Trial Outcomes & Findings for New Fabric Attenuation Device in Endovascular Interventional Radiology II (PREFER II) (NCT NCT01611454)

NCT ID: NCT01611454

Last Updated: 2021-11-19

Results Overview

Radiation attenuation. The null hypothesis is that the XPF thyroid collar is equal to the standard 0.5mm Pb lead equivalent thyroid collar with regard to radiation attenuation/transmission in relative (%) terms. The alternative hypothesis is that the XPF thyroid collar is superior or inferior to the standard thyroid collar. Based on our results obtained during the 60 procedures (PREFER trial), 150 procedures are required to demonstrate a significant difference with an alpha level of 5% and a power of 80%. Radiation attenuation percentage is measure by interrogation of the lead attenuates X-rays counter required to be used in all interventional radiology clinical procedures by each physician operator. The interrogation is done by measuring the energy imparted per unit mass in the counter wore by ionizing radiation to matter at the specified point. The International System of Units (SI) unit of absorbed dose is the joule per kilogram.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

106 participants

Primary outcome timeframe

1 day

Results posted on

2021-11-19

Participant Flow

Participant milestones

Participant milestones
Measure
XPF Thyroid Collar
Administration of the XPF Thyroid Collar. XPF thyroid collar: Interventionalist wear the experimental (XPF) thyroid collar during fluoroscopy guided interventions.
Equivalent Collar
Administration of the Standard 0.5mm lead-equivalent thyroid collar. Standard 0.5mm lead equivalent thyroid collar: Interventionalist wear a standard 0.5mm lead equivalent thyroid collar during fluoroscopy guided interventions.
Overall Study
STARTED
58
48
Overall Study
COMPLETED
40
38
Overall Study
NOT COMPLETED
18
10

Reasons for withdrawal

Reasons for withdrawal
Measure
XPF Thyroid Collar
Administration of the XPF Thyroid Collar. XPF thyroid collar: Interventionalist wear the experimental (XPF) thyroid collar during fluoroscopy guided interventions.
Equivalent Collar
Administration of the Standard 0.5mm lead-equivalent thyroid collar. Standard 0.5mm lead equivalent thyroid collar: Interventionalist wear a standard 0.5mm lead equivalent thyroid collar during fluoroscopy guided interventions.
Overall Study
Lack of Efficacy
18
10

Baseline Characteristics

New Fabric Attenuation Device in Endovascular Interventional Radiology II (PREFER II)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
XPF Thyroid Collar
n=58 Participants
Administration of the XPF Thyroid Collar. XPF thyroid collar: Interventionalist wear the experimental (XPF) thyroid collar during fluoroscopy guided interventions.
Equivalent Collar
n=48 Participants
Administration of the Standard 0.5mm lead-equivalent thyroid collar. Standard 0.5mm lead equivalent thyroid collar: Interventionalist wear a standard 0.5mm lead equivalent thyroid collar during fluoroscopy guided interventions.
Total
n=106 Participants
Total of all reporting groups
Age, Categorical
<=18 years
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Age, Categorical
Between 18 and 65 years
36 Participants
n=5 Participants
26 Participants
n=7 Participants
62 Participants
n=5 Participants
Age, Categorical
>=65 years
22 Participants
n=5 Participants
22 Participants
n=7 Participants
44 Participants
n=5 Participants
Age, Continuous
50 Year
STANDARD_DEVIATION 25 • n=5 Participants
50 Year
STANDARD_DEVIATION 25 • n=7 Participants
50 Year
STANDARD_DEVIATION 25 • n=5 Participants
Sex: Female, Male
Female
26 Participants
n=5 Participants
24 Participants
n=7 Participants
50 Participants
n=5 Participants
Sex: Female, Male
Male
32 Participants
n=5 Participants
24 Participants
n=7 Participants
56 Participants
n=5 Participants
Region of Enrollment
United States
58 participants
n=5 Participants
48 participants
n=7 Participants
106 participants
n=5 Participants

PRIMARY outcome

Timeframe: 1 day

Radiation attenuation. The null hypothesis is that the XPF thyroid collar is equal to the standard 0.5mm Pb lead equivalent thyroid collar with regard to radiation attenuation/transmission in relative (%) terms. The alternative hypothesis is that the XPF thyroid collar is superior or inferior to the standard thyroid collar. Based on our results obtained during the 60 procedures (PREFER trial), 150 procedures are required to demonstrate a significant difference with an alpha level of 5% and a power of 80%. Radiation attenuation percentage is measure by interrogation of the lead attenuates X-rays counter required to be used in all interventional radiology clinical procedures by each physician operator. The interrogation is done by measuring the energy imparted per unit mass in the counter wore by ionizing radiation to matter at the specified point. The International System of Units (SI) unit of absorbed dose is the joule per kilogram.

Outcome measures

Outcome measures
Measure
XPF Thyroid Collar
n=58 Participants
Administration of the XPF Thyroid Collar. XPF thyroid collar: Interventionalist wear the experimental (XPF) thyroid collar during fluoroscopy guided interventions.
Equivalent Collar
n=48 Participants
Administration of the Standard 0.5mm lead-equivalent thyroid collar. Standard 0.5mm lead equivalent thyroid collar: Interventionalist wear a standard 0.5mm lead equivalent thyroid collar during fluoroscopy guided interventions.
Percentage Change
79.7 percentage change
Standard Deviation 25.8
71.9 percentage change
Standard Deviation 34.2

SECONDARY outcome

Timeframe: 1 day

Operators are asked directly after each procedure to rate the wearing comfort, graded worst to best. 0 means low comfort (worse outcome) and 100 is the best comfort level (best outcome) with wearing the collar.

Outcome measures

Outcome measures
Measure
XPF Thyroid Collar
n=58 Participants
Administration of the XPF Thyroid Collar. XPF thyroid collar: Interventionalist wear the experimental (XPF) thyroid collar during fluoroscopy guided interventions.
Equivalent Collar
n=48 Participants
Administration of the Standard 0.5mm lead-equivalent thyroid collar. Standard 0.5mm lead equivalent thyroid collar: Interventionalist wear a standard 0.5mm lead equivalent thyroid collar during fluoroscopy guided interventions.
Wearing Comfort of the Collar on a Scale From 0-100.
85.0 score on a scale
Standard Deviation 8.8
83.3 score on a scale
Standard Deviation 13.1

SECONDARY outcome

Timeframe: 1 day

Population: XPF thyroid collar and the equivalent collar are combined under one outcome measure as the outcome measure is comparing the arms and not as individual measures.

(day 1) Operators are asked directly after each procedure to rate the wearing comfort Radiation exposure will be monitored with radiation detectors (TLDs, 2 attached to the collar) which the participant is required to wear. Exposure is measured as the energy imparted per unit mass by ionizing radiation to the matter at the specified time of the procedure. The International System of Units (SI) unit of absorbed dose is the joule per kilogram. The special name for this unit is the gray (Gy). For purposes of radiation protection and assessing dose or risk to humans in general terms, the quantity normally calculated is the mean absorbed dose in an organ or tissue.

Outcome measures

Outcome measures
Measure
XPF Thyroid Collar
n=106 Participants
Administration of the XPF Thyroid Collar. XPF thyroid collar: Interventionalist wear the experimental (XPF) thyroid collar during fluoroscopy guided interventions.
Equivalent Collar
n=106 Participants
Administration of the Standard 0.5mm lead-equivalent thyroid collar. Standard 0.5mm lead equivalent thyroid collar: Interventionalist wear a standard 0.5mm lead equivalent thyroid collar during fluoroscopy guided interventions.
Radiation Exposure (uSv) for for Both the Thyroid and Equivalent Collars
272.3 Gy
Standard Deviation 373.3
98.2 Gy
Standard Deviation 203.1

SECONDARY outcome

Timeframe: 1 day

Population: XPF caps and the equivalent caps are combined under one outcome measure as the outcome measure is comparing the arms and not as individual measures.

(day 1) Operators are asked directly after each procedure to rate the wearing comfort Radiation exposure will be monitored with radiation detectors, which the participant is required to wear. Exposure is measured as the energy imparted per unit mass by ionizing radiation to the matter at the specified time of the procedure. The International System of Units (SI) unit of absorbed dose is the joule per kilogram. The special name for this unit is the gray (Gy). For purposes of radiation protection and assessing dose or risk to humans in general terms, the quantity normally calculated is the mean absorbed dose in an organ or tissue.

Outcome measures

Outcome measures
Measure
XPF Thyroid Collar
n=106 Participants
Administration of the XPF Thyroid Collar. XPF thyroid collar: Interventionalist wear the experimental (XPF) thyroid collar during fluoroscopy guided interventions.
Equivalent Collar
n=106 Participants
Administration of the Standard 0.5mm lead-equivalent thyroid collar. Standard 0.5mm lead equivalent thyroid collar: Interventionalist wear a standard 0.5mm lead equivalent thyroid collar during fluoroscopy guided interventions.
Radiation Exposure (uSv) for XPF Caps and the Equivalent Caps
224.1 Gy
Standard Deviation 266.1
48.1 Gy
Standard Deviation 124.7

Adverse Events

XPF Thyroid Collar

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Equivalent Collar

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Raul Herrera, MD. Director Miami Cardiac and Vascular Institute

Baptist Health South Florida

Phone: 786-596-3505

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place