title: [Role of 18FDG-PET/CT in the management and gross tumor volume definition for radiotherapy of head and neck cancer; single institution experiences based on long-term follow-up].
abstract: The purpose of our work is evaluation of the impact of 18FDG-PET/CT on the complex management of locoregionally advanced (T3-4N1-3) head and neck squamous cell cancer (LAHNSC), and on the target definition for 3D conformal (3DCRT) and intensity-modulated radiotherapy (IMRT). 18FDG-PET/CT were performed on 185 patients with LAHNSC prior to radiotherapy/chemoradiation in the treatment position between 2006 and 2011. Prior to it 91 patients received induction chemotherapy (in 20 cases of these, baseline PET/CT was also available). The independently delineated CT-based gross tumor volume (GTVct) and PET/CT based ones (GTVpet) were compared. Impact of PET/CT on the treatment strategy, on tumor response evaluation to ICT, on GTV definition furthermore on overall and disease-specific survival (OS, DSS) was analysed. PET/CT revealed 10 head and neck, 2 lung cancers for 15 patients with carcinoma of unknown primary (CUP) while 3 remained unknown. Second tumors were detected in 8 (4.4%), distant metastasis in 15 (8.2%) cases. The difference between GTVct and GTVpet was significant (p=0.001). In 16 patients (14%) the GTVpet were larger than GTVct due to multifocal manifestations in the laryngo-pharyngeal regions (4 cases) or lymph node metastases (12 cases). In the majority of the cases (82 pts, 72%) PET/CT-based conturing resulted in remarkable decrease in the volume (15-20%: 4 cases, 20-50%: 46 cases, >50%: 32 cases). On the basis of the initial and post-ICT PET/CT comparison in 15/20 patients more than 50% volume reduction and in 6/20 cases complete response were achieved. After an average of 6.4 years of follow-up the OS (median: 18.3±2.6 months) and DSS (median: 25.0±4.0 months) exhibited close correlation (p=0.0001) to the GTVpet. In cases with GTVpet <10 cm3 prior to RT, DSS did not reach the median, the mean is 82.1±6.1 months, while in cases with GTVpet 10-40 cm3 the median of the DSS was 28.8±4.9 months (HR = 3.57; 95% CI: 1.5-8.3), and in those with GTVpet >40 cm3 the median DSS was 8.4±0.96 months (HR= 11.48; 95% CI: 5.3-24.9). Our results suggest that 18FDG-PET/CT plays an important role for patient with LAHNSC, by modifying the treatment concept and improving the target definition for selective RT modalities. Volumetric PET/CT-based assessment of the tumor response after ICT gives valuable contribution to further therapy planning.
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Katalin
authors.initials: K
authors.lastname: Hideghéty
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Adrienne
authors.initials: A
authors.lastname: Cserháti
authors.affiliation: Nukleáris Medicina Tanszék, Szegedi Tudományegyetem, Szeged, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Besenyi
authors.affiliation: Sürgõsségi Betegellátó Osztály, Bács-Kiskun Megyei Kórház, Kecskemét, Hungary.
authors.forename: Levente
authors.initials: L
authors.lastname: Zag
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Szilvia
authors.initials: S
authors.lastname: Gaál
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Együd
authors.affiliation: Klinikum rechts der Isar, Technische Universität München, Department of Radiation Oncology, München, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Mózes
authors.affiliation: Klinikai Központ, Debreceni Egyetem, Onkológiai Intézet, Debrecen, Hungary.
authors.forename: Erika
authors.initials: E
authors.lastname: Szántó
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Melinda
authors.initials: M
authors.lastname: Csenki
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Rusz
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Varga
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Dobi
authors.affiliation: Onkoterápiás Klinika, Szegedi Tudományegyetem, Szeged, Hungary. katalin.hideghety@gmail.com.
authors.forename: Anikó
authors.initials: A
authors.lastname: Maráz
authors.affiliation: Nukleáris Medicina Tanszék, Szegedi Tudományegyetem, Szeged, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Pávics
authors.affiliation: Pozitron Diagnosztika Központ, Budapest, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Lengyel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002173:Cancer Care Facilities; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D006814:Hungary; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging / Q000532:radiotherapy; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted; D000077195:Squamous Cell Carcinoma of Head and Neck; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18