Somatostatin Receptor Imaging in Patients With Suspected Cardiac Sarcoidosis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Somatostatin Receptor Imaging in Patients With Suspected Cardiac Sarcoidosis (NCT02546388), a non-randomized na study. The primary outcome is Number of Participants Characterized by Abnormal or Negative Uptake.

2. Clinical Question

3. Trial Design

The registry identifies this as a completed, nonrandomized, single-group study with no masking. Enrollment is listed as 17. The record names two interventions: Indium-111 Pentreotide (OctreoScan) and Gallium-68 DOTATATE. Although the interventions appear in separate groups, the record explicitly cautions that the arms are not a like-for-like control comparison.

The study summary describes the research purpose as assessing whether OctreoScan or DOTATATE could help doctors diagnose cardiac sarcoidosis. The arm descriptions say that patients meeting the stated eligibility conditions would receive an injection of the corresponding radiotracer. For DOTATATE, imaging is described as occurring 1 hour after injection. Further details of the OctreoScan imaging protocol are not reported in the registry record.

The primary outcome is framed as a participant count classified by abnormal or negative uptake, and its timeframe is listed as 1 hour. The outcome description refers to correlating localization and the number of increased radiotracer foci between FDG-PET and DOTATATE studies. The record also explains that OctreoScan was initially planned but was abandoned after DOTATATE became FDA approved, citing superior image quality, lower radiation, and a shorter protocol as the reasons for that change.

These design details matter for interpretation. A nonrandomized study does not create exchangeable treatment groups through random assignment, and this record does not describe an independent control group. The posted information therefore supports a description of the study’s purpose and design, not a causal comparison between the two tracers. The statistical analysis plan is 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

Analysis population for the primary outcome, as defined in the registry: We initially planned to do OctreoScan, but Dotatate became FDA approved in the process. Due to the superior image quality, lower radiation, and shorter protocol for Dotatate, we decided to abandon OctreoScan.

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 Participants Characterized by Abnormal or Negative Uptake, measured over 1 hour.

The primary outcome is titled “Number of Participants Characterized by Abnormal or Negative Uptake.” It is a count outcome: it concerns how many participants fall into the stated uptake characterization, rather than a mean measurement or a time-to-event quantity. The registry lists the unit as participants and the timeframe as 1 hour.

The outcome description says the study aimed to correlate the localization and number of increased radiotracer foci between FDG-PET and DOTATATE studies. In general, comparing imaging findings can help describe whether two imaging approaches identify uptake in corresponding locations or show similar patterns. Such a comparison is not, by itself, evidence of diagnostic accuracy. Accuracy requires a clearly defined reference standard and an analysis that compares test classifications with that standard; those details are not reported in the registry record.

The outcome title and its description use related but not identical wording: the title refers to abnormal or negative uptake, while the description refers to localization and increased foci. The registry record does not explain how these classifications were defined, how the participant-level count was derived, or how discordant findings were handled. It also does not report the outcome counts. Consequently, the endpoint can be described by its registered purpose, but its operational definition and observed result cannot be reconstructed from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count measure?

A count outcome records the number of participants meeting a defined classification. It differs from a continuous outcome, which records a measurement along a scale, and from a time-to-event outcome, which includes information about when an event occurs. The registered primary outcome is a count, with participants named as the unit. To interpret such a count, readers need to know the exact classification rule and the population to which the count applies. The registry record does not provide those operational details or the observed count.

What does correlation between imaging findings mean?

In general, correlation describes how two sets of measurements or classifications vary together. For imaging, a comparison might consider whether detected findings occur in corresponding locations, or whether the number of detected foci varies similarly across approaches. Correlation does not necessarily mean that the methods agree for each participant, and it does not establish that either method correctly identifies disease. Agreement, correlation, and diagnostic accuracy answer different questions. A diagnostic accuracy analysis additionally depends on a specified reference standard and rules for classifying positive and negative findings. Those analysis details are not reported in the registry record.

The registered outcome description refers to localization and the number of increased foci between FDG-PET and DOTATATE studies, while the outcome title refers to participants characterized by abnormal or negative uptake. The record does not explain how these concepts were translated into a participant-level result. That uncertainty makes it difficult to determine precisely what a reported count would represent even if the counts were available.

How should estimates and uncertainty be read?

In general, an estimate summarizes the observed data, while a confidence interval communicates the range of values compatible with those data under the analysis assumptions. A narrow interval indicates greater precision than a wide interval, but neither an estimate nor its interval automatically proves a causal effect. For this study, the registry record does not report an effect estimate or confidence interval for the primary outcome. It also does not report a p-value or an analysis method for that endpoint. Statistical significance and precision therefore cannot be assessed from the posted results.

For a count outcome, the analysis also depends on the denominator: how many participants were eligible for the endpoint and had data available. The record lists enrollment but does not report the primary analysis population, missing imaging data, or exclusions. It would be inappropriate to assume that every enrolled participant contributed to every outcome.

What does nonrandomized allocation imply?

Random assignment is a design method intended to balance measured and unmeasured participant characteristics across groups on average. Nonrandomized allocation does not provide that protection. Consequently, observed group differences can be associated with differences in participant selection or study procedures as well as with the intervention. Here, the record specifically cautions that the listed arms are not a like-for-like control comparison. The change from planned OctreoScan use to DOTATATE use is also described, but the registry does not report a detailed account of how that change affected recruitment or analysis.

Absence of masking can matter when outcomes involve interpretation or classification. In general, knowledge of the imaging approach may influence subjective readings unless assessment procedures guard against that possibility. The record lists no masking, but does not describe reader procedures or whether image assessments were blinded to other information.

What are the planning calculations for?

In general, a sample-size illustration estimates how much data a future study might need under specified assumptions. The record describes planning illustrations using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is expressed as a stated fraction of the observed effect. These are planning assumptions, not evidence that the trial was designed with those assumptions. The record says the illustrations are computed from the observed effect, but it does not report the primary outcome result needed to interpret that effect in this account.

Such illustrations are not observed power. Observed power is not a substitute for reporting an effect estimate and its uncertainty. A planning calculation should be read as conditional on its assumptions, including the effect size chosen and the analysis model. It does not show that the completed study achieved a particular power, nor does it compensate for missing outcome reporting. The trial’s own sample-size justification and statistical plan are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study evaluates several outcomes, comparisons, or analysis choices. In general, repeated statistical testing can increase the chance of obtaining at least one apparently notable result by chance. How this issue is handled depends on which outcomes were prespecified, which tests were planned, and whether an adjustment or a hierarchy of tests was used. The registry record lists 2 outcome measures but does not report a multiplicity strategy or identify how analyses were prioritized. It lists no analysis entries, so the performed testing cannot be reconstructed.

Missing data also affect interpretation. A participant may be enrolled without having a usable result for a particular imaging endpoint. The registry record does not report missing imaging data, reasons for missingness, exclusions, or the method used to handle incomplete observations. It does not describe an analysis population or state whether all enrolled participants were included in the primary outcome analysis. Thus, the enrollment figure should not be treated as the endpoint denominator.

The record does not report whether analyses were conducted according to an intention-to-treat approach, a per-protocol approach, or another definition. Those labels have specific implications for which participants are included and how deviations are handled. Without an analysis-population definition, readers cannot tell how the posted outcome counts, if reported elsewhere, would relate to the participants enrolled or assigned to an intervention.

These omissions do not establish that multiplicity or missing-data problems occurred. They mean that the registry record does not provide enough information to assess how those issues were addressed. A complete interpretation would require prespecified analysis details, endpoint definitions, participant flow, and the results for each relevant outcome.

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 serious adverse event figures separately for the Indium-111 Pentreotide (OctreoScan) and Gallium-68 DOTATATE groups. For OctreoScan, 0 serious adverse events are listed among 4 participants at risk. For DOTATATE, 0 serious adverse events are listed among 13 participants at risk. The record also lists 0 other adverse events in the corresponding at-risk groups and 0 deaths in both groups.

These entries are descriptive counts, not proof that the interventions carry no risk. A zero count means that no events of that type are recorded in the listed group during the registry’s reported safety accounting. It does not show what would happen in a larger or different population, and it does not provide a precise estimate of the likelihood of uncommon events.

The registry record does not report further details about event definitions, observation duration, collection procedures, or completeness of safety follow-up. The group figures should not be treated as a controlled comparison, because allocation was nonrandomized and the record cautions that the arms are not like-for-like control groups. Safety counts also do not answer the primary imaging question.

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

The study record documents an investigation of somatostatin receptor imaging in patients with suspected cardiac sarcoidosis. It identifies OctreoScan and DOTATATE as the imaging approaches of interest and describes an intended comparison of uptake findings with FDG-PET. It also records a shift from planned OctreoScan use to DOTATATE during the study process.

What the record does not provide is the primary outcome result. There are no reported counts for participants characterized by abnormal or negative uptake, no estimate of the relationship between the imaging findings, and no confidence interval or statistical test for that outcome. As a result, the registry record cannot show how often the specified findings occurred or how precisely any association was estimated.

The study’s nonrandomized design and lack of masking are relevant to interpretation. The listed groups cannot be taken as a randomized head-to-head test, and the record cautions against treating them as like-for-like controls. Even if group results were available, differences would need to be interpreted in light of participant selection, study procedures, and how imaging findings were assessed. The record does not give enough information to resolve those issues.

The registry therefore supports conclusions about the stated research question, intervention descriptions, design, and recorded safety counts. It does not support a conclusion about diagnostic accuracy, comparative effectiveness, or whether either imaging approach improves diagnosis. Those claims would require outcome data and methodological details that are not reported in the registry record.

13. Why This Trial Matters Statistically

This study raises a statistical question that is important in diagnostic imaging research: what exactly is being compared when two approaches identify uptake in the same clinical setting? The registry describes a goal of relating the localization and number of increased foci between FDG-PET and DOTATATE studies. Distinguishing correlation, agreement, and diagnostic accuracy is essential because each describes a different property of test results.

The design also illustrates why allocation and study evolution matter. The record identifies a nonrandomized, unmasked study and notes that OctreoScan was initially planned before the study moved to DOTATATE. It explicitly warns that the groups are not a like-for-like control comparison. Those details constrain what any group contrast could mean, independent of whether a numerical difference appears large or small.

Outcome definition and denominator are equally important. A count of participants with a specified uptake classification can be interpreted only when the classification rule, eligible analysis population, and missing observations are clear. The registry record does not report these details or the primary outcome counts. Without them, neither the observed pattern nor its precision can be evaluated.

The record is therefore useful for identifying the intended endpoint and design limitations, while also showing the importance of complete results reporting. A clear report would connect the registered imaging question to operational definitions, analysis populations, methods, and estimates with uncertainty. In their absence, the study’s statistical contribution cannot be judged from this registry record alone.

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 primary limitation for interpreting the study is that the registry record does not report the primary outcome counts or an analysis of the stated imaging relationship. The endpoint’s title refers to participants characterized by abnormal or negative uptake, while its description refers to localization and increased foci. The record does not define how those terms were operationalized or how a participant was classified.

The record does not report participant flow, the primary analysis population, missing imaging results, exclusions, or reasons for missing data. Enrollment is listed, but it cannot be assumed to equal the number included in the endpoint analysis. The registry also does not describe the statistical analysis plan, reader procedures, or the handling of multiple outcomes and analyses.

Design limitations are specific and explicit: allocation was nonrandomized, masking was absent, and the listed intervention groups are not described as like-for-like controls. The record says the study moved from planned OctreoScan use to DOTATATE. It does not detail the timing or analytical consequences of that transition. These features limit causal interpretation and make a direct comparison between intervention groups inappropriate.

The safety entries are counts without reported details about definitions, follow-up, or ascertainment. They can be read as recorded events, but not as proof of no risk. Finally, although the record describes the study as completed, completion status does not supply the missing outcome estimates. These limitations mean that the registry record documents study intent and selected design features more fully than it documents the primary statistical findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Somatostatin Receptor Imaging in Patients With Suspected Cardiac Sarcoidosis — NCT02546388.
• Registry record last updated 2020-04-09; status last verified 2020-04.
• Results first posted 2020-03-25.
• 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 record describes a completed, nonrandomized, unmasked, single-group study of somatostatin receptor imaging in patients with suspected cardiac sarcoidosis. Enrollment is listed as 17. The named interventions are Indium-111 Pentreotide (OctreoScan) and Gallium-68 DOTATATE. The primary outcome concerns the number of participants characterized by abnormal or negative uptake, with a stated timeframe of 1 hour.

The outcome description refers to correlating localization and the number of increased foci between FDG-PET and DOTATATE studies. The record says OctreoScan was initially planned and later abandoned in favor of DOTATATE. It cautions that the intervention groups are not a like-for-like control comparison. Serious adverse event counts are listed as 0 in both groups. Primary outcome results, analysis methods, missing-data details, and the statistical analysis plan are not reported in the registry record.