To hear about similar clinical trials, please enter your email below
Trial Title:
Searching for Masses and Calcifications at the Same Time in Breast Cancer Screening
NCT ID:
NCT05975736
Condition:
Mammography
Breast Cancer
Radiology
Conditions: Official terms:
Breast Neoplasms
Study type:
Interventional
Study phase:
N/A
Overall status:
Recruiting
Study design:
Allocation:
Randomized
Intervention model:
Parallel Assignment
Intervention model description:
One group of observers will get separate blocks of each of four conditions. The other
group will see all conditions, intermixed.
Primary purpose:
Basic Science
Masking:
None (Open Label)
Masking description:
Participants will not know the goals of the study but they will be fully informed about
the conditions and asked to respond "as quickly and accurately as possible".
Intervention:
Intervention type:
Behavioral
Intervention name:
Search only for masses
Description:
Participants search the simulated mammogram for simulated masses.
Arm group label:
Blocked Trials
Arm group label:
Mixed Trials
Intervention type:
Behavioral
Intervention name:
Search only for calcifications
Description:
Participants search the simulated mammogram for simulated calcifications.
Arm group label:
Blocked Trials
Arm group label:
Mixed Trials
Intervention type:
Behavioral
Intervention name:
Search for both together
Description:
Search the simulated mammogram for both simulated masses and simulated calcifications at
the same time.
Arm group label:
Blocked Trials
Arm group label:
Mixed Trials
Intervention type:
Behavioral
Intervention name:
Search for one after the other
Description:
Search the simulated mammogram for first for simulated masses and then for simulated
calcifications sequentially (or vice versa).
Arm group label:
Blocked Trials
Arm group label:
Mixed Trials
Summary:
Brief Summary
A task like breast cancer screening (mammography) can be described as a "hybrid search"
task. In basic visual search tasks, observers search for a target among distractors that
are not the target. In hybrid search, observers search for two or more target types. In
mammography, observers are searching for masses, calcifications ("calcs"), and some other
signs of cancer like architectural distortion. In this experiment, the investigators have
created a simulated version of mammography where non-expert (non-radiologist) observers
can look for simulated masses and calcs. There are two types of stimuli, a 2D version
(like an x-ray) and a 3D version (like the output of Digital Breast Tomosynthesis - DBT).
The question that is being asked is whether it is better to ask about masses and calcs
separately (first one, then the other) or to just let observers look for both at the same
time.
Detailed description:
Brief Summary
A task like breast cancer screening (mammography) can be described as a "hybrid search"
task. In basic visual search tasks, observers search for a target among distractors that
are not the target. In hybrid search, observers search for two or more target types. In
mammography, observers are searching for masses, calcifications ("calcs"), and some other
signs of cancer like architectural distortion. In this experiment, the investigators have
created a simulated version of mammography where non-expert (non-radiologist) observers
can look for simulated masses and calcs. There are two types of stimuli, a 2D version
(like an x-ray) and a 3D version (like the output of Digital Breast Tomosynthesis - DBT).
The question that is being asked is whether it is better to ask about masses and calcs
separately (first one, then the other) or to just let observers look for both at the same
time.
Extended protocol
NOTE: This registration is linked to a Human Subjects registration in ASSIST. That, in
turn, is part of an NCI Grant, CA207490. The grant describes many proposed experiments
and notes that many others might be done as follow-up studies. At the suggestion of the
NIH, the investigators grouped these studies into three "studies", each covering multiple
experiments. The experiment described here is part of "Study ID 386409 Projects 1,2,3:
Experiments with Non experts". It is not possible to register a set of experiments
through the PRS system in CT.gov and it is not possible to file an annual report for the
grant (RPPR) without an NCT number for projects that have started collecting
participants. Accordingly, the investigators are describing one experiment here that
would be part of the "Project 2" bundle of studies.
These experiments take what is known about "hybrid search" tasks from the lab and applies
it to clinical mammography. Hybrid search tasks are tasks that involve looking for more
than one type of target at the same time (e.g. search for this pillow and any animal in
the scene in front of you).
Standard 2D mammography and 3D DBT can be thought of as hybrid search tasks. That is,
mammography can be thought of as a hybrid search for masses and calcifications. What is
the optimal way to do this task? Should readers look for both types of targets at the
same time or should they be asked to look for one target type and then the other. It is
likely that the sequential approach improves accuracy but at some cost in time. The
investigators will test that hypothesis of a "speed/accuracy tradeoff".
The investigators have developed a version of the 2D mammography task that can be run on
non-experts. Breast parenchyma is simulated with 1/fk noise (k=1.8 - 2.8). Artificial
masses and calcifications (calcs) can be added to this background. Masses are relatively
low contrast blobs that are deemed to be "bad" if they have many irregular bumps and
benign if they are smoother. Calcs are brighter, higher contrast, small spots. These are
deemed to be benign unless they form a cluster of nearby spots in the image. The task is
designed to be hard. The goal is performance producing a d' value in the range of 2.0 to
2.5. Bad and benign stimuli are selected from uniformly distributed stimuli sets. For
masses, when the target is 'bad', bad mass is randomly selected from 5 levels of
bumpiness. The same rule is applied for selecting benign stimuli from five less-bumpy
levels. For calcifications, the number of pixels in a cluster is randomly selected
between 4~12.
There are four conditions to be tested in the first experiment:
1. Search for masses alone
2. Search for calcs alone
3. Search for both together
4. Search for one after the other (mass -> calc) or (calc -> mass)
In addition, there are two different ways of presenting the four conditions. These could
be considered to be two arms of the study. Either participants could see each condition
in a block of 100 trials or the four conditions could be mixed into one set of 400 trials
(with breaks every 100 trials to keep the pacing of the experiment consistent.
In the initial experiment, target prevalence will be 60%. In future experiments, lower
prevalence will be tested. The measures of interest are accuracy and RT and the most
interesting question is whether the sequential condition produces any benefits that might
be worth the presumed cost in time.
The 3D version is like the 2D version except that a volume of 1/fk noise is created and
masses and calcs are added so that they fade in and out of view as the observer scrolls
through "slices" through the 3D volume. This simulates DBT.
Criteria for eligibility:
Criteria:
Inclusion Criteria:
- Age over 18 yrs
- Pass Ishihara color vision test
Exclusion Criteria:
- vision less than 20/25 with correction
- history of neuromuscular or visual disorders
Gender:
All
Minimum age:
18 Years
Maximum age:
N/A
Healthy volunteers:
Accepts Healthy Volunteers
Locations:
Facility:
Name:
Brigham and Women's Hospital
Address:
City:
Boston
Zip:
02215
Country:
United States
Status:
Recruiting
Contact:
Last name:
Ava A Mitra, BA
Phone:
617-525-3681
Email:
amitra@bwh.harvard.edu
Contact backup:
Last name:
Jeremy M Wolfe, PhD
Phone:
617-851-1166
Email:
jwolfe@bwh.harvard.edu
Start date:
September 1, 2022
Completion date:
September 1, 2028
Lead sponsor:
Agency:
Brigham and Women's Hospital
Agency class:
Other
Source:
Brigham and Women's Hospital
Record processing date:
ClinicalTrials.gov processed this data on November 12, 2024
Source: ClinicalTrials.gov page:
https://clinicaltrials.gov/ct2/show/NCT05975736