99mTc Sestamibi Scans In Thyroglobulin Positive Scan Negative Differentiated Thyroid Cancer (DTC) Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for 99mTc Sestamibi Scans In Thyroglobulin Positive Scan Negative Differentiated Thyroid Cancer (DTC) Patients (NCT03065218), a na phase 4 study. The primary outcome is Lesion Detection on 99mTc Sestamibi Study.

2. Clinical Question

The clinical question is one of detection in a specifically described clinical setting, not a comparison of two treatments. The registry’s eligibility description focuses on patients whose blood marker is elevated despite negative diagnostic imaging. The scan is intended to provide another imaging assessment in that setting. Because the study has no concurrent comparator, the record does not frame the question as whether sestamibi performs better than another scan or management strategy. The primary endpoint description also does not state a formal diagnostic accuracy comparison against an independent reference standard.

3. Trial Design

This is a phase 4, single-group study of 99mTc sestamibi in differentiated thyroid cancer. The registry lists allocation as not applicable and masking as none. Enrollment was 4. The listed start date is 2016-10, the primary completion date is 2021-02-15, and the status is terminated. The reason for termination is not reported in the registry record.

Participants received a single intravenous injection of 25 mCi 99mTc sestamibi, followed by imaging for 45 minutes. The study description outlines an injection, a waiting period of 60 to 90 minutes, imaging while lying face up as the camera moves from the head to approximately the knees, and review by a nuclear medicine physician. The arm description notes that further imaging might be required at the onsite physician’s discretion. These details describe the scan procedure, not a comparison between assigned treatment groups.

The primary outcome is listed as a participant count for lesion detection on the 99mTc sestamibi study, with a timeframe of 1 year. The registry says that any area of radioactivity would be graded by two blinded nuclear medicine physicians to determine whether the uptake focus was metastatic disease. The record does not report how many participants met this endpoint, and it lists no analyses. It therefore does not provide an observed endpoint estimate or an inferential comparison.

With a single group and no masking, the study can describe findings in participants who underwent the scan, but its design does not by itself establish comparative performance against a control group. The small enrollment also means that the record offers limited information about how frequently findings would occur in a wider population. The protocol’s sample-size justification and the reason the study was terminated 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

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: Patients who met study inclusion criteria.

6. Primary Endpoint

The registry lists the primary outcome as Lesion Detection on 99mTc Sestamibi Study, measured over 1 year.

The primary endpoint is the count of participants with lesion detection on the 99mTc sestamibi study. The outcome is classified as a participant count, rather than a measure of time until an event or a continuous measurement. The registry describes an uptake focus as being assessed by two blinded nuclear medicine physicians, who determine whether it represents metastatic disease.

This endpoint is relevant to the stated study aim because the clinical question is whether the scan can identify a possible source of elevated thyroglobulin when standard diagnostic imaging is negative. A participant-level count provides a direct summary of how many people meet the endpoint definition. It does not, on its own, describe the number of separate lesions, the location of findings, or diagnostic accuracy against an independent reference standard.

The timeframe is listed as 1 year. The registry record does not report the observed endpoint count, the number of participants with evaluable scans, or a confidence interval. It also does not report a fuller operational definition for resolving disagreement between the two readers, or whether additional confirmation was required after a focus was judged suspicious. Those details should not be inferred from the endpoint label.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is binary at the participant level: a participant either meets the lesion-detection definition or does not. The registry labels the outcome as a count of participants. In a complete results report, a count could be paired with its denominator to describe the observed frequency of the endpoint. The registry record does not report either the endpoint count or an evaluable-participant denominator, so no such estimate is available.

A confidence interval is a way to express the uncertainty around an estimated quantity. In general, wider intervals indicate less precision, while narrower intervals indicate greater precision under the assumptions of the method used. For a binary endpoint, an interval would characterize uncertainty about the underlying event frequency, not uncertainty about whether a particular participant’s scan is correct. No confidence interval is reported for this endpoint, and none can be reconstructed without the outcome data.

A hypothesis test addresses a specified statistical question under a defined analysis plan. A p-value, when reported, describes how compatible the observed data are with a specified null model; it does not measure the probability that a hypothesis is true, and it does not establish clinical importance. The registry lists no analyses and reports no p-value. There is no basis in the posted record to infer whether any hypothesis test was planned or conducted.

The endpoint depends on classifying uptake foci. The registry describes review by two blinded nuclear medicine physicians, which makes reader assessment part of the outcome process. Blinding can reduce the influence of some knowledge on interpretation, but the record does not state what information was masked, how reader disagreements were handled, or whether a separate adjudication procedure was used. Agreement statistics are not reported. These procedural details matter because classification choices can affect a participant-level endpoint.

The absence of a concurrent comparator defines what can be estimated. This single-group study can, in principle, describe findings among participants who receive the scan, but it cannot estimate a relative effect against another imaging approach or a no-scan group. The allocation entry is not applicable, consistent with the single-group design. The record does not describe adjustment for participant characteristics or a planned diagnostic accuracy analysis.

Over-dispersion is a general issue in count analyses when observed variability exceeds what a simple model assumes. It matters because a model that underestimates variability can produce intervals that are too narrow or tests that are too optimistic. In this study, the primary outcome is a count of participants meeting a binary endpoint, not a reported count of lesion events. The registry provides no statistical model or outcome data, so there is no evidence to assess over-dispersion or its relevance to an actual analysis.

Planning calculations are distinct from observed results. The record’s stated planning illustration uses a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a stated fraction of the observed effect. Such a calculation is hypothetical for this single-group study because it assumes two arms for illustration. It is not an observed power calculation, does not show that the study was designed with those assumptions, and does not supply evidence about the scan’s performance. No planning sample-size values are reported in the registry record, and the study’s own sample-size justification is not reported.

The registry does not provide a statistical analysis plan, a model specification, an estimate of effect, a standard error, or an inferential result. General statistical concepts can explain what those quantities would mean, but they cannot fill in missing data. In particular, enrollment is not equivalent to the number with a completed scan, and it is not evidence that the primary endpoint was observed for every participant. The analysis population and handling of incomplete observations are not reported.

For this record, the central methodological distinction is between a defined measurement and a posted result. The endpoint description specifies what investigators intended to count. The enrollment and study status describe the trial record. Neither reveals the endpoint outcome. Until a result is reported, readers cannot assess the magnitude, precision, or consistency of lesion detection in the enrolled group.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("99mTc Sestamilbi")
n      <- c(4)
events <- c(1)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  99mTc Sestamilbi  4  1  25.0  0.6  80.6  4.6  69.9  5.3  71.6

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary outcome measure and no analyses. It does not report a multiplicity plan, including whether additional outcomes or subgroup comparisons were prespecified or how any family of statistical tests would be handled. Because no inferential results are posted, the effect of multiple testing cannot be evaluated. The record does not report an interim analysis plan, stopping boundaries, or whether any interim review occurred.

Missing-data handling is also not reported in the registry record. The enrollment count does not establish how many participants completed imaging, had an interpretable scan, or were included in an endpoint analysis. No analysis population is described, and there is no reported rule for participants with missing scans, incomplete follow-up, or indeterminate imaging findings. It would therefore be inappropriate to treat all enrolled participants as having either a positive or negative endpoint.

The endpoint timeframe is listed as 1 year, but the record does not describe the extent of follow-up actually completed by participants. It does not report whether outcome assessment was available for all enrolled participants or how deviations from the planned scan procedure would be handled. These omissions limit assessment of the reliability and completeness of any possible outcome analysis.

The reason for termination is not reported in the registry record. The record also does not establish whether termination affected the planned analyses or the availability of results. Without a statistical analysis plan and participant-level accounting, the implications of missing data, outcome selection, or analysis choices cannot be determined.

12. 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 adverse-event record lists 4 participants at risk for serious adverse events and 0 participants affected. It also lists 4 participants at risk for other adverse events and 0 affected. Deaths are listed as 0. These are the posted safety counts; they should be read as counts for the recorded study group, not as evidence that risk is absent.

With 4 enrolled participants, the safety observations cover a small group. A count of zero affected participants in this record cannot rule out events that might occur in a larger population, and it does not establish comparative safety because there is no control group. The registry does not list top serious adverse-event terms. It does not report additional detail about how safety events were collected, their observation period, or whether any participants lacked safety follow-up.

The safety counts should also be kept separate from the primary imaging outcome. The absence of recorded adverse events does not provide information about whether the scan detected a lesion, and the lack of a reported imaging result does not alter the posted safety counts.

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

This record documents a study designed to examine 99mTc sestamibi imaging in a defined group of differentiated thyroid cancer patients: those with elevated thyroglobulin and negative diagnostic imaging. It reports a single-group design, enrollment of 4 participants, a scan procedure, and a participant-count endpoint based on physician assessment of uptake foci. Those details describe the study’s purpose and structure.

The record does not report how many participants had lesion detection. It therefore does not establish the observed frequency of detection in this group. No estimate, confidence interval, or statistical test is posted. The record also does not report diagnostic accuracy against a reference standard, so the endpoint description cannot be interpreted as a sensitivity or specificity estimate.

The results do not support a comparison with another imaging procedure, because no comparator group is described. Nor do they establish whether the scan changes clinical management or improves patient outcomes; those outcomes are not reported. The registry status of terminated does not explain why the study ended, and it does not indicate the direction of any unreported finding.

The safety record lists no affected participants for serious or other adverse events and no deaths among the recorded participants at risk. Those observations describe the recorded study group only. Given the enrollment, they cannot establish the frequency of uncommon harms or compare safety with another approach.

The appropriate conclusion is narrow: the registry record contains a study plan and limited enrollment information but no posted primary outcome analysis. It can inform readers about the question investigators intended to address, but it cannot answer that question with the data currently reported in the record.

14. Why This Trial Matters Statistically

This study raises an important statistical distinction between asking a diagnostic question and having enough reported information to answer it. A clearly stated population, scan procedure, and endpoint make the intended assessment understandable. Yet the endpoint count itself is not reported. Without that result, readers cannot estimate how often the scan was classified as detecting a lesion in the enrolled group.

The single-group design also shapes interpretation. Detection can be described within a group, but comparative performance requires an appropriate comparison or reference framework. The registry does not report a concurrent comparator or diagnostic accuracy analysis. This means the design details alone cannot establish whether one imaging method is more informative than another, or how a scan finding relates to an independently confirmed disease status.

Enrollment is another essential part of the statistical context. Four participants were enrolled, but the record does not say how many completed scanning or contributed an evaluable primary outcome. Even when outcomes are reported, a small group generally yields limited precision and makes individual observations influential. Here, missing outcome information prevents even a descriptive estimate.

The record also illustrates why trial status and findings must be distinguished. The study is listed as terminated, but the reason is not reported. Status cannot be used as a substitute for outcome data, and it should not be interpreted as evidence for or against the scan. Likewise, zero recorded adverse events in the enrolled group do not establish absence of risk.

Statistically, the most consequential feature is not a particular estimate but the lack of a posted estimate. Clear outcome reporting, participant accounting, and an analysis description would be needed to assess magnitude, precision, and the limits of the findings. Until then, the documented record supports description of the research question and design, not a conclusion about scan performance.

15. 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 registry record contains no primary endpoint result, despite identifying lesion detection as the primary outcome. It does not report the number of participants whose scans were completed or evaluable, so enrollment cannot serve as the endpoint denominator. No confidence interval, p-value, or estimate of diagnostic performance is reported.

The design is single group and has no concurrent comparator. As a result, the record cannot support a comparative estimate between sestamibi and another imaging method. The endpoint definition relies on physician grading of uptake, but details about reader disagreement, adjudication, and independent confirmation are not reported. No sensitivity, specificity, or other diagnostic accuracy measure is listed.

Only 4 participants were enrolled. This limits the amount of information available even if complete outcome data existed, and makes the absence of participant-level outcome accounting especially consequential. The registry does not report whether all participants received the scan, whether additional imaging was performed, or whether each participant completed the stated timeframe.

The study is listed as terminated, but the reason for termination is not reported. The protocol, statistical analysis plan, sample-size justification, analysis populations, missing-data procedures, and multiplicity strategy are also not reported in the registry record. These omissions prevent assessment of whether the posted information reflects all planned analyses or how incomplete observations would have been handled.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: 99mTc Sestamibi Scans In Thyroglobulin Positive Scan Negative Differentiated Thyroid Cancer (DTC) Patients — NCT03065218.
• Registry record last updated 2022-07-26; status last verified 2022-07.
• Results first posted 2022-07-26.
• 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.

19. Record Summary

NCT03065218 is a phase 4, single-group study of 99mTc sestamibi imaging in differentiated thyroid cancer patients with elevated thyroglobulin and negative diagnostic imaging. The registry lists allocation as not applicable, no masking, enrollment of 4, and status as terminated. The listed primary completion date is 2021-02-15.

The primary outcome is a participant count for lesion detection on the sestamibi study, with review by two blinded nuclear medicine physicians. The registry record does not report the outcome count or any analyses. It lists 0 participants affected by serious adverse events, 0 affected by other adverse events, and 0 deaths among 4 participants at risk in each adverse-event category. The reason for termination and the study’s own sample-size justification are not reported in the registry record.