Table 3.

Reirradiation of head and neck tumors

Study	Study type	Study period (years)	n	Technique	PCT (%)	OF (%)	Morphology	Observation median (months)	Results	Toxicity
McDonald et al. [79]	Retro	2004-2014	61	PSPT	29	47.5	HNSCC (37), others (24)	29	2-year: LR —19.7%; OS - 32.7%	Stage III — in 8 (necroses); IV —in 4: blindness —1, necrosis — 1; V — in 3
Phan et al. [54]	Pro	2011-2015	60	PSPT (n=15) IMPT (n=45)	73	58	HNSCC (40), others (20)	13.6	1-year: LRS-68.4%; OS - 83.8%	Acute stage III (30%): tubes; late stage lll-V (16.7%)
Romesser et al. [53]	Retro	2011-2014	92	PSPT	39	39	HNSCC (52), others (40)	13.3	1-year: LRR-25.1%; OS - 65.2%	Late stage lll-V (14.1%)
Hayashi et al. [48]	Pro	2009-2013	25	PSPT	—	46	HNSCC	24	2-year: LR - 30%; OS - 46%	Stage IV — in 1

Notes: n — number of patients; PSPT — passive scattering proton therapy; OF — operation frequency; PCT — polychemotherapy application frequency; PhT — photon therapy; IMRT — intensity-modulated radiation therapy; LR — local recurrence; LC — local control; LRC — loco-regional control; OS — overall survival; LRS — local recurrence survival; PFS — progression-free survival; LRR — loco-regional recurrence; PINSCC — head and neck squamous cell carcinoma; retro — retrospective; pro — prospective.