High-LET radiotherapy for adenoid cystic carcinoma of the head and neck: 15 years’ experience with raster-scanned carbon ion therapy

• Published in: Radiotherapy and oncology 2016-02, Vol.118 (2), p.272-280
• Main Authors: Jensen, Alexandra D, Poulakis, Melanie, Nikoghosyan, Anna V, Welzel, Thomas, Uhl, Matthias, Federspil, Philippe A, Freier, Kolja, Krauss, Jürgen, Höss, Angelika, Haberer, Thomas, Jäkel, Oliver, Münter, Marc W, Schulz-Ertner, Daniela, Huber, Peter E, Debus, Jürgen
• Format: Article
• Language: English
• Subjects: ACC; Adenoid cystic carcinoma; Adolescent; Adult; Aged; Aged, 80 and over; Carbon ion therapy; Carbon ions; Carcinoma, Adenoid Cystic - radiotherapy; Cohort Studies; Disease-Free Survival; Female; Follow-Up Studies; Heavy Ion Radiotherapy - methods; Hematology, Oncology and Palliative Medicine; Humans; IMRT; Male; Malignant salivary gland tumors; Middle Aged; MSGTs; Raster-scanning; Salivary Gland Neoplasms - radiotherapy; Survival Rate; Treatment Outcome; Young Adult
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2015.05.010

Abstract Purpose Locoregional control (LC) in malignant salivary gland tumors is dose-dependent, initial results with particle therapy were promising. We report our experience with raster-scanned, intensity-controlled carbon ion therapy (C12) and IMRT in 309 patients with pathologically confirmed adenoid cystic carcinoma (ACC) of the head and neck. Patients and methods Treatment records of patients treated with C12 between 08/1998 and 05/2013 were evaluated regarding tumor stage, treatment, toxicity (CTCAE v3), LC, progression-free survival (PFS) and overall survival (OS). Response assessment was carried out according to RECIST1.1. Results Tumor stages were mostly advanced (T4a/b: 60%, macroscopic disease: 71%), most common sites of origin were the paranasal sinus (37%). At a median follow-up at 33.9 months, LC, PFS, and OS at 3 and 5 year estimates are 83.7%/58.5%, 67.8%/56.1%, and 88.9%/74.6%. LC correlates with T-stage but neither nodal stage, age, relapse state, nor margin status. RECIST did not correlate with LC or survival rates. Conclusion IMRT plus C12 boost results in good control and survival rates at moderate toxicity. Margin status did not correlate with LC in T4 tumors, extensive and potentially mutilating surgical procedures may have to be re-evaluated. RECIST assessment did not correlate with either LC or survival rates; potentially more meaningful radiological parameters need to be developed.