Intensity Modulated Radiotherapy (IMRT) With Carbon Ion Boost in the Multimodal Treatment of Salivary Duct Carcinoma

Sebastian Adeberg; Paul Windisch; Felix Ehret; Melissa Baur; Sati Akbaba; Thomas Held; Denise Bernhardt; Matthias F Haefner; Juergen Krauss; Steffen Kargus; Christian Freudlsperger; Peter Plinkert; Christa Flechtenmacher; Klaus Herfarth; Juergen Debus; Stefan Rieken

doi:10.3389/fonc.2019.01420

Intensity Modulated Radiotherapy (IMRT) With Carbon Ion Boost in the Multimodal Treatment of Salivary Duct Carcinoma

Front Oncol. 2019 Dec 20:9:1420. doi: 10.3389/fonc.2019.01420. eCollection 2019.

Authors

Sebastian Adeberg^{1

2

3

4}, Paul Windisch¹, Felix Ehret¹, Melissa Baur¹, Sati Akbaba^{1

2}, Thomas Held^{1

2}, Denise Bernhardt^{1

2}, Matthias F Haefner^{1

2}, Juergen Krauss⁵, Steffen Kargus⁶, Christian Freudlsperger⁶, Peter Plinkert⁷, Christa Flechtenmacher⁸, Klaus Herfarth^{1

2

4}, Juergen Debus^{1

2

3

4

5}, Stefan Rieken^{1

2

4}

Affiliations

¹ Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.
² Heidelberg Institute for Radiation Oncology, Heidelberg, Germany.
³ Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
⁴ Heidelberg Ion-Beam Therapy Center, Heidelberg, Germany.
⁵ National Center for Tumor Diseases, Heidelberg, Germany.
⁶ Department of Oral and Maxillofacial Surgery, Heidelberg University Hospital, Heidelberg, Germany.
⁷ Department of Otorhinolaryngology, Heidelberg University Hospital, Heidelberg, Germany.
⁸ Department of Pathology, Heidelberg University Hospital, Heidelberg, Germany.

Abstract

Background: To assess outcomes and treatment related toxicity following intensity-modulated radiotherapy (IMRT) and a Carbon Ion Radiotherapy (CIRT) boost for salivary duct carcinoma (SDC). Methods: Twenty-eight consecutive patients with SDC who underwent a postoperative (82%) or definitive (18%) radiation therapy between 2010 and 2017 were assessed in this retrospective single-center analysis. CIRT boost was delivered with median 18 Gy(RBE) in 6 daily fractions, followed by an TomoTherapy^®-based IMRT (median 54 Gy in 27 daily fractions). Treatment-related acute toxicity was assessed according to CTCAE Version 4. Results: Tumors were most commonly located in the major salivary glands (n = 25; 89%); 23 patients (82%) received previous surgery (R0: 30%; R1: 57%; R2: 4%; RX: 19%). Median follow-up was 30 months. Four patients (14%) experienced a local relapse and 3 (11%) developed locoregional recurrence. The two-year local control (LC) and locoregional control (LRC) was 96 and 93%, respectively. Median disease-free survival (DFS) was 27 months, metastasis-free survival (MFS) was 69 months, and overall survival (OS) was 93 months. Acute grade 3 toxicity occurred in 11 patients (mucositis, dermatitis, xerostomia; n = 2 each (7%) were the most common) and 2 osteonecroses of the mandibular (grade 3) occurred. No patients experienced grade ≥4 toxicities. Conclusions: Multimodal therapy approaches with surgery followed by IMRT and CIRT boost for SDC leads to good local and locoregional disease control. However, the frequent occurrence of distant metastases limits the prognosis and requires optimization of adjuvant systemic therapies.

Keywords: bimodal radiotherapy; carbon ion radiotherapy; intensity-modulated radiotherapy; radiation therapy; salivary gland; toxicity.