Table 2.

Overview of study designs, accrual periods, patient numbers, tumour stages and sites, treatments and assessment tools of the 20 selected studies

References	Study design, accrual period, T stage	Total N	CRT N	N CRT + relevant outcome	Tumour site	Treatment/type of issue	Evaluation tool
Ackerstaff et al. [11]	Prospective period unknown TIII–IV	50	50	Voice, 26	Oropharynx, oral cavity, hypopharynx, trans-, supraglottic, piriformis sinus,	RADPLAT, QoL aspects	FACT H&N UW HN QoL
Ackerstaff et al. [12]	Prospective 1999–2004 TIII–IV	236	207	Voice/speech, 126	Oral cavity, oropharynx, hypopharynx	IA CRT versus IV CRT	EORTC QLQ-H&N35 TSQ
Boscolo-Rizzo et al. [13]	Retrospective 2001–2004 TII–IV	72 (67)	28	Speech, 28	Hypolaryngeal–pharyngeal larynx	CRT versus surgery ± RT	EORTC QLQ-H&N35
Carrara-de Angelis et al. [14]	Prospective 1999–2001 TII–IV	43 (19)	15	Voice, 15	Pyriform sinus, transglottic, supraglottic, glottic	CRT versus reference values	Vowel/a/:CRP (GRBAS) by 2/3 trained listeners, acoustics
Dietz et al. [15]	Prospective 1997–2000 TII–IV	30	30	Voice, 28	Hypopharynx, glottic, supraglottic	Accelerated CRT—organ preservation	LENT-SOMA 5-p-scale
Dubois et al. [16]	Prospective period unknown TII–III	22	10	Voice, 10/12	Pyriform sinus	CRT vs normal	VHI, GRBAS 3 listeners, acoustics, vowel/a/
El Deiry et al. [17]	Retrospective 1991–2002 TI–IV (stages 3–4)	54	27	Speech, 27	Oropharynx, hypopharynx, larynx	CRT versus surgery ± RT	HNCI
Fung et al. [18]	Prospective period unknown TII–IV	56 (97)	37	Voice, 37 speech, 27	Larynx	CRT vs surgery ± RT	PSS HN VRQoL
Hanna et al. [19]	Retrospective period unknown T?(stages 3–4)	42	19	Speech, 15	Larynx, hypopharynx	CRT vs TL + pRT	EORTC QLQ-H&N35
Kazi et al. [20]	Prospective period unknown T?(stages 3–4)	42	15	Voice, 14	Hypopharynx, larynx supraglottic	Induction CT + RT vs TLE ± RT vs normals	Sustained vowel/i/, connected speech EGG, acoustic analysis
Knab et al. [21]	Retrospective 1996–2002 TIV	32	20	Voice, 20	Supraglottic, glottic	CRT, 3 treatment regimen	Voice quality scored by single radiation oncologist/otolaryngo–logist, poorest score if differing
Lo Tempio et al. [22]	Prospective period unknown T? (stages 2–4)	49	15	Speech, 15	Larynx	CRT versus TLE + RT	UW HN QoL
Meleca et al. [23]	Retrospective 1997–2000 TII–IV	14	12	Voice, 14	Larynx	CRT	VHI, acoustics, aerodynamics 5-point scale by 3 clinicians, stroboscopy 5-point scale
Mittal et al. [24]	Prospective period unknown T?(stages 3–4)	39	39	Voice/speech, 26	Oropharynx, nasopharynx, hypopharynx, larynx	CRT; tissue/dose compensation versus no compensation	FACT H&N, PSS H&N, McMaster RQ, F-LTOAC, conversational speech recordings
Newman et al. [25]	Prospective unknown period TII–IV	30	30	Speech, 20	Oral pharyngeal larynx	RADPLAT versus CRT	F-LTOAC (correct/incorrect)
Orlikoff et al. [27]	Prospective TII–IV 1994–1996	12	12	Voice, 12	Supraglottic vocal fold	CRT versus control	Acoustics, aerodynamics, EGG, stroboscopy, G from GRBAS (clinician and patient)
Psyrri et al. [26]	Prospective, 1992–1996 TI–IV (stage 3–4)	42	18	Voice, 15	Nasopharynx	CRT versus induct C	PSS H&N
Samant et al. [28]	Prospective 1993–1995 TII–IV	25	25	Speech/voice, 24	Piriform sinus	RADPLAT	Self-designed 3-point outcome scale
Woodson et al. [29]	Prospective period unknown TIII–IV	16	16	Voice, 15	Oropharynx, oral cavity, pharynx, hypopharynx, piriform sinus, glottic supraglottic	RADPLAT vs controls; laryngeal versus non-laryngeal	Overall voice quality (mean of 5–7-point scales), patient interview, acoustics, aerodynamics
Worden et al. [30]	Prospective period unknown TIV	36	27	Speech, 11	Hypopharynx, glottic, supraglottic,	IC + CRT for responders	PSS H&N, Understandability of speech