), respectively. The overall false-referral rate was 4.6% (62/1342); false-referral rates of stage I, II, and III disease were 5.0% (26/521), 3.8% (26/693), and 7.8% (10/128), respectively. No occult thoracic metastasis occurred within 12 months of staging chest-CT. Nineteen patients showed significant ancillary findings besides lung metastasis, including primary lung cancer (n = 9). The overall diagnostic yield of ancillary findings was 1.7% (23 of 1342).

Conclusions

The incidence of pulmonary metastasis was near zero for pathologic stages I/II and slightly higher (although still low; 1.6%). for stage III. Considering its low diagnostic yield and substantial false-referral rates, staging chest-CT might not be useful in patients with operable breast cancer.

Detection of distant metastases in rectal cancer: contrast-enhanced CT vs whole body MRI

OBJECTIVES

To evaluate the diagnostic performance of whole-body MRI (WB-MRI) including contrast-enhanced T1-weighted imaging (T1WI) and WB-DWI in rectal cancer initial staging.

METHODS

This retrospective study was approved by the IRB and the requirement of informed consent was waived. From September 2013 to Feb 2015, patients who underwent rectal MRI including WB-MRI, as well as chest and abdominopelvic CT for initial staging, were included. WB-MRI consisted of contrast-enhanced T1-weighted imaging and DWI covering neck to the pelvis. Three radiologists reviewed WB-MRI and CECT independently for the M-classification. The diagnostic performance of CECT and WB-MRI was compared using a reference standard incorporating histology, FDG-PET results, and clinical follow-up.

RESULTS

A total of 139 patients (male:female = 89:50, mean age 63.2 ± 12.4 years) were included and metastasis was observed in 15.2% (21/139). WB-MRI showed significantly higher specificity (96.7% [114/118] vs. 85.6% [101/118], p = 0.001) and positive predictive value (PPV) (80% [16/20] vs. 48.5% [16/33], p < 0.001) than CECT. However, there were no significant differences in sensitivity (76.2% [16/21] for both, p > 0.99) and negative predictive value (95.3% [101/106] at CECT vs. 95.8% [114/119] at WB-MRI, p = 0.77) between CECT and WB-MRI.

CONCLUSIONS

WB-MRI showed higher specificity and PPV than CECT in newly diagnosed rectal cancer. Adding WB-MRI to standard rectal MRI is a feasible option for initial staging workup of rectal cancer.

KEY POINTS

• WB-MRI showed a higher specificity and PPV than those of CECT for identifying metastasis at initial staging workup of rectal cancer. • WB-MRI and CECT did not show a significant difference in sensitivity and NPV for the M-classification. • WB-MRI can be used as an alternative to CECT for the initial M-classification modality in newly diagnosed rectal cancer.