This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Histologic Assessment of the Difference Between 18F-2-fluoro-2-deoxy_D-glucose Positron Emission Mammography(PEM) and Magnetic Resonance Imaging (MRI) of the Breast (NCT01249157), a na na study. The primary outcome is To Evaluate the Accuracy of Preoperative 18FDG PEM.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01249157 |
| Phase | NA |
| Condition | Breast Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 6 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Memorial Sloan Kettering Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned patients with breast cancer who were to have staging breast MRI. The registry says consenting patients in this group would be offered 18FDG PEM within 30 days. It also states that the first 5 patients who consented were used for training purposes only. The registry does not provide analyzed participant characteristics or a more detailed description of the population contributing to an accuracy estimate.
Intervention
The imaging examination of interest was Positron Emission Mammography using 18FDG, a radioactive glucose-based tracer. The registry describes PEM and MRI together as the intervention and states that the study aimed to compare the value of FDG PEM with contrast-enhanced breast MRI. It does not report an analyzed PEM result.
Comparator
Contrast-enhanced breast MRI was the imaging modality used for descriptive comparison. This was not a randomized, like-for-like control comparison: the registry lists allocation as NA and the model as single group. The record describes offering PEM to patients undergoing staging MRI, rather than assigning participants to separate treatment groups.
Primary question
The stated primary aim was to evaluate the accuracy of preoperative 18FDG PEM using pathology as the gold standard, and descriptively compare that accuracy with breast MRI in an exploratory analysis intended to generate data for future studies. The registry reports zero total participants analyzed for this outcome, so it supplies no observed accuracy estimate or descriptive comparison.
3. Trial Design
NCT01249157 was a single-group imaging study involving patients with breast cancer who were to have staging breast MRI. The registry describes an offer of 18FDG PEM within 30 days of MRI. If a participant had a breast MRI performed at an outside institution within 30 days, the record says that MRI could be used if a radiologist determined it was adequate; the displayed description ends before giving further detail. The study intervention is listed as PEM and MRI, and no separate control arm is described.
The design was not randomized: allocation is listed as NA, masking as none, and the model as single group. The study is classified as phase NA. These entries describe the registry record; they do not establish details about procedures or analytic decisions that the record does not report. The sponsor is Memorial Sloan Kettering Cancer Center. Enrollment is listed as 6, with a study start of 2010-11 and primary completion of 2012-08. The status is terminated. The reason for termination is not reported in the registry record.
The primary outcome timeframe is 2 years. Its stated purpose is to evaluate preoperative PEM accuracy against pathology and make an exploratory, descriptive comparison with MRI. The first 5 patients who consented were used for training purposes only. The registry reports no analyzed participants for the primary outcome and lists zero analyses. It therefore does not establish that the planned accuracy evaluation or MRI comparison produced results. Details such as a prespecified statistical analysis plan, enrollment rationale, and any interim analyses are not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Preoperative 18FDG PEM and MRI |
|---|---|
| STARTED | 1 |
| COMPLETED | 0 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Preoperative 18FDG PEM and MRI |
|---|---|
| Withdrawal by Subject | 1 |
Analysis population for the primary outcome, as defined in the registry: No data displayed because Outcome Measure has zero total participants analyzed.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: The first 5 patients who consent to the study will be intended for training purposes only.
| Characteristic | Unit | Preoperative 18FDG PEM and MRI |
|---|---|---|
| Participants analysed | 1 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as To Evaluate the Accuracy of Preoperative 18FDG PEM, measured over 2 years.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is described as evaluating the accuracy of preoperative 18FDG PEM using pathology as the gold standard. In this setting, pathology from standard-of-care breast surgery is intended to serve as the reference against which imaging findings are assessed. The registry also describes an exploratory, descriptive comparison with breast MRI and says the aim was to generate data for future studies.
General: An accuracy endpoint asks how well an assessment agrees with a defined reference. The specific summary measure and its operational definition matter: different measures can emphasize different types of disagreement between imaging and pathology. The registry does not state whether accuracy was to be expressed as an overall proportion, by lesion, by patient, or through other measures. It does not report definitions for a positive imaging result, the matching procedure between imaging and pathology, or how ambiguous and multiple findings would be handled.
No primary outcome result is displayed because the registry reports zero total participants analyzed. There is consequently no reported accuracy estimate, uncertainty interval, or MRI comparison to interpret. The purpose of the endpoint is clear from the description, but its numerical result and the detailed rules used to calculate it are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically relevant diagnostic question but does not provide an analyzed result for it. The primary outcome is preoperative 18FDG PEM accuracy using pathology as the reference, with an exploratory descriptive comparison to breast MRI. Yet the outcome population is explicitly reported as having zero total participants analyzed, and the record lists zero analyses. The posted results therefore do not quantify how often PEM agreed with pathology or how that performance compared descriptively with MRI.
Enrollment is listed as 6, but enrollment is not the same as the number contributing to an endpoint analysis. The first 5 consenting patients were used for training purposes only, according to the outcome description. The record does not identify an analyzed set or explain how the remaining enrolled participants were handled. It would be inappropriate to treat the enrollment count as a denominator for accuracy, or to infer a result from the training description.
There is no estimate or confidence interval for the endpoint in the registry record. General: A confidence interval describes the uncertainty around an estimate under the assumptions of the analysis; it does not fix bias or limitations in the underlying data. Without an estimate, its precision cannot be assessed. Nor can readers judge whether apparent differences between PEM and MRI would be compatible with sampling variability, because no comparative result is displayed.
The record calls the MRI comparison exploratory and descriptive, not a randomized comparison. The imaging modalities were not assigned as competing arms, and the study is identified as single group with allocation NA. A descriptive comparison, even if data were available, would not by itself establish that one modality caused a better outcome or was superior under a controlled comparison. The record gives no results to support even a descriptive performance contrast.
Interpretation is also limited by missing analytic detail. The endpoint description does not give the accuracy metric, analysis unit, handling of indeterminate results, or interval-estimation method. These details are not reported in the registry record. The status is terminated, but the reason and its relation, if any, to the absence of analyzed results are not reported. The sound reading is therefore that the registry records a planned diagnostic evaluation and a small enrollment, but no posted primary endpoint analysis from which diagnostic performance can be concluded.
9. Statistical Methods Explained
The registry describes a diagnostic-accuracy objective, rather than a treatment-effect comparison. PEM images were to be assessed against pathology from standard-of-care breast surgery, which the outcome description calls the gold standard. MRI was to be compared descriptively in an exploratory analysis. Since no participants are reported as analyzed for the endpoint, the record contains no observed accuracy statistic and no estimated difference or association to interpret.
What does accuracy against pathology mean?
General: A diagnostic-accuracy analysis compares the classification or finding from an imaging assessment with a reference classification. Pathology is the stated reference in this study. The interpretation depends on how imaging findings and pathology findings are defined and matched. The registry describes the broad comparison but does not report those operational rules. In particular, it does not specify how a positive finding was defined, whether the unit was a patient or lesion, or what happened when results were uncertain or could not be matched.
General: Accuracy can be represented in different ways. A single overall agreement measure may conceal whether errors occur through missed findings or through findings that pathology does not confirm. Measures such as sensitivity and specificity address different aspects of classification, but the registry does not state that either was the planned primary measure. No such value should be inferred from the endpoint title alone. The posted outcome contains no numerical result with which to assess these properties.
Why is pathology the reference?
General: A reference standard gives the diagnostic assessment a comparison point. Here, the registry identifies pathology from standard-of-care breast surgery as that reference. The reference is central to interpreting accuracy because the endpoint is agreement with pathology, not a direct measure of later health outcomes. The registry's description does not provide information on pathology review procedures, whether readers were blinded to imaging, or how disagreement among pathologists would be resolved. Those details are not reported in the registry record.
What does the MRI comparison establish?
The stated MRI comparison is exploratory and descriptive. General: Descriptive comparisons can characterize observed results but do not, by themselves, isolate a causal effect or establish superiority. This study is listed as single group, with allocation NA and masking none; it is not a randomized comparison with separate assigned arms. The record describes offering PEM to patients having staging MRI, so the intended comparison is between imaging assessments in a clinical work-up, not between randomized groups. Since no primary analysis is posted, no observed comparison can be interpreted.
How should uncertainty be understood?
General: An estimate describes a result in the analyzed data, while a confidence interval communicates uncertainty around that estimate under the model's assumptions. More limited data often yield less precise estimates, but the actual precision depends on the data and method. There is no estimate or interval for this endpoint in the registry record. No claim about the magnitude or precision of diagnostic accuracy is therefore possible. The enrollment entry of 6 does not substitute for the number analyzed, which is reported as zero.
What do the planning assumptions mean?
The statistical planning assumptions associated with the record describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; they describe the effect to detect as a stated fraction of an observed effect. For time-to-event calculations, the stated convention is total events using Schoenfeld; other calculations are expressed as participants per arm. These are planning assumptions, not a description of the study's reported design: this trial is listed as single group and is not a randomized two-arm comparison. Planning illustrations are not observed power and do not establish what this study enrolled or analyzed. The record does not report the trial's own sample-size justification. Because no primary outcome analysis is displayed, the basis and relevance of any observed-effect illustration cannot be assessed from the posted outcome.
Other analytic choices that could affect an accuracy result, including the handling of missing or indeterminate assessments and any adjustment for multiple measures, are not reported in the registry record. General statistical explanations clarify what such choices mean, but they cannot fill in absent protocol details or create a result where none is posted.
10. Multiplicity, Missing Data and Analysis Populations
The registry describes a primary accuracy objective and an exploratory descriptive comparison with MRI. It does not report a statistical analysis plan specifying how multiple outcomes, comparisons, or diagnostic measures would be handled. A multiplicity adjustment, if planned, is not reported in the registry record. Because the primary endpoint has no analyzed result displayed and the record lists zero analyses, the impact of any multiplicity strategy cannot be assessed.
The outcome description states that the first 5 patients who consented were used for training purposes only. It does not describe an analyzed population, or how training data were separated from any evaluation data. Enrollment is listed as 6, while the primary outcome population is reported as zero total participants analyzed. The record does not explain the status or analysis eligibility of the other enrolled participants, so an analysis denominator cannot be reconstructed.
Missing-data methods are not reported in the registry record. The record does not say whether imaging or pathology assessments were missing, how incomplete records would be handled, or whether exclusions were prespecified. It also does not report an intention-to-diagnose population, a per-protocol set, or another analysis population. These omissions matter because diagnostic-accuracy estimates depend on which assessments are included and how incomplete or indeterminate cases are treated. General: Different handling rules can change both the estimate and its uncertainty; without the rules and analyzed data, the direction or size of any effect cannot be determined.
There is no basis in the posted outcome to infer statistical significance, precision, or robustness. The record reports no endpoint analysis and no result, and it does not report whether interim analyses were planned or conducted.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Preoperative 18FDG PEM and MRI | 0 | 1 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Preoperative 18FDG PEM and MRI | 0 of 1 |
The registry lists a group titled “Preoperative 18FDG PEM and MRI.” For that group, the serious-event fields report 1 at risk and 0 affected; the other-event fields also report 1 at risk and 0 affected. These are the counts entered in the record. They should be read as registry entries for that group, not as a safety rate for all 6 enrolled participants: the listed at-risk count is 1, and the record does not explain how that figure relates to overall enrollment or to the primary outcome population.
The deaths field is null, so a death count is not reported in the registry record. No top serious-event terms are listed. The zero affected entries mean that the record displays no affected participants within the stated at-risk count for those event categories. They do not establish the absence of events among a broader population, nor do they resolve the lack of detail about reporting and follow-up. The registry does not report additional information that would explain the safety denominators, event ascertainment, or the implications of terminated status.
General: A zero count in a small or unclear denominator does not prove that an event cannot occur. The denominator, duration and completeness of observation, and reporting rules are needed to understand the scope of a safety finding. The posted entries are sparse and should not be used to make a broader safety conclusion.
12. What the Result Does, and Does Not, Mean
The record documents an intended evaluation of 18FDG PEM for preoperative breast imaging, with pathology as the reference standard and MRI as an exploratory descriptive comparator. It also documents enrollment of 6 and states that the first 5 consenting patients were used for training purposes only. These registry entries describe the study's aim and registry status; they are not evidence of measured diagnostic performance.
The primary endpoint has no displayed data because the registry reports zero total participants analyzed. There is no accuracy estimate, uncertainty interval, or reported comparison with MRI. Thus, the posted results neither show that PEM performed well nor show that it performed poorly. They also do not establish equivalence or a difference between imaging methods. No such conclusion can be drawn without analyzed outcome data and a clearly defined analytic approach.
General: Diagnostic accuracy is specific to the reference standard, definitions, participant spectrum, and interpretation procedures used. Even a reported estimate would need those details and its uncertainty to be understood. The registry record does not give several of these analytic details, and it presents no estimate to evaluate. The stated exploratory purpose was to generate data for future studies, but the record does not supply an analyzed result that can serve that purpose for readers.
The terminated status is recorded, but the reason is not reported in the registry record. It should not be interpreted as evidence about the imaging methods or the study's findings. Likewise, the small listed enrollment cannot be converted into a conclusion about statistical power or endpoint precision, especially when no participants are reported as analyzed. The most defensible interpretation is limited: the registry describes a planned diagnostic study, records enrollment and termination, and posts no primary endpoint result.
13. Why This Trial Matters Statistically
This study matters statistically because it illustrates the difference between a diagnostic question and an available diagnostic result. The clinical aim is specific: compare preoperative PEM findings with pathology, then describe their accuracy relative to MRI. But an objective alone does not provide an estimate. The registry's report of zero analyzed participants means readers cannot evaluate the planned accuracy question from the posted outcome.
The record also makes clear why enrollment, training, and analysis populations should not be treated as interchangeable. Enrollment is listed as 6, while the first 5 consenting participants were used for training purposes only and the outcome reports zero analyzed participants. The record does not explain the path from enrollment to analysis. Without that information, a denominator for the primary endpoint cannot be established.
The stated MRI comparison is exploratory and descriptive, and the trial is single group rather than a randomized allocation to competing arms. This distinction matters: an intended side-by-side diagnostic description would not automatically answer a causal or superiority question. In this case, even the descriptive comparison is not reported as an analyzed result.
Finally, the record shows why a statistical methods description must be paired with data and transparent definitions. Accuracy depends on the diagnostic criteria, analysis unit, reference assessment, and treatment of incomplete or indeterminate findings. Those details are not reported. The example therefore underscores a basic interpretive principle: when the registry contains no analyzed primary outcome, statistical interpretation should stop short of claims about performance, precision, or comparative value.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The central limitation is that the primary outcome has no analyzed data displayed. The registry reports zero total participants analyzed and zero analyses, so neither PEM accuracy against pathology nor its descriptive comparison with MRI can be evaluated. Enrollment of 6 does not supply an outcome denominator.
The first 5 consenting patients were used for training purposes only, but the registry does not explain how training was conducted or identify the participant set intended for formal evaluation. It does not state how many participants completed the imaging and surgery pathway, whether all images had corresponding pathology, or why no participants appear in the primary analysis. These details are not reported in the registry record.
The endpoint description does not define the accuracy metric, unit of analysis, imaging threshold, matching rules, or handling of equivocal results. Nor does it report whether image readers or pathology assessors were masked to other findings. Masking is listed as none at the study level, but further assessment-specific procedures are not reported. The MRI comparison is described as exploratory and descriptive, without analytic detail.
The study is listed as single group, with allocation NA, so it is not a randomized comparison of separate imaging arms. The registry does not report the reason for termination, a sample-size justification for the trial, missing-data methods, multiplicity handling, or interim analyses. The safety group has 1 participant at risk for the listed categories, but the relationship to enrollment is not explained; the deaths field is null. These gaps limit both efficacy and safety interpretation. No unreported explanation should be inferred from the record's status or outcome entries.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Histologic Assessment of the Difference Between 18F-2-fluoro-2-deoxy_D-glucose Positron Emission Mammography(PEM) and Magnetic Resonance Imaging (MRI) of the Breast — NCT01249157.
- Registry record last updated 2015-12-24; status last verified 2015-11.
- Results first posted 2015-12-24.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT01249157 was sponsored by Memorial Sloan Kettering Cancer Center and concerned PEM and MRI for breast cancer. The listed study start was 2010-11, primary completion was 2012-08, and status is terminated. Enrollment is listed as 6. The design is single group, with allocation NA and masking none.
The primary aim was to assess preoperative 18FDG PEM accuracy using pathology as the gold standard and descriptively compare it with breast MRI in an exploratory analysis. The first 5 consenting patients were used for training purposes only. The primary outcome timeframe is 2 years, but the registry reports zero total participants analyzed and zero analyses. No primary accuracy estimate or MRI comparison is posted. The reason for termination and the detailed analysis methods are not reported in the registry record.