MyT3 8 - Oncologic Imaging

Purpose:

To predict the response to neoadjuvant therapy in patients with locally advanced rectal cancer (LARC) using texture features of MRI staging examination, to customise therapeutic management.

Methods and materials:

The dataset is composed of 52 patients acquired in two different institutions with different MR scanners and protocols. All colorectal cancers were manually segmented on the T2-w images. CRCs were classified as non-responders (R-) if their TRG score was >=3 and responder (R+) otherwise. 39 quantitative features were extracted from the largest segmented slice, including volume, mean, standard deviation, percentiles, skewness, kurtosis, and texture parameters from GLCM and GLRLM matrices from both T2w and ADC maps. Patients from institution A and B were randomly used as training and testing dataset. A stepwise logistic regression model was created using 70% of lesions (36) as a training set and 30% as testing set (16) randomly selected.

Results:

The dataset included 21 R- and 31 R+ tumours. Accuracy on the training set was 98% (35/36), with sensitivity and specificity of 100% (21/21) and 95% (14/15), respectively. Accuracy on the testing set was 87% (14/16), with sensitivity, specificity, NPV and PPV of 86% (8/9), 89% (6/7), 89% and 86% respectively.

Conclusion:

This study demonstrates the possibility to recognize, analyzing MRI staging examination, patients that will not respond to conventional neoadjuvant therapies, to customize treatment and avoid the use of ineffective therapies, preventing unnecessary toxicity and costs.

Limitations:

This study is limited by a manual segmentation with consequent interobserver variability and an external validation dataset.

Ethics committee approval

Ethics committee approval obtained.

Funding:

AIRC5x1000 - Ref. 9970, FPRC5x1000 Ministero Salute 2013, FPRC5x1000 Ministero Salute 2015.

Purpose:

The purpose of this study is to verify the effectiveness and complications occurrence of radiofrequency ablation (RFA) in the treatment of osteoid osteoma (OO) in non-operating room anaesthesia (N.O.R.A.).

Methods and materials:

From 2016 to 2019, 61 patients affected by OO (40 men and 21 women) with an age of 20.7 years on average (range, 4-51 years; 12 patients aged 20 years or younger) underwent computed tomography-guided percutaneous radiofrequency ablation (RFA) in N.O.R.A. (non-operating room anaesthesia). Lesion sites treated were: femur (27), tibia (22), pelvis (2), talar bone (3), distal radius (1), and humerus (6). Mean follow-up time was 36 months. In each case, anaesthesiologic support followed a new protocol (N.O.R.A. protocol), approved by our institute. Primary success rate, complications, symptom-free intervals, and follow-up results were evaluated.

Results:

Pain relief (evaluated with visual analogue scale – VAS) was significant in 97% of patients; it disappeared within 24 hours of the procedure in 44 patients, within 3 days in 10 patients, and within 7 days in 7 patients. After 6 months of observation time, 60 of 61 patients were successfully treated and had no more complaints. In 2 patients, two major complications were found: infection of the site treated, healed with antibiotics, and a nerve lesion, healed with steroid therapy. No other complications were observed.

Conclusion:

RFA is a highly effective, efficient, minimally invasive and a safe method for the treatment of OO following N.O.R.A. protocol.

Limitations:

No randomisation of patients and poor follow-up were identified as limitations.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To evaluate the role of dynamic-combined subtraction and diffusion magnetic resonance imaging (MRI) in the differentiation between residual and necrotic lesions after treatment by trans-arterial chemoembolization (TACE).

Methods and materials:

This prospective study included 50 cases of hepatocellular carcinoma (HCC) patients underwent TACE based on ethical respect and eligibility of patients to do MRI on a 1.5-tesla machine. Diffusion-weighted images (DWI) were done before the dynamic study at different levels. Apparent diffusion coefficient (ADC) maps and subtraction dynamic series were created using a workstation and ADC value was calculated. MR images were interpreted by two different levels experienced observers taking the follow-up findings as regard imaging and arterial hypervascularity blush on repeated TACE as our reference standard. The diagnostic accuracy of dynamic, DWI, subtraction and ADC values for both observers were determined and considered statistically significant at p-value <0.050.

Results:

Dynamic and subtraction studies were superior to DWI as regard their diagnostic accuracy and had the same values. Dynamic and subtraction specificity was 90.5 and 95 % for observer 1 and 2 respectively whereas DWI was 76 and 81 % for the same observers respectively. There was a statistically significant difference in ADC value between residue (n=29) and non-residue (n=21) groups with cut-off value for complete ablation >0.94 and >1.05 for both observer (1) and (2) respectively. The absolute agreement and consistency between the two observers Cohen K =0.9 for both dynamic and subtraction and 0.78 for DWI.

Conclusion:

Each MRI modality has its merit and accuracy in evaluation of HCCs post-TACE.

Limitations:

No pathology due to biopsy sample error post-TACE. No available CT for all patients for comparison.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To increase preoperative diagnosis of lung and pleura tumours and to identify the belonging of metastases in the organs of the chest cavity in cases of multiple localisations of the oncological process with the help of CT-guided transthoracic trepan biopsy to obtain a histological material for verification and selection of a specific treatment.

Methods and materials:

In the period from January to September 2019, we had made a transthoracic pulmonary biopsy of 27 patients with primary and secondary tumours and with lung and pleura nodes. 11 of them were patients with one localization of oncological process. There were 3 patients with primary non-verified tumours of the chest cavity. And 13 patients had multiple localisations of oncological process. The size of the nodes and tumours varied from 9mm to 11sm.

Results:

Histological results were obtained from all investigated nodes and tumours of 27 patients. Biopsy gave a histological answer about the origin of the node or tumour, which made it possible to select the treatment for patients correctly and specifically. According to histological research, 3 patients had tumours and changes which were not related to the oncological disease. 6 patients were diagnosed lung cancer as the second localisation of oncological process. 18 patients had the continuation of the main process and we received the information about the genesis of metastases in cases of primary multiple localisation.

Conclusion:

Obtainig a biopsy of tumour tissue makes it possible to get information about the genesis of metastases in cases of synchronous and metachronous cancers. CT guided transthoracic biopsy helps to get tumour tissue material, carry out molecular genetic studies and makes it possible to individualise approaches to the patient’s treatment.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To analyse the role of DW-MRI in early prediction of response to treatment in cervical cancer patients after chemo-radiation (RT).

Methods and materials:

Between September 2017-August 2019, 68 women with histologically proven cervical cancer underwent DW-MRI in our centre before and after the completion of neoadjuvant RT. Two radiologists, with respectively 4-20 years of MR experience, measured tumour volume (TV) and ADC mean in consensus. Three regions of interest were drawn on a single DW image, avoiding areas of necrosis, and on the corresponding ADC map: the mean ADC was obtained. According to response evaluation criteria in solid tumours, treatment response was classified as complete (CR) partial (PR) response, stable disease (SD) or progression (PD). Comparisons were made with Mann-Whitney and Chi-square tests.

Results:

68 women aged between 31-85 years (average 55), affected by squamous cell carcinoma were analysed. The mean time from RT to the MRI was 23 days (range 2-55). CR was observed in 39 patients, PR in 17. No PD was observed. After RT, TV was higher in PR and SD than in CR (p=0.001). TV reduction was lower in PR than in CR (p=0.01). ADC was lower before RT than after, respectively 0.82 and 1.25 *10^-3 mm^2/s (p<0.001), and △ADC was higher in CR than in SD (p=0.035); while no statistically significant differences were observed in ADC values in PR and SD, ADC in CR was higher than in PR, respectively 1.32 and 1.02 *10^-3 mm^2/s (p<0.017).

Conclusion:

DW-MRI is useful for evaluating response to treatment after RT and for predicting CR.

Limitations:

This study is a retrospective study and includes scarcer numerosity of population.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

Trans-arterial chemoembolisation is chosen for patients with hepatocellular-carcinoma who falls into BCLC-stage B usually helps in the local control of the tumour burden. So it is necessary to monitor the results post TACE treatment for deciding further management. CECT/MRI abdomen is taken as the gold standard in considering the treatment response following treatment. In this study, we evaluated the role of ARFI-elastography to measure stiffness in deep tissues. As a response evaluation tool in HCC patients treated by TACE.

Methods and materials:

A total of 95 lesions from 54 patients were evaluated with elastography before and after TACE procedure and findings were correlated with Triphasic CECT scans. The difference in enhancing areas in follow up CT scans were assessed and categorised and was compared with the difference in ARFI-Max values attained on ARFI-elastography on follow-up. It was also compared with the difference in stiffer areas within the lesion of follow-up. The lesions were categorised into lesions within a cirrhotic liver and lesions within a non-cirrhotic liver. Various parameters were compared using Kappa, weighted Kappa, Kruskal Wallis test and linear regression analysis.

Results:

In our study, HCCs showed variable stiffness but predominantly the lesions were stiffer as compared to normal liver. Brighter areas on elastography represent the stiffer portions of the tumour which may represent the residual tumour post-treatment. There were 57 tumours in a cirrhotic background and 38 tumours in a non-cirrhotic background. We found that there is a statistically significant agreement on evaluation.

Conclusion:

ARFI-elastography is a safe, non-invasive, rapid and novel technique which can be effectively used as a response evaluation tool after TACE in patients with hepatocellular-carcinoma especially when other imaging modalities are contraindicated.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

n/a

Purpose:

Irreversible electroporation (IRE) of the pancreas is an increasingly used method for unresectable pancreatic cancer that can be used in cytoreduction followed by surgical treatment and shows promising results in palliative care. It is claimed that IRE is not causing thermal effect comparing to radiofrequency and microwave ablation. Aim of the study is to assess the early post-IRE changes in signal intensities in the ablation zone with emphasis on thermal effect and vascularisation.

Methods and materials:

We retrospectively analysed the MRI studies of 24 patients (10 F, 14M, aged 35-71) with unresectable pancreatic cancer during or shortly after chemotherapy. Standard IRE procedure was performed. MR images were performed on 1,5T and 3T scanners one day before IRE procedure and up to 7-days after. A standard protocol for pancreas was performed including T1W, TW2, DWI/ADC, DCE with subtraction series.

Results:

Signal intensities in the ablated zone on T1-FatSat images after contrast media administration with subtraction was in the range 0-6,25. The ADC values after IRE were significantly higher compared to pre-IRE measurements. Signs of thermal effect were seen as gas bubbles close to the electrodes after CT-guided percutaneous procedures were performed. On MR images in 83,3% of patients, they were seen as small, hypointense zones in electrodes placement on T1-FatSat contrasted-enhanced images.

Conclusion:

Low SI values in the ablated zones on T1-FatSat+CM images with subtraction proves that all vascular bed within the ablation zone was completely damaged. Growth of ADC values after IRE is the effect of cellular water displacement to intercellular space what is a sign of cytolysis. IRE can create thermal effect on exposed tissues.

Limitations:

This study is limited by a small group of patients and that it is performed as a single centre study.

Ethics committee approval

All applied procedures were approved by a local ethical committee.

Funding:

No funding was received for this work.

"Purpose:

In this study, we aimed to compare the diagnostic value of contrast-enhanced CT and PET/MRI in patients with abdominal malignancy.

Methods and materials:

Between January 2016 and May 2019, 77 patients with intraabdominal primary tumours with PET/MRI and contrast-enhanced CT examination were screened with retrospectively. PET/MRI and contrast-enhanced CT images of the patients were evaluated by two independent radiologists and the common consensus was obtained. Histopathological findings were taken as reference. Diagnostic value of two different modalities for the primary tumour, metastatic focus and lymphadenopathy were compared.

Results:

PET/MRI and CT , respectively, regardless of the histology of the primary tumour, 100% of primary tumours ( 77 patients) and 98,7 % of primary tumours ( 76 patients); 100% of lymph node involvement( 24 patients) and 91,6% of lymph node involvement (22 patients), 100% of distant metastases (36 patients) 97,2% of distant metastases (35 patients) has detected. There was no statistically significant difference between the PET/MRI and CT in terms of primary tumour (p = 0.32), lymph node metastasis (p = 0.15) and distant metastasis (p = 0.32). In addition, it provided additional information in 6,6% (1/15 patients) of patients in detecting multiple foci in hepatocellular carcinoma, regardless of our aim. In addition, PET/MRI detected undetectable brain and extremity metastases in 19.4% (7/36 patients ) of patients compared with CT.

Conclusion:

The biggest advantage of PET/MRI is the low ionising radiation. PET/MRI is superior to CT in lymph node and distant metastasis detection.

Limitations:

The main limitation of this study is low patient number.

Ethics committee approval

The institutional review board approved the study; the requirement for informed consent was waived since the study was retrospective investigation.

Funding:

No funding was received for this work.

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