Amyloid Plaque Deposition in Chemotherapy-Induced Cognitive Impairment: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Amyloid Plaque Deposition in Chemotherapy-Induced Cognitive Impairment (NCT02317783), a na phase 2 study. The primary outcome is Number of Scans With Abnormal [18F]Flutemetamol Uptake.

2. Clinical Question

3. Trial Design

The registry describes a phase 2, single-group study sponsored by the University of Utah. Breast cancer is listed as the condition, and the study title concerns amyloid plaque deposition in chemotherapy-induced cognitive impairment. The registry lists enrollment of 15 and a status of terminated. The reason for termination is not reported in the registry record.

All participants were described as completing three imaging sessions on separate days: [18F]Flutemetamol-PET/CT, FDG-PET/CT, and MRI. The order depended on participant and radioisotope availability, and the sessions were to be completed within 2 month. The primary outcome description specifies that [18F]Flutemetamol-PET/CT scans were acquired within 30 days of confirmed cognitive impairment via neuropsychological testing. Images were reviewed after completion of all study procedures.

The study had no randomized allocation, no masking, and no parallel comparator. These design features matter for interpretation: the primary outcome is a count of scans meeting an imaging criterion, not an estimated difference between assigned treatments. The registry does not describe a control population, a before-and-after comparison, or a diagnostic accuracy comparison against an independent reference standard.

The listed start date is 2018-01-31, and the primary completion date is 2019-09-24. Those dates provide the registry's timing information but do not establish when each participant completed imaging or when outcome assessment occurred. The record does not report the number of participants who completed each imaging session or clarify whether enrollment of 15 represents the number assessed for the primary outcome.

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

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Scans With Abnormal [18F]Flutemetamol Uptake, measured over [18F]Flutemetamol-PET/CT scans were acquired within 30 days of confirmed cognitive impairment via neuropsychological testing. Images were reviewed following completion of all study procedures..

The primary endpoint is the number of scans with abnormal [18F]Flutemetamol uptake. The registry says uptake was assessed visually according to the approved Vizamyl prescribing information, with each scan graded positive or negative for abnormal uptake. This makes the recorded endpoint a count of scans classified as positive, rather than a continuous measurement of uptake or a score describing its intensity.

A binary visual classification can provide a clear, prespecified way to summarize whether scans meet an imaging criterion. Counting positive scans can describe how often that criterion was observed in the group assessed. It does not, by itself, establish why uptake occurred, whether the classification corresponds to a clinical diagnosis, or whether the imaging finding is associated with cognitive outcomes.

The timeframe states that scans were acquired within 30 days of confirmed cognitive impairment via neuropsychological testing and reviewed after all study procedures were completed. The registry does not report the actual count, the number of scans evaluated, or a result estimate. It also does not describe reader blinding, agreement between readers, or how an indeterminate image would be handled. Without the posted outcome data, the frequency of positive scans and the precision of that frequency cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a descriptive imaging outcome rather than a randomized comparison. The primary endpoint counts scans classified as positive for abnormal [18F]Flutemetamol uptake. The analysis needed to summarize that endpoint would depend on the number of scans assessed and the number classified as positive. Neither quantity is reported as an outcome result in the registry record, so no numerical estimate or precision measure can be interpreted.

What does a binary scan classification represent?

In general, a binary outcome records one of two categories, such as positive or negative. A count of positive scans adds together observations in the positive category. A count is not itself a rate unless its denominator is also known. A proportion uses both the number of positive observations and the number assessed; an uncertainty interval around a proportion can indicate how precisely the observed proportion estimates a broader underlying frequency. These are general statistical concepts, not results reported for this study. The registry gives no primary-outcome count, denominator, proportion, or interval.

The unit described for the primary endpoint is scans. It is therefore important not to automatically treat scans as participants. The protocol description says participants were to complete imaging sessions on separate days, but the registry does not report how many scans were completed, whether every participant contributed a scan eligible for the primary outcome, or whether any scans were excluded. If observations from the same participant are counted separately, they may not be statistically independent. The registry does not state how repeated observations, if any, were handled.

Why does the design affect interpretation?

In general, a single-group study can describe observations in the group assessed, but it cannot estimate a between-group difference when no comparator group is present. Random allocation and masking are also absent according to the registry. Those features do not prevent a descriptive scan count, but they limit what can be inferred about causal effects and can leave assessment vulnerable to influences that a controlled design might address. The registry does not report an independent reference standard for judging the visual scan classifications.

For a binary visual assessment, reader agreement and adjudication procedures can affect how consistently scans are classified. The record says that images were reviewed after completion of study procedures and that visual criteria were based on the approved Vizamyl prescribing information. It does not report the number of readers, whether readers were blinded to participant information, how disagreements were resolved, or whether repeat readings were conducted. The statistical consequences of those assessment details cannot be evaluated from the record.

What do the planning assumptions mean?

The registry includes a generic planning illustration described as using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of an observed effect. Such assumptions concern hypothetical sample-size planning; they are not observed trial results, and a planning calculation is not observed power. The record does not report the numerical planning outputs or the observed effect used for that illustration.

Those two-arm assumptions do not match the registered single-group design. A two-arm planning illustration should not be interpreted as a description of the trial's actual allocation, analysis, or achieved precision. The registry does not report a trial-specific sample-size justification, a target based on a stated primary-outcome frequency, or a statistical plan connecting the illustration to this study.

What analysis results are missing?

The registry lists no analysis results. It does not report a point estimate, confidence interval, hypothesis test, adjusted model, or participant-level analysis population for the primary endpoint. In general, a confidence interval describes a range of estimates compatible with the data and the method used; it does not repair missing outcome reporting or establish causality. Without a reported estimate and its denominator, neither an interval nor a test result can be interpreted for this study. The choice of an appropriate inferential method also depends on the actual observations and analysis plan, neither of which is reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures, including the primary number of scans with abnormal [18F]Flutemetamol uptake and a secondary measure concerning the number of scans positive for [18F]Flutemetamol uptake. The descriptions appear related, but the record does not explain whether they use distinct definitions or analysis populations. The exact relationship between these measures is not reported in the registry record.

When a study examines multiple outcomes or performs multiple statistical tests, the chance of at least one apparently unusual result can increase. General approaches to multiplicity include defining a primary outcome in advance and specifying how secondary tests will be interpreted or adjusted. The registry identifies a primary outcome, but a multiplicity strategy, testing hierarchy, or adjustment method is not reported in the registry record. No analyses are listed, so the effect of any multiplicity handling cannot be assessed.

The record does not state how missing or incomplete imaging data would be handled, whether participants with incomplete sessions would contribute available scans, or how indeterminate visual classifications would be treated. It also does not report an analysis population for the primary outcome or explain how the enrolled group relates to participants with usable scans. These details matter because the denominator used for a scan count or proportion determines what population the result describes.

Interim analyses, stopping rules, and a prespecified statistical analysis plan are not reported in the registry record. The terminated status does not establish whether an interim review occurred or whether outcome data were analyzed. Without these details and without posted outcome results, the registry does not support an assessment of missing-data bias, multiplicity, or the consistency of the analysis with a prespecified plan.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists 10 participants at risk for serious adverse events and 0 participants with serious adverse events. It also lists 10 participants at risk for other adverse events and 0 participants with other adverse events. Deaths are listed as 0. These figures describe the adverse-event entries in the registry; they do not supply additional detail about the types, timing, duration, or severity of non-serious events.

The adverse-event denominator of 10 differs from the registry's enrollment of 15. The record does not explain that difference, so the safety figures should be read using the stated at-risk count rather than assumed to cover every enrolled participant. The registry also does not explain the safety collection period or provide an account of participants who were not included in that denominator.

Zero recorded events in the listed group means no events were entered in these categories for the stated at-risk group. It does not establish that no event could occur, and it does not provide a comparison with another group. Because this is a single-group study and the registry lists no comparator, these figures do not estimate a comparative safety difference. They are limited registry entries, not a complete characterization of safety.

12. What the Result Does, and Does Not, Mean

The registry record establishes that investigators planned a single-group imaging study in people with breast cancer and cognitive impairment associated with chemotherapy. It specifies a primary endpoint based on visual classification of [18F]Flutemetamol-PET/CT scans and describes additional imaging with FDG-PET/CT and MRI. It also lists enrollment of 15, a terminated status, and adverse-event counts for 10 participants at risk.

The record does not report the primary endpoint result. It therefore does not show how many scans were classified as abnormal, what fraction of assessed scans that count represents, or how precise an estimate of scan positivity would be. There are no posted outcome analyses from which to assess associations between imaging findings and cognitive impairment. The stated objective of gathering pilot data does not substitute for reported results.

Even a reported positive-scan count from this design would describe observations in the assessed group, not establish that chemotherapy caused amyloid deposition or that the imaging classification explains cognitive impairment. Without a comparator and an analysis plan, differences between groups, causal effects, and diagnostic performance cannot be inferred from the registered design alone. The record also does not describe the basis for the visual classification beyond reference to the approved prescribing information.

The safety entries report zero serious adverse events, zero other adverse events, and zero deaths among the stated at-risk group of 10. These entries should not be generalized to all 15 listed as enrolled, because the record does not reconcile the denominators. Nor do they establish comparative safety or rule out events that were not captured in the registry entries.

Overall, the registry is informative about the study's intended imaging procedures and endpoint, but its missing outcome analyses limit conclusions about what the study observed. The terminated status adds context about the trial's disposition; without a recorded reason, it does not explain the absence of results or indicate what conclusions investigators reached.

13. Why This Trial Matters Statistically

This study illustrates a basic distinction between a registered research question and a reportable result. The registry identifies a specific primary endpoint: a count of scans visually classified as having abnormal [18F]Flutemetamol uptake. But an endpoint definition does not reveal the observed data. Without the count and the number of scans assessed, readers cannot determine the frequency of positive classifications or the precision of that estimate.

The study also shows why the unit of analysis should be clear. Participants were described as completing imaging sessions, while the primary outcome is expressed as a count of scans. A scan-level count and a participant-level count answer different questions. The registry does not report how many scans were analyzed or how multiple observations from one participant, if present, were handled. Those omissions prevent a clear account of the analyzed population and statistical dependence.

Design and analysis need to be interpreted together. This is a single-group study without allocation to a comparator, so the primary outcome is descriptive rather than a randomized treatment contrast. Generic two-arm planning assumptions listed in the record do not change that design and should not be mistaken for the study's analysis plan. More broadly, planning calculations do not demonstrate that a study had adequate precision or observed power.

Finally, a terminated registry entry with no posted analysis results demonstrates the limits of relying on registration information alone. The record can communicate what investigators intended to assess and some basic design details, yet leave the central empirical question unanswered. Clear reporting of endpoint denominators, analysis populations, uncertainty, missing data, and termination context would be needed to evaluate the imaging findings statistically.

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 most direct limitation is the absence of posted primary-outcome results. The registry specifies the visual positive-or-negative scan classification but does not report the number of scans assessed or the number judged abnormal. This prevents estimation of the endpoint frequency and its precision.

The registry lists enrollment of 15, but does not report how many participants completed all imaging sessions, how many contributed scans to the primary endpoint, or whether any scans were excluded. The adverse-event entries use an at-risk count of 10, with no explanation of how that count relates to enrollment. These differences limit interpretation of both outcome coverage and safety coverage.

The single-group design has no registered comparator, and masking is listed as none. The record does not report an independent reference standard, reader blinding, inter-reader agreement, or adjudication of discrepant visual classifications. Accordingly, it does not allow evaluation of comparative performance or the reproducibility of the scan assessment.

The registry describes imaging order as dependent on participant and radioisotope availability, with sessions intended to be completed within 2 month. It does not report actual completion timing or whether order differences affected image interpretation. The reason for termination is not reported in the registry record, nor are interim analyses, stopping criteria, missing-data procedures, or a detailed statistical analysis plan.

These limitations are specific to the information recorded for this study. They do not establish that procedures or analyses were not conducted; they indicate that the registry record does not report them. In particular, the status of terminated and the absence of posted analyses do not explain why outcome results are unavailable.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Amyloid Plaque Deposition in Chemotherapy-Induced Cognitive Impairment — NCT02317783.
• Registry record last updated 2024-11-20; status last verified 2024-10.
• Results first posted 2024-11-20.
• 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.

18. Record Summary

The registry describes a University of Utah phase 2, single-group imaging study concerning amyloid plaque deposition in chemotherapy-induced cognitive impairment among people with breast cancer. It lists enrollment of 15, status as terminated, start date 2018-01-31, and primary completion date 2019-09-24.

Participants were described as completing [18F]Flutemetamol-PET/CT, FDG-PET/CT, and MRI. The primary endpoint was the number of scans with abnormal [18F]Flutemetamol uptake, classified visually as positive or negative. The registry record does not report the primary outcome result or any analysis results. It lists 0 serious adverse events, 0 other adverse events, and 0 deaths among 10 participants at risk in each listed adverse-event category; the difference between this count and enrollment is not explained.