Interobserver reproducibility of cervical lymph node measurements at CT in patients with head and neck squamous cell carcinoma

Inter- and intraobserver agreement for CT measurement of mandibular and medial retropharyngeal lymph nodes is excellent in dogs with histologically confirmed oral melanoma

Mandibular and medial retropharyngeal lymph nodes are routinely evaluated with CT when staging dogs with oral melanomas. While size alone is considered inadequate for detecting nodal metastasis, it is critical in evaluating treatment response, as clinical decisions are based on changes in size. It is common for different radiologists to measure the size of pre- and posttreatment lymph nodes in the same patient. The objective of this retrospective, observer agreement study was to evaluate the inter- and intraobserver agreement in measuring canine mandibular and medial retropharyngeal lymph nodes by a diverse population of veterinary radiologists and trainees. Fourteen dogs with documented oral melanoma and head CT studies identified from records of a single institution were included in this study. North American veterinary radiologists and trainees were recruited to measure the mandibular and medial retropharyngeal lymph nodes; in triplicate. Prior to performing the study measurements, participants completed a training tool demonstrating the lymph node measurements. Overall, interobserver intraclass correlation coefficient (ICC) was 0.961 (95% confidence interval [CI]: 0.946, 0.972) and intraobserver ICC was 0.977 (95% CI: 0.968, 0.983), indicating excellent agreement (ICC > 0.9 considered excellent). Similar findings were noted following sub-analysis for most variables (experience, size, laterality, axis of measurement). These results suggest that follow-up measurement of the long and short axis of the mandibular lymph nodes and short axis of the medial retropharyngeal lymph nodes in the transverse plane, performed by different veterinary radiologists using the same method of measure, should have minimal impact on clinical decision making.

Canine anal sac gland carcinoma with regional lymph node metastases treated with sacculectomy and lymphadenectomy: Outcome and possible prognostic factors

The staging system commonly used in canine anal sac gland carcinoma (ASGC) is a revised Tumour-Node-Metastasis (TNM) system published in 2007. This staging system consists in four stages and, for dogs with nodal metastases, the size of the metastatic lymph node (mLN) defines the N stage. However, we hypothesise that (1) the mLN size has no prognostic significance when the mLN can be excised, (2) a high number of mLNs is associated with poorer prognosis and (3) the measurement of the mLN on imaging is not reproducible. To investigate these hypotheses, medical records and diagnostic images of dogs with ASGC and mLN, treated with sacculectomy and lymphadenectomy, with or without chemotherapy, were reviewed. Interobserver variability for mLN measurement was assessed. Prognostic factors including mLN size and number were investigated. Time to documented progression (TDP) and disease-specific survival (DSS) were evaluated. Progression-free interval (PFI) was analysed with interval-censored data analysis. Fifty-seven dogs were included. The median PFI, TDP and DSS were 110 (95%CI 61.5-185.5), 196 (95%CI 162-283) and 340 days (95%CI 321-471), respectively. For measurement of the largest mLN, interobserver agreement was excellent but limits of agreement reached 39.7%. Neither the size of the largest mLN nor the use of adjuvant chemotherapy were associated with outcome. The number of mLNs was associated with outcome and having more than four mLNs was associated with shorter PFI (p < .001), TDP (p = .004) and DSS (p < .001). While mLN size measurement was not consistently reproducible and did not influence outcome in our cohort, number of mLNs did. Further studies are required for development of a revised staging system.

Retrospective comparison of approaches to evaluating inter-observer variability in CT tumour measurements in an academic health centre

BACKGROUND

A growing number of research studies have reported inter-observer variability in sizes of tumours measured from CT scans. It remains unclear whether the conventional statistical measures correctly evaluate the CT measurement consistency for optimal treatment management and decision-making. We compared and evaluated the existing measures for evaluating inter-observer variability in CT measurement of cancer lesions.

METHODS

13 board-certified radiologists repeatedly reviewed 10 CT image sets of lung lesions and hepatic metastases selected through a randomisation process. A total of 130 measurements under RECIST 1.1 (Response Evaluation Criteria in Solid Tumors) guidelines were collected for the demonstration. Intraclass correlation coefficient (ICC), Bland-Altman plotting and outlier counting methods were selected for the comparison. The each selected measure was used to evaluate three cases with observed, increased and decreased inter-observer variability.

RESULTS

The ICC score yielded a weak detection when evaluating different levels of the inter-observer variability among radiologists (increased: 0.912; observed: 0.962; decreased: 0.990). The outlier counting method using Bland-Altman plotting with 2SD yielded no detection at all with its number of outliers unchanging regardless of level of inter-observer variability. Outlier counting based on domain knowledge was more sensitised to different levels of the inter-observer variability compared with the conventional measures (increased: 0.756; observed: 0.923; improved: 1.000). Visualisation of pairwise Bland-Altman bias was also sensitised to the inter-observer variability with its pattern rapidly changing in response to different levels of the inter-observer variability.

CONCLUSIONS

Conventional measures may yield weak or no detection when evaluating different levels of the inter-observer variability among radiologists. We observed that the outlier counting based on domain knowledge was sensitised to the inter-observer variability in CT measurement of cancer lesions. Our study demonstrated that, under certain circumstances, the use of standard statistical correlation coefficients may be misleading and result in a sense of false security related to the consistency of measurement for optimal treatment management and decision-making.

Combining pretreatment plasma Epstein-Barr virus DNA level and cervical node necrosis improves prognostic stratification in patients with nasopharyngeal carcinoma: A cohort study

This study aimed to evaluate the prognostic value of combining pretreatment Epstein‐Barr virus (EBV) DNA level and cervical node necrosis (CNN) for patients with nasopharyngeal carcinoma (NPC) receiving intensity‐modulated radiotherapy (IMRT). A total of 607 incident nonmetastatic NPC patients treated with IMRT ± chemotherapy were reviewed. Patients were divided into four groups based on EBV DNA level and CNN status. The primary endpoint was progression‐free survival (PFS). Kaplan‐Meier curves with log‐rank test were applied to compare survival outcomes and the Cox proportional model was used to identify independent prognostic factors. Pretreatment EBV DNA level and CNN status were independent prognostic factors. Patients in the low‐level EBV DNA group or non‐CNN group had significantly better 5‐year PFS. Multivariate analyses demonstrated that CNN was an independent prognostic factor for overall survival (OS) (HR = 1.927, 95% CI: 1.129‐3.290, P = .016), PFS (HR = 1.492, 95% CI: 1.005‐2.214, P = .047), distant metastasis‐free survival (DMFS) (HR = 1.661, 95% CI: 1.044‐2.644, P = .032), but not locoregional relapse‐free survival. EBV DNA levels correlated significantly with CNN with a correlation coefficient of .324 (P < .001). Compared with low‐level EBV DNA and non‐CNN grouping, high‐level EBV DNA and CNN grouping had poor PFS. The combined classification was an independent prognostic factor for OS (P < .001), PFS (P = .001), and DMFS (P = .018). Pretreatment plasma EBV DNA level and CNN status both closely correlated with prognosis of NPC patients in the IMRT era. Combined EBV DNA level and CNN status improves risk stratification and prognostic value.

Brain MRI findings in acute hepatic encephalopathy in liver transplant recipients

Acute hepatic encephalopathy has significant morbidity and mortality in liver transplant recipients unless it is promptly treated. We evaluated the brain magnetic resonance (MR) imaging findings associated with acute hepatic encephalopathy in transplant recipients. We retrospectively reviewed the clinical and imaging data and outcomes of twenty-five liver transplant patients (16 male; mean age, 49.3 years) with clinically diagnosed acute hepatic encephalopathy and forty liver transplant patients (20 males; mean age, 45.5 years) without neurological symptoms suggestive of hepatic encephalopathy at our institution. Bilateral symmetric hyperintensities of the insular cortex and cingulate gyrus were observed in twenty-one patients (84.00%), bilateral symmetric extensive increased cortical signal intensity (involving two or more regions) was observed in 72.00% of the patients, leptomeningeal enhancement in 73.68%, and visualization of prominent venules in 52.00%. The most common symptom at diagnosis was rigidity (n = 14), and the plasma ammonia levels ranged from 68.63 to 192.16 μmol/L. After active treatment, 17 patients gradually recovered, four patients suffered from mild or moderate neurologic deficits, and four patients with widespread brain edema died. The specific brain MR imaging features were bilateral symmetric increased cortical signal intensity, especially in the insular cortex and cingulate gyrus, leptomeningeal enhancement, visualization of the prominent venules, and widespread brain edema. These features may indicate poor prognosis and should alert radiologists to the possibility of acute hepatic encephalopathy in liver transplant recipients and encourage clinicians to prepare appropriate treatment in advance.

Value of extranodal extension detected by computed tomography for predicting clinical response after chemoradiotherapy in head and neck squamous cell cancer

OBJECTIVES

Radiological extranodal extension (rENE) upon CT is obtained before concurrent chemoradiation therapy (CCRT) for head and neck squamous cell carcinoma (HNSCC). We evaluated the prognostic value of rENE, rather than pathologically proven ENE, in patients who received CCRT for HNSCC.

MATERIALS AND METHODS

We reviewed 117 patients. We divided the patients into rENE(+) and rENE(-) groups and evaluated overall survival (OS) and disease-specific survival (DSS), and factors affecting these outcomes.

RESULTS

Median follow-up was 37.4 months; 31 patients (26.2%) died and 26 (22.2%) had recurrence. Thirty patients were rENE(+) and these had worse 5-year OS (74% vs. 94%, p < .01) and DSS (42% vs. 84%, p < .01) rates compared with the rENE(-) group (n = 87). rENE (hazard ratio [HR] 3.57, p < .05) and complete response (HR 3.55, p < .05) affected OS. Clinical T stage (HR 2.86, p < .05), rENE (HR 2.88, p < .05), and complete response (HR 7.03, p < .01) affected DSS. rENE(+) increased risk of incomplete response (IR) compared with the rENE(-) group (p < .05).

CONCLUSIONS

CT findings suggesting ENE predicts treatment response to CCRT and prognosis, and could be used to determine the treatment modality for HNSCC.

Quantification of fat infiltration in the sacroiliac joints with ankylosing spondylitis using IDEAL sequence

AIM

To quantitatively assess fat infiltration in the sacroiliac joints (SIJs) of patients with ankylosing spondylitis (AS) by measuring the fat/water signal ratios of periarticular bone marrow with iterative decomposition of water and fat with echo asymmetry and least square estimation (IDEAL).

MATERIALS AND METHODS

Routine SIJ magnetic resonance imaging (MRI) and IDEAL were performed on 40 patients with AS and 30 healthy subjects. The fat infiltration regions (FIRs) and normal-appearing regions (NARs) of patients were measured based on the fat/water signal intensity on IDEAL.

RESULTS

AS patients had higher fat/water signal ratios on FIRs and NARs (65.4-85.4%, p<0.05, and 44.1-70.7%, p<0.05, respectively) compared to healthy controls (38.3-43.3%). After treatment, the fat/water signal ratios of FIRs and NARs decreased (42.1-53.7% and 41.5-50.3%, respectively), but they remained higher than in the healthy controls (p<0.05). The fat infiltration was detected more effectively with a fat fraction map of the IDEAL sequence (95%) than other sequences, including the T1-weighted sequence (65%), and the fat/water signal ratios of the sacrum and ilium between the left and right sides of SIJs were approximately the same.

CONCLUSION

The findings of this study suggest that IDEAL may be useful as a quantitative and objective method for evaluating the fat infiltration in the periarticular bone marrow of SIJs with AS; additionally, the sensitivity of IDEAL is better than that of routine sequences in detecting micro-fat infiltration of SIJs, and IDEAL can be used to quantitatively measure the adipose content and monitor patient follow-up after AS treatment.