Re-irradiation of adenoid cystic carcinoma: Analysis and evaluation of outcome in 52 consecutive patients treated with raster-scanned carbon ion therapy

Abstract

Despite high applied doses, C12 re-irradiation shows moderate side-effects, response rates even in these heavily pre-treated patients are encouraging and present a good alternative to palliative chemotherapy. Though most local recurrences occur within the high-dose area, further dose escalation should be viewed with caution.

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

“…While this is a compromise clinicians often have to accept, it is nevertheless an issue, which needs to be discussed with the patient. The risk of local relapse has to be explained to the patient especially since salvage re-irradiation in our experience rarely leads to long-term LC [38]. The rate of distant disease progression underlines the importance of identifying and introducing systemically active agents in the primary situation.…”

“…Though the overall incidence in this large patient cohort may be low, we still wish to advise caution when treating patients with dose escalation following extensive resections in or near the skull base. While carotid blowout may be more common in re-irradiation of head and neck tumors [38,42], prior surgery and doses >70 Gy were identified as risk factors [42], the risk of carotid artery damage and permanent CSF leakage may limit further dose escalation at these sites.…”

Carbon Ion Radiotherapy: A Review of Clinical Experiences and Preclinical Research, with an Emphasis on DNA Damage/Repair

“…The HIT team reported results of re-irradiation using CIRT for 52 patients with adenoid cystic carcinoma of the head and neck. Treatments were well tolerated without grade > 2 toxicity and with excellent control and survival rates [178]. The NIRS group reported an interesting phase I/II CIRT dose escalation study on recurrent, previously resected but not irradiated, rectal cancers.…”

NOTCH1 and SOX10 are Essential for Proliferation and Radiation Resistance of Cancer Stem–Like Cells in Adenoid Cystic Carcinoma

“…Treatment options for ACC are currently limited to surgery with or without radiation, consistent with limited insight into its molecular drivers (1). ACC has a high recurrence rate and dismal survival in part because of its intrinsic resistance to radio- and chemotherapies (2). Existence of cancer stem cells (CSC) in ACC has been suggested (3), but their molecular identity remained elusive due to difficulties with ACC culture.…”