PhD ceremony Ms. L.M.A. Schreurs: FDG-PET/CT in staging and treatment of esophageal cancer

PhD ceremony: Ms. L.M.A. Schreurs

Dissertation: FDG-PET/CT in staging and treatment of esophageal cancer

Promotor(s): prof. J.T.M. Plukker, prof. J.A. Langendijk

Faculty: Medical Sciences

To determine the best treatment for each esophageal cancer patient, it is important to examine the extent to which a cancer has developed by spreading. This is called staging. For this purpose, every patient undergoes an endoscopic ultrasound (EUS), a multidetector computed tomography (md-CT) and a positron emission tomography with labeled glucose (FDG-PET). A good sequence of these procedures is essential to prevent unnecessary investigations and costs. After a state-of-the-art staging, routine ultrasound of the neck is useless because it does not improve the accuracy of staging and has no therapeutic consequences for patients with cervical metastases. However, it is still indicated to achieve cytological biopsies of suspected lymph nodes. In a theoretical, statistical analysis, the ability to predict surgical resectability of each modality was analyzed, not only as a single test but also after one or two tests outcomes. In the sequence FDG-PET / md-CT / EUS, 15% of invasive EUS could be prevented. This order is more sensitive (78% vs. 50%) and specific (94-97% vs. 80%) than the conventional staging model consisting of md-CT, EUS and a selective FDG-PET on indication. Also the additional value of FGD-PET/CT was investigated. PET/CT fusion improved in 30% of the esophageal cancer patients the nodal staging concerning exact localization and number. Application of FDG-PET/CT in radiotherapy planning leads to significant changes of the radiation volumes in 38% of the patients. These treatment plan modifications by FDG-PET/CT resulted in significant changes in dose distributions to heart and lungs.