Impact and prognostic value of 18F-fluorodeoxyglucose positron emission tomography-computed tomography scan in the evaluation of residual head and neck cancer: Single-center experience from Pakistan.

BACKGROUND: Overview of clinical impact of positron emission tomography-computed tomography (PET-CT) scans in patients with head and neck carcinomas at our center. METHODS: Retrospective review of posttreatment 18F-fluorodeoxyglucose (18F-FDG) PET-CT scans in patients with head and neck carcinomas with risk of residual disease. Clinical outcome served as the reference standard. RESULTS: This study included 93 patients (65.6% males, mean age: 48.8 years ± 17.2 standard deviation) with squamous cell carcinoma as most frequent histopathology (91.4%). PET-CT scans were performed on average 6 months posttreatment. Diagnostic accuracy, positive predictive value, and negative predictive value of PET-CT for disease were found to be 88%, 88%, and 92%, respectively. A median follow-up of 24 months was available for 91 patients. Kaplan-Meier curves showed significantly higher disease-free survival with negative PET-CT as compared to positive PET-CT (P = 0.01) and maximum standardized uptake values of <5.0 (P = 0.01). CONCLUSION: FDG PET-CT has diagnostic and prognostic implications in treated patient of head and neck cancers.

Aggressive Disease Course of Papillary Thyroid Carcinoma with Focal Undifferentiated Component: A Case Report.

We report an aggressive papillary thyroid carcinoma (PTC) with focal undifferentiated component in a 32-year-old female. She had limited disease confined within the thyroid gland at diagnosis. Within 12 months of thyroidectomy and radioiodine ablation, thyroglobulin (Tg) levels were elevated. Second radioiodine ablative dose was given, however, stimulated Tg levels showed an upward trend with negative iodine scan within 12 months. An 18F fludeoxyglucose-avid solitary pulmonary nodule that was detected on positron emission tomography/computed tomography scan was resected followed by empiric radioiodine therapy. Within the next 10 months she developed multifocal bone metastases. The multifocal disease was rendered inoperable and treated with external beam radiation. The patient is on follow-up, and the Tg level continues to rise with local disease progression. In a small percentage of patients, PTC behaves as a very aggressive disease despite treatment. Focally undifferentiated thyroid carcinoma is an expression of the extreme end of the spectrum of differentiated thyroid carcinoma.