This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Gallium-68 PSMA-11 PET Imaging in Prostate Cancer Patients (NCT03803475), a na phase 3 study. The primary outcome is Detection Rate of PSMA-11 PET for Positive Disease by Prostate Specific Antigen (PSA) Group.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03803475 |
| Phase | Phase 3 |
| Condition | Prostate Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 485 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Thomas Hope |
| Results posted | Yes |
2. Clinical Question
Population
People with prostate cancer undergoing imaging are the population described. The registry records enrollment of 485 participants. For the primary outcome, the number analyzed in each row is defined by the participants who had that detected PSA level at imaging. The record does not report the number in each PSA group or further eligibility details.
Intervention
The imaging agent is Ga-68 labeled PSMA-11, also described as PSMA-HBED-CC. The arm description says it is administered intravenously once, on an outpatient basis, before PET imaging. The listed intervention devices are PET/CT and PET/MRI. The record does not clarify which modality each participant received or how modality use was determined.
Comparator
This is a single-group study, with allocation listed as not applicable and no masking. There is no randomized control arm or like-for-like comparator described. The study therefore concerns detection by the imaging approach, rather than a comparative treatment effect between assigned groups.
Primary question
The primary question is the detection rate of PSMA-11 PET for positive disease, reported separately by PSA group at imaging. The stated definition is the proportion of patients with prostate cancer who are true positives confirmed by imaging, based on local reads for metastatic-disease detection. The registry does not include the rates themselves, their uncertainty, or the PSA-group results.
3. Trial Design
The registry describes a phase 3, single-group imaging study in prostate cancer. Enrollment is recorded as 485. Allocation is listed as not applicable, and masking is listed as none. These features mean the record does not describe random assignment or a blinded comparison between groups. The study is marked completed, with a start date of 2018-10-11 and primary completion date of 2020-08-25.
The intervention arm is described as Ga-68 labeled PSMA-11 PET PSMA. The imaging agent, also called PSMA-HBED-CC in the record, is administered intravenously a single time before PET imaging. The arm description gives an injected dose of 3 to 7 millicurie (mCi) +/- 10%. PET/CT and PET/MRI are both listed as devices, but the record does not state how participants were assigned to or distributed between those imaging modalities. It also does not report whether imaging protocols differed across sites.
The brief study description says the investigators are evaluating the imaging agent’s ability to detect prostate cancer. The primary outcome focuses more specifically on detection of metastatic disease by local reads and stratifies the detection rate according to PSA group at imaging. This is a diagnostic-imaging question, not a test of a therapeutic intervention against a control treatment.
The registry record does not report the detailed eligibility criteria, recruitment setting, number of participating sites, handling of repeat scans, or the full image-reading process. It also does not describe the reference standard used to confirm positive disease beyond the wording in the outcome definition. These omissions limit how fully the design and the meaning of a positive detection can be reconstructed from the registry record alone.
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
| Stage | Ga-68 Labeled PSMA-11 PET PSMA |
|---|---|
| STARTED | 485 |
| COMPLETED | 484 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Ga-68 Labeled PSMA-11 PET PSMA |
|---|---|
| Physician Decision | 1 |
Analysis population for the primary outcome, as defined in the registry: The Number Analyzed for each Row indicates the number of participants with each detected level of PSA
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.
| Characteristic | Unit | Ga-68 Labeled PSMA-11 PET PSMA |
|---|---|---|
| Participants analysed | 485 | |
| Age, Continuous | years | 70.13 (48 to 92) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 485 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 16 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 441 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 28 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 26 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 3 |
| Race (NIH/OMB): Black or African American | Participants | 8 |
| Race (NIH/OMB): White | Participants | 408 |
| Race (NIH/OMB): More than one race | Participants | 2 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 38 |
| Region of Enrollment: United States | participants | 485 |
6. Primary Endpoint
The registry lists the primary outcome as Detection Rate of PSMA-11 PET for Positive Disease by Prostate Specific Antigen (PSA) Group, measured over 1 day.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | proportion |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the detection rate of PSMA-11 PET for positive disease, stratified by PSA group at the time of imaging. The registry defines detection rate as the proportion of patients who have prostate cancer and are true positives confirmed by imaging, based on local reads for metastatic-disease detection. The number analyzed in each row is described as the number of participants with that detected level of PSA.
A detection rate expresses how often the imaging assessment identifies positive disease within the specified group. PSA stratification is relevant because the endpoint is intended to be considered across PSA levels rather than as a single pooled result. Separate rates could describe whether detection varies across these groups, but the registry record does not report the group definitions, denominators, observed rates, or uncertainty estimates.
In general, diagnostic detection measures can help describe the performance of an imaging approach for identifying a target finding in a defined population. Their interpretation depends on how positive disease is established, who is included in the denominator, and how images are read. Here, the record refers to confirmation by imaging and local reads, but does not describe the confirmation procedure or independent adjudication. It also does not report sensitivity, specificity, predictive values, or false-positive and false-negative counts. Those measures cannot be inferred from the stated endpoint definition alone.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the study question and endpoint but does not provide the outcome estimates needed to answer the detection question numerically. Although it describes a PSA-stratified detection rate and lists five outcome measures, it records no analysis results. There are no reported detection rates, group denominators, confidence intervals, test statistics, or p-values in the record. As a result, the posted information does not establish how often the imaging approach detected positive disease in this study or how precise any estimated rate was.
The planned endpoint is a proportion: true-positive findings among the specified patients with prostate cancer, organized by PSA group at imaging. A proportion is interpretable only alongside its denominator and a clear definition of the positive finding. The record explains that the number analyzed for each row corresponds to participants with each detected PSA level, but does not give those counts or explain the PSA group boundaries. Without the group-level counts and results, comparisons across PSA strata cannot be assessed.
The single-group design is central to interpretation. It describes imaging in the enrolled cohort, not a randomized comparison with another imaging strategy or a control group. Allocation is not applicable, and masking is listed as none. The study therefore cannot, from this design description alone, quantify a between-arm difference. It also cannot separate the performance of the agent from other aspects of image acquisition and interpretation unless those are specified and analyzed. The record does not report enough detail to assess that separation.
Local reads are part of the endpoint definition. In general, local interpretation reflects readings made in the study’s clinical or site context; differences in reader practice can affect the consistency of a detection measure. The registry does not describe reader training, blinding to clinical information, central review, agreement between readers, or adjudication of discordant readings. These aspects of measurement are therefore not assessable from the record.
The listed enrollment of 485 should not be treated as the primary endpoint’s analyzed denominator. The record defines row-specific analysis counts by PSA group but does not report those counts, and enrollment does not by itself establish that every participant contributed an evaluable scan or outcome. The number with missing or unevaluable imaging, if any, is not reported in the registry record.
The study is marked completed, but completion status does not substitute for posted results. The appropriate statistical conclusion is limited: the registry documents a completed single-group imaging study and its intended detection-rate endpoint, while the numerical findings and their precision are not reported in the registry record. No claim about the magnitude or consistency of detection can be made from the endpoint description alone.
9. Statistical Methods Explained
The registry record describes the outcome and the study structure, but does not provide a statistical analysis plan or analysis estimates. Statistical concepts can help explain what would be needed to interpret a detection-rate result, while keeping clear that the registry does not report those details for this study.
What does a detection rate represent?
In general, a detection rate is a proportion formed by counting participants with the specified positive finding and relating that count to the defined group being assessed. Here, the record defines the target as true-positive findings among patients with prostate cancer, with detection based on local reads. For an estimate to be interpretable, the positive-finding rule and denominator need to be clear. The registry describes the broad definition and says the row-specific number analyzed reflects the participants in each PSA group, but it does not report the actual counts, the PSA group boundaries, or the resulting proportions.
The endpoint is stratified by PSA group at imaging. In general, stratification presents results separately across groups defined by a characteristic, rather than combining everyone into a single estimate. This can make variation across groups visible, but it does not by itself establish that differences between groups are statistically meaningful. That requires the group estimates and an appropriate assessment of uncertainty. Neither is reported in the registry record.
How would uncertainty be assessed?
In general, a confidence interval describes the range of estimates compatible with the observed data under the method used. For a proportion, its width depends in part on the number of observations and the proportion observed. A narrow interval indicates greater precision under the chosen method; a wide interval indicates more uncertainty. The registry record does not report confidence intervals or identify a method for calculating them, so the precision of the detection rates cannot be assessed.
A p-value, in general, evaluates how compatible data are with a specified null hypothesis under a statistical model. Its meaning depends on the hypothesis, test, assumptions, and analysis population. The registry does not report p-values, a hypothesis test, or a statistical comparison for the primary outcome. The PSA-stratified endpoint description alone should not be read as evidence that a formal comparison across PSA groups was performed.
What does the study design allow?
The study is described as single-group, with allocation not applicable and no masking. In general, a single-group design can summarize observations in the cohort, but it lacks a randomized concurrent control for estimating a comparative effect. The endpoint is an imaging detection measure, so an interpretation also depends on the process used to determine whether disease was present. The record does not detail a separate reference standard, central image review, or adjudication process. These missing details limit the assessment of measurement validity and potential reader-related variation.
The registry lists PET/CT and PET/MRI as devices, while the arm description specifies administration of the imaging agent before PET imaging. The distribution of participants across imaging modalities and any modality-specific analyses are not reported. Consequently, the registry does not support a statistical comparison between PET/CT and PET/MRI.
What can planning calculations tell the reader?
In general, a sample-size planning calculation asks how many observations a future study might need under stated assumptions. It is not an estimate of the result’s precision by itself, and it is not observed power. The planning illustration described for this record uses a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. Those assumptions do not match the registry’s single-group design, and the observed effect and numeric planning results are not reported in the registry record. Such an illustration should therefore not be interpreted as the study’s original design justification or as evidence about the study’s ability to detect an effect.
Over-dispersion is a general concern when data vary more than a simple statistical model expects; if present and unaccounted for, uncertainty can be understated. The endpoint is a proportion, but the registry does not describe a model or report a dispersion parameter. There is no basis in the record for determining whether over-dispersion was assessed or whether it is relevant to the reported analysis.
Overall, the record supports explanation of the endpoint and design, but not reconstruction of the statistical analysis. The analysis population, missing-data procedures, interval method, hypothesis tests, covariate adjustments, and any sensitivity analyses are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists five outcome measures and no analysis records. It does not identify which outcomes were treated as confirmatory beyond labeling the detection-rate measure as primary, nor does it report a testing hierarchy or an adjustment for multiple comparisons. The primary outcome is stratified by PSA group, but the group definitions and any formal tests across groups are not reported in the registry record. Without that information, it is not possible to determine how multiplicity was handled or whether any inferential claims were planned for the strata.
The analysis population is also not fully specified. Enrollment is recorded as 485, while the primary outcome definition says each row’s number analyzed reflects participants with the corresponding PSA level. The group-specific counts and the number with evaluable images are not reported. The record does not state whether all enrolled participants were included, whether participants were excluded after enrollment, or how missing PSA values and unevaluable scans were handled.
Missing-data methods, including any imputation, complete-case analysis, or sensitivity analysis, are not reported in the registry record. The timing and handling of withdrawals or protocol deviations are also not described. These omissions matter because a detection proportion depends on who contributes to its numerator and denominator. No assumptions about missing results or analysis populations should be inferred from the enrollment figure alone.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Ga-68 Labeled PSMA-11 PET PSMA | 0 | 485 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Ga-68 Labeled PSMA-11 PET PSMA | 0 of 485 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Ga-68 Labeled PSMA-11 PET PSMA | 0 of 485 |
The registry’s safety summary lists 485 participants at risk for serious adverse events and 485 at risk for other adverse events in the Ga-68 Labeled PSMA-11 PET PSMA group. It reports zero participants affected in each of those categories and zero deaths. These figures describe the posted safety summary for the listed group.
Zero reported events in a registry summary does not establish that no event could occur, nor does it describe risk outside this study. The record does not provide event-level descriptions, follow-up details, or information on how adverse events were collected and classified. It also does not report a comparison group. The counts should therefore be read as the recorded figures, not as a comparative safety estimate or a guarantee about individual outcomes.
12. What the Result Does, and Does Not, Mean
The study asks whether Ga-68 PSMA-11 PET detects positive disease in patients with prostate cancer, with the stated detection rate organized by PSA group at imaging. The record establishes that this was a phase 3, single-group study and describes administration of the imaging agent before PET imaging. It also defines the primary outcome in terms of true-positive findings based on local reads.
Those descriptions do not provide the results. The registry record contains no reported detection-rate estimates, PSA-stratum counts, confidence intervals, or analysis results. It therefore cannot show the observed frequency of detection, how estimates varied across PSA groups, or how precisely the study estimated those rates. The record also does not report sensitivity, specificity, or other diagnostic accuracy measures.
The design has no randomized comparator, and no masking is listed. Findings from a single cohort can describe what was recorded in that cohort, but they do not establish a comparative advantage over another imaging method. The record does not report the distribution of PET/CT and PET/MRI use, so it also cannot support a comparison between those modalities. Details about the reference standard, reader procedures, and missing or unevaluable imaging are absent, limiting assessment of how the endpoint was determined.
The enrollment figure of 485 is not a substitute for the number analyzed for the primary endpoint. The record says analyses are organized by detected PSA level but does not provide the group-specific denominators. Likewise, the completed status indicates the registry’s study status, not that numerical findings are available in the posted results.
The responsible interpretation is therefore narrow: the registry documents the intended imaging question and study design, but does not report the primary endpoint results needed to judge the observed detection rates or their precision. It does not support a conclusion about how well the imaging approach performed, how results differed by PSA group, or how it compared with another approach.
13. Why This Trial Matters Statistically
This study is statistically notable as a diagnostic-imaging study with a single-group design and a PSA-stratified proportion as its primary endpoint. The distinction between describing a detection rate and estimating a comparative effect is important: the registry describes the former and does not include a randomized comparator for the latter. The primary question is therefore about observed detection within the study cohort, not an assigned-treatment contrast.
The endpoint definition also illustrates why diagnostic measures depend on clear outcome ascertainment. The record refers to true positives, imaging confirmation, metastatic-disease detection, and local reads. How positive disease was confirmed and how readers applied the criteria can affect what a detection proportion represents. Those operational details are not reported in the registry record, so readers cannot assess the extent of standardization or independent verification.
Stratification by PSA group makes the intended reporting more clinically and statistically specific than a single overall rate, but requires the group boundaries, counts, and estimates to be interpretable. Those details and results are not posted. The study’s listed enrollment cannot replace stratum-specific denominators or reveal precision.
Finally, the record illustrates the difference between a completed study and an evaluable statistical report. The design, intervention, and endpoint are described, while the analysis results and key methods are absent. This limits what can be concluded from the registry entry and makes transparent reporting of estimates, uncertainty, populations, and image-reading procedures important for interpretation.
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.
Several limitations specific to this record constrain interpretation. The primary detection-rate estimates and PSA-group denominators are not reported in the registry record, so neither the magnitude nor precision of the endpoint can be evaluated. Although the endpoint is stratified by PSA group, the group definitions are absent. Enrollment of 485 does not show how many participants contributed to each analysis.
The endpoint relies on local reads, but the registry does not describe reader qualifications, blinding to clinical information, standardization, central review, or adjudication. It also does not explain how positive disease was confirmed beyond the outcome wording. Without these details, measurement consistency and the role of the reference standard cannot be assessed.
The study is single-group and unmasked, with no like-for-like control comparison. PET/CT and PET/MRI are listed, but their use by participant and any modality-specific results are not reported. The record also lacks detailed eligibility criteria, site information, missing-data procedures, and a statistical analysis plan. These are limitations of the information available in the registry record; they do not establish what procedures may or may not have been used outside the recorded description.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Gallium-68 PSMA-11 PET Imaging in Prostate Cancer Patients — NCT03803475.
- Registry record last updated 2021-08-24; status last verified 2021-07.
- Results first posted 2021-08-24.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT03803475 is a completed phase 3, single-group study of Ga-68 PSMA-11 PET imaging in prostate cancer, with enrollment recorded as 485. Allocation is listed as not applicable and masking as none. The agent is described as administered intravenously once before PET imaging; PET/CT and PET/MRI are listed as devices.
The primary outcome is a detection rate for positive disease based on local reads, stratified by PSA group at imaging. The registry lists five outcome measures but no analysis records. It does not report the detection-rate estimates, group-specific denominators, confidence intervals, or detailed statistical methods. The posted safety summary records zero serious adverse events, zero other adverse events, and zero deaths in the listed group.