Evaluation of lymph nodes with RECIST 1.1

Node-RADS: a systematic review and meta-analysis of diagnostic performance, category-wise malignancy rates, and inter-observer reliability

OBJECTIVE

To perform a systematic review and meta-analysis to estimate diagnostic performance, category-wise malignancy rates, and inter-observer reliability of Node Reporting and Data System 1.0 (Node-RADS).

METHODS

Five electronic databases were systematically searched for primary studies on the use of Node-RADS to report the possibility of cancer involvement of lymph nodes on CT and MRI from January 1, 2021, until April 15, 2024. The study quality was assessed by modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and Quality Appraisal of Diagnostic Reliability (QAREL) tools. The diagnostic accuracy was estimated with bivariate random-effects model, while the pooled category-wise malignancy rates were obtained with random-effects model.

RESULTS

Six Node-RADS-CT studies and three Node-RADS-MRI studies covering nine types of cancer were included. The study quality was mainly damaged by inappropriate index test and unknown timing according to QUADAS-2, and unclear blindness during the rating process according to QAREL. The area under hierarchical summary receiver operating characteristic curve (95% conventional interval) was 0.92 (0.89-0.94) for Node-RADS ≥ 3 as positive and 0.91 (0.88-0.93) for Node-RADS ≥ 4 as positive, respectively. The pooled malignancy rates (95% CIs) of Node-RADS 1 to 5 were 4% (0-10%), 31% (9-58%), 55% (34-75%), 89% (73-99%), and 100% (97-100%), respectively. The inter-observer reliability of five studies was interpreted as fair to substantial.

CONCLUSION

Node-RADS presented a promising diagnostic performance with an increasing probability of malignancy along higher category. However, the evidence for inter-observer reliability of Node-RADS is insufficient, and may hinder its implementation in clinical practice for lymph node assessment.

KEY POINTS

Question Node-RADS is designed for structured reporting of the possibility of cancer involvement of lymph nodes, but the evidence supporting its application has not been summarized. Findings Node-RADS presented diagnostic performance with AUC of 0.92, and malignancy rates for categories 1-5 ranged from 4% to 100%, while the inter-observer reliability was unclear. Clinical relevance Node-RADS is a useful tool for structured reporting of the possibility of cancer involvement of lymph nodes with high diagnostic performance and appropriate malignancy rate for each category, but unclear inter-observer reliability may hinder its implementation in clinical practice.

Imaging Evaluation of Mediastinal and Hilar Lymphadenopathy: Approach, Classification, and Differential Diagnosis

Mediastinal and hilar lymphadenopathy is a frequent finding in thoracic imaging, necessitating thorough evaluation to distinguish between transient, reactive, malignant, and non-malignant causes. This review explores the anatomy, function, and drainage patterns of thoracic lymph nodes, including the International Association for the Study of Lung Cancer (IASLC) classification system, which standardizes lymph node stations for lung cancer staging and broader diagnostic applications. Imaging modalities such as chest radiography (CXR) and computed tomography (CT) play crucial roles in assessing lymphadenopathy, with CT being the preferred tool due to its ability to characterize size, shape, borders, density, and enhancement patterns. Specific imaging features, including nodal size thresholds, calcification patterns, necrosis, and distribution, help narrow differential diagnoses, distinguishing between malignant and benign conditions such as tuberculosis, sarcoidosis, lymphoma, and metastases. Additionally, the involvement of extra-mediastinal nodes can provide diagnostic clues to systemic diseases. A systematic imaging approach enhances diagnostic accuracy, guiding appropriate clinical management and tissue sampling when necessary.

[68Ga]Ga-PSMA-617 PET/MRI for imaging patients suspected of hepatocellular carcinoma

PURPOSE

Radiolabeled probes targeting prostate-specific membrane antigen (PSMA) have been used in prostate cancer. Moreover, PSMA is also overexpressed on neovessels in hepatocellular carcinoma (HCC). This study aimed to preliminarily evaluate the diagnostic effectiveness of [68Ga]Ga-PSMA-617 PET/MRI for HCC.

METHODS

Patients suspected of HCC were prospectively enrolled in this single-center study (NCT05006326, 2021-08-16) to perform [68Ga]Ga-PSMA-617 PET/MRI, along with contrast enhanced CT (ceCT) or ceMRI. The main suspicious intrahepatic lesions were resected and pathologically verified. Visual evaluation of [68Ga]Ga-PSMA-617 PET/MRI images was performed on all lesions. Maximum standard uptake value (SUVmax), mean standard uptake value (SUVmean), tumor-to-liver ratio (TLR), tumor-to-blood ratio (TBR), and tumor-to-parotid ratio (TPR) were measured or calculated. The diagnostic efficiency of different modalities was summarized. PSMA expression was evaluated by immunohistochemistry and the correlation of PSMA expression and [68Ga]Ga-PSMA-617 uptake in HCC primary tumors was quantitatively analyzed.

RESULTS

A total of 12 patients (ten men and two women; mean age 58.75 ± 12.08 years) were included. Ten patients were diagnosed with HCC, 2 with intrahepatic cholangiocarcinoma (ICC), and 4 with hemangioma. The SUVmax, TLR, TBR, and TPR of HCC primary tumors were higher than those of ICC and hemangioma. The diagnostic accuracy of [68Ga]Ga-PSMA-617 PET/MRI for primary HCC was 82.4%. When combined with ceCT or ceMRI, the accuracy increased to 88.2%. A moderate correlation was observed between SUVmax and mean PSMA expression in HCC primary tumors (R = 0.788).

CONCLUSION

Utilizing a hybrid PET/MRI system to combine [68Ga]Ga-PSMA-617 PET/MRI with ceMRI is a promising one-stop solution for the accurate diagnosis of HCC.

TRIAL REGISTRATION

NCT05006326. Registered August 16, 2021, https://clinicaltrials.gov/study/NCT05006326 .

The clinical value of computed tomography Hounsfield unit for diagnosing palpable inguinal lymph node metastasis in patients with penile cancer

Background

Computed tomography (CT) Hounsfield units (HUs) of pathologically confirmed metastatic inguinal lymph nodes (ILNs) were proved to be higher than negative ones. We designed this study to explore the clinical value of CT HU for diagnosing palpable ILN metastasis in patients with penile cancer.

Methods

A total of 32 patients with penile cancer, including 84 palpable ILNs, were recruited in this study. They all performed 5-mm layer pelvic contrast-enhanced CT (CE-CT) before treatment. The palpable ILNs were matched with CT image. By using radiologic software PACS, the layer with a maximum cross-sectional area of target lymph node was selected, and the short axis was defined as diameter. We outlined the edge of target lymph nodes, and the software automatically calculated its area, maximum CT HU, and average CT HU. All target ILNs were biopsied by surgery to confirm the presence of metastasis.

Results

Compared with non-metastatic ILNs, metastatic ILNs had larger diameter, area, maximum non-contrast CT (NC-CT) HU, maximum arterial-phase CE-CT (ACE-CT) HU, average NC-CT HU, and average ACE-CT HU, with statistically significant differences (P < 0.05). Receiver operating characteristic analysis showed the all six parameters (maximum NC-CT HU, maximum ACE-CT HU, average NC-CT HU, average ACE-CT HU, diameter, and area) had significant diagnostic value for ILN metastasis, with an area under the curve of 0.847, 0.853, 0.900, 0.919, 0.809, and 0.789, respectively. The average ACE-CT HU (cutoff: 40.5) had the highest accuracy as 0.857, and maximum NC-CT HU (cutoff: 51.5) had the highest sensitivity of 0.897.

Conclusion

ILN CT HU was clinically valuable for the diagnosis of palpable ILN metastasis in patients with newly diagnosed penile cancer.

Automatic cervical lymph nodes detection and segmentation in heterogeneous computed tomography images using deep transfer learning

To develop a deep learning model using transfer learning for automatic detection and segmentation of neck lymph nodes (LNs) in computed tomography (CT) images, the study included 11,013 annotated LNs with a short-axis diameter ≥ 3 mm from 626 head and neck cancer patients across four hospitals. The nnUNet model was used as a baseline, pre-trained on a large-scale head and neck dataset, and then fine-tuned with 4,729 LNs from hospital A for detection and segmentation. Validation was conducted on an internal testing cohort (ITC A) and three external testing cohorts (ETCs B, C, and D), with 1684 and 4600 LNs, respectively. Detection was evaluated via sensitivity, positive predictive value (PPV), and false positive rate per case (FP/vol), while segmentation was assessed using the Dice similarity coefficient (DSC) and Hausdorff distance (HD95). For detection, the sensitivity, PPV, and FP/vol in ITC A were 54.6%, 69.0%, and 3.4, respectively. In ETCs, the sensitivity ranged from 45.7% at 3.9 FP/vol to 63.5% at 5.8 FP/vol. Segmentation achieved a mean DSC of 0.72 in ITC A and 0.72 to 0.74 in ETCs, as well as a mean HD95 of 3.78 mm in ITC A and 2.73 mm to 2.85 mm in ETCs. No significant sensitivity difference was found between contrast-enhanced and unenhanced CT images (p = 0.502) or repeated CT images (p = 0.815) during adaptive radiotherapy. The model's segmentation accuracy was comparable to that of experienced oncologists. The model shows promise in automatically detecting and segmenting neck LNs in CT images, potentially reducing oncologists' segmentation workload.

Dedicated software to harmonize the follow-up of oncological patients

Objective

To test and evaluate a sofware dedicated to the follow-up of oncological CT scans for potential use in the Radiology department.

Materials and methods

In this retrospective study, 37 oncological patients with baseline and follow-up CT scans were reinterpreted using a dedicated software. Baseline CT scans were chosen from the imaging reports available in our PACS (picture archiving and communicatin systems). Follow-up interpretations were independently assessed with the software. We evaluated the target lesion sums and the tumor response based on RECIST 1.1 (Response Evaluation Criteria in Solid Tumors).

Results

There was no significant difference in the target lesion sums and the tumor response assessments between the PACS data and the imaging software. There was no over or underestimation of the disease with the software. There was a sigificant deviation (progression versus stability) in three cases. For two patients, this difference was related to the evaluation of the response of non-target lesions. The difference in the third patient was due to comparison with a previous CT scan than to the baseline exam. There was a miscalculation in 13 % of the reports and in 28 % of the cases the examination was compared to the previous CT scan. Finally, the tumor response was not detailed in 43 % of the follow-up reports.

Conclusion

The use of dedicated oncology monitoring software could help in reducing intepretation time and in limiting human errors.

Imaging of the Major Salivary Glands in Rheumatic Disease

Salivary gland involvement is a common feature of rheumatologic disease. The authors review the anatomy of the major salivary glands and the uses of imaging modalities such as ultrasound, MRI, computed tomography, sialography, and scintigraphy in evaluating the major salivary glands in rheumatologic disease.

Multifrequency Magnetic Resonance Elastography Detects Small Abdominal Lymph Node Metastasis by High Stiffness

OBJECTIVES

Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 is a clinical and research standard for evaluating malignant tumors and lymph node metastasis. However, quantitative analysis of nodal status is limited to measurement of short axis diameter (SAD), and metastatic lymph nodes below 10 mm in SAD are often not detected. The purpose of this study was to evaluate the value of multifrequency magnetic resonance elastography (MRE) when added to RECIST 1.1 for detection of lymph node metastasis.

MATERIALS AND METHODS

Twenty-five benign and 82 metastatic lymph nodes were prospectively examined by multifrequency MRE at 1.5 T using tomoelastography postprocessing at 30, 40, 50, and 60 Hz (total scan time of 4 minutes). Shear wave speed as a surrogate of soft tissue stiffness was provided in m/s. Positron emission tomography-computed tomography was used as reference standard for identification of abdominal lymph node metastasis from histologically confirmed primary tumors. The diagnostic performance of MRE was compared with that of SAD according to RECIST 1.1 and evaluated by receiver operating characteristic curve analysis using generalized linear mixed models and binary logistic mixed models. Sensitivity, specificity, and predictive values were calculated for different cutoffs.

RESULTS

Metastatic lymph nodes (1.90 ± 0.57 m/s) were stiffer than benign lymph nodes (0.98 ± 0.20 m/s, P < 0.001). An area under the curve of 0.95 for a cutoff of 1.32 m/s was calculated. Using a conservative approach with 1.0 specificity, we found sensitivity (SAD/MRE/MRE + SAD, 0.56/0.84/0.88), negative predictive values (0.41/0.66/0.71), and overall accuracy (0.66/0.88/0.91) to be improved using MRE and even higher for combined MRE and SAD.

CONCLUSIONS

Multifrequency MRE improves metastatic abdominal lymph node detection by 25% based on higher tissue stiffness-even for lymph nodes with an SAD ≤10 mm. Stiffness information is quick to obtain and would be a promising supplement to RECIST.

RECIST 1.1 assessments variability: a systematic pictorial review of blinded double reads

Reader variability is intrinsic to radiologic oncology assessments, necessitating measures to enhance consistency and accuracy. RECIST 1.1 criteria play a crucial role in mitigating this variability by standardizing evaluations, aiming to establish an accepted "truth" confirmed by histology or patient survival. Clinical trials utilize Blind Independent Centralized Review (BICR) techniques to manage variability, employing double reads and adjudicators to address inter-observer discordance effectively. It is essential to dissect the root causes of variability in response assessments, with a specific focus on the factors influencing RECIST evaluations. We propose proactive measures for radiologists to address variability sources such as radiologist expertise, image quality, and accessibility of contextual information, which significantly impact interpretation and assessment precision. Adherence to standardization and RECIST guidelines is pivotal in diminishing variability and ensuring uniform results across studies. Variability factors, including lesion selection, new lesion appearance, and confirmation bias, can have profound implications on assessment accuracy and interpretation, underscoring the importance of identifying and addressing these factors. Delving into the causes of variability aids in enhancing the accuracy and consistency of response assessments in oncology, underscoring the role of standardized evaluation protocols and mitigating risk factors that contribute to variability. Access to contextual information is crucial. CRITICAL RELEVANCE STATEMENT: By understanding the causes of diagnosis variability, we can enhance the accuracy and consistency of response assessments in oncology, ultimately improving patient care and clinical outcomes. KEY POINTS: Baseline lesion selection and detection of new lesions play a major role in the occurrence of discordance. Image interpretation is influenced by contextual information, the lack of which can lead to diagnostic uncertainty. Radiologists must be trained in RECIST criteria to reduce errors and variability.

Analysis of tumor microenvironment alterations in partially responsive rectal cancer patients treated with neoadjuvant chemoradiotherapy

PURPOSE

Achieving a pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (NCRT) remains a challenge for most patients with rectal cancer. Exploring the potential of combining NCRT with immunotherapy or targeted therapy for those achieving a partial response (PR) offers a promising avenue to enhance treatment efficacy. This study investigated the impact of NCRT on the tumor microenvironment in locally advanced rectal cancer (LARC) patients who exhibited a PR.

METHODS

This was a retrospective, observational study. Five patients demonstrating a PR after neoadjuvant treatment for LARC were enrolled in the study. Biopsy samples before treatment and resected specimens after treatment were stained with a panel of 26 antibodies targeting various immune and tumor-related markers, each labeled with distinct metal tags. The labeled samples were then analyzed using the Hyperion imaging system.

RESULTS

Heterogeneity within the tumor microenvironment was observed both before and after NCRT. Notably, tumor-associated macrophages, CD4 + T cells, CD8 + T cells, CD56 + natural killer cells, tumor-associated neutrophils, cytokeratin, and E-cadherin exhibited slight increase in abundance within the tumor microenvironment following treatment (change ratios = 0.78, 0.2, 0.27, 0.32, 0.17, 0.46, 0.32, respectively). Conversely, the number of CD14 + monocytes, CD19 + B cells, CD45 + CD4 + T cells, collagen I, α-smooth muscle actin, vimentin, and β-catenin proteins displayed significant decreases post-treatment (change ratios = 1.73, 1.92, 1.52, 1.25, 1.52, 1.12, 2.66, respectively). Meanwhile, Foxp3 + regulatory cells demonstrated no significant change (change ratio = 0.001).

CONCLUSIONS

NCRT has diverse effects on various components of the tumor microenvironment in LARC patients who achieve a PR after treatment. Leveraging combination therapies may optimize treatment outcomes in this patient population.

Agreement between PSMA-RADS and E-PSMA systems in classifying [18F]PSMA-1007 PET/CT lesions among prostate cancer patients: exploring the correlation between lesion size and uptake

PURPOSE

To determine the agreement between the PSMA-RADS and E-PSMA standardized reporting systems in the classification of [18F]PSMA-1007-uptaking lesions identified on PET/CT scan in patients with prostate cancer (PCa) and post-prostatectomy with suspected recurrent disease (local recurrence, regional nodal involvement and distant metastases), based on biochemical recurrence, while also exploring the correlation between lesion size and tracer uptake.

MATERIALS AND METHODS

A retrospective cross-sectional study of 32 post-prostatectomy PCa patients who had suspected recurrent disease based on biochemical recurrence post-prostatectomy (prostate-specific antigen values that are 0.2 ng/mL or higher) underwent [18F]PSMA-1007 PET/CT scan. The recurrent disease PCa lesions were characterized and subsequently classified using two standardized reporting systems (PSMA-RADS and E-PSMA). The lesions were grouped based on anatomical site, their size and SUVmax were compared using Kruskal-Wallis test with Dunn-Bonferroni post hoc tests. Spearman correlation coefficients were calculated between the size of the lesions and their SUVmax of the radiotracer [18F]PSMA-1007 for all the lesions and when grouped by anatomical site. Additionally, the agreement between lesion classifications was assessed using Cohen's kappa index.

RESULTS

Only 32 (69.98 ± 8.27, men) patients met the inclusion criteria, a total of 149 lesions with avid uptake of [18F]PSMA-1007 were identified. Positive correlation (r = 0.516, p < 0.001) was observed between the size of the metastatic prostate cancer lymph node lesions and their [18F]PSMA-1007 uptake. Substantial agreement was noted between the PSMA-RADS and E-PSMA classification system scores among all lesions (κ = 0.70, p < 0.001), with notable discrepancies primarily among lymph node lesions.

CONCLUSION

Our findings revealed a positive correlation between the size of the metastatic prostate cancer lymph node lesions and [18F]PSMA-1007 uptake, and although there was substantial agreement between the PSMA-RADS and E-PSMA classification systems, there were discrepancies mainly among the lymph node lesions.

Incidental lymphadenopathy in renal transplantation

INTRODUCTION

Iliac lymphadenectomy is performed to provide anastomotic access during the vascular implantation procedure in renal transplantation. Iliac lymph nodes (LNs) are often enlarged, but there are no standardised guidelines for the management of incidentally enlarged LNs during transplantation. We aimed to evaluate histological findings of LNs sent for examination at our unit.

METHODS

Patients were evaluated in two distinct date cycles. In the first cycle, lymphadenectomy and histological assessment were performed at the discretion of the transplanting surgeon. In the second cycle, all incidentally enlarged LNs were sent for histological assessment, regardless of size.

RESULTS

In the first cycle (n = 76), 11 patients (14.47%) had incidentally enlarged iliac LNs on lymphadenectomy and histology showed only reactive changes. In the second cycle (n = 165), eight patients (4.85%) had incidentally enlarged LNs on lymphadenectomy. One patient was found to have mature B cell chronic lymphocytic leukaemia. The patient was referred to haematology and a "watch and wait" approach was taken, with the patient still alive at last follow-up (511 days post-transplantation).

DISCUSSION

There are currently no published guidelines on the management of incidentally enlarged iliac LNs during transplantation. Current literature suggests that clinically significant lymphadenopathy needs to be investigated in all patients. Based on our centre's experience of a 5.26% (1 in 19) positive pathological LN sampling, we recommend that all incidental LNs with suspicious features and/or that are greater than 10mm in diameter should be considered for histological, microbiological and molecular assessment as appropriate.

Towards a Simplified and Cost-Effective Diagnostic Algorithm for the Surveillance of Intraductal Papillary Mucinous Neoplasms (IPMNs): Can We Save Contrast for Later?

The increased detection of pancreatic cysts in recent years has triggered extensive diagnostic investigations to clarify their potential risk of malignancy, resulting in a large number of patients undergoing numerous imaging follow-up studies for many years. Therefore, there is a growing need for optimization of the current surveillance protocol to reduce both healthcare costs and waiting lists, while still maintaining appropriate sensibility and specificity. Imaging is an essential tool for evaluating patients with intraductal papillary mucinous neoplasms (IPMNs) since it can assess several predictors for malignancy and thus guide further management recommendations. Although contrast-enhanced magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) has been widely recommended by most international guidelines, recent results support the use of unenhanced abbreviated-MRI (A-MRI) protocols as a surveillance tool in patients with IPMN. In fact, A-MRI has shown high diagnostic performance in malignant detection, with high sensitivity and specificity as well as excellent interobserver agreement. The aim of this paper is, therefore, to discuss the current available evidence on whether the implementation of an abbreviated-MRI (A-MRI) protocol for cystic pancreatic lesion surveillance could improve healthcare economics and reduce waiting lists in clinical practice without significantly reducing diagnostic accuracy.

Advancing Tailored Treatments: A Predictive Nomogram, Based on Ultrasound and Laboratory Data, for Assessing Nodal Involvement in Endometrial Cancer Patients

Assessing lymph node metastasis is crucial in determining the optimal therapeutic approach for endometrial cancer (EC). Considering the impact of lymphadenectomy, there is an urgent need for a cost-effective and easily applicable method to evaluate the risk of lymph node metastasis in cases of sentinel lymph node (SLN) biopsy failure. This retrospective monocentric study enrolled EC patients, who underwent surgical staging with nodal assessment. Data concerning demographic, clinicopathological, ultrasound, and surgical characteristics were collected from medical records. Ultrasound examinations were conducted in accordance with the IETA statement. We identified 425 patients, and, after applying exclusion criteria, the analysis included 313 women. Parameters incorporated into the nomogram were selected via univariate and multivariable analyses, including platelet count, myometrial infiltration, minimal tumor-free margin, and CA 125. The nomogram exhibited good accuracy in predicting lymph node involvement, with an AUC of 0.88. Using a cutoff of 10% likelihood of nodal involvement, the nomogram displayed a low false-negative rate of 0.04 (95% CI 0.00-0.19) in the training set. The adaptability of this straightforward model renders it suitable for implementation across diverse clinical settings, aiding gynecological oncologists in preoperative patient evaluations and facilitating the design of personalized treatments. However, external validation is mandatory for confirming diagnostic accuracy.

PD-1/PD-L1 Inhibitors Plus Antiangiogenic Drugs Versus Sorafenib as the First Line Treatment for Advanced Hepatocellular Carcinoma: A Phase 3 RCTs Based Meta-Analysis

BACKGROUND

For advanced hepatocellular carcinoma (HCC), sorafenib remains the established therapy. PD-1/PD-L1 inhibitors plus antiangiogenic drugs (PIAD) as a new therapeutic approach for advanced HCC is still a subject of clinical debate regarding whether they offer improved treatment outcomes. This study was conducted to compare the two treatments in terms of antitumor efficacy and safety.

METHODS

Randomized controlled trials (RCTs) comparing PIAD and sorafenib for advanced HCC were retrieved from six databases. Survival (overall survival [OS] and progression-free survival [PFS]) were the main outcomes measured. Secondary endpoints included responses, adverse events (AEs), and effects on quality of life.

RESULTS

Seven studies based on four RCTs (CARES-310, COSMIC-312, IMbrave150, and ORIENT-32) were included. The PIAD group exhibited better OS (hazard ratio [HR]: 0.69, 95% confidence interval [CI]: [0.53, 0.89], P = 0.005), and PFS (HR: 0.60, 95% CI: [0.53, 0.67], P < 0.00001). The survival advantages of OS and PFS were confirmed in almost all subgroups. The PIAD group exhibited higher OS rates at 6-18 months and PFS rates at 6-12 months. Additionally, the objective response rate, disease control rate, complete response, and partial response were higher in PIAD group. The PIAD group had a delayed decline in quality of life, physical functioning, and role functioning. However, the PIAD group experienced more grades 3-5 and serious AEs, along with treatment discontinuation, dose reduction, and dose interruption.

CONCLUSIONS

PIAD appears to be better than sorafenib for advanced HCC with better survival and responses. However, its higher rate of AEs requires cautious attention.

Clinical Course of Patients With Mediastinal Lymph Node Tuberculosis and Risk Factors for Paradoxical Responses

BACKGROUND

Paradoxical responses (PR) occur more frequently in lymph node tuberculosis (LNTB) than in pulmonary tuberculosis and present difficulties in differential diagnosis of drug resistance, new infection, poor patient compliance, and adverse drug reactions. Although diagnosis of mediastinal LNTB has become much easier with the development of endosonography, limited information is available. The aim of this study was to investigate the clinical course of mediastinal LNTB and the risk factors associated with PR.

METHODS

Patients diagnosed with mediastinal LNTB via endosonography were evaluated retrospectively between October 2009 and December 2019. Multivariable logistic regression was applied to evaluate the risk factors associated with PR.

RESULTS

Of 9,052 patients who underwent endosonography during the study period, 158 were diagnosed with mediastinal LNTB. Of these, 55 (35%) and 41 (26%) concurrently had pulmonary tuberculosis and extrapulmonary tuberculosis other than mediastinal LNTB, respectively. Of 125 patients who completed anti-tuberculosis treatment, 21 (17%) developed PR at a median of 4.4 months after initiation of anti-tuberculosis treatment. The median duration of anti-tuberculosis treatment was 6.3 and 10.4 months in patients without and with PR, respectively. Development of PR was independently associated with age < 55 years (adjusted odds ratio [aOR], 5.72; 95% confidence interval [CI], 1.81-18.14; P = 0.003), lymphocyte count < 800/μL (aOR, 8.59; 95% CI, 1.60-46.20; P = 0.012), and short axis diameter of the largest lymph node (LN) ≥ 16 mm (aOR, 5.22; 95% CI, 1.70-16.00; P = 0.004) at the time of diagnosis of mediastinal LNTB.

CONCLUSION

As PR occurred in one of six patients with mediastinal LNTB during anti-tuberculosis treatment, physicians should pay attention to patients with risk factors (younger age, lymphocytopenia, and larger LN) at the time of diagnosis.

Localization, tissue biology and T cell state - implications for cancer immunotherapy

Tissue localization is a critical determinant of T cell immunity. CD8+ T cells are contact-dependent killers, which requires them to physically be within the tissue of interest to kill peptide-MHC class I-bearing target cells. Following their migration and extravasation into tissues, T cells receive many extrinsic cues from the local microenvironment, and these signals shape T cell differentiation, fate and function. Because major organ systems are variable in their functions and compositions, they apply disparate pressures on T cells to adapt to the local microenvironment. Additional complexity arises in the context of malignant lesions (either primary or metastatic), and this has made understanding the factors that dictate T cell function and longevity in tumours challenging. Moreover, T cell differentiation state influences how cues from the microenvironment are interpreted by tissue-infiltrating T cells, highlighting the importance of T cell state in the context of tissue biology. Here, we review the intertwined nature of T cell differentiation state, location, survival and function, and explain how dysfunctional T cell populations can adopt features of tissue-resident memory T cells to persist in tumours. Finally, we discuss how these factors have shaped responses to cancer immunotherapy.

The role of computed tomography features in assessing response to neoadjuvant chemotherapy in locally advanced gastric cancer

OBJECTIVE

To compare the computed tomography (CT) images of patients with locally advanced gastric cancer (GC) before and after neoadjuvant chemotherapy (NAC) in order to identify CT features that could predict pathological response to NAC.

METHODS

We included patients with locally advanced GC who underwent gastrectomy after NAC from September 2016 to September 2021. We retrieved and collected the patients' clinicopathological characteristics and CT images before and after NAC. We analyzed CT features that could differentiate responders from non-responders and established a logistic regression equation based on these features.

RESULTS

We included 97 patients (69 [71.1%] men; median [range] age, 60 [26-75] years) in this study, including 66 (68.0%) responders and 31 (32.0%) non-responders. No clinicopathological variable prior to treatment was significantly associated with pathological response. Out of 16 features, three features (ratio of tumor thickness reduction, ratio of reduction of primary tumor attenuation in arterial phase, and ratio of reduction of largest lymph node attenuation in venous phase) on logistic regression analysis were used to establish a regression equation that demonstrated good discrimination performance in predicting pathological response (area under receiver operating characteristic curve 0.955; 95% CI, 0.911-0.998).

CONCLUSION

Logistic regression equation based on three CT features can help predict the pathological response of patients with locally advanced GC to NAC.

False-positive supraclavicular lymph node detected on chest computed tomography in oncology patients: Clinical implication based on subsequent neck ultrasonography and ultrasonography-guided tissue sampling

PURPOSE

The purpose of this study was to assess the prevalence and clinical implications of false-positive supraclavicular lymph node (LN) detected on chest computed tomography (CT), using subsequent neck ultrasonography (US) and US-guided tissue sampling.

METHODS

Among 172 patients with suspected supraclavicular LNs identified on CT, 87 underwent neck US or US-guided tissue sampling. Receiver operating characteristic curve and logistic regression analyses were performed to determine the diagnostic performance of US and independent predictors of false-positive LNs.

RESULTS

Among 87 patients, 49 (56.3%) were pathologically confirmed as metastases, 26 (29.9%) were negative for malignancy, and 12 (13.8%) had pseudolesions or schwannomas. The diagnostic indices were as follows: sensitivity, 91.8%; specificity, 92.3%; PPV, 95.7%; NPV, 85.7%; and accuracy, 92.0% (AUC = 0.921; 95% CI: 0.832-0.970, p < 0.001). The false-positive group had a higher mean age than the true-positive group (mean age, 69.8 ± 9.2 vs. 63.9 ± 9.8, p = 0.003). Logistic regression analyses revealed that age ≥ 65 years was the only independent predictor of false-positive LNs (OR = 4.391; 95% CI: 1.037-18.582; p = 0.044).

CONCLUSION

Subsequent US can be helpful for evaluating suspicious supraclavicular LNs detected on CT to establish appropriate management, especially in older patients.

A comparison of the prognostic performance of the Lugano 2014 and RECIL 2017 response criteria in patients with NHL from the phase III GOYA and GALLIUM trials

The Lugano 2014 criteria are the standard for response assessment in lymphoma. We compared the prognostic performance of Lugano 2014 and the more recently developed response evaluation criteria in lymphoma (RECIL 2017), which relies primarily on computed tomography and uses unidimensional measurements, in patients with previously untreated diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) from the phase III GOYA and GALLIUM trials, respectively. Concordance between responses according to the Lugano 2014 and RECIL 2017 criteria was analyzed. Landmark analyses of progression-free survival (PFS) and overall survival (OS) by end of treatment (EOT) and end of induction (EOI) response status according to RECIL 2017 and Lugano 2014 criteria, and prognostic value of response at EOT/EOI were also compared. Overall, 1333 patients were included from GOYA and 502 from GALLIUM. Complete response (CR) status according to RECIL 2017 criteria showed high concordance with complete metabolic response (CMR) status by Lugano 2014 criteria in both GOYA (92.5%) and GALLIUM (92.4%). EOT and EOI CR/CMR status by both criteria was highly prognostic for PFS in GOYA (RECIL 2017 [CR]: hazard ratio [HR], 0.35 [95% confidence interval [CI] 0.26-0.46]; Lugano 2014 [CMR]: HR, 0.35 [95% CI 0.26-0.48]; both p < .0001) and GALLIUM (RECIL 2017 [CR]: HR, 0.35 [95% CI 0.23-0.53]; Lugano 2014 [CMR]: HR, 0.21 [95% CI 0.14-0.31]; both p < .0001). In conclusion, response categorization by RECIL 2017 is similar to that by Lugano 2014 criteria, with high concordance observed. Both were prognostic for PFS and OS.

Imaging lymph node regression can predict the pathological tumor regression grade in gastric cancer after neoadjuvant treatment

BACKGROUND

Neoadjuvant chemotherapy has become the standard treatment for locally advanced gastric cancer. The tumor regression grade system is an effective and widely used tool for the evaluation of treatment response to neoadjuvant chemotherapy. However, whether tumor regression grade could be predicted using clinical characteristics is uncertain.

METHODS

A total of 287 locally advanced gastric cancer patients from 2014 to 2021 were retrospectively included. According to the College of American Pathologists' tumor regression grade system, patients were classified into response group (tumor regression grade 0-1) and non-response group (tumor regression grade 2-3). Associations between clinical characteristics and neoadjuvant chemotherapy response were performed by the logistic regression model. The Kaplan-Meier method was used to estimate the survival. A prediction scoring system was constructed based on the β coefficients of multivariate analysis. The receiver operating characteristic curve and decision curve analysis were used to evaluate the performance of the predictive scoring system.

RESULTS

Survival analysis showed that patients with tumor regression grades 0 to 1 had significantly better disease-free survival and overall survival than the tumor regression grades 2 to 3. Tumor differentiation, ycT stage, immunotherapy, and lymph node regression were independent predictors of pathological response to neoadjuvant chemotherapy. We further developed a scoring system to predict the tumor regression grade. The receiver operating characteristic and decision curve analysis showed good predictive performance of the scoring system.

CONCLUSION

Lymph node regression could be used as a predictor for pathological response. We developed a scoring system to predict the treatment response of patients with gastric cancer receiving neoadjuvant chemotherapy. The scoring system based on the predictors could provide guidance for making clinical decisions.

Stereotactic Body Radiation Therapy Salvage for Lymph Node Recurrent Prostate Cancer in the Era of PSMA PET Imaging

PURPOSE OF REVIEW

Our understanding of patterns of prostate cancer recurrence after primary treatment of localized disease has significantly evolved since the development of positron emission tomography (PET) agents targeting prostate cancer. Previously, most biochemical recurrences were not associated with imaging correlates when restaging with computed tomography (CT), magnetic resonance imaging (MRI), or bone scintigraphy and, hence, were typically assumed to represent occult metastases. A rising prostate specific antigen (PSA) after previous local therapy prompting a PET scan showing uptake limited to regional lymph nodes is an increasingly common clinical scenario as advanced prostate cancer imaging becomes more widely utilized. The optimal management strategy for patients who have lymph node recurrent prostate cancer is both unclear and evolving, particularly in terms of local and regionally directed therapies. Stereotactic body radiation therapy (SBRT) utilizes ablative radiation doses with steep gradients to achieve local tumor control while sparing nearby normal tissues. SBRT is an attractive therapeutic modality due to its efficacy, favorable toxicity profile, and flexibility to administer elective doses to areas of potential occult involvement. The purpose of this review is to briefly describe how SBRT is being implemented in the era of PSMA PET for the management of solely lymph node recurrent prostate cancer.

RECENT FINDINGS

SBRT has been shown to effectively control individual lymph node tumor deposits within the pelvis and retroperitoneum for prostate cancer and is well-tolerated with a favorable toxicity profile. However, a major limitation thus far has been the lack of prospective trials supporting the use of SBRT for oligometastatic nodal recurrent prostate cancer. As further trials are conducted, its exact role in the treatment paradigm of recurrent prostate cancer will be better established. Although PET-guided SBRT appears feasible and potentially beneficial, there is still considerable uncertainty about the use of elective nodal radiotherapy (ENRT) in patients with nodal recurrent oligometastatic prostate cancer. PSMA PET has undoubtedly advanced imaging of recurrent prostate cancer, revealing anatomic correlates for disease recurrence that previously went undetected. At the same time, SBRT continues to be explored in prostate cancer with feasibility, a favorable risk profile, and satisfactory oncologic outcomes. However, much of the existing literature comes from the pre-PSMA PET era and integration of this novel imaging approach has led to greater focus on new and ongoing clinical trials to rigorously evaluate this approach and compare to other established treatment modalities utilized for oligometastatic, nodal recurrence of prostate cancer.

Automated localization and segmentation of cervical lymph nodes on contrast-enhanced CT using a 3D foveal fully convolutional neural network

BACKGROUND

In the management of cancer patients, determination of TNM status is essential for treatment decision-making and therefore closely linked to clinical outcome and survival. Here, we developed a tool for automatic three-dimensional (3D) localization and segmentation of cervical lymph nodes (LNs) on contrast-enhanced computed tomography (CECT) examinations.

METHODS

In this IRB-approved retrospective single-center study, 187 CECT examinations of the head and neck region from patients with various primary diseases were collected from our local database, and 3656 LNs (19.5 ± 14.9 LNs/CECT, mean ± standard deviation) with a short-axis diameter (SAD) ≥ 5 mm were segmented manually by expert physicians. With these data, we trained an independent fully convolutional neural network based on 3D foveal patches. Testing was performed on 30 independent CECTs with 925 segmented LNs with an SAD ≥ 5 mm.

RESULTS

In total, 4,581 LNs were segmented in 217 CECTs. The model achieved an average localization rate (LR), i.e., percentage of localized LNs/CECT, of 78.0% in the validation dataset. In the test dataset, average LR was 81.1% with a mean Dice coefficient of 0.71. For enlarged LNs with a SAD ≥ 10 mm, LR was 96.2%. In the test dataset, the false-positive rate was 2.4 LNs/CECT.

CONCLUSIONS

Our trained AI model demonstrated a good overall performance in the consistent automatic localization and 3D segmentation of physiological and metastatic cervical LNs with a SAD ≥ 5 mm on CECTs. This could aid clinical localization and automatic 3D segmentation, which can benefit clinical care and radiomics research.

RELEVANCE STATEMENT

Our AI model is a time-saving tool for 3D segmentation of cervical lymph nodes on contrast-enhanced CT scans and serves as a solid base for N staging in clinical practice and further radiomics research.

KEY POINTS

• Determination of N status in TNM staging is essential for therapy planning in oncology. • Segmenting cervical lymph nodes manually is highly time-consuming in clinical practice. • Our model provides a robust, automated 3D segmentation of cervical lymph nodes. • It achieves a high accuracy for localization especially of enlarged lymph nodes. • These segmentations should assist clinical care and radiomics research.

Whole-Body Magnetic Resonance Imaging (MRI) for Staging Melanoma Patients in Direct Comparison to Computed Tomography (CT): Results from a Prospective Positron Emission Tomography (PET)/CT and PET/MRI Study

PURPOSE

The consideration of radiation exposure is becoming more important in metastatic melanoma due to improved prognoses. The aim of this prospective study was to investigate the diagnostic performance of whole-body (WB) magnetic resonance imaging (MRI) in comparison to computed tomography (CT) with ¹⁸F-FDG positron emission tomography (PET)/CT and ¹⁸F-PET/MRI together with a follow-up as the reference standard.

METHODS

Between April 2014 and April 2018, a total of 57 patients (25 females, mean age of 64 ± 12 years) underwent WB-PET/CT and WB-PET/MRI on the same day. The CT and MRI scans were independently evaluated by two radiologists who were blinded to the patients' information. The reference standard was evaluated by two nuclear medicine specialists. The findings were categorized into different regions: lymph nodes/soft tissue (I), lungs (II), abdomen/pelvis (III), and bone (IV). A comparative analysis was conducted for all the documented findings. Inter-reader reliability was assessed using Bland-Altman procedures, and McNemar's test was utilized to determine the differences between the readers and the methods.

RESULTS

Out of the 57 patients, 50 were diagnosed with metastases in two or more regions, with the majority being found in region I. The accuracies of CT and MRI did not show significant differences, except in region II where CT detected more metastases compared to MRI (0.90 vs. 0.68, p = 0.008). On the other hand, MRI had a higher detection rate in region IV compared to CT (0.89 vs. 0.61, p > 0.05). The level of agreement between the readers varied depending on the number of metastases and the specific region, with the highest agreement observed in region III and the lowest observed in region I.

CONCLUSIONS

In patients with advanced melanoma, WB-MRI has the potential to serve as an alternative to CT with comparable diagnostic accuracy and confidence across most regions. The observed limited sensitivity for the detection of pulmonary lesions might be improved through dedicated lung imaging sequences.

German specialists treating testicular cancer follow different guidelines with resulting inconsistency in assessment of retroperitoneal lymph-node metastasis: clinical implications and possible corrective measures

BACKGROUND

Testicular germ cell tumors (GCTs) are aggressive but highly curable tumors. To avoid over/undertreatment, reliable clinical staging of retroperitoneal lymph-node metastasis is necessary. Current clinical guidelines, in their different versions, lack specific recommendations on how to measure lymph-node metastasis.

OBJECTIVE

We aimed to assess the practice patterns of German institutions frequently treating testicular cancer for measuring retroperitoneal lymph-node size.

METHODS

An 8-item survey was distributed among German university hospitals and members of the German Testicular Cancer Study Group.

RESULTS

In the group of urologists, 54.7% assessed retroperitoneal lymph nodes depending on their short-axis diameter (SAD) (33.3% in any plane, 21.4% in the axial plane), while 45.3% used long-axis diameter (LAD) for the assessment (42.9% in any plane, 2.4% in the axial plane). Moreover, the oncologists mainly assessed lymph-node size based on the SAD (71.4%). Specifically, 42.9% of oncologists assessed the SAD in any plane, while 28.5% measured this dimension in the axial plane. Only 28.6% of oncologists considered the LAD (14.3% in any plane, 14.3% in the axial plane). None of the oncologists and 11.9% of the urologists (n = 5) always performed an MRI for the initial assessment, while for follow-up imaging, the use increased to 36.5% of oncologists and 31% of urologists. Furthermore, only 17% of the urologists, and no oncologists, calculated lymph-node volume in their assessment (p = 0.224).

CONCLUSION

Clear and consistent measurement instructions are urgently needed to be present in all guidelines across different specialistic fields involved in testicular cancer management.

Head-to-head comparisons of [68Ga]Ga-PSMA-11 PET/CT, multiparametric MRI, and prostate-specific antigen for the evaluation of therapeutic responses to neoadjuvant chemohormonal therapy in high-risk non-metastatic prostate cancer patients: a prospective study

PURPOSE

The optimal tool to evaluate the tumour therapeutic responses to neoadjuvant chemohormonal therapy (NCHT) in patients with high-risk non-metastatic prostate cancer (PCa) remains uncertain. We compared the role of [⁶⁸Ga]-labeled prostate-specific membrane antigen (PSMA)-11 positron emission tomography/computerized tomography ([⁶⁸Ga]Ga-PSMA-11 PET/CT), multiparametric MRI (mpMRI), and prostate-specific antigen (PSA) and assessed the practical value of the recent European Association of Urology and European Association of Nuclear Medicine (EAU/EANM) recommended criteria of PSMA PET/CT to evaluate the therapeutic responses to NCHT in patients with high-risk non-metastatic PCa.

METHODS

This prospective study included 72 high-risk non-metastatic PCa patients receiving NCHT followed by radical prostatectomy from June 2021 to March 2022. PSA testing, [⁶⁸Ga]Ga-PSMA-11 PET/CT, and mpMRI scanning were conducted in all patients before and after NCHT. Therapeutic responses to NCHT were evaluated with PSA, RECIST 1.1, PERCIST 1.0, and EAU/EANM recommended criteria. Postoperative pathological results were considered the reference standard. A favourable pathological response was defined as pathologic complete remission (pCR) or minimal residual disease (MRD). Diagnostic accuracy was assessed by sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), positive predictive value (PPV), negative predictive value (NPV), and Cohen's kappa index. Logistic regression analysis was used to determine the independent predictive value of [⁶⁸Ga]Ga-PSMA-11 PET/CT-derived parameters.

RESULTS

All cases experienced a marked decrease in PSA levels after NCHT. Twenty-four (33.33%) cases experienced a favourable pathological response, including five (6.94%) cases of pCR and 19 (26.39%) cases of MRD. According to the results of [⁶⁸Ga]Ga-PSMA-11 PET/CT, EAU/EANM recommended criteria indicated that 20 (27.78%) cases had a CR, whereas PERCIST 1.0 criteria indicated that 23 (31.94%) cases had a CR. There was a strong association between EAU/EANM recommended criteria and PERCIST 1.0 criteria (Pearson's R=0.857). The sensitivity (75.00%, 79.17% vs. 58.33%, 58.33%), specificity (95.83%, 91.67% vs. 83.33%, 68.75%), PLR (18.00, 9.50 vs. 3.50, 1.87), NLR (0.26, 0.23 vs. 0.50, 0.61), PPV (90.0%, 82.6% vs. 63.6%, 48.3%), and NPV (88.5%, 89.8% vs. 80.0%, 76.7%) of [⁶⁸Ga]Ga-PSMA-11 PET/CT (including EAU/EANM recommended criteria and PERCIST 1.0 criteria) to predict favourable pathological responses were all superior to those of mpMRI and nadir PSA. The kappa index to predict a favourable pathological response was 0.257 for PSA, 0.426 for RECIST 1.1, 0.716 for PERCIST 1.0, and 0.739 for EAU/EANM recommended criteria. Multivariate logistic analysis revealed that the post-NCHT maximum standardized uptake value (SUVmax) before radical prostatectomy was an independent predictor of a favourable pathological response to NCHT.

CONCLUSIONS

[⁶⁸Ga]Ga-PSMA-11 PET/CT had a better concordance with a favourable pathological response to NCHT compared with nadir PSA and mpMRI. EAU/EANM recommended criteria and PERCIST 1.0 criteria performed equally to identify pathological responders when [⁶⁸Ga]Ga-PSMA-11 PET/CT was used as a therapeutic response assessment tool.

Diagnostic Accuracy of Slow-Capillary Endobronchial Ultrasound Needle Aspiration in Determining PD-L1 Expression in Non-Small Cell Lung Cancer

INTRODUCTION

The role of EBUS-TBNA in the diagnosis and staging of lung cancer is well established. EBUS-TBNA can be performed using different aspiration techniques. The most common aspiration technique is known as "suction". One alternative to the suction technique is the slow-pull capillary aspiration. To the best of our knowledge, no studies have assessed the diagnostic yield of slow-pull capillary EBUS-TBNA in PD-L1 amplification assessment in NSCLC. Herein, we conducted a single-centre retrospective study to establish the diagnostic yield of slow-pull capillary EBUS-TBNA in terms of PD-L1 in patients with NSCLC and hilar/mediastinal lymphadenopathies subsequent to NSCLC.

MATERIALS AND METHODS

Patients with hilar and/or mediastinal lymph node (LN) NSCLC metastasis, diagnosed by EBUS-TBNA between January 2021 and April 2022 at Pulmonology Unit of "Ospedali Riuniti di Ancona" (Ancona, Italy) were enrolled. We evaluated patient characteristics, including demographic information, CT scan/ FDG-PET features and final histological diagnoses, including PD-L1 assessment.

RESULTS

A total of 174 patients underwent EBUS-TBNA for diagnosis of hilar/mediastinal lymphadenopathies between January 2021 and April 2022 in the Interventional Pulmonology Unit of the "Ospedali Riuniti di Ancona". Slow-pull capillary aspiration was adopted in 60 patients (34.5%), and in 30/60 patients (50.0%) NSCLC was diagnosed. EBUS-TBNA with slow-pull capillary aspiration provided adequate sampling for molecular biology and PD-L1 testing in 96.7% of patients (29/30); in 15/29 (51.7%) samples with more than 1000 viable cells/HPF were identified, whereas in 14/29 (48.3%) samples contained 101-1000 viable cells/HPF.

CONCLUSION

These retrospective study shows that slow-pull capillary aspiration carries an excellent diagnostic accuracy, almost equal to that one reported in literature, supporting its use in EBUS-TBNA for PD-L1 testing in NSCLC.

New Imaging Techniques

The chapter discusses the advancement of new imaging techniques, the role of imaging in CCA diagnosis, anatomical and morphological classification, ultrasound screening of CCA, ultrasound findings of MF-CCA, PI-CCA, ID-CCA, the use of CT in CCA diagnosis, staging and treatment planning, CT volumetry and estimation of future liver remnant, post-treatment follow-up and surveillance, MRI imaging, Positron Emission Tomography (PET)/CT, limitations to contrast studies and resolution, internal receivers for CCA imaging, and in vitro imaging of CCA.

Prognostic Evaluation of Metastatic Castration Resistant Prostate Cancer and Neuroendocrine Prostate Cancer with [68Ga]Ga DOTATATE PET-CT

Objectives: Prostate cancer is well known to express high levels of somatostatin receptors and preliminary data suggests that PET imaging with the somatostatin analog, [68Ga]Ga-DOTATATE, may allow for whole body staging of patients with metastatic castration resistant prostate cancer (mCRPC) and neuroendocrine prostate cancer (NePC). This study explores the utility of [68Ga]Ga-DOTATATE PET-CT to identify metastatic deposits in men with mCRPC and NePC and prognosticate disease progression. Methods: [68Ga]Ga-DOTATATE PET-CT was performed in 17 patients with mCRPC and of those, 2/17 had NePC. A semiquantitative analysis with standardized uptake values (SUV) (e.g., SUVmax, SUVmean) was performed for each metastatic lesion and reference background tissues. [68Ga]Ga-DOTATATE uptake in metastatic deposits was further classified as: mild (less than liver), moderate (up to liver average), or marked (greater than liver). Serial prostate-specific antigen measurements and patient survival were followed up to 3 years after PET imaging to assess response to standard of care treatment. Results: All patients had at least one metastatic lesion with identifiable [68Ga]Ga-DOTATATE uptake. Marked [68Ga]Ga-DOTATATE uptake was found in 7/17 patients, including both NePC patients, and all were non-responders to systemic therapy and died within the follow up period, with a mean time to death of 8.1 months. Three patients had mild [68Ga]Ga-DOTATATE uptake, and all were responders to systemic therapy and were alive 36 months after [68Ga]Ga-DOTATATE imaging. Conclusions: [68Ga]Ga-DOTATATE is able to identify mCRPC and NePC metastatic deposits, and lesions with [68Ga]Ga-DOTATATE uptake > liver may portend poor outcomes in patients with mCRPC.

Towards automated organs at risk and target volumes contouring: Defining precision radiation therapy in the modern era

Precision radiotherapy is a critical and indispensable cancer treatment means in the modern clinical workflow with the goal of achieving "quality-up and cost-down" in patient care. The challenge of this therapy lies in developing computerized clinical-assistant solutions with precision, automation, and reproducibility built-in to deliver it at scale. In this work, we provide a comprehensive yet ongoing, incomplete survey of and discussions on the recent progress of utilizing advanced deep learning, semantic organ parsing, multimodal imaging fusion, neural architecture search and medical image analytical techniques to address four corner-stone problems or sub-problems required by all precision radiotherapy workflows, namely, organs at risk (OARs) segmentation, gross tumor volume (GTV) segmentation, metastasized lymph node (LN) detection, and clinical tumor volume (CTV) segmentation. Without loss of generality, we mainly focus on using esophageal and head-and-neck cancers as examples, but the methods can be extrapolated to other types of cancers. High-precision, automated and highly reproducible OAR/GTV/LN/CTV auto-delineation techniques have demonstrated their effectiveness in reducing the inter-practitioner variabilities and the time cost to permit rapid treatment planning and adaptive replanning for the benefit of patients. Through the presentation of the achievements and limitations of these techniques in this review, we hope to encourage more collective multidisciplinary precision radiotherapy workflows to transpire.

What are the implications of radiologically abnormal cardiophrenic lymph nodes in advanced ovarian cancer? An analysis of tumour burden, surgical complexity, same-site recurrence and overall survival

INTRODUCTION

Our paper evaluates the relationship between radiologically abnormal cardiophrenic lymph nodes (CPLN) in advanced ovarian cancer and pattern of disease distribution, tumour burden, surgical complexity, rates of cytoreduction and same-site recurrence. Impact of suspicious CPLN and CPLN dissection on overall survival also determined.

MATERIALS AND METHODS

Retrospective review of index CT imaging for 151 consecutive patients treated for stage III/IV ovarian malignancy in a large UK cancer centre to identify radiologically abnormal CPLN. Corresponding surgical, histo-pathological and survival data analysed.

RESULTS

42.6% of patients had radiologically 'positive' CPLN on index CT. Radiological identification of CPLN involvement demonstrated a sensitivity of 82% within our centre. Patients with cardiophrenic lymphadenopathy on pre-operative CT had significantly more co-existing ascites (p = 0.003), omental (p = 0.01) and diaphragmatic disease (p < 0.0001). At primary debulking (PDS), suspicious CPLN were associated with significantly higher surgical complexity scores, without feasibility of complete cytoreduction being impacted. Cardiophrenic involvement at initial diagnosis was associated with same-site relapse at recurrence (p = 0.001). No significant difference in overall survival was demonstrated according to CPLN status following either PDS or delayed debulking (DDS). CPLN dissection did not improve patient outcomes.

CONCLUSION

Radiological identification of abnormal CPLN is reliable. Suspicious CPLN appear to represent a surrogate marker of tumour volume - in particular, heralding upper abdominal disease - and should prompt anticipation of high complexity surgery and referral to an appropriate centre. Patients with prior CPLN involvement are more likely to develop same-site recurrence at relapse. Our survival data suggests cardiophrenic LN disease does not worsen patient prognosis and that the therapeutic benefit of CPLN dissection remains unclear.

Intraoperative challenges after induction therapy for non-small cell lung cancer: Effect of nodal disease on technical complexity

Objectives

Neoadjuvant therapy has been theorized to increase complexity of non-small cell lung cancer resections; however, specific factors that contribute to intraoperative challenges after induction therapy have not been well described. We aimed to characterize the effect of nodal involvement and nodal treatment response on surgical complexity after neoadjuvant therapy.

Methods

We identified patients treated with neoadjuvant therapy followed by anatomic lung resection for cN + non-small cell lung cancer between 2010 and 2020. Patients were categorized according to clinical N1 versus N2 disease. To evaluate the effect of nodal response to therapy, thoracic radiologists measured clinically suspected and pathologically involved lymph nodes before and after induction therapy. Operative reports were reviewed to identify technical challenges specifically related to nodal disease. Categorical outcomes were compared using Fisher exact test.

Results

One hundred twenty-four patients met inclusion criteria, among whom 107 (86.3%) were treated with neoadjuvant chemotherapy, whereas chemoradiation (n = 8) and targeted therapy (n = 9) were less common. In cases with N1 disease, 8/38 (21.0%) required proximal pulmonary arterial control, whereas this was necessary in only 2/88 (2.3%) of N2 cases (P = .001). Likewise, sleeve resection and arterioplasty were needed more frequently during resection of N1 disease (7/38, 18.4%) versus N2 disease (0/88, P < .001). Increased nodal response to therapy was associated with greater likelihood of requiring change in vascular approach (P = .011).

Conclusions

After induction therapy, N1 disease was associated with greater need for complex surgical maneuvers than N2 disease. Likewise, substantial treatment response was associated with increased intraoperative technical challenges. Recognizing such factors enables surgical teams to engage in appropriate operative planning to ensure patient safety.

Clinical impact of tumour burden on the efficacy of PD-1/PD-L1 inhibitors plus chemotherapy in non-small-cell lung cancer

BACKGROUND

Programmed cell death 1 (PD-1)/programmed cell death ligand (PD-L1) inhibitors plus chemotherapy (ICI + Chemo) is the standard treatment for advanced non-small-cell lung cancer (NSCLC). However, the impact of tumour burden on the efficacy of ICI + Chemo remains unknown.

METHODS

We retrospectively evaluated 92 patients with advanced NSCLC treated with ICI + Chemo. Tumour burden was assessed as the sum of the longest diameter of the target lesion (BSLD) and number of metastatic lesions (BNMLs). We categorised the patients into three groups based on the combined BSLD and BNML values.

RESULTS

Sixty-eight patients (74%) had progressive disease or died. Forty-four patients (48%) in the low-BSLD group had a median progression-free survival (PFS) of 9.5 months, whereas patients in the high-BSLD group had a median PFS of 4.6 months (hazard ratio [HR] = 0.54, p = 0012). Twenty-five patients (27%) in the low-BNML group had a median PFS of 9.6 months, whereas patients in the high-BNML group had a median PFS of 6.5 months (HR = 0.51, p = 0.029). Low-BSLD and low-BNML were associated independently with improved PFS in multivariate analysis. Analysis of the tumour burden combined with BSLD and BNML revealed a trend towards improved PFS as the tumour burden decreased, with median PFS of 22.3, 8.7, and 3.9 months in the low- (N = 13), medium- (N = 42) and high-burden (N = 37) groups respectively.

CONCLUSIONS

Our findings demonstrated that a high tumour burden negatively impacts the efficacy of ICI + Chemo in patients with advanced NSCLC.

A first-in-human study of [68Ga]Ga-CDI: a positron emitting radiopharmaceutical for imaging tumour cell death

PURPOSE

This study assesses human biodistribution, radiation dosimetry, safety and tumour uptake of cell death indicator labelled with ⁶⁸Ga ([⁶⁸Ga]Ga-CDI), a novel radiopharmaceutical that can image multiple forms of cell death.

METHODS

Five participants with at least one extracranial site of solid malignancy > 2 cm and no active cancer treatment in the 8 weeks prior to the study were enrolled. Participants were administered 205 ± 4.1 MBq (range, 200-211 MBq) of [⁶⁸Ga]Ga-CDI and 8 serial PET scans acquired: the first commencing immediately and the last 3 h later. Participants were monitored for clinical, laboratory and electrocardiographic side effects and adverse events. Urine and blood radioactivity was measured. Spherical volumes of interest were drawn over tumour, blood pool and organs to determine biodistribution and calculate dosimetry. In one participant, tumour specimens were analysed for cell death using terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining.

RESULTS

[⁶⁸Ga]Ga-CDI is safe and well-tolerated with no side effects or adverse events. [⁶⁸Ga]Ga-CDI is renally excreted, demonstrates low levels of physiologic uptake in the other organs and has excellent imaging characteristics. The mean effective dose was 2.17E - 02 ± 4.61E - 03 mSv/MBq. It images constitutive tumour cell death and correlates with tumour cell death on histology.

CONCLUSION

[⁶⁸Ga]Ga-CDI is a novel cell death imaging radiopharmaceutical that is safe, has low radiation dosimetry and excellent biodistribution and imaging characteristics. It has potential advantages over previously investigated radiopharmaceuticals for imaging of cell death and has progressed to a proof-of-concept trial.

TRIAL REGISTRATION

ACTRN12621000641897 (28/5/2021, retrospectively registered).

Predicting the efficacy of first-line immunotherapy by combining cancer cachexia and tumor burden in advanced non-small cell lung cancer

Background

Cancer cachexia and tumor burden predict efficacies of programmed cell death‐1 (PD‐1)/programmed death‐ligand 1 (PD‐L1) inhibitors and chemotherapy or pembrolizumab in non‐small cell lung cancer (NSCLC). There are no predictive models that simultaneously assess cancer cachexia and tumor burden.

Methods

In the present retrospective study, we reviewed the medical records of patients with advanced NSCLC who received cancer immunotherapy as first‐line systemic therapy. Clinical immune predictive scores were defined according to multivariate analysis of progression‐free survival (PFS) and overall survival (OS).

Results

A total of 157 patients were included in the present study (75 treated with PD‐1/PD‐L1 inhibitors + chemotherapy; 82, pembrolizumab monotherapy). Multivariate analysis for PFS revealed that PD‐L1 tumor proportion scores <50%, a total target lesion diameter ≥76 mm, and cancer cachexia were independently associated with poor PFS. Multivariate analysis for OS revealed that ≥4 metastases and cancer cachexia were significantly associated with poor OS. In the immune predictive model, the median PFS was 21.7 months in the low‐risk group (N = 41); 7.6 in the medium‐risk group (N = 64); and 3.0 in the high‐risk group (N = 47). The median OS were not reached, 22.4 and 9.1 months respectively. Our immune predictive model was significantly associated with PFS (p < 0.001) and OS (p < 0.001).

Conclusion

We proposed the immune predictive model, including tumor burden and cancer cachexia, which may predict the efficacy and survival outcome of first‐line immunotherapy in advanced NSCLC.

Clinical group and modified TNM stage for rhabdomyosarcoma: A review from the Children's Oncology Group

The Children's Oncology Group (COG) uses Clinical Group (CG) and modified Tumor Node Metastasis (TNM) stage to classify rhabdomyosarcoma (RMS). CG is based on surgicopathologic findings and is determined after the completion of initial surgical procedure(s) but prior to chemotherapy and/or radiation therapy. The modified TNM stage is based on clinical and radiographic findings and is assigned prior to any treatment. These systems have evolved over several decades. We review the history, evolution, and rationale behind the current CG and modified TNM classification systems used by COG for RMS. Data from the seven most recently completed and reported frontline COG trials (D9602, D9802, D9803, ARST0331, ARST0431, ARST0531, ARST08P1) were analyzed, and confirm that CG and modified TNM stage remain relevant and useful for predicting prognosis in RMS. We propose updates based on recent data and discuss factors warranting future study to further optimize these classification systems.

What's in a node? The clinical and radiologic significance of Virchow's node

In 1848, Rudolf Ludwig Karl Virchow described an association of left supraclavicular lymphadenopathy with abdominal malignancy. The left supraclavicular lymph node later became commonly referred to as Virchow's node. Charles-Emile Troisier went on to describe the physical exam finding of an enlarged left supraclavicular lymph node, later termed Troisier's sign. Subsequent studies confirmed a predilection of abdominal and pelvic malignancies to preferentially metastasize to the left supraclavicular node. Identification of a pathologically enlarged left supraclavicular node raises the suspicion for abdominopelvic malignancy, particularly in the absence of right supraclavicular lymphadenopathy, and provides a safe and easy target for biopsy. Supraclavicular lymph nodes also represent a great target for diagnosis of metastatic thoracic malignancies, although thoracic malignancies can involve either right or left supraclavicular nodes and do not show a predilection for either. This article presents a review of the history, anatomy, pathophysiology, clinical significance, radiological appearance, and biopsy of Virchow's node. Key points are illustrated with relevant cases.

Comparison of clinical behavior between mucinous ovarian carcinoma with infiltrative and expansile invasion and high-grade serous ovarian carcinoma: a retrospective analysis

Background

The aim of this study was to evaluate the clinicopathological factors and prognosis of mucinous carcinoma (MC) with infiltrative invasion, MC with expansile invasion, and high-grade serous carcinoma (HGSC).

Methods

Cases of MC and HGSC between 1984 and 2019 were identified. The clinicopathological factors and prognosis of MC with infiltrative invasion or expansile invasion and HGSC were retrospectively compared. Although our present study included cases in our previous studies, we extended observational period when analysis was performed. Accordingly, our study added increased cases and survival analysis was newly conducted.

Results

After pathological review, 27 cases of MC with infiltrative invasion, 25 cases of MC with expansile invasion, and 219 cases of HGSC were included. MC had a better prognosis in terms of progression-free survival (PFS, p < 0.01) and overall survival (OS, p < 0.01) than HGSC for all International Federation of Gynecology and Obstetrics (FIGO) stages; however, multivariate analysis did not show statistical differences in PFS and OS. There were no statistically significant differences in PFS and OS for all FIGO stages between MC with infiltrative invasion and HGSC. However, in cases with FIGO stages II to IV, MC with infiltrative invasion had worse PFS (p < 0.01) and OS (p < 0.01) than HGSC. In univariate analysis, MC with infiltrative invasion was a worse prognostic factor for PFS (hazard ratio [HR] 2.83, p < 0.01) and OS (HR 3.83, p < 0.01) than HGSC. Compared with HGSC, MC with expansile invasion had better PFS (p < 0.01) and OS (p < 0.01). Multivariate analysis demonstrated that MC with expansile invasion was a better prognostic factor for PFS (HR 0.17, p < 0.01) and OS (HR 0.18, p = 0.03) than HGSC.

Conclusions

Compared to the prognosis of HGSC, that of MC was different according to the invasive pattern and FIGO stage. Therefore, future study may be needed to consider this association.

The lymphatic system and sentinel lymph nodes: conduit for cancer metastasis

The lymphatic system is a complicated system consisting of the lymphatic vessels and lymph nodes draining the extracellular fluid containing cellular debris, excess water and toxins to the circulatory system. The lymph nodes serve as a filter, thus, when the lymph fluid returns to the heart, it is completely sterile. In addition, the lymphatic system includes the mucosa-associated lymphoid tissue, such as tonsils, adenoids, Peyers patches in the small bowel and even the appendix. Taking advantage of the drainage system of the lymphatics, cancer cells enter the lymphatic vessels and then the lymph nodes. In general, the lymph nodes may serve as a gateway in the majority of cases in early cancer. Occasionally, the cancer cells may enter the blood vessels. This review article emphasizes the structural integrity of the lymphatic system through which cancer cells may spread. Using melanoma and breast cancer sentinel lymph node model systems, the spread of early cancer through the lymphatic system is progressive in a majority of cases. The lymphatic systems of the internal organs are much more complicated and difficult to study. Knowledge from melanoma and breast cancer spread to the sentinel lymph node may establish the basic principles of cancer metastasis. The goal of this review article is to emphasize the complexity of the lymphatic system. To date, the molecular mechanisms of cancer spread from the cancer microenvironment to the sentinel lymph node and distant sites are still poorly understood and their elucidation should take major priority in cancer metastasis research.

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.

Efficient and Accurate Extracting of Unstructured EHRs on Cancer Therapy Responses for the Development of RECIST Natural Language Processing Tools: Part I, the Corpus

PURPOSE

Electronic health records (EHRs) are created primarily for nonresearch purposes; thus, the amounts of data are enormous, and the data are crude, heterogeneous, incomplete, and largely unstructured, presenting challenges to effective analyses for timely, reliable results. Particularly, research dealing with clinical notes relevant to patient care and outcome is seldom conducted, due to the complexity of data extraction and accurate annotation in the past. RECIST is a set of widely accepted research criteria to evaluate tumor response in patients undergoing antineoplastic therapy. The aim for this study was to identify textual sources for RECIST information in EHRs and to develop a corpus of pharmacotherapy and response entities for development of natural language processing tools.

METHODS

We focused on pharmacotherapies and patient responses, using 55,120 medical notes (n = 72 types) in Mayo Clinic’s EHRs from 622 randomly selected patients who signed authorization for research. Using the Multidocument Annotation Environment tool, we applied and evaluated predefined keywords, and time interval and note-type filters for identifying RECIST information and established a gold standard data set for patient outcome research.

RESULTS

Key words reduced clinical notes to 37,406, and using four note types within 12 months postdiagnosis further reduced the number of notes to 5,005 that were manually annotated, which covered 97.9% of all cases (n = 609 of 622). The resulting data set of 609 cases (n = 503 for training and n = 106 for validation purpose), contains 736 fully annotated, deidentified clinical notes, with pharmacotherapies and four response end points: complete response, partial response, stable disease, and progressive disease. This resource is readily expandable to specific drugs, regimens, and most solid tumors.

CONCLUSION

We have established a gold standard data set to accommodate development of biomedical informatics tools in accelerating research into antineoplastic therapeutic response.

Prognostic similarity between ovarian mucinous carcinoma with expansile invasion and ovarian mucinous borderline tumor: A retrospective analysis

There is a similarity of histological features and survival between ovarian mucinous carcinoma (MC) with expansile invasion and ovarian mucinous borderline tumor (MBT). The aim of this study was to compare the clinical outcomes of MC with expansile invasion with those of MBT based on the 2020 World Health Organization (WHO) criteria.A pathological review was performed on patients with MC, ovarian MBT, and seromucinous borderline tumors that underwent surgery at our hospital between 1984 and 2019. Clinicopathological features were compared retrospectively between MC with expansile invasion and MBT.Among 83 cases of MC, 85 cases of MBT, and 12 cases of seromucinous borderline tumor, 25 MC cases with expansile invasion and 98 MBT cases were included through review. MC cases with expansile invasion were diagnosed with advanced International Federation of Gynecology and Obstetrics (FIGO) stages more frequently (P = .02) than that of MBT cases. In addition, patients with MC with expansile invasion received adjuvant chemotherapy more often (P < .01) than that of patients with MBT. There were no statistically significant differences in recurrence rate (P = .10) between MC with expansile invasion and MBT. Progression-free survival (PFS) was worse in MC cases with expansile invasion than that in MBT cases (P = .01). However, a multivariate analysis for PFS showed that histological subtype, FIGO stage, and adjuvant chemotherapy were not an independent prognostic factor.The prognostic outcome of MC with expansile invasion might mimic those of MBT. These results showed ovarian borderline tumor treatment could be applied to MC treatment.

Systematic Review and Meta-Analysis of Post-Treatment PET/CT in HPV-Associated Oropharyngeal Cancer

OBJECTIVE

To perform a systematic review with meta-analysis to investigate the utility of post-treatment PET/CT specifically in HPV-associated oropharyngeal squamous cell carcinoma following curative intent treatment.

METHODS

Random-effects meta-analysis was used to pool data from 7 observational studies (2013-2019) obtained from a database search of PubMed, Web of Science, and EMBASE using an a priori protocol with dual independent evaluation for inclusion, risk of bias assessment for acceptable methodology, and extraction of data for analysis. PET/CT results, treatment failure, imaging and interventions subsequent to PET/CT findings, and efficacy of salvage therapy were extracted.

RESULTS

Of the 907 post-treatment scans, PET/CT results were largely negative (76.2%; 95% CI, 63.4-85.6) and least often positive (11.3%; 95% CI, 8.8-14.4). PET/CT results were equivocal for 22.5% (95% CI, 12.5-36.9) and equivocal/positive for 34.2% of patients (95% CI, 25.1-44.5). Patients with an initial positive scan had the highest treatment failure rates (43.1%; 95% CI, 21.4-67.7) and those with an initial negative scan had the lowest rates (7.4%; 95% CI, 5.7-9.7). The equivocal and equivocal/positive scans had intermediate prevalence of 16.5% (95% CI, 9.4-27.6) and 16.7% (95% CI, 9.1-28.7), respectively.

CONCLUSION

The low treatment failure rate following a negative PET/CT scan is reassuring, but the data are consistent with treatment failure rates up to 9.7% suggesting follow-up of these patients is prudent. Additionally, the low positive predictive value for treatment failure observed alludes to use of post-treatment PET/CT in HPV-associated disease frequently leading to unnecessary subsequent imaging and intervention.

Enhanced Antitumor Response to Immune Checkpoint Blockade Exerted by Cisplatin-Induced Mutagenesis in a Murine Melanoma Model

Sequencing data from different types of cancers including melanomas demonstrate that tumors with high mutational loads are more likely to respond to immune checkpoint blockade (ICB) therapies. We have previously shown that low-dose intratumoral injection of the chemotherapeutic DNA damaging drug cisplatin activates intrinsic mutagenic DNA damage tolerance pathway, and when combined with ICB regimen leads to tumor regression in the mouse YUMM1.7 melanoma model. We now report that tumors generated with an in vitro cisplatin-mutagenized YUMM1.7 clone (YUMM1.7-CM) regress in response to ICB, while an identical ICB regimen alone fails to suppress growth of tumors generated with the parental YUMM1.7 cells. Regressing YUMM1.7-CM tumors show greater infiltration of CD8 T lymphocytes, higher granzyme B expression, and higher tumoral cell death. Similarly, ex-vivo, immune cells isolated from YUMM1.7-CM tumors-draining lymph nodes (TDLNs) co-incubated with cultured YUMM1.7-CM cells, eliminate the tumor cells more efficiently than immune cells isolated from TDLNs of YUMM1.7 tumor-bearing mice. Collectively, our findings show that in vitro induced cisplatin mutations potentiate the antitumor immune response and ICB efficacy, akin to tumor regression achieved in the parental YUMM1.7 model by ICB administered in conjunction with intratumoral cisplatin injection. Hence, our data uphold the role of tumoral mutation burden in improving immune surveillance and response to ICB, suggesting a path for expanding the range of patients benefiting from ICB therapy.

Automated mapping and N-Staging of thoracic lymph nodes in contrast-enhanced CT scans of the chest using a fully convolutional neural network

PURPOSE

To develop a deep-learning (DL)-based approach for thoracic lymph node (LN) mapping based on their anatomical location.

METHOD

The training-and validation-dataset included 89 contrast-enhanced computed tomography (CT) scans of the chest. 4201 LNs were semi-automatically segmented and then assigned to LN levels according to their anatomical location. The LN level classification task was addressed by a multi-class segmentation procedure using a fully convolutional neural network. Mapping was performed by firstly determining potential level affiliation for each voxel and then performing majority voting over all voxels belonging to each LN. Mean classification accuracies on the validation data were calculated separately for each level and overall Top-1, Top-2 and Top-3 scores were determined, where a Top-X score describes how often the annotated class was within the top-X predictions. To demonstrate the clinical applicability of our model, we tested its N-staging capabilities in a simulated clinical use case scenario assuming a patient diseased with lung cancer.

RESULTS

The artificial intelligence(AI)-based assignment revealed mean classification accuracies of 86.36 % (Top-1), 94.48 % (Top-2) and 96.10 % (Top-3). Best accuracies were achieved for LNs in the subcarinal level 7 (98.31 %) and axillary region (98.74 %). The highest misclassification rates were observed among LNs in adjacent levels. The proof-of-principle application in a simulated clinical use case scenario for automated tumor N-staging showed a mean classification accuracy of up to 96.14 % (Top-1).

CONCLUSIONS

The proposed AI approach for automatic classification of LN levels in chest CT as well as the proof-of-principle-experiment for automatic N-staging, revealed promising results, warranting large-scale validation for clinical application.

Automated detection and segmentation of thoracic lymph nodes from CT using 3D foveal fully convolutional neural networks

BACKGROUND

In oncology, the correct determination of nodal metastatic disease is essential for patient management, as patient treatment and prognosis are closely linked to the stage of the disease. The aim of the study was to develop a tool for automatic 3D detection and segmentation of lymph nodes (LNs) in computed tomography (CT) scans of the thorax using a fully convolutional neural network based on 3D foveal patches.

METHODS

The training dataset was collected from the Computed Tomography Lymph Nodes Collection of the Cancer Imaging Archive, containing 89 contrast-enhanced CT scans of the thorax. A total number of 4275 LNs was segmented semi-automatically by a radiologist, assessing the entire 3D volume of the LNs. Using this data, a fully convolutional neuronal network based on 3D foveal patches was trained with fourfold cross-validation. Testing was performed on an unseen dataset containing 15 contrast-enhanced CT scans of patients who were referred upon suspicion or for staging of bronchial carcinoma.

RESULTS

The algorithm achieved a good overall performance with a total detection rate of 76.9% for enlarged LNs during fourfold cross-validation in the training dataset with 10.3 false-positives per volume and of 69.9% in the unseen testing dataset. In the training dataset a better detection rate was observed for enlarged LNs compared to smaller LNs, the detection rate for LNs with a short-axis diameter (SAD) ≥ 20 mm and SAD 5-10 mm being 91.6% and 62.2% (p < 0.001), respectively. Best detection rates were obtained for LNs located in Level 4R (83.6%) and Level 7 (80.4%).

CONCLUSIONS

The proposed 3D deep learning approach achieves an overall good performance in the automatic detection and segmentation of thoracic LNs and shows reasonable generalizability, yielding the potential to facilitate detection during routine clinical work and to enable radiomics research without observer-bias.

RECIST 1.1 and lesion selection: How to deal with ambiguity at baseline?

Response Evaluation Criteria In Solid Tumors (RECIST) is still the predominant criteria base for assessing tumor burden in oncology clinical trials. Despite several improvements that followed its first publication, RECIST continues to allow readers a lot of freedom in their evaluations. Notably in the selection of tumors at baseline. This subjectivity is the source of many suboptimal evaluations. When starting a baseline analysis, radiologists cannot always identify tumor malignancy with any certainty. Also, with RECIST, some findings can be deemed equivocal by radiologists with no confirmatory ground truth to rely on. In the specific case of Blinded Independent Central Review clinical trials with double reads using RECIST, the selection of equivocal tumors can have two major consequences: inter-reader variability and modified sensitivity of the therapeutic response. Apart from the main causes leading to the selection of an equivocal lesion, due to the uncertainty of the radiological characteristics or due to the censoring of on-site evaluations, several other situations can be described more precisely. These latter involve cases where an equivocal is selected as target or non-target lesions, the management of equivocal lymph nodes and the case of few target lesions. In all cases, awareness of the impact of selecting a non-malignant lesion will lead radiologists to make selections in the most rational way. Also, in clinical trials where the primary endpoint differs between phase 2 (response-related) and phase 3 (progression-related) trials, our impact analysis will help them to devise strategies for the management of equivocal lesions.