Table 1.

Studies Included in This Review and Risk Assessment of Individual Studies According To Higgins and Green.³⁹

						Risk of bias in individual studies
Author	No. of patients	Site	Prescribed dose	Modality	PCM’s parameters	Study method	SG	AC	BP	IO	SO	OS
Ricchetti et al 40	26	Oropharynx	70 Gy	kV CT weekly	Volume, mean dose	Prospective pilot study, consecutive patients	+	?	?	–	?	?
Kumarasiri et al 41	23	Oropharynx	60-70 Gy	CBCT daily	Volume, thickness, mean dose	Retrospective analysis	?	?	?	+	?	?
Duffy et al 44	5	More sites	60-70 Gy	CBCT weekly	Volume, mean dose, V50	Retrospective analysis	–	?	?	+	?	?
Eisbruch et al 42	29	Base of tongue, larynx, tonsil, hypopharynx	70 Gy	Endoscopy (3 months after), kV CT (pre, 3 months after)	Thickness	Trial phase I, consecutive patients	+	?	?	–	?	?
Popovtzer et al 43	12	Tonsil, base of tongue, unknown, nasopharynx, hypopharynx	70 Gy	MRI (before and 3 months after)	Signal intensity, mean dose, thickness	Prospective pilot study	?	?	?	–	?	?
Meheissen et al 45	46	Oropharynx	70 Gy	MRI (before, mid, after)	Signal intensity	Randomized trial phase II/III	+	–	–	+	?	+
Messer et al 46	72	Nasopharynx	70 Gy	MRI (before, early after, follow up)	Signal intensity, mean dose	Retrospective analysis	–	?	?	+	?	?
Minh Tam Truong et al 47	15	Nasopharynx, oropharynx, hypopharynx, other	70 Gy	CT (second, fourth, sixth week and 6 weeks after)	Blood flow, blood volume, mean transit time, capillary permeability	Prospective single arm study	?	?	?	–	?	?

Abbreviations: AC, allocation concealment; BP, blinding of participants, personnel, and outcome; CBCT, cone-beam computed tomography; CT, computed tomography; kV CT, kilovolt computed tomography; IO, incomplete outcome data; MRI, magnetic resonance imaging; OS, other sources of bias; PCM, pharyngeal constrictor muscles; SG, sequence generation; SO, selective outcome reporting; V50, volume of the PCM receiving more than 50 Gy.