[(18)F]2-fluoro-2-deoxy-D-glucose PET/CT in mediastinal masses

Surgical outcomes in mediastinal mature teratoma

Background

This study was aimed at reporting the clinical characteristics and perioperative surgical outcomes of mediastinal mature teratoma managed in a single surgical unit.

Methods

This is a retrospective analysis of 35 cases of mediastinal mature teratoma cases managed in a tertiary level thoracic surgery center over 10 years. A comprehensive analysis of perioperative surgical outcomes including complications was performed.

Results

Males (n = 22, 62.8%) were predominant in the study group. Mean age of the cohort was 31.2 ± 13.3 years. The diagnosis was unruptured mature teratoma in 17(48.6%), ruptured mature teratoma in 8 (22.8%) and mature cystic teratoma in 10 (28.6%) patients. The mean duration from symptoms was 5.5 months (range: 1 - 84 months). Open surgery was done in 22 patients (62.8%) followed by video-assisted thoracoscopic surgery in 4 (11.4%) and robotic surgery in 9 patients (25.7%). Conversion from minimal access surgery to open surgery was in 2 patients (5.7%). The mean duration of intercostal chest drainage (ICD) was 6.3 ± 1.3 days, and mean hospital stay averaged 5.8 ± 2.7 days. Most common postoperative complication was prolonged post-operative air leak (> 7 days) in 5 patients (14.3%). The peri-operative mortality was in 1 (2.8%) patient. Ruptured teratoma was a strong predictor of postoperative complications (p = 0.008).

Conclusion

Complete surgical resection is primary and effective treatment modality for mediastinal mature teratoma. A tailored approach is needed, considering the factors like tumor size, location, and relation with surrounding structures.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-024-01882-8.

Artificial Intelligence-Driven Diagnosis of Pancreatic Cancer

Pancreatic cancer is among the most challenging forms of cancer to treat, owing to its late diagnosis and aggressive nature that reduces the survival rate drastically. Pancreatic cancer diagnosis has been primarily based on imaging, but the current state-of-the-art imaging provides a poor prognosis, thus limiting clinicians' treatment options. The advancement of a cancer diagnosis has been enhanced through the integration of artificial intelligence and imaging modalities to make better clinical decisions. In this review, we examine how AI models can improve the diagnosis of pancreatic cancer using different imaging modalities along with a discussion on the emerging trends in an AI-driven diagnosis, based on cytopathology and serological markers. Ethical concerns regarding the use of these tools have also been discussed.

Mediastinal Germ Cell Tumors: A Review and Update on Pathologic, Clinical, and Molecular Features

Mediastinal germ cell tumors (MGCTs) are the most common extragonadal germ cell tumors (GCTs) and most often arise in the anterior mediastinum with a male predilection. MGCTs also have a predilection for patients with Klinefelter syndrome and possibly other genetic conditions. MGCTs, as GCTs at other extragonadal sites, are thought to arise from germ cells improperly retained during migration along the midline during embryogenesis. Similar to their counterparts in the testes, MGCTs are classified into seminomatous and nonseminomatous GCTs. Seminomatous MGCT represents pure seminoma, whereas nonseminomatous MGCTs encompass pure yolk sac tumors, embryonal carcinoma, choriocarcinoma, mature or immature teratoma, and mixed GCTs with any combination of GCT types, including seminoma. Somatic-type or hematologic malignancies can also occur in association with a primary MGCT. MGCTs share molecular findings with GCTs at other sites, most commonly the presence of chromosome 12p gains and isochromosome i(12p). Treatment includes neoadjuvant chemotherapy followed by surgical resection of residual tumor, with the exception of benign teratomas, which require only surgical resection without chemotherapy. In this review, we highlight and provide an update on pathologic, clinical, and molecular features of MGCTs. Immunohistochemical profiles of each tumor type, as well as differential diagnostic considerations, are discussed.

Mediastinal Masses: 18F-FDG-PET/CT Features Based on the International Thymic Malignancy Interest Group Classification

Imaging plays a key role in the management of mediastinal masses. In an effort to standardize the analysis of the mediastinum, the International Thymic Malignancy Interest Group (ITMIG) has proposed a three compartments-based diagnostic classification, intended for clinicians and radiologists. Several articles have documented its usefulness to guide the diagnosis using cross-sectional imaging. Similarly, fluorine-18-radiolabeled fluorodeoxyglucose positron emission tomography combined to computed tomography (¹⁸F-FDG-PET/CT) can be useful in this setting, either as a first-line diagnostic technique, or in addition to cross-sectional imaging. In this article, which is thought as an aid for nuclear medicine physicians and radiologists, we aim to present, based on the ITMIG classification, the main mediastinal pathologies that can be observed with ¹⁸F-FDG-PET/CT, and the additional diagnostic value that can be expected from this technique. For this purpose, we segmented the mediastinum according to the ITMIG classification, and reviewed the available literature for each of the corresponding organs and/or disease. Given the importance of the clinical context for the interpretation of PET imaging, we presented each of the diseases according to: (1) their suggestive clinical context; (2) the suggestive features on nonenhanced CT (which is the standard in PET imaging); and (3) the typical ¹⁸F-FDG characteristics. The purpose of this article is to depict the main features of the most common mediastinal diseases that can be encountered with ¹⁸F-FDG-PET/CT, and to highlight its diagnostic value in this setting, alone or in combination with other imaging modalities.

Surgical treatment of benign mediastinal teratoma: summary of experience of 108 cases

Background

Mediastinal teratoma is a rare disease, many cases were reported before, but few articles focus on large case analyses. The objective of this article is to summarize the clinical characteristics of benign mediastinal teratoma and the experience of surgical treatment, especially thoracoscopic surgery for benign mediastinal teratoma.

Methods

The clinical data of 108 patients with benign mediastinal teratoma confirmed by operation and pathology from January 1992 to January 2018 were analyzed retrospectively. The clinical symptoms, imaging examination, surgical methods and prognosis of all patients were analyzed. We compared the difference of thoracoscopic surgery and thoracotomy surgery using 102 patients underwent only chest surgery. Normally distributed continuous variables were compared by independent sample t test. Categorical variables were analyzed by chi-square test.

Results

Imaging examination showed that all 108 cases of mediastinal teratoma were located in the anterior region of mediastinum. All cases underwent surgical resection, postoperative pathology confirmed that all cases were benign. 1 case was taken simple neck collar incision, 5 case was taken median thoracotomy combined with neck incision, other 102 cases were taken thoracoscopic surgery (22) or thoracotomy surgery (80). 4 cases were treated with partial pericardial resection due to adhesions, 12 cases underwent partial pericardial resection, 5 cases underwent lobectomy, 9 cases underwent wedge resection of lobe, and 2 patients underwent anonymous vein angioplasty. 1 case underwent second operation because of postoperative bleeding, 1 case of chylothorax, 1 case of recurrent laryngeal nerve injury, 2 cases of wound infection, 1 case of secondary pulmonary infection. 106 cases were followed up, period from 12 months to 10 years, no recurrence of tumor was found. Comparing to take thoracotomy surgery, patients underwent thoracoscopic surgery has strong advantage on intraoperative blood loss and hospital stay days after surgery (P < 0.05). tumor maximum diameter is larger for thoracotomy surgery group, as well as more patients suffer estimated adhesions from preoperative imaging. so we compared above parameters in patients with tumor diameter less than 10 cm with or without estimated adhesions from preoperative imaging, a strong advantage still can be found in thoracoscopic surgery group, inpatients with estimated adhesions from preoperative imaging, intraoperative blood loss (38.75 ± 15.53 vs 169.17 ± 208.82., P = 0.04) and hospital stay days after surgery (5.50 ± 0.93 vs 9.43 ± 6.54., P = 0.04) were better. In patients without estimated adhesions from preoperative imaging, intraoperative blood loss (46.67 ± 10.00 vs 110.53 ± 123.13., P = 0.06) and hospital stay days after surgery (4.70 ± 1.16 vs 7.53 ± 2.32., P = 0.01) were better. Especially, in thoracoscopic surgery group, hospital stay days after surgery was significantly shorter.

Conclusion

The clinical manifestations and imaging performance of benign mediastinal teratoma were complicated, and the surgical treatment was effective. Compared with traditional thoracotomy surgery, thoracoscopic surgery can improve patients’ quality of life, less intraoperative blood loss, and less hospital stay days after surgery, so if condition is permitted, thoracoscopic surgery should be a better choice.

Is SUVmax Helpful in the Differential Diagnosis of Enlarged Mediastinal Lymph Nodes? A Pilot Study

Objective

To explore the diagnostic value of maximum standard uptake value (SUVmax) from ¹⁸F-FDG PET/CT images in enlarged mediastinal lymph nodes of unknown etiology.

Methods

We performed a retrospective study of patients with enlarged mediastinal lymph nodes on ¹⁸F-FDG PET/CT scans. SUVmax and the short axis and long axis of lymph nodes were recorded. These parameters were compared among the five commonest causes of mediastinal lymphadenopathy: lymphoma, metastatic disease, sarcoidosis, tuberculosis, and lymphadenitis. Histopathologic diagnosis was recorded as the final golden standard.

Results

A total of 94 patients (62 men and 32 women; age range 7-85 y) were included with final diagnoses of 42 patients with benign pathology and 52 patients with malignancies. The sensitivity, specificity, and the accuracy of PET/CT in diagnosis of the benign and malignant mediastinal lymph nodes were 94.2%, 73.8%, and 85.1%, respectively. The SUVmax of benign and malignant groups were 13.10 ± 5.21 and 12.59 ± 5.50, respectively, which had no statistical difference (P > 0.05). However, the long axis and the short axis of lymph nodes in the benign and malignant groups were 2.86 ± 1.02 cm, 1.77 ± 0.60 cm and 6.04 ± 3.83 cm, 3.95 ± 2.08 cm, respectively (P < 0.05). The diagnostic values of PET/CT were higher than those of the long or short axis. However, the specificity of PET/CT was lower (73.8%) than that from the long or short axis (90.5% and 92.9%, respectively), although no statistical difference existed. Among the five common causes of mediastinal lymphadenopathy, significant differences could be seen in SUVmax and in the long axis and the short axis of lymph nodes (P < 0.05).

Conclusions

SUVmax, a commonly used semiquantitative measurement, was not helpful for differentiation between benign and malignant lesions in patients with enlarged mediastinal lymph nodes in this study. Many benign lesions, such as sarcoidosis and tuberculosis, had high FDG uptake, possibly a trend that the size of the lymph nodes seems to have some diagnostic value.

Management of large mediastinal masses: surgical and anesthesiological considerations

Large mediastinal masses are rare, and encompass a wide variety of diseases. Regardless of the diagnosis, all large mediastinal masses may cause compression or invasion of vital structures, resulting in respiratory insufficiency or hemodynamic decompensation. Detailed preoperative preparation is a prerequisite for favorable surgical outcomes and should include preoperative multimodality imaging, with emphasis on vascular anatomy and invasive characteristics of the tumor. A multidisciplinary team should decide whether neoadjuvant therapy can be beneficial. Furthermore, the anesthesiologist has to evaluate the risk of intraoperative mediastinal mass syndrome (MMS). With adequate preoperative team planning, a safe anesthesiological and surgical strategy can be accomplished.