18F-FMISO PET Guided Dose Escalation in Nasopharyngeal Carcinoma - a Feasibility and Planning Study

Inclusion Criteria: * T3-T4 disease with no evidence of distant metastasis. * Histological diagnosis of WHO Type II or III NPC * No evidence of distant metastases in staging work up (including lung, liver and bone imaging). * Planned for upfront radiotherapy and/or chemotherapy. * Cross sectional imaging of the primary and neck disease (MRI preferred) * Performance status of ECOG grade 0 or 1 * No prior tumour therapy * At least 21 years of age, of either sex. * Negative serum pregnancy test within 14 days prior to registration for women of childbearing potential; * Adequate bone marrow, renal and hepatic function defined as follows: Bone marrow: WBC \> 3000 / mm3 (ANC \> 1500 / mm3 ) Platelets \> 100 000 / mm3. Hb \> 10 gm/dl Renal: serum creatinine within institutional normal range(or) lower than the lower limit of institutional normal range : calculated creatinine clearance \> 50 ml / min Hepatic: enzymes (SAP, SGOT) \< 2x normal: bilirubin \< 24 mol / l. Exclusion Criteria: * Allergic to 18F-fluoromisonidazole or Nitroimidazoles * Planned for neoadjuvant chemotherapy * Uncontrolled hypercalcaemia: calcium 2.7 mmol/L (10.8 mg/dL). * Other serious concomitant systemic disorders incompatible with the study (at the discretion of the investigator). * Have serious active infection. * Pregnant or lactating female subjects and subjects with reproductive potential not implementing adequate contraceptive measures