Comparative analysis of the N staging for lung cancer and the impact of incorporation of lymph node size on CT

Objective: To assess the discrimination performance of N staging in the current 9th edition for lung cancer and to investigate the value of lymph node (LN) size in improving discrimination in clinical N staging. Materials and Methods: Patients who underwent lobectomy or pneumonectomy for lung cancer from January 2013 to April 2021 were retrospectively analyzed. The clinical and pathologic N categories were reclassified retrospectively according to the 9th edition (N0, N1, N2a, N2b), the 8th edition’s proposal (N0, N1a, N1b, N2a1, N2a2, N2b), and the 7th edition (N0, N1, N2). The prognostic discrimination performance for overall survival (OS) was evaluated using the concordance index (C-index) and compared across each edition. To investigate the value of LN size consideration, the short-axis diameter of the largest clinically positive LN was measured on preoperative CT, and the optimal threshold for a LN size was defined. Prognostic and discrimination performances were assessed based on the LN size cutoff descriptor. Results: A total of 4753 patients were included in the study. The performance of the 9th edition surpassed that of the 7th edition in both pathologic and clinical staging. Compared with the 8th edition’s proposal, the 9th edition showed comparable performance in pN2 (C-index, 0.560 vs. 0.569, p=0.213) but lower performance in pN1 (0.500 vs. 0.539, p=0.048), resulting in a slightly lower C-index in the total population (0.666 vs. 0.667, p=0.020). For clinical staging, no significant difference of performance between the 9th edition and the 8th edition’s proposal. For LN size analysis, the cutoff value was defined as 15 mm and patients were classified into cN0, cN1 (<15 mm), cN1 (≥15 mm), cN2a, cN2b (<15 mm), and cN2b (≥15 mm). cN1 (≥15 mm) had higher mortality risk relative to cN1 (<15 mm) and the risk of cN1 (≥15 mm) was comparable to that of cN2b. This LN-size classification improved discrimination within the cN1 (C-index from 0.500 to 0.579, p<0.05). Conclusion: The revision of N category in the 9th edition appears reasonable, as it offers enhanced prognostic discrimination compared with the 7th edition and is comparable to the 8th edition’s proposal. An additional descriptor for N1 would be necessary to further refine the N category. In this regard, the cN (≥15 mm) could be an effective descriptor in the clinical staging of N1.Docto

Histogram analysis of arterial spin labeling perfusion data to determine the human papillomavirus status of oropharyngeal squamous cell carcinomas

Purpose To evaluate the correlation between histogram parameters derived from pseudo-continuous arterial spin labeling (PCASL) and human papillomavirus (HPV) status in patients with oropharyngeal squamous cell carcinoma (OPSCC). Methods This study included a total of 58 patients (HPV-positive: n = 45; -negative: n = 13) from a prospective cohort of consecutive patients aged &gt;= 18 years, who were newly diagnosed with oropharyngeal squamous cell carcinoma. All patients were required to have undergone pre-treatment MRI with PCASL to measure regional perfusion. The region of interest was drawn by two radiologists, encompassing the entire tumor volume on all corresponding slices. Differences in the histogram parameters derived from tumor blood flow (TBF) in ASL were assessed for HPV-positive and -negative patients. Receiver operating characteristic curve analysis was performed to determine the best differentiating parameters, and a leave-one-out cross-validation was used. Results Patients with HPV-positive OPSCC showed a significantly lower overall standard deviation and 95th percentile value of tumor blood flow (P &lt; .007). The standard deviation of TBF was the single best predictive parameter. Leave-one-out cross-validation tests revealed that the area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity were 0.745, 75.9%, 75.6%, and 76.9%, respectively. Conclusion PCASL revealed differences in perfusion parameters according to HPV status in patients with OPSCC, reflecting their distinct histopathology

Rare Neurovascular Diseases in Korea: Classification and Related Genetic Variants

Rare neurovascular diseases (RNVDs) have not been well-recognized in Korea. They involve the central nervous system and greatly affect the patients' lives. However, these diseases are difficult to diagnose and treat due to their rarity and incurability. We established a list of RNVDs by referring to the previous literature and databases worldwide to better understand the diseases and their current management status. We categorized 68 RNVDs based on their pathophysiology and clinical manifestations and estimated the prevalence of each disease in Korea. Recent advances in genetic, molecular, and developmental research have enabled further understanding of these RNVDs. Herein, we review each disease, while considering its classification based on updated pathologic mechanisms, and discuss the management status of RNVD in Korea