Alzheimer's Disease
Conditions
Keywords
Amyloid imaging, Positron Emission Tomography, 18F-AV-45, florbetapir F 18, Diagnostic imaging
Brief summary
Re-read of brain amyloid scans acquired in previous AV-45 clinical studies by readers trained using updated reading methodology. The scans in this study came from subjects who had Alzheimer's Disease (AD) or Mild Cognitive Impairment (MCI).
Interventions
DRUGflorbetapir F 18
IV injection, 370MBq (10mCi), single dose (intervention for Study A05 participants, source of scans for this study)
Sponsors
Avid Radiopharmaceuticals
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
SINGLE
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Participants: * Inclusion Criteria AD: * Male or female \>=50 years of age * Meet National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) criteria for probable AD with Mini-Mental State Examination (MMSE) score of 10-24 * Inclusion Criteria MCI: * Male or female \>=50 years of age * Have a Clinical Dementia Rating (CDR) of 0.5 * MMSE \>24 *
Exclusion criteria
* Have a history or current diagnosis of other neurologic disease * Have had or currently have a diagnosis of other neurodegenerative disease * Have participated in experimental therapy targeted to amyloid plaque Readers: •Private nuclear medicine physicians with no prior training in reading florbetapir-PET scans
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Inter-reader Agreement - Median Kappa Statistic | 50-60 min after injection | Seven readers blinded to all clinical information using the binary read methodology (amyloid positive/negative). Simple kappa statistics were calculated for each reader versus the other 6 readers. Primary outcome measure was the median kappa of each reader versus the other 6 readers. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Overall Inter-reader Agreement - Fleiss' Kappa | 50-60 min after injection | Seven readers blinded to all clinical information using the binary read methodology (amyloid positive/negative). Fleiss' kappa was calculated across all inter-reader comparisons. |
Participant flow
Recruitment details
NO SUBJECTS WERE ENROLLED IN THIS STUDY - this study re-read 40 scans obtained from 25 mild cognitive impairment (MCI) subjects and 15 Alzheimer's Disease (AD) subjects randomly selected from Study A05 (NCT00702143).
Participants by arm
| Arm | Count |
|---|---|
| A05 Florbetapir-PET Scans Subjects who received a valid florbetapir-PET scan in Study A05 (NCT00702143) | 40 |
| Total | 40 |
Baseline characteristics
| Characteristic | A05 Florbetapir-PET Scans |
|---|---|
| Age, Continuous | 72.7 years STANDARD_DEVIATION 9.38 |
| Region of Enrollment United States | 40 participants |
| Sex: Female, Male Female | 20 Participants |
| Sex: Female, Male Male | 20 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 |
Outcome results
Primary
Inter-reader Agreement - Median Kappa Statistic
Seven readers blinded to all clinical information using the binary read methodology (amyloid positive/negative). Simple kappa statistics were calculated for each reader versus the other 6 readers. Primary outcome measure was the median kappa of each reader versus the other 6 readers.
Time frame: 50-60 min after injection
Population: Seven private practice nuclear medicine physicians with no prior training in reading florbetapir-PET scans each rated 40 florbetapir-PET scans (7 readers x 40 scans = 280 scan reads) as either amyloid positive or negative.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| A05 Florbetapir-PET Scans | Inter-reader Agreement - Median Kappa Statistic | Reader 1 | 0.72 median kappa |
| A05 Florbetapir-PET Scans | Inter-reader Agreement - Median Kappa Statistic | Reader 4 | 0.75 median kappa |
| A05 Florbetapir-PET Scans | Inter-reader Agreement - Median Kappa Statistic | Reader 5 | 0.68 median kappa |
| A05 Florbetapir-PET Scans | Inter-reader Agreement - Median Kappa Statistic | Reader 6 | 0.83 median kappa |
| A05 Florbetapir-PET Scans | Inter-reader Agreement - Median Kappa Statistic | Reader 7 | 0.68 median kappa |
| A05 Florbetapir-PET Scans | Inter-reader Agreement - Median Kappa Statistic | Reader 2 | 0.70 median kappa |
| A05 Florbetapir-PET Scans | Inter-reader Agreement - Median Kappa Statistic | Reader 3 | 0.25 median kappa |
Secondary
Overall Inter-reader Agreement - Fleiss' Kappa
Seven readers blinded to all clinical information using the binary read methodology (amyloid positive/negative). Fleiss' kappa was calculated across all inter-reader comparisons.
Time frame: 50-60 min after injection
Population: Seven private practice nuclear medicine physicians with no prior training in reading florbetapir-PET scans each rated 40 florbetapir-PET scans (7 readers x 40 scans = 280 scan reads) as either amyloid positive or negative.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| A05 Florbetapir-PET Scans | Overall Inter-reader Agreement - Fleiss' Kappa | 0.61 Fleiss' kappa |