👉 Most notable are the lower doses to ipsilateral (left) cochlea, right-sided structures, and expanded cord with the proton plan. The mean oral cavity dose was also significantly lower.
Dosimetric superiority of protons in the skull base region is largely due to the absence of dose deposition distal to the target, or “exit dose”. This phenomenon is explained by the distinctive Bragg Peak that protons have which allows for a rapid fall-off of the irradiation dose beyond the target. Contralateral structures were significantly spared with the proton plan. As previously established, proton beam therapy remains the therapy of choice for pediatric patients given their long term survival and concerns for secondary malignancy, as well as lower doses to most if not all normal structures of interest.
👉 Proton Therapy re-irradiation of the head and neck provides effective tumor control with acceptable acute and late toxicity profiles, likely secondary to the decreased dose to surrounding normal, albeit previously irradiated tissue.
👉 Proton Therapy is a feasible option for ACC for the non-skull based head and neck in the definitive and postoperative setting, offering low rates of acute and late toxicities. Patients with metastatic disease also had acceptable outcomes and local treatment was well tolerated.
👉 Proton Therapy offers durable local control and survival in patients with nasal cavity and paranasal sinus malignancy. Even patients with recurrent tumor or with prior radiation history could achieve encouraging outcomes.
👉 with Proton Therapy the long-term chemosensory outcomes are preserved.
👉 IMPT showed dosimetry advantages over IMRT and lower rates of acute toxicities while both had comparable treatment outcomes.
👉 Proton Therapy for SCC of the larynx demonstrates a high rate of overall survival, local-regional control, and disease-free survival with low toxicity profile.
👉 rates of locoregional control were high and treatment was well tolerated.
Gland: A Seven-Year Experience – Hanania et al.
👉 IMPT for treatment 724 of the parotid gland manifests in low rates of acute and chronic toxicity 725 while maintaining dosimetric coverage and high rates of biological control. 726 Skin V30 may predict for radiation dermatitis.
👉 RBE in brain is 1.18
Abstracts published in International Journal of Radiation Oncology • Biology • Physics, Volume 106, Issue 5, April 1, 2020