Influence of FDG-PET on primary nodal target volume definition for head and neck carcinomas

• Published in: Acta oncologica 2016-10, Vol.55 (9-10), p.1099-1106
• Main Authors: van Egmond, Sylvia L, Piscaer, Vera, Janssen, Luuk M, Stegeman, Inge, Hobbelink, Monique G, Grolman, Wilko, Terhaard, Chris H
• Format: Article
• Language: English
• Subjects: Aged; Carcinoma, Squamous Cell - diagnostic imaging; Carcinoma, Squamous Cell - pathology; Carcinoma, Squamous Cell - therapy; Chemoradiotherapy, Adjuvant; Female; Fluorodeoxyglucose F18 - administration & dosage; Follow-Up Studies; Head and Neck Neoplasms - diagnostic imaging; Head and Neck Neoplasms - pathology; Head and Neck Neoplasms - therapy; Humans; Male; Neck Dissection; Neoplasm Recurrence, Local - diagnostic imaging; Neoplasm Recurrence, Local - pathology; Neoplasm Recurrence, Local - therapy; Neoplasm Staging; Positron Emission Tomography Computed Tomography - methods; Radiation Dosage; Radiopharmaceuticals - administration & dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated; Retrospective Studies; Salvage Therapy - methods; Squamous Cell Carcinoma of Head and Neck; Tomography, X-Ray Computed - methods
• ISSN: 0284-186X; 1651-226X
• DOI: 10.1080/0284186X.2016.1182643

The role of 2-[ F]-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in routine diagnostic staging remains controversial. In case of discordance between FDG-PET and CT, a compromise has to be made between the risk of false positive FDG-PET and the risk of delaying appropriate salvage intervention. Second, with intensity modulated radiation therapy (IMRT), smaller radiation fields allow tissue sparing, but could also lead to more marginal failures. We retrospectively studied 283 patients with head and neck carcinoma scheduled for radiotherapy between 2002 and 2010. We analyzed the influence of FDG-PET/CT versus CT alone on defining nodal target volume definition and evaluated its long-term clinical results. Second, the location of nodal recurrences was related to the radiation regional dose distribution. In 92 patients, CT and FDG-PET, performed in mold, showed discordant results. In 33%, nodal staging was altered by FDG-PET. In 24%, FDG-PET also led to an alteration in nodal treatment, including a nodal upstage of 18% and downstage of 6%. In eight of these 92 patients, a regional recurrence occurred. Only two patients had a recurrence in the discordant node on FDG-PET and CT and both received a boost (high dose radiation). These results support the complementary value of FDG-PET/CT compared to CT alone in defining nodal target volume definition for radiotherapy of head and neck cancer.