title: The Clinical Usefulness of (18)F-Fluorodeoxyglucose Positron Emission Tomography (PET) to Predict Oncologic Outcomes and PET-Based Radiotherapeutic Considerations in Locally Advanced Nasopharyngeal Carcinoma.
abstract: OBJECTIVE
  We investigated (18)F-fluorodeoxyglucose positron emission tomography (PET)-derived parameters as prognostic indices for disease progression and survival in locally advanced nasopharyngeal carcinoma (NPC) and the effect of high-dose radiotherapy for a subpopulation with PET-based poor prognoses.
  
  
  METHODS
  Ninety-seven stage III and Iva-b NPC patients who underwent definitive treatment and PET were reviewed. For each primary, nodal, and whole tumor, maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) were evaluated.
  
  
  RESULTS
  Based on the C-index (0.666) and incremental area under the curve (0.669), the whole tumor TLGwas the most useful predictorfor progression-free survival (PFS); thewhole tumor TLG cut-off value showing the best predictive performance was 322.7. In multivariate analysis, whole tumor TLG was a significant prognostic factor for PFS (hazard ratio [HR], 0.3; 95% confidence interval [CI], 0.14 to 0.65; p=0.002) and OS (HR, 0.29; 95% CI, 0.11 to 0.79; p=0.02). Patients with low whole tumor TLG showed the higher 5-year PFS in the subgroup for only patients receiving intensity modulated radiotherapy (77.4% vs. 53.0%, p=0.01). In the subgroup of patients with high whole tumor TLG, patients receiving an EQD2 ≥ 70 Gy showed significantly greater complete remission rates (71.4% vs. 33.3%, p=0.03) and higher 5-year OS (74.7% vs. 19.6%, p=0.02).
  
  
  CONCLUSIONS
  Our findings demonstrated that whole tumor TLG could be an independent prognostic factor and high-dose radiotherapy could improve outcomes for NPC showing high whole tumor TLG.
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hong In
authors.initials: HI
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jeongshim
authors.initials: J
authors.lastname: Lee
authors.affiliation: Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yun Ho
authors.initials: YH
authors.lastname: Roh
authors.affiliation: Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Mijin
authors.initials: M
authors.lastname: Yun
authors.affiliation: Department of Internal Medicine, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Byoung Chul
authors.initials: BC
authors.lastname: Cho
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chang Geol
authors.initials: CG
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ki Chang
authors.initials: KC
authors.lastname: Keum
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D005500:Follow-Up Studies; D006019:Glycolysis / Q000528:radiation effects*; D006801:Humans; D060828:Induction Chemotherapy; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011829:Radiation Dosage; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D020266:Radiotherapy, Conformal; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies; D017211:Treatment Failure; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18F-fluorodeoxyglucose; Intensity-modulated radiotherapy; Nasopharyngeal carcinoma; Positron emission tomography; Radiotherapy dosage