Abstract Aim of the study In patients from the Dutch TME trial patterns of local recurrence (LR) in rectal cancer were studied. The purpose was to reconstruct the most likely mechanisms of LR and the ...effect of preoperative radiotherapy. Methods 1417 patients were analyzed; 713 were randomized into preoperative radiotherapy and total mesorectal excision (RT + TME), 704 into TME alone. Of the 114 patients with LR, the subsites of LR were determined and related to tumor and treatment factors. Results Overall 5-year LR-rate was 4.6% in the RT + TME group and 11.0% in the TME group. Presacral local recurrences occurred most in both groups. Radiotherapy reduced anastomotic LR significantly, except when after low anterior resection (LAR) distal margins were less than 5 mm. Abdominoperineal resection (APR) mainly resulted in presacral LR. Even after resection with a negative circumferential resection margin, LR-rates were high. Thirty percent of the patients had advanced tumors, which resulted in 58% of all LRs. Lateral LR comprised 20% of all LR. Presacral and lateral LR resulted in a poor prognosis, in contrast to anterior or anastomotic LRs with a relatively good prognosis. Conclusions RT reduces LR in all subsites and is especially effective in preventing anastomotic LR after LAR. APR-surgery mainly results in presacral LR, which may be prevented by a wider resection. In the TME trial many advanced tumors were included, rather requiring chemoradiotherapy instead of RT. Currently, with good imaging techniques, better selection can take place. Especially lateral LR might be a problem in the future.
Abstract Aim The purpose of this multicenter cohort study was to evaluate whether a differentiated treatment of primary rectal cancer based on magnetic resonance imaging (MRI) can reduce the number ...of incomplete resections and local recurrences and improve recurrence-free and overall survival. Methods From February 2003 until January 2008, 296 patients with rectal cancer underwent preoperative MRI using a lymph node specific contrast agent to predict circumferential resection margin (CRM), T- and N-stage. Based on expert reading of the MRI, patients were stratified in: (a) low risk for local recurrence (CRM > 2 mm and N0 status), (b) intermediate risk and (c) high risk (close/involved CRM, N2 status or distal tumours). Mainly based on this MRI risk assessment patients were treated with (a) surgery only (TME or local excision), (b) preoperative 5 × 5 Gy + TME and (c) a long course of chemoradiation therapy followed by surgery after a 6–8 week interval. Results Overall 228 patients underwent treatment with curative intent: 49 with surgery only, 86 with 5 × 5 Gy and surgery and 93 with chemoradiation and surgery. The number of complete resections (margin > 1 mm) was 218 (95.6%). At a median follow-up of 41 months the three-year local recurrence rate, disease-free survival rate and overall survival rate is 2.2%, 80% and 84.5%, respectively. Conclusion With a differentiated multimodality treatment based on dedicated preoperative MR imaging, local recurrence is no longer the main problem in rectal cancer treatment. The new challenges are early diagnosis and treatment, reducing morbidity of treatment and preferably prevention of metastatic disease.
Immunotherapy is regarded as one of the major breakthroughs in cancer treatment. Despite its success, only a subset of patients responds—urging the quest for predictive biomarkers. We hypothesize ...that artificial intelligence (AI) algorithms can automatically quantify radiographic characteristics that are related to and may therefore act as noninvasive radiomic biomarkers for immunotherapy response.
In this study, we analyzed 1055 primary and metastatic lesions from 203 patients with advanced melanoma and non-small-cell lung cancer (NSCLC) undergoing anti-PD1 therapy. We carried out an AI-based characterization of each lesion on the pretreatment contrast-enhanced CT imaging data to develop and validate a noninvasive machine learning biomarker capable of distinguishing between immunotherapy responding and nonresponding. To define the biological basis of the radiographic biomarker, we carried out gene set enrichment analysis in an independent dataset of 262 NSCLC patients.
The biomarker reached significant performance on NSCLC lesions (up to 0.83 AUC, P<0.001) and borderline significant for melanoma lymph nodes (0.64 AUC, P=0.05). Combining these lesion-wide predictions on a patient level, immunotherapy response could be predicted with an AUC of up to 0.76 for both cancer types (P<0.001), resulting in a 1-year survival difference of 24% (P=0.02). We found highly significant associations with pathways involved in mitosis, indicating a relationship between increased proliferative potential and preferential response to immunotherapy.
These results indicate that radiographic characteristics of lesions on standard-of-care imaging may function as noninvasive biomarkers for response to immunotherapy, and may show utility for improved patient stratification in both neoadjuvant and palliative settings.
Objectives
To update the 2012 ESGAR consensus guidelines on the acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for clinical staging and restaging of rectal cancer.
...Methods
Fourteen abdominal imaging experts from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) participated in a consensus meeting, organised according to an adaptation of the RAND-UCLA Appropriateness Method. Two independent (non-voting) Chairs facilitated the meeting. 246 items were scored (comprising 229 items from the previous 2012 consensus and 17 additional items) and classified as ‘appropriate’ or ‘inappropriate’ (defined by ≥ 80 % consensus) or uncertain (defined by < 80 % consensus).
Results
Consensus was reached for 226 (92 %) of items. From these recommendations regarding hardware, patient preparation, imaging sequences and acquisition, criteria for MR imaging evaluation and reporting structure were constructed. The main additions to the 2012 consensus include recommendations regarding use of diffusion-weighted imaging, criteria for nodal staging and a recommended structured report template.
Conclusions
These updated expert consensus recommendations should be used as clinical guidelines for primary staging and restaging of rectal cancer using MRI.
Key Points
•
These guidelines present recommendations for staging and reporting of rectal cancer.
•
The guidelines were constructed through consensus amongst 14 pelvic imaging experts.
•
Consensus was reached by the experts for 92 % of the 246 items discussed.
•
Practical guidelines for nodal staging are proposed.
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A structured reporting template is presented.
Background
Human papillomavirus (HPV)‐positive oropharyngeal squamous cell carcinoma (OPSCC) have better prognosis and treatment response compared to HPV‐negative OPSCC. This study aims to ...noninvasively predict HPV status of OPSCC using clinical and/or radiological variables.
Methods
Seventy‐seven magnetic resonance radiomic features were extracted from T1‐weighted postcontrast images of the primary tumor of 153 patients. Logistic regression models were created to predict HPV status, determined with immunohistochemistry, based on clinical variables, radiomic features, and its combination. Model performance was evaluated using area under the curve (AUC).
Results
Model performance showed AUCs of 0.794, 0.764, and 0.871 for the clinical, radiomic, and combined models, respectively. Smoking, higher T‐classification (T3 and T4), larger, less round, and heterogeneous tumors were associated with HPV‐negative tumors.
Conclusion
Models based on clinical variables and/or radiomic tumor features can predict HPV status in OPSCC patients with good performance and can be considered when HPV testing is not available.
Background
Patients with limited peritoneal metastases from colorectal cancer may be candidates for an aggressive surgical approach including cytoreductive surgery and hyperthermic intraperitoneal ...chemotherapy (CRS–HIPEC). Selection is based on surgical inspection during laparoscopy or laparotomy. The aim of this study was to investigate whether diffusion‐weighted MRI (DW‐MRI) can be used to select patients for CRS–HIPEC.
Methods
This was a prospective study at a tertiary referral centre. Patients with confirmed or suspected colorectal peritoneal metastases scheduled for exploratory laparotomy or laparoscopy were eligible. Two radiologists assessed the peritoneal cancer index (PCI) on CT (CT‐PCI) and DW‐MRI (MRI‐PCI). The reference standard was PCI at surgery. Radiologists were blinded to the surgical PCI and to each other's findings. The main outcome was the accuracy of DW‐MRI in predicting whether patients had resectable disease (PCI less than 21) or not.
Results
Fifty‐six patients were included in the study, of whom 49 could be evaluated. The mean(s.d.) PCI at surgery was 11·27(7·53). The mean MRI‐PCI was 10·18(7·07) for reader 1 and 8·59(7·08) for reader 2. Readers 1 and 2 correctly staged 47 of 49 and 44 of 49 patients respectively (accuracy 96 and 90 per cent). Both readers detected all patients with resectable disease with a PCI below 21 at surgery (sensitivity 100 per cent). No patient was overstaged. The intraclass correlation (ICC) between readers was excellent (ICC 0·91, 95 per cent c.i. 0·77 to 0·96). MRI‐PCI had a stronger correlation with surgical PCI (ICC 0·83–0·88) than did CT‐PCI (ICC 0·39–0·44).
Conclusion
DW‐MRI is a promising non‐invasive tool to guide treatment selection in patients with peritoneal metastases from colorectal cancer.
Promising staging tool
“Node-RADS” addresses the lack of consensus in the radiologic assessment of lymph node involvement by cancer and meets the increasing demand for structured reporting on the likelihood of disease ...involvement. Node Reporting and Data System 1.0 (Node-RADS) systematically classifies the degree of suspicion of lymph node involvement based on the synthesis of established imaging findings. Straightforward definitions of imaging findings for two proposed scoring categories “size” and “configuration” are combined into assessment categories between 1 (“very low likelihood”) and 5 (“very high likelihood”). This scoring system is suitable for assessing likely involvement of lymph nodes on CT and MRI scans. It can be applied at any anatomical site, and to regional and non-regional lymph nodes in relation to a primary tumor location. Node-RADS will improve communication with referring physicians and promote the consistency of reporting for primary staging and in response assessment settings.
Key Points
• Node-RADS standardizes reporting of possible cancer involvement of regional and distant lymph nodes on CT and MRI.
• Node-RADS proposes the scoring categories “size” and “configuration” for assigning the 5-point Node-RADS score from 1 (“very low likelihood”) to 5 (“very high likelihood”).
• Node-RADS aims to increase consensus among radiologists for primary staging and in response assessment settings.
Recently, artificial intelligence (AI)-based applications for chest imaging have emerged as potential tools to assist clinicians in the diagnosis and management of patients with coronavirus disease ...2019 (COVID-19).
To develop a deep learning-based clinical decision support system for automatic diagnosis of COVID-19 on chest CT scans. Secondarily, to develop a complementary segmentation tool to assess the extent of lung involvement and measure disease severity.
The Imaging COVID-19 AI initiative was formed to conduct a retrospective multicentre cohort study including 20 institutions from seven different European countries. Patients with suspected or known COVID-19 who underwent a chest CT were included. The dataset was split on the institution-level to allow external evaluation. Data annotation was performed by 34 radiologists/radiology residents and included quality control measures. A multi-class classification model was created using a custom 3D convolutional neural network. For the segmentation task, a UNET-like architecture with a backbone Residual Network (ResNet-34) was selected.
A total of 2,802 CT scans were included (2,667 unique patients, mean standard deviation age = 64.6 16.2 years, male/female ratio 1.3:1). The distribution of classes (COVID-19/Other type of pulmonary infection/No imaging signs of infection) was 1,490 (53.2%), 402 (14.3%), and 910 (32.5%), respectively. On the external test dataset, the diagnostic multiclassification model yielded high micro-average and macro-average AUC values (0.93 and 0.91, respectively). The model provided the likelihood of COVID-19 vs other cases with a sensitivity of 87% and a specificity of 94%. The segmentation performance was moderate with Dice similarity coefficient (DSC) of 0.59. An imaging analysis pipeline was developed that returned a quantitative report to the user.
We developed a deep learning-based clinical decision support system that could become an efficient concurrent reading tool to assist clinicians, utilising a newly created European dataset including more than 2,800 CT scans.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Background
Adequate MRI-based staging of early rectal cancers is essential for decision-making in an era of organ-conserving treatment approaches. The aim of this population-based study was ...to determine the accuracy of routine daily MRI staging of early rectal cancer, whether or not combined with endorectal ultrasonography (ERUS).
Methods
Patients with cT1–2 rectal cancer who underwent local excision or total mesorectal excision (TME) without downsizing (chemo)radiotherapy between 1 January 2011 and 31 December 2018 were selected from the Dutch ColoRectal Audit. The accuracy of imaging was expressed as sensitivity, specificity, and positive predictive value (PPV) and negative predictive value.
Results
Of 7382 registered patients with cT1–2 rectal cancer, 5539 were included (5288 MRI alone, 251 MRI and ERUS; 1059 cT1 and 4480 cT2). Among patients with pT1 tumours, 54·7 per cent (792 of 1448) were overstaged by MRI alone, and 31·0 per cent (36 of 116) by MRI and ERUS. Understaging of pT2 disease occurred in 8·2 per cent (197 of 2388) and 27·9 per cent (31 of 111) respectively. MRI alone overstaged pN0 in 17·3 per cent (570 of 3303) and the PPV for assignment of cN0 category was 76·3 per cent (2733 of 3583). Of 834 patients with pT1 N0 disease, potentially suitable for local excision, tumours in 253 patients (30·3 per cent) were staged correctly as cT1 N0, whereas 484 (58·0 per cent) and 97 (11·6 per cent) were overstaged as cT2 N0 and cT1–2 N1 respectively.
Conclusion
This Dutch population-based analysis of patients who underwent local excision or TME surgery for cT1–2 rectal cancer based on preoperative MRI staging revealed substantial overstaging, indicating the weaknesses of MRI and missed opportunities for organ preservation strategies.
Graphical Abstract
This population-based study determined the accuracy of routine daily MRI staging of early rectal cancer, whether or not combined with endorectal ultrasonography. The results showed that preoperative MRI led to substantial overstaging in patients who underwent local excision or total mesorectal incision surgery for cT1–2 rectal cancer, indicating the weaknesses of MRI and missed opportunities for organ preservation strategies.
Graphical Abstract
Imaging weakness
Purpose
Detection of peritoneal metastases (PM) is key in the staging and management of gastrointestinal and ovarian cancer patients. The purpose of this meta-analysis was to determine the diagnostic ...performance of CT, PET(CT), and (DW)MRI in detecting PM.
Methods
A literature search in Pubmed, Embase (Ovid), and Scopus was performed (January 1997–May 2018) to identify studies reporting on the accuracy of imaging PM in the diagnostic workup of gastrointestinal or ovarian cancers. Inclusion criteria were region-based or patient-based studies comprising > 15 patients, surgery/histology/radiological follow-up as a reference standard, and sufficient data to construct a 2 × 2 contingency table. Two observers performed data extraction. The sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated using a bivariate random-effects model and hierarchical summary operating curves (HSROC) were generated.
Results
Of 3457 citations retrieved, twenty-four articles met all inclusion criteria. Thirty-seven datasets could be extracted for analysis including 20 for CT, 10 for PET(CT), and 7 for (DW)MRI. The pooled sensitivity, specificity, and DOR for the detection of PM for region-based studies for CT were 68% (CI, 46–84%), 88%(CI, 81–93%), and 15.9 (CI, 4.4–58.0) respectively; 80% (CI, 57–92%), 90% (CI, 80–96%), and 36.5 (CI, 6.7–199.5) for PET(CT), respectively; 92% (CI, 84–96%), 85% (CI, 78–91%), 63.3 (CI, 31.5–127.3) for (DW)MRI. In the patient-based group, not enough studies were included to make a pooled analysis for (DW)MRI and PET(CT).
Conclusion
(DW)MRI and PET(CT) showed comparable diagnostic performance for the detection of peritoneal metastases in ovarian and gastrointestinal cancer patients. Since MRI is more widely available than PET(CT) in clinical practice, this potentially is the imaging method of choice in most centers in the future.
Key Points
• Detection of peritoneal metastases plays an important role in the accurate staging of cancer patients, however, there is no accepted reference standard for the imaging of peritoneal metastases
• This meta-analysis shows that (DW)MRI provided the highest sensitivity for the detection of peritoneal metastases in ovarian and gastrointestinal cancer patients
• Although (DW)MRI and PET(CT) show a comparable overall diagnostic performance, (DW)MRI seems to be the imaging method of choice since it is more available in daily practice than PET(CT).
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