ObjectiveTo investigate the clinical characteristics and treatment of primary mediastinal yolk sac tumor (PMYST). MethodsWe collected the clinical data of PMYST patients who were admitted to the Department of Thoracic Surgery of Peking Union Medical College Hospital from September 2000 to September 2020. The clinical and pathological characteristics, treatment and prognosis of PMYST patients were retrospectively analyzed. Results Finally 18 patients were enrolled, including 17 males and 1 female with a median age of 22.0 (16.6, 26.2) years. Patients had increased level of alpha fetoprotein (AFP). The pathological type can be single yolk sac tumor or combined with other mediastinal germ cell tumors. Chemotherapy and radical surgery were the main treatment methods. Extensive resection was feasible for patients with tumor invasion of other organs. Seven patients developed lung or pleural metastasis after operation, and 3 of them had extrapleural metastasis. One patient recurred within 1 year after surgery. All patients were followed up by telephone or outpatient department. At the last follow-up, 5 patients survived, 9 died, and 4 were lost to follow up, with a median survival of 16.8 months. The median disease-free survival was 14.9 months. The survival rates at 1, 3 and 5 years were 73.3%, 28.6% and 11.8%, respectively. ConclusionPMYST often occurs in young-middle aged male patients. Preoperative puncture can provide an effective diagnostic basis. R0 resection, AFP returning to normal after treatment and no metastasis may be potential indicators of good prognosis. The overall prognosis of PMYST is poor, and some patients can achieve long-term survival after treatment.
Objective To assess the safety and clinical outcomes of segmentectomy in one- or two-staged video-assisted thoracoscopic surgery (VATS) for bilateral lung cancer. MethodsWe retrospectively enrolled 100 patients who underwent VATS segmentectomy for bilateral lung cancer at the Department of Thoracic Surgery of Peking Union Medical College Hospital from December 2013 to May 2022. We divided the patients into two groups: a one-stage group (52 patients), including 17 males and 35 females with a mean age of 55.17±11.09 years, and a two-stage group (48 patients), including 16 males and 32 females with a mean age of 59.88±11.48 years. We analyzed multiple intraoperative variables and postoperative outcomes. Results All 100 patients successfully completed bilateral VATS, and at least unilateral lung received anatomical segmentectomy. Patients in the one-stage group were younger (P=0.040), had lower rate of comorbidities (P=0.030), were less likely to have a family history of lung cancer (P=0.018), and had a shorter interval between diagnosis and surgery (P=0.000) compared with patients in the two-stage group. Wedge resection on the opposite side was more common in the one-stage group (P=0.000), while lobectomy was more common in the two-stage group. The time to emerge from anesthesia in the one-stage group was longer than that in the first and second operations of the two-stage group (P=0.000, P=0.002). Duration of surgery and anesthesia were similar between two groups (P>0.05). Total number of lymph node stations for sampling and dissection (P=0.041) and lymph nodes involved (P=0.026) were less in the one-stage group. Intraoperative airway management was similar between two groups (P>0.05). The one-stage group was associated with lower activities of daily living (ADL) scores. Conclusion Segmentectomy is safe in one- or two-staged VATS for bilateral lung cancer, including contralateral sublobectomy and lobectomy. Duration of surgery and perioperative complications are similar between two groups, but the one-stage group is associated with lower ADL scores. On the basis of comprehensive consideration in psychological factors, physical conditions and personal wishes of patients, one-staged sequential bilateral VATS can be the first choice.
ObjectiveTo propose a lung artery segmentation method that integrates shape and position prior knowledge, aiming to solve the issues of inaccurate segmentation caused by the high similarity and small size differences between the lung arteries and surrounding tissues in CT images. MethodsBased on the three-dimensional U-Net network architecture and relying on the PARSE 2022 database image data, shape and position prior knowledge is introduced to design feature extraction and fusion strategies to enhance the ability of lung artery segmentation. The performance metrics for evaluating the model include Dice Similarity Coefficient (DSC), sensitivity, accuracy, and Hausdorff distance (HD95). ResultsThe study included lung artery imaging data from 203 patients, which were divided into training set (100 patients), validation set (30 patients), and test set (73 patients). Through the backbone network, a rough segmentation of the lung arteries was performed to obtain a complete vascular structure; the branch network integrating shape and position information was used to extract features of small pulmonary arteries, reducing interference from the pulmonary artery trunk and left and right pulmonary arteries. Experimental results show that the segmentation model based on shape and position prior knowledge has a higher DSC (82.81%±3.20% vs. 80.47%±3.17% vs. 80.36%±3.43%), sensitivity (85.30%±8.04% vs. 80.95%±6.89% vs. 82.82%±7.29%), and accuracy (81.63%±7.53% vs. 81.19%±8.35% vs. 79.36%±8.98%) compared to traditional three-dimensional U-Net and V-Net methods. HD95 can reach (9.52±4.29) mm, which is 6.05 mm lower than traditional methods, showing excellent performance in segmentation boundaries. ConclusionThe lung artery segmentation method based on shape and position prior knowledge can achieve precise segmentation of lung artery vessels and has potential application value in tasks such as bronchoscopy or percutaneous puncture surgery navigation.