Role of magnetic resonance imaging to differentiate between borderline and malignant serous epithelial ovarian tumors.

PURPOSE: We aimed to differentiate serous borderline ovarian tumors (SBOT) from serous epithelial ovarian carcinomas (SEOC) using morphological and functional MRI findings, to improve the patient management. METHOD: We retrospectively investigated 24 ovarian lesions diagnosed with SBOT and 64 ovarian lesions diagnosed with SEOC. Additional to the demographic and morphological findings T2W signal intensity ratio, mean apparent diffusion coefficient (ADCmean) and total apparent diffusion coefficient (ADCtotal) values were analyzed and compared between two groups. RESULTS: Bilaterality, pelvic free fluid presence, serum CA-125 level (U/mL), presence of pelvic peritoneal implant were in favor of SEOC. Lower maximum size of solid component and solid size to maximum size ratio, dominantly cystic and solid-cystic appearance, exophytic growth pattern, presence of papiller projection and papillary architecture and internal branching pattern, higher T2W signal intensity ratio, ADCmean and ADCtotal values were in favor of SBOT. CONCLUSION: Our study revealed that morphological and functional imaging findings were valuable in differentiating BSOT from SEOC.

An unusual case of retroperitoneal synovial sarcoma with CT, MRI, and F-18 FDG PET/CT findings.

Synovial sarcoma, predominantly found in the extremities, rarely occurs in the retroperitoneum. Tumors can often grow to a considerable size before diagnosis, which warrant the critical importance of early detection to minimize morbidity and mortality. While the final diagnosis relies on pathologic examination, imaging plays a crucial role in early detection.

Differentiation of lung and breast cancer brain metastases: Comparison of texture analysis and deep convolutional neural networks.

PURPOSE: Metastases are the most common neoplasm in the adult brain. In order to initiate the treatment, an extensive diagnostic workup is usually required. Radiomics is a discipline aimed at transforming visual data in radiological images into reliable diagnostic information. We aimed to examine the capability of deep learning methods to classify the origin of metastatic lesions in brain MRIs and compare the deep Convolutional Neural Network (CNN) methods with image texture based features. METHODS: One hundred forty three patients with 157 metastatic brain tumors were included in the study. The statistical and texture based image features were extracted from metastatic tumors after manual segmentation process. Three powerful pre-trained CNN architectures and the texture-based features on both 2D and 3D tumor images were used to differentiate lung and breast metastases. Ten-fold cross-validation was used for evaluation. Accuracy, precision, recall, and area under curve (AUC) metrics were calculated to analyze the diagnostic performance. RESULTS: The texture-based image features on 3D volumes achieved better discrimination results than 2D image features. The overall performance of CNN architectures with 3D inputs was higher than the texture-based features. Xception architecture, with 3D volumes as input, yielded the highest accuracy (0.85) while the AUC value was 0.84. The AUC values of VGG19 and the InceptionV3 architectures were 0.82 and 0.81, respectively. CONCLUSION: CNNs achieved superior diagnostic performance in differentiating brain metastases from lung and breast malignancies than texture-based image features. Differentiation using 3D volumes as input exhibited a higher success rate than 2D sagittal images.

Papillary Lesions of the Breast: Addition of DWI and TIRM Sequences to Routine Breast MRI Could Help in Differentiation Benign from Malignant.

AIM: We aimed to investigate the magnetic resonance imaging (MRI) features of benign, atypical, or malignant papillary breast lesions and to assess the additional value of diffusion-weighted imaging (DWI) and turbo inversion recovery magnitude (TIRM) sequences to routine breast MRI. BACKGROUND: Differentiation between benign and malignant papillary breast lesions is essential for patient management. However, morphologic features and enhancement patterns of malignant papillary lesions may overlap with those of benign papilloma. METHODS: Seventy-two papillary breast lesions (50 benign, 22 atypical or malignant) were included in the current study, retrospectively. We divided the patients into two groups: benign papillary breast lesions and atypical or malignant papillary breast lesions. Morphologic, dynamic, turbo inversion recovery magnitude (TIRM) values and diffusion features of the papillary lesions were compared between two groups. RESULTS: Benign papillary lesions were smaller in size (p=0.006 and p=0.005, for radiologists 1 and 2 respectively), closer to the areola (p=0.045 and 0.049 for radiologist 1 and 2 respectively), and had higher ADC values (p=0.001 for two radiologists) than the atypical or malignant group. ROC curves showed diagnostic accuracy for ADC (AUC=0.770 and 0.762, p = 0.0001 for two radiologists), and showed a cut-off value of ≤ 957 x 10-6 mm2/s (radiologist 1) and ≤ 910 x 10-6 mm2/s (radiologist 2). CONCLUSION: MRI is a useful method for differentiation between benign and malignant papillary breast lesions. Centrally located, lesser in size, and higher ADC values should be considered benign, whereas peripherally located, larger in size, and lower ADC values should be considered malignant.

A Case of Intratumoral and Hepatic Portal Venous Gas in Patient with Gastric Cancer Liver Metastases.

BACKGROUND: Hepatic portal venous gas [HPVG] is not a common finding in daily practice. It is usually associated with mesenteric ischemia and bowel necrosis in adults. Combination of intratumoral gas in metastatic liver lesions with HPVG is quite rare and thought to be associated with chemotherapy-induced necrosis and infection of the necrotized metastasis Objective: Here we present a case of gastric adenocarcinoma with portal venous and intratumoral gas in metastatic liver lesions due to the infected necrosis. CASE PRESENTATION: The patient was presented to the emergency room with severe abdominal pain and septic condition after the second round of chemotherapy. Hepatic portal venous and intratumoral gas in metastatic liver lesions due to the infected necrosis of liver metastasis was detected in computed tomography images. There were no findings of mesenteric ischemia both clinically and radiologically. Massive intratumoral infected necrosis in metastatic liver lesions and fistulization to the right portal vein branches were detected on abdominopelvic CT. Secondary infection of the necrotic metastases and fistulization to portal vein branches was believed to cause the air in metastatic liver masses and portal venous gas. CONCLUSION: Infected necrosis of metastatic liver lesions and fistulizations to the portal venous structures is extremely rare. Clinicians and radiologists should be aware of such a rare complication because early detection is crucial for patient management..

Diffusion Tensor Imaging Can Discriminate the Primary Cell Type of Intracranial Metastases for Patients with Lung Cancer.

PURPOSE: Histopathological differentiation of primary lung cancer is clinically important. We aimed to investigate whether diffusion tensor imaging (DTI) parameters of metastatic brain lesions could predict the histopathological types of the primary lung cancer. METHODS: In total, 53 patients with 98 solid metastatic brain lesions of lung cancer were included. Lung tumors were subgrouped as non-small cell carcinoma (NSCLC) (n = 34) and small cell carcinoma (SCLC) (n = 19). Apparent diffusion coefficient (ADC) and Fractional anisotropy (FA) values were calculated from solid enhanced part of the brain metastases. The association between FA and ADC values and histopathological subtype of the primary tumor was investigated. RESULTS: The mean ADC and FA values obtained from the solid part of the brain metastases of SCLC were significantly lower than the NSCLC metastases (P < 0.001 and P = 0.003, respectively). ROC curve analysis showed diagnostic performance for mean ADC values (AUC=0.889, P = < 0.001) and FA values (AUC = 0.677, P = 0.002). Cut-off value of > 0.909 × 10-3 mm2/s for mean ADC (Sensitivity = 80.3, Specificity = 83.8, PPV = 89.1, NPV = 72.1) and > 0.139 for FA values (Sensitivity = 80.3, Specificity = 54.1, PPV = 74.2, NPV= 62.5) revealed in differentiating NSCLC from NSCLC. CONCLUSION: DTI parameters of brain metastasis can discriminate SCLC and NSCLC. ADC and FA values of metastatic brain lesions due to the lung cancer may be an important tool to differentiate histopathological subgroups. DTI may guide clinicians for the management of intracranial metastatic lesions of lung cancer.

Diagnostic performance of apparent diffusion coefficient values for the differentiation of intrahepatic cholangiocarcinoma from gastrointestinal adenocarcinoma liver metastases.

BACKGROUND: We aimed to investigate whether there is a difference between intrahepatic cholangiocarcinoma (IHCC) and liver metastases of gastrointestinal system (GIS) adenocarcinoma in terms of apparent diffusion coefficient (ADC) values. PATIENTS AND METHODS: From January 2018 to January 2020, we retrospectively examined 64 consecutive patients with liver metastases due to gastrointestinal system adenocarcinomas and 13 consecutive IHCC in our hospital's medical records. After exclusions, fifty-three patients with 53 liver metastases and 10 IHCC were included in our study. We divided the patients into two groups as IHCC and liver metastases of GIS adenocarcinoma. For mean apparent diffusion coefficient (ADCmean) values, the region of interests (ROI) was placed in solid portions of the lesions. ADCmean values of groups were compared. RESULTS: The mean age of IHCC group was 62.50 ± 13.49 and mean age of metastases group was 61.15 ± 9.18. ADCmean values were significantly higher in the IHCC group compared to the metastatic group (p < 0.001). ROC curves method showed high diagnostic accuracy (AUC = 0.879) with cut-off value of < 1178 x 10-6 mm2/s for ADCmean (Sensitivity = 90.57, Specificity = 70.0, positive predictive value [PPV] = 94.1, negative predictive value [NPV] = 58.3) in differentiating adenocarcinoma metastases from IHCC. CONCLUSIONS: The present study results suggest that ADC values have a potential role for differentiation between IHCC and GIS adenocarcinoma liver metastases which may be valuable for patient management.

A Rare Complication of Microwave Ablation for Renal Cell Carcinoma; Nephrocolic Fistula.

INTRODUCTION: Nephrocolic fistula is a pathological connection between the kidney and colon. Percutaneous tumour ablation therapy is a rare cause of iatrogenic nephrocolic fistulain in the literature. CASE PRESENTATION: Interventional radiologist should be careful especially in patients with repeated ablation. Granulation tissue may lead to unexpected results secondary to tissue fragility and impedance changes. CONCLUSION: In addition, we should keep in mind that there is decreasing hydrodissection benefit in cases with previous ablation. As far as we know, this is the first case report of an iatrogenic ephrocolic fistula after microwave ablation for recurrence renal cell carcinoma.

Efficacy of Shear Wave Elastography in the Differentiation of Acute and Subacute Deep Venous Thrombosis.

ABSTRACT: It is important to know the age of clot formation to determine an appropriate treatment for deep vein thrombosis (DVT). The present study aims to differentiate between acute and subacute DVT using the shear wave elastography (SWE) technique. Patients with complaints no longer than 4 weeks and who were found to have early-stage (acute-subacute) thrombus on ultrasound (US) between January 2020 and May 2020 were included in the study. All of the patients underwent SWE using a Philips Healthcare EPIQ 5 Ultrasound System Inc. device with a high-resolution linear US probe (eL18-4, 22-2 MHz). Included in the study were 50 patients, including 23 with acute DVT and 27 with subacute DVT. Of the patients, 22 were women and 28 were men, and the mean age was 46.32 ± 11.33 years (range: 24-74 years). The mean SWE value was 2.63± 0.16 (2.39-2.96) in patients with acute DVT and 3.34± 0.31 (2.65-3.88) in patients with subacute DVT. The findings were statistically significant in the comparison of the 2 groups using an independent samples t test (P < 0.001). In the receiver operating characteristic analysis, the area under the curve was found to be 97.6%. When the cutoff value was taken as 2.85 according to the area under the curve, sensitivity was found to be 96.3%, and specificity was 91.3%. Thrombus stage plays a critical role in treatment decisions in DVT in the lower extremities. The present study reveals that the shear wave US elastography technique can be used to discriminate between acute and subacute DVT.

Diffusion Tensor Imaging Features of the Auditory Pathways in Patients With Vestibular Schwannoma After Gamma Knife Radiosurgery.

Objective In this study, we aimed to investigate whether there is any change in diffusion tensor imaging (DTI) parameters in ipsilateral and contralateral auditory pathways after Gamma Knife radiosurgery (GKR) in patients with vestibular schwannoma (VS) and the relationship between radiosurgery variables. Methods Sixty-six patients were evaluated with MRI and DTI before and after GKR. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured from the bilateral lateral lemniscus (LL), inferior colliculus (IC), medial geniculate body (MGB), and Heschl's gyrus (HG). Results There was no significant difference in ADC and FA values obtained from bilateral LL, IC, and MGB before and after radiosurgery. However, there was a significant difference between pretreatment and post-radiosurgery contralateral HG ADC values. The ADC values obtained from the contralateral HG and IC positively correlated with the duration after radiosurgery. As the duration after radiosurgery increases, the difference between the ADC values obtained from ipsilateral and contralateral HG also increases. Conclusion The high ADC values in the contralateral HG after radiosurgery may indicate microstructural alterations such as demyelination and axonal loss. Radiation exposure doses to the brainstem and cochlea are the most important factors that can cause microstructural damage to the auditory pathways. When planning radiosurgery, extreme care should be taken to prevent the harmful effects of radiation on the auditory pathways.

Evaluation of Brainstem Subcortical Auditory Pathways with Diffusion Tensor Imaging After Gamma Knife Radiosurgery in Intracanalicular Vestibular Schwannoma.

OBJECTIVE: To investigate changes in DTI (Diffusion Tensor Imaging) parameters in brainstem subcortical auditory pathways after Gamma Knife Radiosurgery (GKR) in patients with intracanalicular vestibular schwannoma (ICVS) and to analyze the relationship between tumor volume and ADC (apparent diffusion coefficient) and FA (fractional anisotropy) values. METHOD: Seventeen patients with ICVS were evaluated before and after GKR. ADC and FA values of the lateral lemniscus (LL) and inferior colliculus (IC) and tumor volume were calculated. Patients who responded to GKR were classified as Group 1 and those who did not respond adequately as Group 2. The relationship between ADC and FA values and changes in tumor volume were analyzed. RESULTS: Tumor volume significantly decreased after GKR. ADC values obtained from the tumor increased after GKR (p:0.002). There was no significant difference in LL and IC before and after GKR in terms of FA and ADC values (n:17). There was a positive correlation between response to treatment and contralateral LL ADC values after GKR (p=0.005, r:0.652). There was a negative correlation between contralateral IC FA values after GKR and response to treatment (p=0.017, r: -0.568). There was a significant difference between Groups 1 and 2 in regards to contralateral LL ADC (p=0.03) and IC FA values (p=0.017). CONCLUSION: Since the cochlear nerve and subcortical auditory pathways have low regeneration potential after nerve damage, ADC and FA changes in LL and IC may be explained with the presence of intracanalicular tumors prior to GKR. Since GKR does not cause additional damage to the subcortical auditory pathways at the brainstem level, we think that GKR is a noninvasive treatment method that can be used safely in patients with ICVS.

Importance of Thalamostriatal Pathway Associated With Neurocognitive Dysfunctions in Children With Neurofibromatosis Type 1: Diffusion Tensor Imaging Findings.

OBJECTIVE: To determine whether there is a difference between healthy control group and children with neurofibromatosis type 1 (NF1) in terms of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values in different regions of the brain associated with neurocognitive functions and to investigate the correlation between diffusion tensor imaging parameters and neurocognitive dysfunctions. METHODS: The study included 28 children with NF1 and 21 controls. Nine distinct areas related to cognitive functions were selected for the analysis. The ADC and FA values were compared. RESULTS: There was a significant difference between NF1 and healthy control in terms of ADC values obtained from all areas. The ADC values at obtained from thalamus and striatum were positively correlated with the full-scale intelligence quotient (IQ), verbal IQ, and performance IQ. CONCLUSIONS: We are speculated that the development of microstructural damage in the thalamostriatal pathway may lead to neurocognitive dysfunction.

Relationship with Programmed Cell Death Ligand 1 (PD-L1) and DTI Features in Brain Metastases of Non-small Cell Lung Cancer: A Preliminary Study.

OBJECTIVE: The purpose of the study was to determine DTI properties of brain metastases in subjects with Non-Small Cell Lung Carcinoma (NSCLC) to evaluate whether there was a correlation between DTI findings and Programmed Cell Death Ligand-1 (PD-L1). METHODS: The study population (n:22) was assigned to PD-L1 negative (Group 1: PD-L1 expression<% 50) (n=11) or positive (Group 2: PD-L1 expression ≥%50) (n=11). We compared ADC and FA values measured from the enhanced solid metastases and peritumoral edema area with PD-L1 protein status. RESULTS: The mean ADC values were lower in group 2 compared to group 1. The peritumoral ADC values were higher in group 2 compared to group 1. Mean peritumoral edema FA values were lower in group 2 compared to group 1. The peritumoral edema nADC values were higher in group 2 compared to group 1. As PD-L1 expression frequency increased, ADC values in the peritumoral edema area increased and FA values decreased. CONCLUSION: We thought that the existence of PD-L1 protein does not affect ADC and FA values of brain metastasis (BM) originating from NSCLC. DTI characteristics of the peritumoral edema area could be a guide in determining the PD-L1 protein status of brain metastases of NSCLC. The relationship between PD-L1 expression status and DTI features in BM from NSCLC could help us to have an idea regarding the response to immunotherapy.

Diffusion Tensor Imaging of Brain Metastases in Patients with Breast Cancer According to Molecular Subtypes.

BACKGROUND AND PURPOSE: Recent studies have shown that diffusion tensor imaging (DTI) parameters are used to follow the patients with breast cancer and correlate well as a prognostic parameter of breast cancer. However, as far as we know, there is no data to compare the DTI features of breast cancer brain metastases according to molecular subtypes in the literature. Our aim is to evaluate whether there are any differences in DTI parameters of brain metastases in patients with breast cancer according to molecular subtypes. METHODS: Twenty-seven patients with breast cancer and 82 metastatic brain lesions were included. We classified subjects into three subgroups according to their hormone expression; Group 0, triple- negative (n; 6, 19 lesions), group 1, HER2-positive (n;16, 54 lesions) and group 2, hormone-- positive group (n; 5, 9 lesions). The apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) values in DTI were measured and compared between three groups. RESULTS: ADC, AD and RD values of group 2 were significantly lower compared to group 0. No significant differences were found in FA, ADC, AD and RD values between the group 0 and 1 and the group 1 and 2. CONCLUSION: Metastasis of aggressive triple-negative breast cancer showed higher ADC values compared to the less aggressive hormone-positive group. Higher ADC values in brain metastases of breast cancer may indicate a poor prognosis, so DTI findings could play a role in planning appropriate treatment.

COVID-19 infection in a membranous nephropathy patient treated with rituximab.

While COVID-19 pandemic continues to affect our country and most countries in the world, we have to make some changes both in our social life and our approach to healthcare. We have to struggle with the pandemic on one hand and also try to follow up and treat our patients with chronic diseases in the most appropriate way. In this period, one of our group of patients who are challenging us for follow-up and treatment are those who should start or continue to use immunosuppressive therapy. In order to contribute to the accumulation of knowledge in this area, we wanted to report a patient who was followed up with the diagnosis of COVID-19 and had been administered rituximab very recently due to a nephrotic syndrome caused by membranous nephropathy.

Apparent Diffusion Coefficient Values for Neuroendocrine Liver Metastases.

RATIONALE AND OBJECTIVES: We aimed to investigate whether there are any differences in apparent diffusion coefficient (ADC) values obtained from liver metastases due to gastroenteropancreatic neuroendocrine tumors (GEP-NET) and adenocarcinomas. MATERIALS AND METHODS: We included 54 patients with 167 liver metastases due to gastroenteropancreatic tumors. We divided the patients into two groups as liver metastases due to GEP-NETs (seven patients with 51 lesions, mean age: 48) and adenocarcinomas (47 patients with 116 lesions, mean age: 61.2). We used the independent samples t-test to compare the ADC and ADCmean values of the two groups and performed a receiver-operating characteristic analysis. RESULTS: ADC and ADCmean values were significantly lower in the GEP-NET group compared with the adenocarcinoma group. Receiver-operating characteristic curve analysis showed a significant difference for ADC and ADCmean values, and area under the curve values were 0.733 and 0.790, respectively. The cut-off values were 933x10-6 mm2/s for ADC and 801x10-6 mm2/s for ADCmean. Diagnostic accuracies of ADC (Sensitivity = 80.2, Specificity = 64.7, PPV = 83.8, NPV = 58.9) and ADCmean (Sensitivity = 63.8, Specificity = 82.4, PPV = 89.2, NPV = 50) were calculated in differentiating adenocarcinoma metastases from GEP-NET metastases. CONCLUSION: The lower ADC and ADCmean values of liver metastases suggest GEP-NET rather than adenocarcinomas. ADC and ADCmean values obtained from liver metastases may be used to differentiate NETs from adenocarcinomas.

Brain Diffusion Tensor Imaging Findings in Hashimoto's Thyroiditis.

BACKGROUND AND PURPOSE: Hashimoto's thyroiditis (HT) is a type of autoimmune thyroid disease. Diffusion tensor imaging (DTI) can evaluate microstructural brain involvement in various diseases. We aimed to investigate whether there were any DTI differences in patients with HT, and the relationship between DTI values and disease duration time and thyroid peroxidase antibodies (TPOAb) levels. METHODS: We prospectively included 36 patients with HT (mean age 41.6 ± 13.8 years, range 18-64 years) and 18 age and sex-matched healthy control subjects (mean age 41.6 ± 13.1 years, range 18-63 years). All patients were euthyroid at the time of imaging. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) values of 15 distinct neuroanatomical locations were measured and compared. RESULTS: FA values of the patients with HT were lower in cingulum, globus pallidus (GP), cerebellar white matter (CWM) than the control (P = .019, .002, and <.001, respectively). MD values of the CWM in patients were higher than the control (P = .008). AD values of patients with HT were lower in the cingulum, posterior limbs of the internal capsule, GP, and putamen (P = .038, .038, .030, and .045, respectively). RD values of cingulum and CWM in HT were higher than controls (P <.001 and P = .011, respectively). There was a negative relationship between the FA values of PLIC and a positive relationship between the MD values of the corona radiata and TPOAb levels were detected. CONCLUSIONS: The current DTI study presented microstructural changes in the neurocognitive-related areas that may be related to accompanying neurological findings in HT.

Ovarian Granulosa Cell Tumor: A Clinicoradiologic Series with Literature Review.

BACKGROUND: Ovarian granulosa cell tumors that originate from the sex cord-stromal cells represent 2% to 5% of all ovarian cancers. These tumors constitute two subgroups according to their clinical and histopathological features: juvenile granulosa cell tumors (JGCT) and adult granulosa cell tumors (AGCT). Granulosa cell tumor (GCT) is considered to be a low-grade malignancy with a favorable prognosis. METHODS: This case series includes four patients who were admitted to our university hospital and had an MRI examination within 5 years. RESULTS: The histopathological subtype of granulosa tumor was the adult type in 3 patients and juvenile type in 1 patient. Even though it is extremely rare, bone metastases were present in one of our patients. Liver metastases were also detected in one patient. The MRI examination of tumors revealed a heterogeneous solid mass that contained cystic components in 3 patients. In one of our patients, the tumor had a multiseptated cystic feature, and all of the tumors were ovoid or round with smooth margins. T1 signal hyperintensity, not suppressed on fat saturation sequences, was observed in 3 patients, which represents its hemorrhagic content. CONCLUSION: Even though granulosa cell tumor shows a wide spectrum in terms of tumor appearance, some common findings have been shown and especially a hemorrhagic content could be a clue for us. The tumor is known to have a good prognosis, but it may have an unpredictable clinical course, so close follow-up is greatly important.

Relationship between KRAS mutation and diffusion weighted imaging in colorectal liver metastases; Preliminary study.

PURPOSE: We aimed to investigate whether there are any differences in apparent diffusion coefficient (ADC) values obtained from colorectal liver metastases (CRLM) according to Kirsten rat sarcoma (KRAS) gene mutation status. METHOD: In this retrospective study, we included 22 patients with 65 liver metastases due to colorectal cancer and performed KRAS gene mutation tests. We divided the patients into two groups as KRAS mutation positive (+) (n:10, 30 lesions) and the wild-type group (n:12, 35 lesions). Mann-Whitney U test was used to compare ADC and ADC mean values of the two groups. In addition, we performed receiver-operating characteristic (ROC) analysis to discriminate the two groups in terms of their ADC and ADCmean values. RESULTS: The ADC and ADCmean values were found to be statistically significantly lower in the KRAS (+) group compared to the wild-type group. ROC curve analysis revealed a statistically significant difference in terms of ADC and ADCmean with area under the curve (AUC) values of 0.680 and 0.760, respectively. The cut-off values for ADC and ADCmean were 986 × 10-6 mm2/s and 823 × 10-6 mm2/s, respectively. CONCLUSION: In our study, the lower ADC and ADCmean values of CRLM are associated with presence of KRAS mutation. ADC and ADCmean values derived from liver metastases due to the colorectal cancer can be used to differentiate KRAS mutation status.

The Utility and Efficiency of Diffusion Tensor Imaging Values to Determine Epidermal Growth Factor Receptor Gene Mutation Status in Brain Metastasis from Lung Adenocarcinoma; A Preliminary Study.

BACKGROUND: This study aims to investigate the existence of any Diffusion Tensor Imaging (DTI) value differences in Brain Metastases (BM) due to lung adenocarcinoma based on the Epidermal Growth Factor Receptor (EGFR) gene mutation status. MATERIAL AND METHODS: 17 patients with 32 solid intracranial metastatic lesions from lung adenocarcinoma were included prospectively. Patients were divided according to the EGFR mutation status as EGFR (+) (group 1, n:8) and EGFR wild type (group 2, n:9). The Fractional Anisotropy (FA), apparent diffusion coefficient (ADC), normalized ADC (nADC), Axial Diffusivity (AD), and Radial Diffusivity (RD) values were measured from the solid component of the metastatic lesions and nADC values were calculated. DTI values were compared between group 1 and group 2. The receiver-operating characteristic analysis was used to obtain cut-off values for the parameters presenting a statistical difference between the EGFR gene mutation-positive and wild type group. RESULTS: There were statistically significant differences in measured ADC, nADC, AD, and RD values between group 1 and group 2. The ADC, nADC, AD, and RD values were significantly lower in group 1. There was no significant difference in FA values between the two groups. Analysis by the ROC curve method revealed a cut-off value of ≤721 x 10-6 mm2/s for ADC (Sensitivity= 72.7, Specificity=85.7); ≤0.820 for nADC (Sensitivity=72.7, Specificity=90.5), ≤ 886 for AD (Sensitivity=81.8, Specificity=81.0), and ≤588 for RD (Sensitivity=63.6, Specificity=90.5) in differentiating EGFR mutation (+) group from wild type group. CONCLUSION: A combination of the decreased ADC, nADC, AD, and RD values in BM due to lung adenocarcinoma can be important for predicting the EGFR gene mutation status. DTI features of the brain metastases from lung adenocarcinoma may be utilized to provide insight into the EGFR mutation status and guide the clinicians for the initiation of targeted therapy.