Recurrence patterns after a decreased dose of 40Gy to the elective treated neck in head and neck cancer.
To investigate the patterns of regional recurrences with emphasis on recurrences in the electively irradiated lymph node regions after dose de-escalation to 40Gy (EQD2Gy) in head and neck cancer.



Two hundred thirty-three patients treated with radio(chemo)therapy using 40Gy (EQD2Gy) to the elective lymph node regions were included. All regional recurrences were reconstructed and projected on the initial radiotherapy planning Computed Tomography studies to identify the localization of recurrence. Furthermore, patient and treatment characteristics were correlated with the regional recurrences to identify risk factors.



The median follow-up in our study was 26months. Overall- and disease-specific survival at 2years were 71.2% (95% CI 65.3-77.1) and 64.2% (95% CI 59.2-69.3), respectively. Local, regional and distant control at 2years was 84.1% (95% CI 79.1-89.2), 89.2% (95% CI 84.3-94.1) and 83.2% (95% CI 76.3-90.1), respectively. Twenty-eight patients experienced a regional recurrence. Fourteen of these patients had a recurrence within the high dose volume (14 of 28). Nine had a recurrence in the electively irradiated lymph node regions (9 of 28) and 5 recurrences occurred outside the target volume. The actuarial rate of recurrence in the electively irradiated lymph node regions was 3.9% (95% CI 1.8-6.0) at 2years. No significant associations could be observed between recurrence in electively irradiated lymph node regions and age, gender, tumor site, stage, or the presence of human papillomavirus in oropharyngeal cancers.



The actuarial rate of recurrence in the electively irradiated lymph node regions was 3.9% (95% CI 1.8-6.0) at 2years. This incidence is comparable to recurrence rates after standard dose of 50Gy, suggesting that lower doses to the elective neck do not result in higher regional recurrences.
Department of Radiation Oncology, KU Leuven - University of Leuven, University Hospitals Leuven, Belgium.
Daan
D
Nevens
Department of Radiation Oncology, Ghent University Hospital, Belgium.
Fréderic
F
Duprez
Department of Radiation Oncology, Université Catholique de Louvain, CHU-UCL-Namur, Belgium.
Jean-François
JF
Daisne
Department of Nuclear Medicine, Ghent University Hospital, Belgium.
Julie
J
Schatteman
Department of Medicine, KU Leuven - University of Leuven, University Hospitals Leuven, Belgium.
Aline
A
Van der Vorst
Department of Radiation Oncology, Ghent University Hospital, Belgium.
Wilfried
W
De Neve
Department of Radiation Oncology, KU Leuven - University of Leuven, University Hospitals Leuven, Belgium. Electronic address: sandra.nuyts@uzleuven.be.
Sandra
S
Nuyts
D000328:Adult; D000368:Aged; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D008198:Lymph Nodes / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D011879:Radiotherapy Dosage
Dose de-escalation; Head and neck cancer; Radiotherapy