Proton re-irradiation of unresectable recurrent head and neck cancers

Abstract

background: This study presents a retrospective analysis (efficacy and toxicity) of outcomes in patients with unresectable recurrence of previously irradiated head and neck (h&N) cancers treated with proton therapy. Locoregional recurrence is the main pattern of failure in the treatment of h&N cancers. proton re-irradiation in patients with relapse after prior radiotherapy might be valid as promising as a challenging treatment option. Materials and methods:From November 2015 to January 2020, 30 patients with in-field recurrence of head and neck cancer, who were not suitable for surgery due to medical contraindications, tumor localization, or extent, received re-irradiation with intensity-modulated proton therapy (IMpT). sites of retreatment included the aerodigestive tract (60%) and the base of skull (40%). The median total dose of prior radiotherapy was 55.0 Gy. The median time to the second course was 38 months. The median re-irradiated tumor volume was 158.1 cm 3 . patients were treated with 2.0, 2.4, and 3.0 GyrBe per fraction, with a median equivalent dose (eQD 2 ) of 57.6 Gy (a/b = 10). radiation-induced toxicity was recorded according to the rTOG/eOrTc criteria. results:The 1-and 2-year local control (Lc), progression-free survival (pFs), and overall survival (Os) were 52.6/21.0, 21.9/10.9, and 73.4/8.4%, respectively, with a median follow-up time of 21 months. The median overall survival was 16 months. acute grade 3 toxicity was observed in one patient (3.3%). There were five late severe side effects (16.6%), with one death associated with re-irradiation. conclusion: re-irradiation with a proton beam can be considered a safe and efficient treatment even for a group of patients with unresectable recurrent h&N cancers.

A Prospective Phase II Study of Automated Non-Coplanar VMAT for Recurrent Head and Neck Cancer: Initial Report of Feasibility, Safety, and Patient-Reported Outcomes

“…In a retrospective review of patients receiving oropharyngeal re-irradiation at MD Anderson Cancer Center, the patients receiving proton therapy experienced lower grade ≥3 toxicity rates (27%) compared to SBRT (32%) or IMRT (41%) [ 48 ]. Other proton head and neck re-irradiation studies have published acute grade ≥3 toxicity rates of 3–30%, and late toxicity rates of 16–25% [ 49 , 50 , 51 , 52 ]. Therefore, the toxicity rates observed from HyperArc treatment thus far compare very favorably to those published for re-irradiation with proton therapy.…”

A narrative review of intensity-modulated proton therapy for head and neck cancer

“…The 1-year LC, PFS, and OS rates were 52.6%, 21.9%, and 73.4%, respectively, and the 2-year LC, PFS, and OS rates were 21.0%, 10.9%, and 8.4%, respectively. Acute grade 3 toxicity was reported in one patient only, while late severe toxicities were reported in 5 cases (16.6%), including three cases of radiation-induced necrosis, one case of trismus, and one death from carotid bleeding, due to carotid blowout syndrome (53). In a disease-specific retrospective review, previously irradiated, recurrent NPC patients (n=17) treated with IMPT had an 18-month OS and LC rates of 54.4% and 66.6%, respectively.…”

Dosimetric Evaluation of Target Motion Effects in Spot-Scanning Proton Therapy: A Phantom Study

“…The Prometheus contains a gantry-less beam delivery system with a horizontal beam specified for upright patient position. 16 The synchrotron provides a narrow scanning beam with an intensity of approximately 10 9 protons per cycle in the energy range of 30 to 330 MeV, which is suitable for both treatment 17 and proton imaging. 18 An energy switch time varies in the range of 1.2 to 1.5 seconds; a spot switch time is typically 5 ms.…”