The Effects on Auditory Function of RADiotherapy and Chemotherapy Treatments for Head and Neck Tumours (EARAD)
Conditions: Head and Neck Neoplasms, Hearing Loss
Sponsor: University of Manchester

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
Pre-Registration: EARAD: Discovery Phase 
Study Information 
 
1. 
Title: The Effects on Auditory Function of Radiotherapy and Chemotherapy Treatments 
for Head and Neck Tumours (EARAD) 
 
2. 
Authors: Jenna Littlejohn, Chris Plack, Catharine West, Kevin Munro, Hannah Guest, 
Marianne Aznar, James Price 
 
 
3. 
Description: This study is designed to measure and locate damage caused by 
radiotherapy only and chemoradiotherapy regimens, specific to the auditory system. This 
will be tested using a robust battery of hearing threshold tests. The participants will have 
been diagnosed with oropharyngeal, nasopharyngeal, parotid gland or brain cancers. 
The test battery will be performed on the participants prior to the start of treatment, and 
at 3 months post-treatment. Additionally, blood tests will be used to identify and monitor 
serum levels of the protein ‘Prestin’, a biomarker for outer hair cells. These will be drawn 
during regular blood draws throughout treatment.  
 
4. 
Hypotheses: 
 
For each ear-specific outcome measure: 
 
H1. The RT group will show a deficit in the treatment ear, post vs. pre treatment 
H2. The effect of treatment for the RT group will be greater in the treatment compared to 
the control ear 
H3. The CRT group will show a deficit in the treatment ear, post vs. pre treatment 
H4. The CRT group will show a deficit in the control ear, post vs. pre treatment 
H5. The effect of treatment for the CRT group will be greater in the treatment compared 
to the control ear 
H6. Effects of CRT will be greater than RT in the treatment ear 
 
 
For each non-ear-specific outcome measure: 
 
H7. The RT group will show a deficit post vs. pre treatment 
H8. The CRT group will show a deficit post vs. pre treatment 
H9. CRT group will show greater deficits than RT group 
 
 
H10. For each basic auditory measure, the effects of RT treatment will vary depending 
on the dose to each substructure associated with the measure 

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
H11. Effects on DTT will vary depending on the RT dose to different substructures 
 
Design Plan 
 
5. 
Study type: Observational Study  
 
6. 
Blinding: No blinding is involved in this study. 
 
7. 
Study design: We have a two-group, repeated measures study design. Each participant 
is given the battery of hearing tests twice (before and after treatment), and repeated 
serum levels of Prestin checked. Each participant is compared to their earlier 
measurements. There are two groups, one for participants receiving Radiotherapy only 
treatment, and one for those receiving Chemoradiotherapy treatment. Once each 
individual is assessed and the group’s results amalgamated in accordance with a variety 
of variables, like variables, for example those of a certain age or gender, will be 
compared across groups. 
 
Sampling Plan 
 
8. 
Existing data: Registration prior to creation of data: As of the date of submission of this 
research plan for preregistration, the data have not yet been collected, created, or 
realized.  
 
 
9. 
Data collection procedures: Participants will be recruited by research nurses at the 
Christie Hospital, having been recently diagnosed with oropharyngeal, nasopharyngeal, 
parotid gland or brain cancers. Those who want to take part will be consented by the 
nurses. Criteria for inclusion include diagnosis with one of these cancers, being over the 
age of 18, and no significant prior hearing loss. Hearing will be screened at the hearing 
lab. For those with occluding wax which would contraindicate continuing with testing, 
procedures are being put into place to allow wax removal on site by a trained 
professional. High levels of wax will be identified by the research nurses at the time of 
consenting, and forwarded onto the researchers, so that wax removal can be arranged 
ahead of time. Participants will be paid at a rate of £10 per hour, with travel via public 
transport or personal vehicle refunded. Taxis will be provided where necessary. Testing 
is expected to take 2.5 hrs on each of two testing sessions, 5 hrs total. These sessions 
will take place prior to the start of treatment, and 3 months post treatment. Blood will be 
taken at the Christie hospital, stored, frozen and processed at a later date.  
 
 
 

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
10. 
Sample size: Our target sample size is 50 participants, with 25 undergoing radiotherapy 
only treatment, and 25 undergoing Chemoradiotherapy treatment. 
 
11. 
Sample size rationale:  
 
For the power calculation, we used the effect size from Herrmann et al. (2006), who 
reported an effect of 0.1-0.2 dB/Gy.  We wrote a small simulation programme that draws 
dose values from the observed distribution with mean and SD of ~16 Gy, draws a 
random effect size of mean 0.15 dB/Gy with SD of 0.03 dB/Gy. Assuming a 
measurement uncertainty of 2.5 dB, the expected correlation between dose and hearing 
loss is 0.628. With 40 patients and assuming a lower actual correlation of 0.37, there is a 
99% power to detect true correlation. Because we will use multiple testing, the actual 
power will be somewhat lower, but it is extremely likely that the most sensitive 
substructure will be detected. 
Variables 
 
12. 
Measured variables: 
12.1. Pure tone audiometry average thresholds measured at 0.5, 1, 2, 4, 8, 10, 12.5, 
14 (kHz), L & R ears 
Grouped (averaged) as:     
0.5 kHz – 1 kHz (Low) 
  
 
 
 
2 kHz – 4 kHz (Medium)  
8 kHz – 14 kHz (High) 
12.2. DPOAE at 0.5-10kHz, L & R ears 
12.3. ABR at 11 clicks/sec at 75 dB peSPL for 6000 repetitions, L& R ears 
12.4. Digit Triplet Test threshold, L & R ears 
12.5. Coordinate Response Measure 
12.6. Tinnitus functional index 
12.7. Quality of life form EQ-5D Extended 
12.8.  Speech, Spatial and Qualities of Hearing 
12.9.  Prestin levels 
12.10. Qualitative interview 
 
Data Mining Procedure 
 
13. 
The radiotherapy plans (CT scan, structure set and dose distribution) from all 
participants will be collected from the clinical database at the Christie. The dose 
distributions from all patients will be spatially normalized using deformable image 
registration to a common frame of reference (i.e. one “reference patient”).  
Analysis Plan 
 
14. 
For H1, H3, H4, t-test or non-parametric equivalent: pre vs. post 

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
For H2, H5, ANOVA with factors: Ear (treatment, control), Time (pre, post) 
For H6. ANOVA with factors: Time (pre, post), Group (RT, CRT) 
 
For H7, H8, t-test or non-parametric equivalent: pre vs. post 
For H9. ANOVA with factors: Time (pre, post), Group (RT, CRT) 
 
H10, H11. A Cox regression will be performed on a per-voxel basis in order to identify 
dose-sensitive substructures associated with the hearing outcome measures. Statistical 
significance will be investigated using permutation testing. 
 
 
 
 
Pre-Registration EARAD: Validation Phase 
 
Study Information 
 
1. 
Description: This phase is designed to identify and validate the hearing test most predictive 
of damage to the auditory substructure most associated with speech in noise deficit, as 
identified in the discovery phase via data mining. As in the discovery phase, it will involve 
testing patients undergoing RT only and combined CRT for oropharyngeal, 
nasopharyngeal parotid gland and brain tumours. This cohort will be independent of those 
for the discovery phase.  
 
2. 
Hypotheses:  
 
H1: RT dosage to the substructure identified in the Discovery phase as being 
most associated with speech in noise deficit will be associated with speech in 
noise deficits in the validation phase 
 
H2: The test identified in the Discovery phase as most predictive of damage to 
that substructure will be associated with damage to that substructure 
 
H3. The test identified in the Discovery phase as most predictive of damage to 
that substructure will be associated with speech-in-noise deficits 
 
Sampling Plan 
 
3. 
Data collection procedures: Participants will be recruited by research nurses at the Christie 
Hospital, having been recently diagnosed with oropharyngeal, nasopharyngeal or parotid 

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
gland cancers. Those who want to take part will be consented by the nurses. Criteria for 
inclusion include diagnosis with one of these cancers, being over the age of 18, and no 
significant prior hearing loss. Hearing will be screened at the hearing lab. For those with 
occluding wax which would contraindicate continuing with testing, procedures are being 
put into place to allow wax removal on site by a trained professional. High levels of wax will 
be identified by the research nurses at the time of consenting, and forwarded onto the 
researchers, so that wax removal can be arranged ahead of time. Participants will be paid 
at a rate of £10 per hour, with travel via public transport or personal vehicle refunded. 
Testing is expected to take 2 hrs on each of two testing sessions,4 hrs total. These 
sessions will take place prior to the start of treatment, and 3 months post treatment. Blood 
will be taken at the Christie hospital, stored, frozen and processed at a later date.  
 
4. 
Sample size: Our target sample size is 50 participants, with 25 undergoing radiotherapy 
only treatment, and 25 undergoing Chemoradiotherapy treatment. 
 
5. 
Sample size rationale:  
 
The Validation phase will again use a cohort of 40 patients in the same two groups (50 to 
be recruited to allow for 80% compliance) as for the Discovery phase. Since multiple 
testing is avoided, the statistical power of the Validation phase (around 99%) will be much 
greater than in the Discovery phase. 
 
 
Variables 
 
6. 
Measured variables 
 
6.1. 
Test most sensitive to dose to identified substructure in Discovery phase 
6.2. 
Audiometry 
6.3. 
DTT 
6.4. 
Prestin levels 
6.5. 
Qualitative interview 
 
Analysis Plan 
 
Pearson’s correlations or non-parametric equivalents to test for associations between variables. 
 
 
 
 
 

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
 
 
Pre-Registration: EARAD: Retrospective Study 
Study Information 
 
 
1. 
Description: This study is designed to measure and locate damage caused by RT 
regimens, specific to the auditory system. This will be tested using a robust battery of 
hearing threshold tests. The participants will have previously been diagnosed and 
treated with RT for unilateral oropharyngeal, nasopharyngeal or parotid gland cancers. 
The test battery will be performed on the participants post-treatment, up to a limit of 5 
years post-treatment. There will be two age-matched control groups, those with hearing 
impairment and those without.  Additionally, blood tests will be used to identify serum 
levels of the protein ‘Prestin’, a biomarker for outer hair cells. These will be drawn during 
the testing session. 
 
2. 
Hypotheses: 
 
For each ear-specific outcome measure: 
 
H1. The RT group will show a deficit in the treatment ear compared to the control ear 
 
 
For all outcome measures: 
 
H2. The RT group will show a deficit as compared to the normal hearing controls 
 
For the Prestin measure: 
 
H3. The RT group will show lower levels of serum Prestin compared to normal hearing 
controls 
H4. The age matched normal hearing control group will have higher serum Prestin levels 
compared to hearing impaired control group 
H5. The age matched hearing impaired control group will have higher serum Prestin 
levels compared to the RT group 
 
 
Relation to substructures: 
 
H6. For each basic auditory measure, the effects of RT treatment will vary depending on 
the dose to each substructure associated with the measure 
H7. Effects on DTT will vary depending on the RT dose to different substructures 
 

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
Design Plan 
 
3. 
Study type: Observational Study  
 
4. 
Blinding: No blinding is involved in this study. 
 
5. 
Study design: We have a three-group, single measures study design. Each participant is 
given the battery of hearing tests once, and serum levels of Prestin checked during this 
session. There are three groups, one for participants receiving unilateral RT treatment, 
and two age-matched control groups, those with hearing impairment and those without. 
If the RT group have a significant hearing loss overall, the hearing-impaired control 
group will be group matched in terms of average audiogram from 1-8 kHz with the RT 
group. Once each individual is assessed and the group’s results amalgamated in 
accordance with a variety of variables, they will be compared across groups. 
 
Sampling Plan 
 
6. 
Existing data: Registration prior to creation of data: As of the date of submission of this 
research plan for preregistration, the data have not yet been collected, created, or 
realized.  
 
 
7. 
Data collection procedures: Participants will be identified by research nurses at the 
Christie Hospital, having previously received treatment for oropharyngeal, 
nasopharyngeal or parotid gland cancers, up to a period of five years post treatment. 
Those who want to take part will be by the PhD student. Criteria for inclusion include 
diagnosis with one of these cancers, being over the age of 18, and no significant prior 
hearing loss. Hearing will be screened at the hearing lab. For those with occluding wax 
which would contraindicate continuing with testing, procedures are being put into place 
to allow wax removal on site by a trained professional. Participants will be paid at a rate 
of £10 per hour, with travel via public transport or personal vehicle refunded. Testing is 
expected to take 2.5 hrs. Blood will be taken at a site to be determined, stored, frozen 
and processed at a later date.  
 
 
8. 
Sample size: Our target sample size is 50 for each group. 
 
9. 
Sample size rationale:  
 
For the power calculation, we used the effect size from Herrmann et al. (2006), who 
reported an effect of 0.1-0.2 dB/Gy.  We wrote a small simulation programme that draws 
dose values from the observed distribution with mean and SD of ~16 Gy, draws a 

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
random effect size of mean 0.15 dB/Gy with SD of 0.03 dB/Gy. Assuming a 
measurement uncertainty of 2.5 dB, the expected correlation between dose and hearing 
loss is 0.628. With 40 patients and assuming a lower actual correlation of 0.37, there is a 
99% power to detect true correlation. Because we will use multiple testing, the actual 
power will be somewhat lower, but it is extremely likely that the most sensitive 
substructure will be detected. 
Variables 
 
10. 
Measured variables: 
12.1. Pure tone audiometry average thresholds measured at 0.5, 1, 2, 4, 8, 10, 12.5, 
14 (kHz), L & R ears 
Grouped (averaged) as:     
0.5 kHz – 1 kHz (Low) 
  
 
 
 
2 kHz – 4 kHz (Medium)  
8 kHz – 14 kHz (High) 
12.2. DPOAE at 0.5-10kHz, L & R ears 
12.3. ABR at 11 clicks/sec at 75 dB peSPL for 6000 repetitions, L& R ears 
12.4. Digit Triplet Test threshold, L & R ears 
12.5.  Coordinate Response Measure 
12.6. Tinnitus functional index 
12.7. Quality of life form EQ-5D Extended 
12.8.  Speech, Spatial and Qualities of Hearing 
12.9.  Prestin levels 
12.10.  Qualitative interview 
 
Data Mining Procedure 
 
11. 
The radiotherapy plans (CT scan, structure set and dose distribution) from all 
participants will be collected from the clinical database at the Christie. The dose 
distributions from all patients will be spatially normalized using deformable image 
registration to a common frame of reference (i.e. one “reference patient”).  
Analysis Plan 
 
14. 
For H1, t-test or non-parametric equivalent: Treatment ear vs control ear 
 
 
For H2, t-test or non-parametric equivalent: Group (RT, Normal Hearing Controls) 
 
For H3, H4, H5. t-test or non-parametric equivalent: Group (RT, Hearing Impaired 
Controls, Normal Hearing Controls) 
 
H6, H7. A Cox regression will be performed on a per-voxel basis in order to identify 
dose-sensitive substructures associated with the hearing outcome measures. Statistical 

EARAD Study, pre-registration and study protocol. IRAS Project ID:247959.  10.08.2022   
 
significance will be investigated using permutation testing.