title: Salivary Gland. Photon beam and particle radiotherapy: Present and future.
abstract: Salivary gland cancers (SGCs) are rare diseases and their treatment depends upon histology, stage and site of origin. Radical surgery is the mainstay of treatment but radiotherapy (RT) plays a key role in both the postoperative and the inoperable setting, as well as in recurrent disease. In the absence of prospective randomized trials, a wide retrospective literature suggests postoperative RT (PORT) in patients with high risk pathological features. SGCs, and adenoid cystic carcinoma (ACC) in particular, are known to be radio-resistant tumors and should therefore respond well to particle beam therapy. Recently, excellent outcome has been reported with radical carbon ion RT (CIRT) in particular for ACC. Both modern photon- and hadron-based treatments are effective and are characterized by a favourable toxicity profile. But it is not clear whether one modality is superior to the other for disease control, due to the differences in patients' selection, techniques, fractionation schedules and outcome measurements among clinical experiences. In this paper, we review the role of photon and particle RT for malignant SGCs, discussing the difference between modalities in terms of biological and technical characteristics. RT dose and target volumes for different histologies (ACC versus non-ACC) have also been taken into consideration.
authors.affiliation: Radiotherapy 2 Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. Electronic address: ester.orlandi@istitutotumori.mi.it.
authors.forename: Ester
authors.initials: E
authors.lastname: Orlandi
authors.affiliation: Radiotherapy 2 Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Nicola Alessandro
authors.initials: NA
authors.lastname: Iacovelli
authors.affiliation: Clinical Department, CNAO (National Center for Oncological Hadrontherapy), Pavia, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Bonora
authors.affiliation: Medical Physics, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Cavallo
authors.affiliation: Clinical Department, CNAO (National Center for Oncological Hadrontherapy), Pavia, Italy; Radiotherapy Division, European Institute of Oncology, Milan, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Fossati
mesh_terms: D006801:Humans; D017785:Photons; D011878:Radiotherapy / Q000379:methods*; D012468:Salivary Gland Neoplasms / Q000532:radiotherapy*
keywords: Adenoid cystic carcinoma; Carbon ion therapy; Definitive radiotherapy; Intensity modulated radiation therapy; Malignant salivary gland cancers; Particle beam therapy; Postoperative radiotherapy; Proton therapy