Retrospective Study On The Influencing Factors Of Survival Rate After Treatments Of Oral Cancer

THE CLINICAL UTILITY OF POSITRON EMISSION TOMOGRAPHY FOR INITIAL DIAGNOSIS AND FOLLOW UP CHECK IN ORAL AND MAXILLOFACIAL CANCER PATIENTS

BACKGROUND: Positron Emission Tomography(PET) with [18F]-fluorodeoxyglucose (FDG) is a new imaging technique that has the advantage of imaging metabolic changes linked to malignancy. PET-FDG can provide a functional image of the regional biochemistry which may be more sensitive and accurate for detecting the presence of tumor in early stage. Recently, the clinical use of PET scan has been studied in many cancers but, there is a few clinical reports in oral and maxillofacial cancers. We have evaluated the ability of PET-FDG for initial diagnosis and detection of early subclinical recurrent malignancies in follow up check. PATIENTS AND METHODS: PET-FDG studies were performed in 33 patients from october, 1997 to september, 1998. 14 patients underwent PET-FDG evaluation for initial diagnosis and 19 patients for follow up check. RESULTS: Evaluated for initial diagnosis, PET-FDG was found to have an overall accuracy of 79%, sensitivity of 90%, specificity of 60%, positive predictive rate of 80% and negative predictive rate of 75%. Evaluated for follow up check, PET-FDG demonstrated accuracy of 84%, sensitivity of 91%, specificity of 75%, positive predictive rate of 83% and negative predictive rate of 86%. CONCLUSION: These data indicate that PET-FDG scan appears to be effective in initial diagnosis and detection of early recurrent oral and maxillofacial malignancies. The informations gained with PET-FDG can be included for essential treatment planning because of possibility of detection for early subclinical malignancies and distant metastases.

THE UTILITY OF POSITRON EMISSION TOMOGRAPHY IN ORAL AND MAXILLOFACIAL CANCER

Positron emission tomography(PET) is a diagnostic method that creates high resolution, 3-Dimentional tomographic images of the distribution of positron emitting radionuclides in human body. Computed tomography(CT) and magnetic resonance imaging(MRI) are routinely used to delineate the presence and extent of primary and metastatic oral and maxillofacial malignancy. Because the CT and MRI criteria for malignancy depend upon morphology, these imaging techniques have limitations in their ability to identify malignant tissue when fascial planes are distorted or destroyed. PET has the advantage of imaging metabolic changes that appear to be linked to malignancy. Recently, PET has shown promise in the early detection of primary and metastatic oral and maxillofacial canter and has been used to evaluate the tumor response to chemotherapy and radiotherapy. We report cases of diagnosis of oral and maxillofacial cancers and review the literatures to determine whether PET is effective in identifying oral and maxillofacial tumors.

PHOTODYNAMIC THERAPY FOR EARLY TONGUE CANCER

The standard methods of treatment in oral and maxillofacial cencer are surgery, radiotherapy and chemotherapy. But all of them can induce significant morbidities, surgery in this area can cause remarkable junctional and esthetic problems. The applications of photodynamic therapy(PDT) has been studying and trying in these days to minimize post-treatment complications. It can almost directly affect tumor cells except surrounding normal tissues, so we are able to reduce post-operative complications. But there can be a couple of complications after PDT, as like skin photosensitivity, so therapists must attend to its use and completely understand their mechanism before doing it. In our clinic, PDT was tried in an early tongue cancer patient using topically applied delta-aminolaevulinic acid (delta-ALA). The 64-year-old man was gargled with 5% delta-ALA 4 hours before irradiation. The previous punched biopsy was reported as well differentiated squamous cell carcinoma(T1N0M0). Light of 635nm wave-length from argon-pumper dye laser was used. Total 150J/cm2 was applied. After 10 days, PDT was applied again in a small suspicious area, 10 days after then, small area was excised and examined histologically. It was revealed as cancer free. Now, the patient was periodically checked up. Conclusively, PDT can be thought to be a acceptable alternative and promising method in treating of early oral and maxillofacial cancer.