Gallium-68 PSMA-11 PET in Intermediate to High-risk Preprostatectomy Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Gallium-68 PSMA-11 PET in Intermediate to High-risk Preprostatectomy Patients (NCT02919111), a na phase 2, phase 3 study. The primary outcome is Sensitivity of PSMA PET for the Detection of Regional Nodal Metastases Compared to Pathology at Radical Prostatectomy.

2. Clinical Question

The study is registered as NCT02919111 and is marked completed. Its stated purpose is to assess the ability of Ga-68-PSMA-11 PET to detect prostate cancer in patients with high-risk disease before prostatectomy. The primary outcome is narrower: sensitivity for regional nodal metastases compared with pathology at radical prostatectomy. This distinction matters because an overall claim about detecting prostate cancer is not the same as a measured estimate for nodal disease.

The design is single-group, with no masking and no randomized allocation. The comparison is therefore between an imaging test and a pathology-based reference, not between treatment groups. The registry lists outcomes concerning extra-pelvic nodal and visceral metastases as well as adverse events. Their presence in the outcome list describes planned or registered questions, but does not by itself establish that numerical results were reported.

The primary result, its precision, and the number of participants contributing to the sensitivity analysis are not reported in the registry record. Without those details, readers cannot determine how many participants had regional nodal disease, how many were correctly identified by imaging, or how uncertain any estimated sensitivity might be. The study question is clear, but the posted record does not provide enough outcome information to answer it quantitatively.

3. Trial Design

NCT02919111 is a completed study sponsored by the University of California, San Francisco. It is described as phase 2 and phase 3, with a single-group model, no masking, and no randomized allocation. The registry lists enrollment of 299. Start is recorded as 2016-09-23 and primary completion as 2019-12-31. These are registry dates and do not establish when each participant was imaged or assessed.

Participants receive Ga-68 labeled PSMA-11 PET. According to the arm description, imaging is followed by PET/CT or PET/MRI approximately 55-70 minutes later. The registry does not report further details about how the choice between these imaging approaches was made, the imaging interpretation process, or the timing of surgery for individual participants.

Because there is a single group, there is no randomized treatment comparison. The primary endpoint uses pathology at radical prostatectomy as the reference for classifying imaging findings. The endpoint description also allows follow-up scans for up to 1 year to be used in analysis. How those scans were incorporated into participant-level classification is not reported in the registry record.

The registry lists 17 outcome measures, including the primary sensitivity outcome and secondary measures of sensitivity, specificity, positive predictive value, negative predictive value, and adverse events. It lists zero analyses. That does not establish that analyses were never conducted; it means analysis details and numerical estimates are not reported in the registry record. The protocol’s statistical analysis plan, eligibility criteria, analysis populations, and handling of participants without evaluable imaging or pathology are also not reported in the registry record.

The design is suitable for describing agreement between an imaging test and a reference standard within the studied group, but it does not provide a concurrent control group for a causal comparison. Interpretation depends on how accurately and consistently the imaging and reference assessments were made, who was included in the analysis, and how missing or indeterminate results were handled. Those details 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.

6. Primary Endpoint

The registry lists the primary outcome as Sensitivity of PSMA PET for the Detection of Regional Nodal Metastases Compared to Pathology at Radical Prostatectomy, measured over Up to 1 year.

The primary endpoint is sensitivity of PSMA PET for detecting regional nodal metastases compared with pathology at radical prostatectomy. Sensitivity describes the proportion of participants who have the condition of interest and whose test result is positive. In this study, the target condition is regional nodal metastasis, the test is PSMA PET, and pathology is the principal reference stated in the endpoint title.

In general, sensitivity addresses how often a test identifies disease among those who have it. It does not, on its own, describe how often a positive scan is correct among all positive scans, nor does it describe how often a negative scan is correct. Those are different questions, addressed by predictive values; specificity addresses the classification of participants without the target condition. The registry lists some of these measures among secondary outcomes for other metastatic sites.

The endpoint description classifies positive imaging with positive pathology as a true positive and positive imaging with negative pathology as a false positive. It also describes negative imaging with positive pathology as a false negative. Its wording about negative imaging and negative pathology identifies true negatives. Follow-up scans for up to 1 year can be used in the analysis, but the precise rules for doing so are not reported in the registry record.

Sensitivity is used because missing disease among participants who truly have it is a distinct diagnostic performance concern. An estimate requires both a count of participants with the target condition and a count of those participants whose imaging was positive. The numerical estimate, its confidence interval, and the relevant counts are not reported in the registry record. Consequently, the endpoint definition is available, but its observed performance cannot be assessed from the posted results described in the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record specifies a single-group diagnostic study with a sensitivity endpoint. Statistical interpretation of such an endpoint begins by distinguishing the target condition from the test result. Here, the target condition is regional nodal metastasis and the index test is PSMA PET. Pathology at radical prostatectomy is named as the comparator or reference in the primary outcome title. Each participant’s test result and disease classification can be considered together to form positive and negative classifications, as described in the endpoint definition.

What sensitivity measures

In general, sensitivity is the proportion of participants with the target condition whose test result is positive. A sensitivity estimate answers a conditional question: among those classified as having disease, how many had a positive scan? It does not directly answer the probability that disease is present after a positive scan. That latter question concerns positive predictive value. Negative predictive value asks how often a negative result corresponds to absence of disease, while specificity concerns test results among participants without the target condition. These measures answer related but distinct diagnostic questions.

The registry defines true positives, false positives, false negatives, and true negatives in relation to imaging and pathology. These classifications depend on having both an interpretable imaging result and an appropriate reference assessment. If either is unavailable or indeterminate, the participant may not contribute to a straightforward calculation. The registry record does not report how such cases were handled, how many were present, or which participants were included in the primary analysis.

Reference standards and follow-up

Pathology at radical prostatectomy is the named reference for the primary sensitivity outcome. The outcome description also says that follow-up scans for up to 1 year can be used in analysis. In general, using more than one source of disease information can affect classification if sources disagree or become available at different times. A transparent analysis plan would specify how each source is used, but those rules are not reported in the registry record. The record also does not say whether image readers were blinded to pathology or whether pathology reviewers were blinded to imaging.

A sensitivity estimate is typically accompanied by a confidence interval. In general, a confidence interval conveys the uncertainty associated with an estimate under the assumptions of the statistical method. Its width is affected by the amount of information available, including the number of participants with the target condition. It is not a guarantee that the true value lies within the interval, nor does it describe all sources of bias. No sensitivity estimate or confidence interval is reported in the registry record.

Single-group design

The single-group design means that the study does not assign participants to competing imaging strategies or to a randomized control arm. The primary comparison is within participants, between imaging classification and pathology-based disease classification. This can support estimation of diagnostic performance in the studied group if the analysis is clearly defined and the reference assessment is adequate. It does not, by itself, establish how performance compares with another test, how imaging changes clinical decisions, or whether any downstream outcome is altered.

For diagnostic measures, the participants included and the way disease status is established are central to interpretation. The registry lists enrollment of 299, but the number with evaluable scans, pathology, and the target condition is not reported in the registry record. Enrollment should not be substituted for the analysis denominator. The record also does not report an analysis population definition or a participant flow explaining exclusions and missing assessments.

Multiplicity and secondary outcomes

The registry lists 17 outcome measures, including multiple diagnostic measures and safety outcomes, and lists zero analyses. In general, when many outcomes or comparisons are examined, the chance of finding an apparently notable result by chance can increase unless the analysis plan addresses multiplicity. Different approaches can prioritize a primary outcome, adjust statistical testing, or present secondary findings as exploratory. The registry record does not report whether any multiplicity procedure was planned or used. No adjustment or unadjusted significance results should be inferred from the list of outcomes.

The sample-size section is a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; for these non-time-to-event outcomes, its values are expressed as participants per arm. These are planning illustrations, not observed power and not a description of the trial’s own design. The trial itself is single-group, so the illustrative equal-allocation comparison is not the registered trial design. The registry does not report its own sample-size justification or the assumptions used to plan enrollment.

Interpretation of safety counts

The posted safety figures are counts of participants affected, not estimates of diagnostic sensitivity or a comparison of randomized treatment groups. In general, a zero count in a category means no participants were recorded in that category in the posted results; it does not establish that the risk is absent. Interpretation also depends on event definitions, follow-up completeness, and the duration and method of safety surveillance. Those details are not reported in the registry record.

Statistical methods are only one part of evidence quality. The way scans are acquired and read, the completeness of pathology verification, participant selection, missing data, and analysis rules can influence diagnostic estimates. The registry record does not report enough information to assess these aspects. The lack of a posted primary estimate is especially important: without the estimate and its precision, readers cannot evaluate the study’s central statistical result.

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("Ga-68 Labeled PSMA-11 PET")
n      <- c(299)
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  Ga-68 Labeled PSMA-11 PET  299  1  0.3  0.0  1.8  0.1  1.9  0.1  1.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 17 outcome measures and zero analyses. The primary outcome is sensitivity for regional nodal metastases compared with pathology at radical prostatectomy. Other listed outcomes include measures of performance for extra-pelvic nodal and visceral metastases, as well as adverse-event outcomes. The registry record does not report a statistical analysis plan, an order of testing among outcomes, or any method for controlling multiplicity. It is therefore not possible to determine whether secondary analyses were planned as confirmatory or exploratory, or how their interpretation was intended to account for multiple outcomes.

Missing-data handling is also not reported in the registry record. The primary endpoint requires a disease classification and an imaging classification, while the description allows follow-up scans for up to 1 year. The record does not say how participants without pathology, without an interpretable scan, with indeterminate findings, or with incomplete follow-up were handled. It also does not report the number of participants with missing assessments or whether any sensitivity analyses addressed missing information.

Analysis populations are not reported in the registry record. The enrollment listing of 299 does not establish how many participants contributed to the primary endpoint or to each secondary outcome. No participant flow or outcome-specific denominator is available in the record. This limits assessment of whether the analyzed group represents all enrolled participants and how exclusions may affect interpretation.

In general, multiplicity procedures, missing-data methods, and clearly defined analysis populations help readers distinguish a prespecified primary finding from exploratory results and understand the limits of the data. Their absence from the registry record does not show that no such methods were used, but it prevents independent assessment of those choices.

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 5% reporting threshold.

The registry lists 299 participants at risk in the Ga-68 labeled PSMA-11 PET group. The posted counts are zero affected by serious adverse events, zero affected by other adverse events, and zero deaths. These are participant counts in the registry record; they are not estimates of the primary diagnostic endpoint and do not compare separate randomized groups.

The outcome list includes the number of participants with Grade 3 treatment-related adverse events. However, the posted safety figures do not give a separate Grade 3 count. The available serious and other adverse-event counts should not be treated as a specific Grade 3 result unless the registry explicitly identifies them that way, which it does not in the record.

In general, zero recorded events in a category means that none were posted for that category and group. It does not prove that an event is impossible or that all potential events were captured. Interpretation depends on the definitions used, how events were collected, duration of observation, and completeness of follow-up. These details are not reported in the registry record. The record also does not provide event narratives or information about severity beyond the listed categories. The safety figures should therefore be read as limited registry counts rather than a complete characterization of safety.

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

The study asks whether Ga-68 labeled PSMA-11 PET can identify regional nodal metastases before prostatectomy when compared with pathology. The registry record gives the primary endpoint definition and describes a single-group study, but it does not report the observed sensitivity, its confidence interval, or the number of participants contributing to the analysis. As a result, the posted record does not establish how well the imaging test performed for the primary question or how precisely that performance was estimated.

Even when a diagnostic estimate is available, sensitivity is only one part of test performance. It describes positive test results among participants with disease, but does not alone describe false-positive results, the probability of disease after a positive scan, or the probability of no disease after a negative scan. The registry lists other diagnostic measures for additional disease sites, but their numerical results are not reported in the registry record.

The study’s single-group design also matters. It compares imaging classification with pathology rather than comparing randomized groups receiving different strategies. It therefore does not, on its own, show whether one imaging approach is better than another, whether the scan changes management, or whether any difference in a later clinical outcome is attributable to imaging. Those questions are not answered by the primary sensitivity endpoint.

The record’s safety counts are zero for serious adverse events, other adverse events, and deaths among 299 participants at risk. They describe the posted categories and should not be interpreted as proof of no risk. Details about follow-up duration and event ascertainment are not reported in the registry record.

The appropriate statistical conclusion is limited: the registry documents a completed study designed to evaluate a diagnostic test, but the central numerical result and important analysis details are not reported in the registry record. The study question and endpoint can be described; the magnitude, precision, and broader implications of the result cannot be determined from the posted information.

14. Why This Trial Matters Statistically

This trial is statistically notable for the distinction between a diagnostic question and a treatment comparison. The study is single-group and its primary outcome evaluates sensitivity against pathology. That calls for methods that classify each participant’s imaging and reference-standard results, rather than an estimate of a difference between randomized arms. Readers should not interpret the enrollment listing as a comparison group or as the denominator for every diagnostic outcome.

The endpoint also illustrates why the target condition and reference standard must be explicit. Sensitivity concerns participants who have the disease of interest, so the number with regional nodal metastases is essential to understanding the precision of the estimate. The registry record states how sensitivity is defined but does not report the estimate, the disease-positive denominator, or a confidence interval. Thus, the methodological question is visible while the central quantitative evidence is not.

Use of pathology alongside imaging provides a framework for evaluating test classification, while the allowance for follow-up scans for up to 1 year raises questions about how evidence from different time points is combined. Those rules and the handling of incomplete assessments are not reported in the registry record. These details are important because classifications and analysis populations can affect diagnostic estimates.

The registry lists multiple secondary diagnostic and safety outcomes but no analyses. This makes it important to distinguish registered outcomes from results actually available for interpretation. The record also describes a planning illustration, but it is not the trial’s own design or observed power. The stated trial design remains single-group, with no randomized allocation.

Ultimately, the statistical importance of the record lies in both what it specifies and what remains unavailable. The primary question, design, and endpoint definition are identifiable. The primary result, precision, and analysis details are not reported in the registry record, limiting what can be concluded about diagnostic 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 most important trial-specific limitation in the available record is that the primary sensitivity estimate is not reported in the registry record. Its confidence interval, disease-positive count, and number of participants analyzed are also not reported. Without them, the central endpoint cannot be evaluated for magnitude or precision.

The registry identifies pathology at radical prostatectomy as the comparison for the primary endpoint and permits follow-up scans for up to 1 year. It does not report how follow-up information was incorporated, how disagreements between imaging and pathology were resolved, or how participants without complete assessments were classified. The methods for scan interpretation and pathology assessment are not reported in the registry record.

The record lists enrollment of 299, but does not report the analysis population or outcome-specific denominators. Eligibility criteria, participant characteristics, missing-data handling, and participant flow are not reported in the registry record. These omissions make it difficult to assess who contributed to each outcome and how representative the analysis group may be.

The study has no randomized comparator group and no masking. A single-group diagnostic design can address test classification against a reference, but it cannot provide a randomized comparison of imaging strategies. The registry record does not describe reader blinding or other procedures that could influence interpretation of the test and reference results.

Finally, the record lists 17 outcome measures and zero analyses, without reporting a statistical analysis plan or multiplicity approach. Safety follow-up details and definitions are also not reported in the registry record. These limits concern the information available in the registry record; they do not establish which methods may have been used outside it.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Gallium-68 PSMA-11 PET in Intermediate to High-risk Preprostatectomy Patients — NCT02919111.
• Registry record last updated 2020-12-10; status last verified 2020-11.
• Results first posted 2020-12-10.
• 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

NCT02919111 is a completed, single-group study sponsored by the University of California, San Francisco, evaluating Ga-68 labeled PSMA-11 PET in patients with prostate cancer before prostatectomy. The record lists phase 2 and phase 3, no masking, no randomized allocation, and enrollment of 299. The primary outcome is sensitivity for regional nodal metastases compared with pathology at radical prostatectomy, with follow-up scans for up to 1 year permitted in analysis.

The intervention description says participants receive Ga-68 labeled PSMA-11 PET and undergo PET/CT or PET/MRI approximately 55-70 minutes later. The registry lists 17 outcome measures and zero analyses. It reports zero participants affected by serious adverse events, zero affected by other adverse events, and zero deaths among 299 at risk.

The primary sensitivity result, its precision, participant-level analysis details, missing-data methods, and statistical analysis plan are not reported in the registry record. The available record therefore describes the study question and design but does not provide the numerical result needed to assess the primary diagnostic outcome.