Nasopharyngeal Carcinoma (NPC) : The value of 18-Florine Fluorodeoxyglucose (FDG) Positron Emission Tomography Computed Tomography (PET / CT) in comparison to conventional imaging modalities Computed Tomography (CT) and Magnetic Resonance Imaging (MRI)

摘要

PURPOSE: To evaluate the clinical usefulness of 18F FDG PET/CT in the management of NPC in comparison to conventional imaging modalities. METHODS: This retrospective study was done at Ospedale Niguarda, Milan, Italy. Data acquired from 24 NPC patients between May 2003 and December 2006. They had FDG PET/CT and CT or MRI during initial diagnosis and at follow up. Each findings was tabulated and compared with tissue biopsy at diagnosis and clinical status during follow up after therapy. Statistical calculation was done to derive the value of each modalities.RESULTS; The sensitivity and accuracy of PET / CT and CT / MRI are equally high at diagnosis. At follow up, a negative PET / CT finding suggests complete remission with sensitivity and negative predictive value of 100%. CONCLUSIONS: 18F FDG PET/CT is a potential modality to be utilized in following up NPC patients for evaluating response to therapy. Acknowledgement Author wishes to express appreciation to The Department of Nuclear Medicine, Radiology Head and Neck Surgery, Ospedale Niguarda, Milan , Italy for kind hospitality and participation in this collaboration activity. This study was supported by unrestricted grants from Associazione Italiana per la Ricerca sul Cancro (AIRC) and Oncologia Ca’ Granda Onlus (OCGO) Fondazione. Introduction NPC is common among the Chinese populations especially in the south China and South East Asia region with incidence of 20 to 50 per 100 000 individuals [1,2]. Despite being uncommon among other ethnic groups including the Europeans, incidence has been reported among the south Indian community as well as in the North African community [3].Ebstein Barr Viral (EBV) infection is thought to play an important role in initiating the development of this tumour. Multiple literature review revealed coexistence between EBV infection and NPC [4,5,6,7,8,9,10]. Kenneth and colleagues suggested that EBV status can be a reliable predictor for overall survival of NPC patients[11]. Most NPC patients commonly manifest themselves with painless enlarged lymph nodes in the neck which are often bilateral. When these are in association with positive EBV’s DNA, they are highly suspicious for nodal disease from NPC primary [12]. Other clinical features include nasal obstruction and epistaxis which may occur as a result of local tumor infiltration. Patients may also present with hearing problems like hearing loss, tinnitus or recurrent otitis media. In advanced cases, there may be cranial nerve dysfunction. A more generalized presentation like sore throat and headache are not uncommon. These clinical presentations are looked for at diagnosis and follow up. Besides histological typing, early detection and accurate staging at diagnosis and restaging at follow up are important prognostic determinants. Early and accurate staging at diagnosis will ensure proper treatment deliveries as prevalence of head and neck metastases is as high as 40% at the time of initial presentation. Accurate restaging after therapy is also important to determine treatment response and to answer the question whether the patient requires change in pre planned treatment regime. In current practice, conventional imaging modalities like CT and MR are routinely employed to assist clinicians in staging NPC patients. Fused integrated morphological and functional imaging modality PET/CT is another possible useful new tool to be utilized in the assessment of NPC patients. This study was conducted in view to evaluate the role of fused Positron Emission Tomography/Computed Tomography (PET/CT) in the management of NPC patients. Materials and methods Patients This study was approved by the institutional review board of the hospital.Retrospective data from 33 patients between May 2003 to December 2006, from Nuclear Medicine Department, Ospedale Niguarda, and Milan, Italy were reviewed. These are confirmed cases of nasopharyngeal carcinoma from histopathological tissue biopsy. The results were collected and