Assessment of Post-surgical Improvement in Obstructive Sleep Apnea Patients After Imaging of Upper Respiratory Airway Using Cone Beam Computed Tomography (CBCT) and Drug-Induced Sleep Endoscopy (DISE) Versus Drug-Induced Sleep Endoscopy Only: A Validity Study
Conditions: Obstructive Sleep Apnea
Sponsor: Cairo University

 
 
Assessment of Post-surgical improvement in Obstructive Sleep Apnea Patients after 
imaging of Upper Respiratory Airway using Cone Beam Computed Tomography 
(CBCT) and Drug-Induced Sleep Endoscopy (DISE) versus Drug-Induced Sleep 
Endoscopy Only:  A Validity Study 
 
Registered at www.clinicaltrials.gov. ID: OCS05051989 
 
 
 
Protocol submitted to 
Faculty of Dentistry, Cairo University 
for partial fulfilment of the requirements for the Ph.D. Degree in Oral and Maxillofacial Radiology,  
Faculty of Dentistry, Cairo University 
 
By 
Marco Emad Shawky Isaac 
Teaching Assistant of Oral Medicine, Periodontology, Diagnosis and Oral Radiology Department, 
Faculty of Oral and Dental Medicine,  
Delta University for Science and Technology 
BDS 2011, MSc, MFDS RCSD 
 
 
Date: 22/01/2021 
 
 
 
 
 
 
 
 
 

 
 
Supervisors’ signature 
Head of the department’s 
signature 
1- Dr. Dina Mohammed El-Beshlawy  
Associate Professor of Oral and Maxillofacial 
Radiology Department,  
Faculty of Dentistry, Cairo University 
Prof. Mohamed El-Sorougy  
Head of Department and Professor of 
Oral and Maxillofacial Radiology 
Department, Faculty of Dentistry, Cairo 
University 
2- Dr. Sarah Mohammed Kenawy 
Lecturer of Oral and Maxillofacial Radiology 
Department, Faculty of Dentistry, Cairo 
University 
 
3- Dr. Ahmed Abdel-Fatah Farag  
El-Sobky  
Associate Professor of ENT Department, Faculty 
of Medicine, Mansoura University 
 
 
 
 
Code:  RAD 7-1-1 

 
I- Study Protocol: 
A) Study design and setting 
1. Study design 
In this validity two-arm study, a total of (70) patients will be included; all are diagnosed with OSA and will 
undergo surgical treatment after appropriate planning. Patients will be classified into two equal groups (with 
allocation ratio 1:1). Patients of the study group will be examined after scanning with CBCT at both ends of 
expiration and inspiration and DISE. Control group patients will be examined by DISE only. 
These (70) patients will be selected by the ENT specialist according to the following; 
• A multidisciplinary approach will be performed to diagnose OSA patients who are indicated for 
surgery. Firstly, a comprehensive assessment of patients’ history will be performed; including 
evaluation of all risk factors and complete sleep history (Epstein et al. 2009). 
• Epworth Sleepiness Scale (ESS) which consists of eight section questionnaire that defines the 
frequency of an individual to fall asleep during regular daily activities will be obtained from the 
patients (Johns 1992, Sharkey et al. 2013). 
• Afterward, a proper physical examination will be performed including a thorough clinical 
examination of the oropharynx, nasopharynx, and hypopharynx to evaluate any anatomical 
abnormalities as impotency of the nasal airway, elongated soft palate or uvula, enlarged lingual 
tonsils, and any other pathological conditions of tongue, palate, and tonsils. 
• Then, Polysomnography (PSG) (sleep study) will be performed to allow proper evaluation of normal 
and abnormal physiological sleep episodes. Apnea/Hypopnea    Index (AHI) will be reported to 
detect the severity of OSA and patients were classified into mild (AHI = 5-14 / hour), moderate (AHI 
= 15-30 / hour) and severe (AHI  >30 / hour) (Maspero et al. 2015). 
• All patients in both groups will undergo upper airway surgery, DISE will be performed by the same 
ENT surgeon to detect the level of collapse in the upper airway which will be assessed by LwPTL 
and VOTE classifications, emphasizing on the primary structures contributing at upper airway 
collapse, either alone or in combination: the larynx, palate, tongue and pharyngeal lateral walls.  
• 
Study group participants only will be scanned by CBCT twice; once at the end of inspiration and the 
other at the end of expiration while they are gently holding their breath for as long as possible. 
(Woodson 2003) 
• In the study group, surgical procedures decision will be taken after appropriate assessment to sites of 
collapse in CBCT views at both ends of expiration and inspiration vies in combination to DISE. 
• Finally, strict post-operative instructions will be given to patients of both groups. 
 2. Settings 
This study will be carried out on patients attending outpatient clinics in the ENT department, Faculty of 
Medicine, Mansoura University, Egypt. CBCT scans of surgical candidates of OSA patients will be included 

 
according to the proposed eligibility criteria. 
B) Participants 
1. Eligibility criteria and selection methods 
Inclusion Criteria: 
• Patients’ age is more than 18 years old. 
• Patients are indicated for upper respiratory airway surgery based on adequate history taking, proper 
clinical examination, and sleep study. 
• Patients refusing non-surgical treatment procedures as Continuous Positive Airway Pressure (CPAP) 
treatment. 
• Systemically medically free patients. 
Exclusion Criteria: 
• Patients who are refusing the surgical approach as a treatment option. 
• Patients who have undergone previous surgeries in the upper respiratory airway. 
• Pregnant women. 
• Patients who didn’t follow post-operative instructions. 
• Patients who are not able to come for the follow-up appointments. 
Follow up: 
• Patients who strictly follow post-operative instructions will perform another sleep study after 3 
months from the day of the surgery. 
• Percentage of AHI reduction will be calculated which in turn indicates post-surgical improvement. 
2. Matching criteria and allocation ratio 
The patients will be randomly allocated to the intervention groups using computer-generated random 
numbers that will be performed by the main investigator (Marco Isaac). The patients will be allocated in a 
ratio of 1:1 (35 patients in each group). 
The two groups will be equally clinically examined before surgical procedures. Then the decision of which 
group will be scanned with CBCT and which won’t will be taken according to the randomized numbers 
placed in opaque sealed envelopes. The number will be picked by the main investigator (Marco Isaac). 
The main investigator will be responsible for the generation of allocation sequence and will assign the 
patients to the 2 intervention groups. The main investigator will also be responsible for patient enrolment. 
 
C) Variables 
1. Details about variables 

 
• Mean AHI reduction percentage. 
• Level of Collapse of the upper respiratory airway. 
• The volume of the upper respiratory airway. 
2. Data sources and management  
• The level of the collapse of the upper respiratory airway will be determined by an expert ENT 
surgeon with DISE. 
• Radiographic assessment will be performed using the iCAT FLX V17-Series CBCT machine 
(Imaging Science International, ISI, PA, USA). Quick scan imaging protocol of 16cm x 13cm Field 
Of View (FOV) (120 KV, 5 mA, 2 sec) and 0.3 mm voxel size.  
• Participants are required to wear a protective lead apron during scanning. The position of the X-ray 
tube will be adjusted to minimize the extent of scanning and to ensure the lowest radiation dose as 
much as possible. To prevent motion artifacts, participants will be instructed not to move their head, 
body, tongue, and jaws during scanning. 
• Raw DICOM data from CBCT scanning will be checked to evaluate whether there were any motion 
artifacts in images at coronal, horizontal, and sagittal planes.  
• CBCT scans at both ends of inspiration and expiration will be analyzed using Invivo5 software. 
• For the second outcome, CBCT images will be interpreted by three oral and maxillofacial 
radiologists independently; blinded from demographic data of the patients, DISE findings, and the 
results of each other.  
• Each radiologist will evaluate the CBCT images for assessment of the level of collapse and 
assessment of the secondary outcomes. One radiologist will assess all the outcomes twice with more 
than 1month interval. Intra-observer and inter-observer variability of CBCT findings will be 
evaluated. 
3. Addressing potential sources of bias 
No source of bias. CBCT images will be interpreted by three oral and maxillofacial radiologists 
independently blinded from demographic data of the patients, DISE findings, and the results of each other. 
                                              
D) Study size 
1. Study size 
This study aims to assess surgical improvement in OSA patients after imaging of upper Respiratory Airway 
using CBCT and DISE using mean AHI reduction percentage. According to the results of (Pang et al. 
2020), the mean of AHI reduction percentage and the minimal clinically important difference estimated by 
the expert was 21.6. By adopting an alpha (α) level of 0.05 (5%) and a power of 80%, the predicted sample 
size is 35 per group with a total of 70. To compensate for losses during follow up, the sample will be 

 
increased by 20% to be 84 participants in total.  Sample size calculation was achieved using PS: Power and 
Sample Size Calculation software Version 3.1.2 (Vanderbilt University, Nashville, Tennessee, USA).  
E) Quantitative variables  
1. Handling of quantitative variables in the analyses 
The volume of the upper respiratory airway will be determined and correlated with its level of collapse. 
F) Statistical methods 
1. Statistical methods  
Data will be analyzed using SPSS (statistical package for social sciences) version 22. Qualitative data will 
be presented as number and percent, Quantitative data will be tested for normality by the Kolmogrov-
Smirnov test then described as mean and standard deviation for normally distributed data and median and 
range for non-normally distributed. The appropriate statistical test will be applied according to the data type 
with the following suggested tests: Chi-Square for the categorical variable. Student t-test and Mann Whitney 
U test for continuous variables.  
 
II. Ethics and dissemination: 
a. Research ethics approval 
The study protocol will be submitted to the Ethics commute in the Faculty of Dentistry, Cairo University for 
approval.  
b. Protocol amendments 
Any amendments in the protocol will be reported to the main and co-supervisors. 
c. Informed consent 
After discussing the treatment plan with the patient and educating the patient with all the data needed, an 
arabic consent form will be signed by the willing participants. 
d. Confidentiality 
• All study-related information will be stored securely.  
• All reports, data, scans, and administrative forms will be identified by a coded ID (identification) 
number only to maintain participant confidentiality.  
• All personal data that contain names or other identifiers including age, sex, identification number, 
address, phone number, work address, and any other information will be stored separately from the 
study records and identified by a code number. 
e. Declaration of interest 
There is no conflict of interest. 

 
f. Access to data 
Investigator, Co-supervisors, and main supervisor will have access to the final trial data set . 
g. Dissemination policy 
The Investigator will communicate his results with other participants and healthcare providers through the 
publication of the protocol and the research final results and recommendations. This will be done through 
publication websites and journals concerned with Oral and Maxillofacial Radiology specialty, For Sharing 
the recommended clinical application obtained from the final results of the research. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
III- Appendix: 
1- Epworth Sleepiness Scale (ESS): 
 
 
 

 
 
2- Informed Consent: