68 Ga-PSMA for High Risk Prostate Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for 68 Ga-PSMA for High Risk Prostate Cancer (NCT04614363), a na phase 1, phase 2 study. The primary outcome is Proportion of Patients With Lymph Node Involvement.

2. Clinical Question

The study’s broader objective was to evaluate distribution of 68GA-PSMA-11 in tissues and determine whether the imaging findings altered planned clinical management. That objective is distinct from a randomized comparison of clinical outcomes. Imaging findings may be compared descriptively with conventional imaging, but the posted record does not report those comparison results or an analysis of management changes.

The registry identifies the study as a prospective, single-center, open-label pilot and lists an enrollment of 80. Its population includes both localized high risk prostate cancer and biochemical recurrence; the primary endpoint description is narrower, referring to clinically localized disease. The record does not provide additional eligibility details or clarify how the primary endpoint population was defined for analysis.

3. Trial Design

The registry describes a prospective, single-center, open-label pilot study of 68 Ga-PSMA-11 before PET/CT imaging. It lists the phase as PHASE1 and PHASE2, an enrollment of 80, and a single-group model. The record gives the study status as completed, with a start date of 2020-10-13 and a primary completion date of 2022-02-26.

The intervention is listed as 68Ga-PSMA. The brief summary says the imaging agent was administered once, on an outpatient basis, before PET/CT imaging. The arm description states that PET/CT findings were to be compared with conventional imaging, identified as bone scan and CT. That planned imaging comparison should not be mistaken for a randomized trial comparison: allocation is listed as NA, masking as none, and the model as single group. The record does not describe a concurrent randomized control arm.

The study included descriptions for localized high risk prostate cancer and biochemical recurrence. The adverse-event record reports 30 participants at risk in the localized high risk prostate cancer group and 50 in the biochemical recurrence group. These are safety-group figures; the registry does not explain in the posted record how these group counts relate to the enrollment figure or define the analysis populations for efficacy outcomes.

The registry identifies four outcome measures, including a primary endpoint and secondary outcomes concerning uptake intensity as a predictor of clinical outcome or aggressiveness, and the number of patients with suspicious lesions. It records zero analyses. Detailed protocol procedures, recruitment flow, timing of assessments beyond the listed endpoint timeframe, and statistical methods are not reported in the registry record. The study’s sample-size justification is also 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 with high risk prostate cancer scheduled for prostatectomy and patients with biochemical recurrence will receive a single IV dose of 3-7 mCi of 68Ga-PSMA (study drug) followed by PET/CT imaging 60-90 minutes after injection.

6. Primary Endpoint

The registry lists the primary outcome as Proportion of Patients With Lymph Node Involvement, measured over 18 months.

The primary endpoint is the proportion of patients with lymph node involvement. The registry operationalizes it as the number of patients with cTxNoMo, described as clinically localized disease, whose final histological examination found lymph node involvement as determined by 68GA-PSMA-11 PET/CT. The unit is participants, and the listed timeframe is 18 months.

This endpoint addresses whether imaging identifies findings associated with lymph node involvement that is subsequently assessed by histology. Histological examination is the stated basis for determining involvement in the endpoint description; the registry does not report the details of that assessment or how disagreements between imaging and histology would be handled. Nor does it specify whether the primary measure is intended as a diagnostic accuracy measure, a detection rate, or another summary beyond the listed count and proportion.

In general, a participant count can describe how many people in a defined group had an outcome, while a proportion relates that count to the number assessed. Interpretation depends on a clearly defined analysis population and complete outcome ascertainment. The registry does not report the primary endpoint count, denominator, estimated proportion, confidence interval, or a statistical test. As a result, the endpoint’s observed value and its precision cannot be assessed from the posted record.

The endpoint is not itself a clinical outcome such as survival or symptom change. It concerns lymph node involvement identified in relation to PET/CT and final histology. The record’s broader management objective and secondary outcomes are separate from this primary endpoint and do not establish what the primary endpoint result was.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the study as prospective, single-center, open-label, and single-group. Those design features matter when interpreting results. A prospective study defines assessments before outcomes are observed, but the registry record does not report the detailed protocol or analysis plan. A single-center study is conducted at one center; its results may reflect that setting and the participants who were enrolled. Open-label means masking is listed as none. The record does not describe any procedures used to limit assessment or reporting bias.

What does a single-group design allow?

In general, a single-group study can describe findings among participants who receive an intervention and can examine how those findings relate to other assessments. It does not create randomized intervention groups for a direct causal comparison. The registry describes comparing 68 Ga-PSMA PET/CT with conventional imaging, but it does not register a randomized allocation between imaging strategies. Any comparison between the imaging findings would therefore need to be interpreted according to the actual measurement and analysis methods, which are not reported in the registry record.

Randomization is generally used to balance measured and unmeasured characteristics between assigned groups, on average. Since the allocation is listed as NA and the model as single group, this study should not be read as a randomized comparison. The record does not report a comparator-group estimate, an adjustment strategy, or a statistical model for comparing imaging results.

What does the primary endpoint measure?

The primary endpoint is a participant count concerning lymph node involvement, with a timeframe of 18 months. The description refers to clinically localized cTxNoMo disease and final histological examination. In general, when a binary outcome is summarized as a count or proportion, the denominator and definition of the analysis population are essential. The registry does not report the endpoint count, denominator, proportion, or how participants without an evaluable histological result were handled.

A confidence interval is a statistical range used to express uncertainty around an estimate under specified assumptions. It helps readers distinguish a precisely estimated quantity from one with substantial uncertainty. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be evaluated from the posted results. A p-value, when used, describes how compatible data are with a specified null model; it does not measure the size or clinical importance of an effect. No primary endpoint test or p-value is reported.

Why does outcome definition matter?

Diagnostic studies depend on clear definitions of the test result, the reference assessment, and the population in which both are evaluated. Here, the primary endpoint description connects 68GA-PSMA-11 PET/CT with lymph node involvement identified on final histological examination. The record does not provide thresholds for a positive imaging result, the timing and procedures for histology, or definitions for classifying uncertain findings. It also does not report sensitivity, specificity, predictive values, or another diagnostic-performance estimate. Those quantities cannot be inferred from the endpoint title alone.

In general, missing or unevaluable assessments can affect estimates if the participants with available data differ from those without them. The registry does not report missing-data counts, reasons for missingness, or an approach to handling missing outcomes. It also does not describe whether all enrolled participants were included in each outcome analysis.

How should the safety counts be read?

The safety record gives serious events, other events, and deaths for the localized high risk prostate cancer and biochemical recurrence groups. These are descriptive counts paired with the number at risk. In general, event counts do not by themselves establish whether an intervention caused an event, and comparisons between groups can be difficult to interpret when group definitions, follow-up, and event ascertainment are not fully described. The registry does not report attribution methods, event-specific follow-up, or a statistical comparison of safety groups.

The record also lists top serious-event terms with percentages: Acute cerebrovascular accident at 3.3%, Encephalopathy at 2.0%, and Prostate cancer metastasis at 2.0%. These figures are reported terms and percentages; the registry does not provide additional detail in the record about their derivation or how they map to the safety groups.

What analysis plan is documented?

The registry records zero analyses. The statistical analysis plan, any prespecified model, hypothesis tests, adjustment for multiple outcomes, and sample-size justification are not reported in the registry record. General statistical concepts can explain how such methods are ordinarily used, but no particular method should be attributed to this trial without a record of it. The study’s completed status does not fill in those methodological details.

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("Localized High Risk Prostate Cancer", "Biochemical Recurrence")
n      <- c(30, 50)
events <- c(4, 28)
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  Localized High Risk Prostate Cancer  30  4  13.3  3.8  30.7  5.3  29.7  5.5  29.8
ARM  Biochemical Recurrence  50  28  56.0  41.3  70.0  42.3  68.8  42.2  68.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures, including the primary endpoint and secondary outcomes concerning uptake intensity as a predictor of clinical outcome or aggressiveness and the number of patients with suspicious lesions. It records zero analyses, and the outcome results are not reported in the registry record. The record does not describe whether there was a prespecified hierarchy among outcomes, how testing across multiple outcomes was to be handled, or whether any adjustment for multiplicity was planned.

In general, multiplicity arises when several outcomes or hypotheses are examined. If each is tested separately, the chance of obtaining at least one apparently notable result can increase. A prespecified analysis strategy can help readers understand which findings are confirmatory and which are exploratory. No such strategy is reported for this study, so it is not possible to classify any outcome as statistically confirmed based on the registry record.

Missing-data methods are also not reported in the registry record. There are no reported counts of missing endpoint assessments, exclusions, withdrawals, or participants without histological examination. The record does not state whether missing outcomes were imputed, omitted, or handled through another approach. These details matter because the primary endpoint depends on histological assessment and an identifiable analysis population.

The analysis populations are not reported in the registry record. The safety entries give 30 participants at risk in the localized high risk prostate cancer group and 50 in the biochemical recurrence group, but those figures do not define the population used for the primary endpoint or secondary outcomes. The record does not state whether analyses included all enrolled participants or only those with evaluable imaging and histology. These omissions limit interpretation of both the reported study design and any conclusions that might otherwise be drawn from the outcome descriptions.

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.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: acute cerebrovascular accident (3.3%), encephalopathy (2.0%), prostate cancer metastasis (2.0%).

The registry reports safety figures for two groups. In localized high risk prostate cancer, 1 serious event is listed among 30 participants at risk, with 0 other events and 0 deaths. In biochemical recurrence, 2 serious events are listed among 50 participants at risk, with 0 other events and 2 deaths. These are descriptive registry entries, not adjusted comparisons between groups.

The registry also lists Acute cerebrovascular accident at 3.3%, Encephalopathy at 2.0%, and Prostate cancer metastasis at 2.0% as top serious-event terms. These percentages should be read as the reported figures; the record does not provide further information about how they were calculated or assigned to the groups. The term list does not establish that an event was caused by the imaging agent.

In general, safety counts are interpreted in light of the number of participants observed, the duration and completeness of follow-up, event definitions, and attribution procedures. The registry does not report these details, nor does it explain the relationship between the listed terms and the group-level serious-event counts. It also does not report a formal safety comparison. The counts therefore describe what the registry records, without establishing comparative risk or causation.

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

The registry describes a prospective pilot study evaluating 68 Ga-PSMA-11 before PET/CT imaging in men with localized high risk prostate cancer or biochemical recurrence. Its primary endpoint concerns lymph node involvement in patients described as having clinically localized disease, assessed through final histological examination. This clarifies the kind of outcome the study intended to examine, but the registry does not report the endpoint result.

Without the primary endpoint count, denominator, and estimate, the observed frequency of lymph node involvement cannot be described. Without an uncertainty measure, the precision of an estimate cannot be assessed. The registry also does not report results for the secondary outcomes or the broader objective of determining whether imaging findings altered planned clinical management.

The record’s reference to conventional imaging does not make this a randomized comparison. The design is listed as single-group, with allocation NA and no masking. The record does not report comparative estimates for PET/CT and conventional imaging, and it does not provide diagnostic-performance measures. It is therefore not possible to determine from the registry record how the imaging approaches compared.

The safety entries report event counts for the localized high risk prostate cancer and biochemical recurrence groups, as well as selected serious-event terms and percentages. These descriptions do not establish whether events were caused by the imaging agent, whether groups differed in risk, or how completely events were ascertained.

In general, a completed study may still have incomplete public outcome reporting. Completion status indicates the registry’s status entry, not that the statistical results are available in the record. The information reported supports describing the study’s design, intended endpoint, and listed safety counts. It does not support a conclusion about the primary endpoint’s observed value, the comparative performance of imaging strategies, or the effect of imaging on clinical management.

14. Why This Trial Matters Statistically

This study is statistically notable because it combines a diagnostic-imaging objective with a registered single-group design. The registry says that PET/CT findings were to be compared with conventional imaging, but allocation is listed as NA and the model is single group. That distinction is important: a comparison of measurements is not automatically a randomized comparison of assigned strategies.

The primary endpoint also relies on linking imaging to final histological examination. In general, this makes clear definitions of the assessed population, the reference assessment, and the handling of missing or uncertain results important to interpretation. The registry record does not report those operational details or the endpoint result. Readers cannot assess diagnostic performance from the endpoint description alone.

The study includes participants described as having localized high risk prostate cancer and biochemical recurrence, while the primary endpoint description focuses on clinically localized disease. The safety entries distinguish these groups, but the registry does not specify how the primary endpoint analysis population was defined. This illustrates why population definitions and denominators are essential when interpreting counts and proportions.

Finally, the registry lists several outcome measures but records zero analyses. Without results, uncertainty estimates, or a documented multiplicity approach, the intended outcomes cannot be separated into confirmatory and exploratory findings on the basis of this record. These are general reporting and interpretation issues; they do not imply any particular outcome for this study. The main statistical contribution of a careful reading is to distinguish the design and questions described from evidence that the registry does not report.

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 leaves important trial-specific details unreported. Although it describes the study as prospective, single-center, open-label, and a pilot, it does not provide the detailed protocol, eligibility criteria, recruitment flow, or assessment procedures. The relationship between the enrollment of 80 and the safety-group counts of 30 and 50 is not explained for outcome-analysis purposes.

The endpoint description identifies a population with cTxNoMo disease and refers to final histological examination, but the record does not give the number assessed, the endpoint estimate, or the method for classifying imaging and histological findings. It does not report the results of comparing PET/CT with bone scan or CT, nor does it report the secondary outcome results or management changes.

The statistical analysis plan, sample-size justification, missing-data methods, analysis populations, and multiplicity strategy are not reported in the registry record. There are no reported primary endpoint confidence intervals or tests. Without these items, the precision and robustness of the intended findings cannot be evaluated from the registry record.

Safety reporting is also limited in context. The record lists serious events, other events, deaths, and selected serious-event terms, but does not report attribution, detailed follow-up, or a formal comparison. The posted information therefore cannot establish causation or explain the relation between individual terms and group-level counts. These limitations concern what the record reports; they do not determine what may appear in other study documents.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: 68 Ga-PSMA for High Risk Prostate Cancer — NCT04614363.
• Registry record last updated 2023-08-28; status last verified 2023-04.
• Results first posted 2022-12-29.
• 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

The registry identifies NCT04614363 as a completed, prospective, single-center, open-label pilot study of 68 Ga-PSMA-11 before PET/CT imaging in men with localized high risk prostate cancer or biochemical recurrence. It lists PHASE1 and PHASE2, a single-group model, and enrollment of 80. The study start date is 2020-10-13 and the primary completion date is 2022-02-26.

The primary endpoint is the number of patients with clinically localized cTxNoMo disease found on final histological examination to have lymph node involvement, as determined by 68GA-PSMA-11 PET/CT, with an 18 months timeframe. The registry record does not report the endpoint result, statistical analyses, or comparative imaging results.

The safety record lists 1 serious event and 0 deaths among 30 participants at risk in localized high risk prostate cancer, and 2 serious events and 2 deaths among 50 participants at risk in biochemical recurrence. It also lists selected serious-event terms and percentages. Detailed analysis methods and the study’s sample-size justification are not reported in the registry record.