Hyun Jung Yoon

Repeat biopsy for mutational analysis of non-small cell lung cancers resistant to previous chemotherapy: adequacy and complications.

PURPOSE To evaluate the feasibility and safety of repeat biopsy for mutational analysis in patients with non-small cell lung cancer (NSCLC) who have a resistance history to previous chemotherapy. MATERIALS AND METHODS This prospective study was institutional review board approved, and written informed consent was obtained from all patients. Of 126 patients referred for repeat biopsy (hereafter, rebiopsy) with NSCLC that was resistant to conventional chemotherapy or epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors, 94 patients (31 men, 63 women; mean age ± standard deviation, 57 years ± 10.3) were selected for rebiopsy. Thirty-two patients were excluded for several reasons after strict review of the chest computed tomography (CT) images. Percutaneous transthoracic lung biopsy was performed with C-arm cone-beam CT guidance. The technical success rates for the rebiopsy and the adequacy rates of specimens for mutational analysis were evaluated. Any biopsy-related complications were recorded. RESULTS The technical success rate for biopsy was 100%. In 75 (80%) of 94 patients, specimens were adequate for mutational analysis. Of 75 specimens, 35 were tested for EGFR mutation, 34 for anaplastic lymphoma kinase gene (ALK) rearrangement, and six for both. The results were positive for EGFR-sensitizing mutation (exon 19 or 21) in 20, for EGFR T790M mutation in five, and for ALK rearrangement in 11. Postprocedural complications occurred in 13 (14%) of 94 patients. CONCLUSION When performed by employing rigorous CT criteria, rebiopsies for the mutational analysis of NSCLCs treated previously with chemotherapy are feasible in all patients and are adequate in approximately four-fifths of patients referred for gene analysis, with acceptable rates of complications.

Decoding Tumor Phenotypes for ALK, ROS1, and RET Fusions in Lung Adenocarcinoma Using a Radiomics Approach.

AbstractQuantitative imaging using radiomics can capture distinct phenotypic differences between tumors and may have predictive power for certain phenotypes according to specific genetic mutations. We aimed to identify the clinicoradiologic predictors of tumors with ALK (anaplastic lymphoma kinase), ROS1 (c-ros oncogene 1), or RET (rearranged during transfection) fusions in patients with lung adenocarcinoma.A total of 539 pathologically confirmed lung adenocarcinomas were included in this retrospective study. The baseline clinicopathologic characteristics were retrieved from the patients’ medical records and the ALK/ROS1/RET fusion status was reviewed. Quantitative computed tomography (CT) and positron emission tomography imaging characteristics were evaluated using a radiomics approach. Significant features for the fusion-positive tumor prediction model were extracted from all of the clinicoradiologic features, and were used to calculate diagnostic performance for predicting 3 fusions’ positivity. The clinicoradiologic features were compared between ALK versus ROS1/RET fusion-positive tumors to identify the clinicoradiologic similarity between the 2 groups.The fusion-positive tumor prediction model was a combination of younger age, advanced tumor stage, solid tumor on CT, higher values for SUVmax and tumor mass, lower values for kurtosis and inverse variance on 3-voxel distance than those of fusion-negative tumors (sensitivity and specificity, 0.73 and 0.70, respectively). ALK fusion-positive tumors were significantly different in tumor stage, central location, SUVmax, homogeneity on 1-, 2-, and 3-voxel distances, and sum mean on 2-voxel distance compared with ROS1/RET fusion-positive tumors.ALK/ROS1/RET fusion-positive lung adenocarcinomas possess certain clinical and imaging features that enable good discrimination of fusion-positive from fusion-negative lung adenocarcinomas.

Adaptive Statistical Iterative Reconstruction-Applied Ultra-Low-Dose CT with Radiography-Comparable Radiation Dose: Usefulness for Lung Nodule Detection.

Objective To assess the performance of adaptive statistical iterative reconstruction (ASIR)-applied ultra-low-dose CT (ULDCT) in detecting small lung nodules. Materials and Methods Thirty patients underwent both ULDCT and standard dose CT (SCT). After determining the reference standard nodules, five observers, blinded to the reference standard reading results, independently evaluated SCT and both subsets of ASIR- and filtered back projection (FBP)-driven ULDCT images. Data assessed by observers were compared statistically. Results Converted effective doses in SCT and ULDCT were 2.81 ± 0.92 and 0.17 ± 0.02 mSv, respectively. A total of 114 lung nodules were detected on SCT as a standard reference. There was no statistically significant difference in sensitivity between ASIR-driven ULDCT and SCT for three out of the five observers (p = 0.678, 0.735, < 0.01, 0.038, and < 0.868 for observers 1, 2, 3, 4, and 5, respectively). The sensitivity of FBP-driven ULDCT was significantly lower than that of ASIR-driven ULDCT in three out of the five observers (p < 0.01 for three observers, and p = 0.064 and 0.146 for two observers). In jackknife alternative free-response receiver operating characteristic analysis, the mean values of figure-of-merit (FOM) for FBP, ASIR-driven ULDCT, and SCT were 0.682, 0.772, and 0.821, respectively, and there were no significant differences in FOM values between ASIR-driven ULDCT and SCT (p = 0.11), but the FOM value of FBP-driven ULDCT was significantly lower than that of ASIR-driven ULDCT and SCT (p = 0.01 and 0.00). Conclusion Adaptive statistical iterative reconstruction-driven ULDCT delivering a radiation dose of only 0.17 mSv offers acceptable sensitivity in nodule detection compared with SCT and has better performance than FBP-driven ULDCT.

T2 values of femoral cartilage of the knee joint: comparison between pre-contrast and post-contrast images.

Objective To retrospectively evaluate the relationship between T2 values of pre- and post-contrast magnetic resonance (MR) images of femoral cartilage in patients with varying degrees of osteoarthritis. Materials and Methods A total of 19 patients underwent delayed gadolinium-enhanced MRI of cartilage. Six regions of interest for T2 value measurement were obtained from pre- and post-contrast T2-weighted, sagittal, multi-slice, multi-echo, source images in each subject. Regions with modified Noyes classification grade 2B and 3 were excluded. Comparison of T2 values between pre- and post-contrast images and T2 values among regions with the grade 0, 1 and 2A groups were statistically analyzed. Results Of a total of 114 regions, 79 regions showing grade 0 (n = 46), 1 (n = 18), or 2A (n = 15) were analyzed. The overall and individual T2 values of post-contrast images were significantly lower than those of pre-contrast images (overall, 35.3 ± 9.2 [mean ± SD] vs. 29.9 ± 8.2, p < 0.01; range of individual, 28.9-37.6 vs. 27.1-36.4, p < 0.01). Pearson correlation coefficients showed a strong positive correlation between pre- and post-contrast images (rho-Pearson = 0.712-0.905). T2 values of pre- and post-contrast images of the grade 0 group were significantly lower than those of the grade 1/2A group (pre T2, p = 0.003; post T2, p = 0.006). Conclusion T2 values of the femoral cartilage of the knee joint are significantly lower on post-contrast images than on pre-contrast images. Furthermore, these T2 values have a strong positive correlation between pre- and post-contrast images.

Synchronous triple primary lung cancers: a case report.

Synchronous primary lung cancers are relatively rare. The accurate diagnosis remains challenging, despite of the routine use of bronchoscopy and computed tomography (CT) of the chest. Herein we report a case of synchronous triple primary cancers of the right lung in a 72-year-old male patient in whom each tumor presented distinct CT imaging findings.

Solid pseudopapillary tumor of the pancreas with hepatic metastasis: spontaneous regression over 10-year follow-up period.

A solid-pseudopapillary tumor (SPT) of the pancreas is known as a low grade malignant tumor with a good prognosis; therefore, surgical intervention is necessary. A 14-year-old boy presented with a large pancreatic SPT and three hepatic metastases. The patient and his family refused surgery. Two serial follow-up CT scans over a period of 13 years demonstrated almost complete disappearance of the pancreatic tumor and three hepatic metastases without relevant treatment. Although there have been a few reports of spontaneous healing of SPT, there has been no report regarding spontaneous disappearance of SPT and distant metastasis. Herein, we report on the spontaneous regression of a large SPT and the disappearance of three hepatic metastases.

Nontuberculous Mycobacterial Tenosynovitis in the Hand: Two Case Reports with the MR Imaging Findings

Nontuberculous mycobacterial infections can cause destructive tenosynovitis of the hand. We report on and discuss the clinical course and distinctive radiologic findings of two patients with hand tenosynovitis secondary to M. marinum and intracellulare infection, which are different from those of the nontuberculous mycobacterial infections reported in the previous literature.

Clinical courses and predictors of outcomes in patients with monoarthritis: a retrospective study of 171 cases

To evaluate the clinical courses and outcomes of patients with monoarthritis and to investigate the predictive factors of clinical outcomes.

Broncho-Pleural Fistula with Hydropneumothorax at CT: Diagnostic Implications in Mycobacterium avium Complex Lung Disease with Pleural Involvement

Objective To determine the patho-mechanism of pleural effusion or hydropneumothorax in Mycobacterium avium complex (MAC) lung disease through the computed tomographic (CT) findings. Materials and Methods We retrospectively collected data from 5 patients who had pleural fluid samples that were culture-positive for MAC between January 2001 and December 2013. The clinical findings were investigated and the radiological findings on chest CT were reviewed by 2 radiologists. Results The 5 patients were all male with a median age of 77 and all had underlying comorbid conditions. Pleural fluid analysis revealed a wide range of white blood cell counts (410–100690/µL). The causative microorganisms were determined as Mycobacterium avium and Mycobacterium intracellulare in 1 and 4 patients, respectively. Radiologically, the peripheral portion of the involved lung demonstrated fibro-bullous changes or cavitary lesions causing lung destruction, reflecting the chronic, insidious nature of MAC lung disease. All patients had broncho-pleural fistulas (BPFs) and pneumothorax was accompanied with pleural effusion. Conclusion In patients with underlying MAC lung disease who present with pleural effusion, the presence of BPFs and pleural air on CT imaging are indicative that spread of MAC infection is the cause of the effusion.