Spot-scanning beam proton therapy vs intensity-modulated radiation therapy for ipsilateral head and neck malignancies: a treatment planning comparison.

Radiation therapy for head and neck malignancies can have side effects that impede quality of life. Theoretically, proton therapy can reduce treatment-related morbidity by minimizing the dose to critical normal tissues. We evaluated the feasibility of spot-scanning proton therapy for head and neck malignancies and compared dosimetry between those plans and intensity-modulated radiation therapy (IMRT) plans. Plans from 5 patients who had undergone IMRT for primary tumors of the head and neck were used for planning proton therapy. Both sets of plans were prepared using computed tomography (CT) scans with the goals of achieving 100% of the prescribed dose to the clinical target volume (CTV) and 95% to the planning TV (PTV) while maximizing conformity to the PTV. Dose-volume histograms were generated and compared, as were conformity indexes (CIs) to the PTVs and mean doses to the organs at risk (OARs). Both modalities in all cases achieved 100% of the dose to the CTV and 95% to the PTV. Mean PTV CIs were comparable (0.371 IMRT, 0.374 protons, p = 0.953). Mean doses were significantly lower in the proton plans to the contralateral submandibular (638.7 cGy IMRT, 4.3 cGy protons, p = 0.002) and parotid (533.3 cGy IMRT, 48.5 cGy protons, p = 0.003) glands; oral cavity (1760.4 cGy IMRT, 458.9 cGy protons, p = 0.003); spinal cord (2112.4 cGy IMRT, 249.2 cGy protons, p = 0.002); and brainstem (1553.52 cGy IMRT, 166.2 cGy protons, p = 0.005). Proton plans also produced lower maximum doses to the spinal cord (3692.1 cGy IMRT, 2014.8 cGy protons, p = 0.034) and brainstem (3412.1 cGy IMRT, 1387.6 cGy protons, p = 0.005). Normal tissue V10, V30, and V50 values were also significantly lower in the proton plans. We conclude that spot-scanning proton therapy can significantly reduce the integral dose to head and neck critical structures. Prospective studies are underway to determine if this reduced dose translates to improved quality of life.

Kandula S ，Zhu X ，Garden AS ，Gillin M ，Rosenthal DI ，Ang KK ，Mohan R ，Amin MV ，Garcia JA ，Wu R ，Sahoo N ，Frank SJ ... -  《-》

Comparing 3DCRT and inversely optimized IMRT planning for head and neck cancer: equivalence between step-and-shoot and sliding window techniques.

Longobardi B ，De Martin E ，Fiorino C ，Dell'oca I ，Broggi S ，Cattaneo GM ，Calandrino R ... -  《RADIOTHERAPY AND ONCOLOGY》

Helical tomotherapy for head and neck squamous cell carcinoma: dosimetric comparison with linear accelerator-based step-and-shoot IMRT.

Murthy V ，Master Z ，Gupta T ，Ghosh-Laskar S ，Budrukkar A ，Phurailatpam R ，Agarwal J ... -  《-》

Dosimetric comparison between 2-dimensional radiation therapy and intensity modulated radiation therapy in treatment of advanced T-stage nasopharyngeal carcinoma: to treat less or more in the planning organ-at-risk volume of the brainstem and spinal cord.

Chau RM ，Teo PM ，Kam MK ，Leung SF ，Cheung KY ，Chan AT ... -  《-》

Volumetric-modulated arc radiotherapy for skull-base and non-skull-base head and neck cancer: a treatment planning comparison with fixed Beam IMRT.

Chen J ，Mok E ，Wang L ，Chen C ，Le QT ... -  《-》