Author of

• 11842

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  P2.15 - Poster Session 2 - Thymoma (ID 191)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Thymoma & Other Thoracic Malignancies
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11846

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    P2.15-004 - Management of primary tumours of the Thymus and usefulness of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET). (ID 1226)

    09:30 - 09:30  |  Author(s): D.S. Moraitis
    • Abstract

    Background
    Thymic epithelial tumours are the predominant lesions that arise in the anterior mediastinum, represent 0.2—1.5% of all malignancies and overall, it is an uncommon malignancy with an incidence of 0.15 cases per 100,000 population. Recent studies have shown the usefulness of [18]F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating between World Health Organization (WHO) histological subgroups of thymic epithelial tumours. We present our experience in the management of patients with primary thymic tumours.

    Methods
    We evaluated retrospectively the medical records of 21 consecutive patients (pts) who underwent thymectomy in our department. All but one patients underwent radical thymectomy through a median sternotomy. One female patient was subjected to transcervical procedure. In all procedures, the upper and lower thymic poles were traced as far into the neck and down toward the diaphragm as necessary to ensure complete resection, and all fatty tissue between the phrenic nerves was included in the resection. Myasthenia gravis was present in 3 pts (14.28 %), while 9 pts (42.85 %) were asymptomatic.Diagnostic procedures included contrast enhanced Computed Tomography of the thorax (21 pts) and/or Magnetic Resonance Imaging (3 pts) and in the case of 7 patients, an FDG PET-CT was performed. The maximum standardized uptake value (SUV~max~) of the tumor, the mean SUV of mediastinum, and the tumor/mediastinum (T/M) ratio (ratio of peak SUV of the tumor to mean SUV of mediastinum) were compared to determine whether primary thymic tumours could be distinguished by [18]F-FDG PET/CT.

    Results
    There were 11 male and 10 female pts with a mean age of 46.09 years. The histopathology examination revealed 13 thymomas, 1 endocrine carcinoma and 7 hyperplasias. Type A thymomas were found in 2 pts (15.38 %), AB in 5 pts (38.46 %), B1 in 2 pts (15.38%), B2 in 1 pt (7.7 %) and B3 in 2 pts (15.38 %), while 2 thymomas were unclassified. The mean diameter of the resected masses was 7.03 cm. Three pts were classified as Masaoka IIA stage (23.07%) and two as Masaoka IIB (15.38%), who received adjuvant radiotherapy. All the others were classified as Masoka I. All tumours were totally resected. The 5 year survival was 100%. There was recurrence of the endocrine carcinoma within 5 years and the pt underwent a reoperation.The SUV~max ~values of thymomas were 2.31+/- 0.59, while the SUV~max~ values of mediastinum were 1.74 +/- 0.08.

    Conclusion
    Tumours of the thymus are an heterogeneous group of tumours, ranging from relatively “benign”thymomas to highly aggressive carcinomas. Surgery continues to be the mainstay of treatment and complete resection of the tumour remains the most important prognostic factor. A recurrence should be completely resected whenever possible, because this approach is associated with good long-term survival. FDG-PET can help characterize various thymic lesions, however, larger prospective studies are further required to substantiate these findings.