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 Pilot Study of 18F-DCFPyL PET/CT in the Evaluation of Men With an Elevated PSA Following Radical Prostatectomy (NCT02523924), a na na study. The primary outcome is Number of Putative Sites of Metastatic Disease as Determined by 18F-DCFPyL PET/CT.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02523924 |
| Phase | NA |
| Condition | Adenocarcinoma of the Prostate |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 50 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins |
| Results posted | Yes |
2. Clinical Question
Population
Men with an elevated PSA following radical prostatectomy. The registry lists adenocarcinoma of the prostate as the condition studied. It does not report further eligibility details or the characteristics of the participants who underwent imaging.
Intervention
18F-DCFPyL PET/CT imaging. The study describes 18F-DCFPyL as a low-molecular-weight PSMA PET/CT imaging agent and identifies imaging with this agent as the study intervention.
Comparator
There was no randomized or concurrent control group. The registry identifies a single-group study, with allocation listed as NA. Conventional imaging and tissue findings appear as subjects of secondary correlations, not as a control arm.
Primary question
How many putative sites of metastatic disease show 18F-DCFPyL uptake considered consistent with prostate cancer during the stated 6-month timeframe? The registry record does not report the primary endpoint result or the criteria used to classify uptake as consistent with prostate cancer.
3. Trial Design
This was a completed pilot study of 18F-DCFPyL PET/CT in men with an elevated PSA following radical prostatectomy. The registry lists the study as single-group, with allocation and phase recorded as NA and masking listed as none. The intervention was 18F-DCFPyL PET/CT imaging; the record does not describe a randomized treatment comparison. Enrollment is listed as 50.
The study began on 2015-06-02, reached primary completion on 2016-11-04, and has completed status. These dates establish the registry’s recorded study timeline; they do not specify the timing of each participant’s imaging or follow-up. The primary endpoint timeframe is stated as 6 months.
The stated aim was to investigate the diagnostic utility of 18F-DCFPyL in this population. Secondary outcomes concern correlations between PET/CT findings and PSA levels, conventional imaging findings, and tissue histology and PSMA expression in biopsied or resected specimens. These are questions about agreement or association across information sources, rather than evidence from a control group. The registry record does not report the results of those correlations.
The record lists 7 outcome measures and 0 analyses. It does not report a statistical analysis plan, a sample-size justification for the study, or whether any planned analyses were changed. The design therefore supports describing the imaging findings recorded in the study, but not a randomized estimate of comparative benefit. The primary endpoint result itself is not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: 19 patients did not meet inclusion criteria.
Overall Study
| Stage | 18F-DCFPyL PET/CT |
|---|---|
| STARTED | 31 |
| COMPLETED | 31 |
| NOT COMPLETED | 0 |
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 | 18F-DCFPyL PET/CT |
|---|---|---|
| Participants analysed | 31 | |
| Age, Continuous | years | 63 (45 to 74) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 31 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 27 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 4 |
| Region of Enrollment: United States | Participants | 31 |
| Months since radical prostatectomy | months | 30 (4 to 152) |
| Gleason grade group: 1 | Participants | 2 |
| Gleason grade group: 2 | Participants | 6 |
| Gleason grade group: 3 | Participants | 13 |
| Gleason grade group: 4 | Participants | 1 |
| Gleason grade group: 5 | Participants | 9 |
| Pathologic stage: pT2 | Participants | 11 |
| Pathologic stage: pT3a | Participants | 14 |
| Pathologic stage: pT3b | Participants | 6 |
| Positive surgical margin | Participants | 13 |
| Prostate Specific Antigen (PSA) | ng/mL | 0.4 (0.2 to 28.3) |
6. Primary Endpoint
The registry lists the primary outcome as Number of Putative Sites of Metastatic Disease as Determined by 18F-DCFPyL PET/CT, measured over 6 months.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is titled “Number of Putative Sites of Metastatic Disease as Determined by 18F-DCFPyL PET/CT.” Its description is the number of sites with 18F-DCFPyL uptake considered consistent with prostate cancer, and its timeframe is 6 months. This endpoint focuses on imaging findings that may be interpreted as possible sites of disease; it is not itself a confirmation by tissue diagnosis.
The registry lists the unit as participants and the parameter as a count of participants, while the description refers to a number of sites. That difference leaves the exact unit of analysis unclear in the registry record: it does not specify whether the reported outcome is intended to count participants with one or more putative sites, the number of sites per participant, or another summary. The registry record also does not report the primary endpoint value, how uptake was classified, how multiple sites within a participant were handled, or how indeterminate scans were treated.
Counting putative sites can describe the distribution of imaging findings in a diagnostic pilot study. It does not, by itself, establish that each finding represents metastatic disease or show how accurately imaging identifies disease. The listed secondary outcomes—correlations with PSA, conventional imaging, and tissue findings—could address related questions, but their results are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a diagnostic imaging pilot in a defined clinical context: men with elevated PSA following radical prostatectomy. Its central outcome concerns putative sites of metastatic disease identified by 18F-DCFPyL PET/CT. The record supplies the endpoint definition and timeframe but does not report the number of participants or sites meeting that definition. No estimate of the primary result, its uncertainty, or the distribution of findings can therefore be described from the registry record.
This absence of a reported primary result is important for interpretation. A stated outcome is not evidence that a particular finding occurred, and the study’s completed status does not supply an effect estimate. The record also does not report sensitivity, specificity, predictive values, diagnostic accuracy, or a comparison of imaging strategies. Those measures should not be inferred from the endpoint title or from the secondary outcomes listed.
The design is single-group, with no randomized comparator. Secondary outcomes propose correlations with PSA levels, bone scan and cross-sectional imaging findings, and histology and PSMA expression in biopsied or resected specimens. These comparisons may help characterize how imaging findings relate to other measurements, but no correlation results are reported. In addition, an association between imaging and another measure would not by itself establish that either one is a definitive reference standard.
The registry lists enrollment as 50, while the serious adverse event summary reports 31 at risk for the listed study group. The record does not explain this difference or establish whether these figures refer to the same analysis population. It reports zero serious adverse events, zero other adverse events, and zero deaths in that group; these are registry figures for the stated group, not evidence about the unreported imaging endpoint.
Overall, the available registry information describes the study’s purpose, design, and planned outcome domains, but does not permit an estimate of diagnostic yield or a conclusion about the diagnostic performance of 18F-DCFPyL PET/CT. The statistical precision of the primary result cannot be assessed because the result and its uncertainty are not reported in the registry record.
9. Statistical Methods Explained
Statistical interpretation starts with the design. This study is listed as single-group, with allocation NA and masking none. In a single-group diagnostic study, the main descriptive task is to characterize findings in the imaged participants. Without a randomized or concurrent control arm, there is no like-for-like treatment comparison from which to estimate a comparative effect. The study’s secondary correlations do not create a control group.
What does a count endpoint describe?
In general, a count records how many events or items meet a specified definition. For this endpoint, the description refers to sites with uptake considered consistent with prostate cancer. A count can communicate the observed frequency or burden of qualifying findings, but it depends on a clear operational definition and on how repeated findings within the same participant are handled. The registry’s unit says participants, whereas its description refers to sites. Because the record does not resolve that distinction, readers cannot determine the precise counting unit from the registry record alone.
Counts can also vary more than a simple probability model would expect when observations cluster within participants or when participants have substantially different underlying rates of findings. This is called over-dispersion: the observed variation exceeds that expected under a more restrictive model. As a general statistical matter, a model that ignores clustering or over-dispersion can give uncertainty estimates that are too small. The record does not report a model for the primary endpoint, whether clustering was considered, or an over-dispersion assessment.
How should uncertainty be considered?
In general, a confidence interval describes the range of values compatible with an estimate under a specified statistical method and its assumptions. It communicates precision as well as the central estimate. The registry record does not report the primary endpoint estimate or a confidence interval, so neither the magnitude nor the precision of the primary finding can be assessed. The same applies to the listed secondary correlations: their estimates and uncertainty are not reported.
For a diagnostic study, interpretation also depends on the target condition and the reference against which imaging is assessed. A correlation with PSA or conventional imaging describes a relationship between measures; it is not automatically a measure of diagnostic accuracy. Histology can provide tissue evidence for sampled lesions, but the registry record does not describe how biopsied or resected specimens were selected, how findings were matched to imaging sites, or how participants without tissue results were handled. It also does not report a reference-standard definition for the primary outcome.
What do the analysis counts imply?
The registry lists 7 outcome measures and 0 analyses. This means that the record includes outcome listings without registered analysis entries. It does not establish which analyses were performed outside the registry, whether results were unavailable, or whether outcomes were changed. The statistical analysis plan, including planned estimands, covariate adjustment, handling of repeated sites, and procedures for missing observations, is not reported in the registry record.
The registry includes a sample-size planning illustration based on a two-arm design, equal allocation, a two-sided significance level of 0.05, and a normal approximation. It describes effects as fractions of an observed effect, and distinguishes participants per arm from total events for time-to-event settings. These are planning assumptions for an illustration, not a statement of this pilot study’s design or its own sample-size justification. Since the study is single-group and the primary result is not reported, the illustration cannot be read as evidence of observed power. Sample-size planning is not a substitute for an effect estimate and its uncertainty.
What can be inferred from the design?
In general, a pilot study can provide descriptive information and help characterize whether a larger diagnostic evaluation may be useful to plan. Its interpretation still requires transparent reporting of the population, endpoint definition, observed results, and uncertainty. Here, the registry records the population context, intervention, endpoint title, and timeframe, but does not report the primary finding or analysis details. Consequently, claims about diagnostic performance, subgroup differences, or reproducibility cannot be evaluated from the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 7 outcome measures, including the primary endpoint and secondary correlations with PSA levels, conventional imaging, and tissue histology and PSMA expression. When several outcomes or analyses are considered, the chance of obtaining at least one apparently notable result can increase. General methods for addressing multiplicity include prespecifying a primary comparison, adjusting inference across selected tests, or treating secondary findings as exploratory. The registry record does not report a multiplicity strategy or the hierarchy among the outcomes beyond identifying one as primary.
The record lists 0 analyses. It does not report which outcomes were analyzed, whether all listed measures were collected, or whether any analysis was prespecified. Therefore, readers cannot determine how multiplicity was handled or distinguish planned analyses from exploratory ones. No outcome-specific p-values or confidence intervals are reported in the registry record.
Missing-data handling is also not reported in the registry record. The record does not state whether all participants had interpretable imaging, how missing PSA or conventional imaging information was handled, or whether tissue specimens were available for every relevant finding. It does not describe an analysis population, exclusions, or a method for handling indeterminate or incomplete observations.
The registry enrollment is 50, while the adverse-event summary lists 31 at risk for the study group. The record does not explain the difference, so it should not be treated as a known count of missing primary outcome observations or as evidence of attrition. Without participant flow and endpoint-specific denominators, the completeness of the primary and secondary outcome data cannot be assessed.
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 |
|---|---|---|---|
| 18F-DCFPyL PET/CT | 0 | 31 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| 18F-DCFPyL PET/CT | 0 of 31 |
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 |
|---|---|
| 18F-DCFPyL PET/CT | 0 of 31 |
The serious adverse event summary lists the 18F-DCFPyL PET/CT group with 31 at risk and 0 serious adverse events. It also lists 31 at risk and 0 other adverse events, and 0 deaths. These figures describe the registry’s safety summary for that group; the record does not provide event definitions, observation details, or a narrative explaining how events were collected.
The at-risk figure in the safety summary is not the same as the registry enrollment figure of 50. The record does not explain the difference, so the safety denominator should be read as reported rather than reconciled with enrollment. The record also does not establish that this safety group matches the population used for the primary endpoint.
Zero events in a registry summary means that no events are recorded in those categories for the stated group. It does not establish that no event could occur, nor does it provide a comparative safety estimate because the study has no control group. The summary should not be interpreted as a full characterization of all possible harms or as a comparison with another imaging approach.
12. What the Result Does, and Does Not, Mean
The registry record describes a pilot evaluation of 18F-DCFPyL PET/CT among men with an elevated PSA following radical prostatectomy. It identifies putative metastatic sites as the primary outcome and lists relationships with PSA, conventional imaging, and tissue findings as secondary outcome domains. This information clarifies what the study set out to examine, but the primary endpoint result and secondary analysis results are not reported in the registry record.
Without observed endpoint values, it is not possible to describe the number of participants with putative sites, the number of sites identified, or the precision of any estimate. The record does not report diagnostic accuracy measures or a comparison with another imaging strategy. The endpoint wording also leaves uncertainty about whether the intended count concerns participants or sites. Those limits prevent an evidence-based statement about the diagnostic performance represented by this study.
The single-group design can support a descriptive account of findings if the results and methods are reported, but it does not provide a randomized comparison. Correlations with conventional imaging or tissue findings, if reported, would address relationships between measures; they would not automatically establish that PET/CT findings are correct or that one approach is superior. The registry record does not report those correlations or enough detail about reference standards to interpret them.
The safety summary records zero serious adverse events, zero other adverse events, and zero deaths among the stated at-risk group. These figures are limited to the registry summary and do not provide a comparative safety assessment. The difference between the enrollment figure and the safety denominator is unexplained in the record.
Thus, the record documents a completed pilot study and its stated questions, but does not provide the findings needed to judge diagnostic yield, precision, or agreement with other evidence. No conclusion about the clinical usefulness of the imaging agent follows from the endpoint listing alone.
13. Why This Trial Matters Statistically
Diagnostic studies need more than a description of the imaging technology: their statistical interpretation depends on a defined population, a clear outcome, and transparent reporting of how imaging findings are assessed. This record makes the clinical context explicit—elevated PSA following radical prostatectomy—and identifies putative sites of disease as the primary outcome. It also names comparisons with PSA, conventional imaging, and tissue findings as secondary questions.
The endpoint’s wording illustrates why operational definitions matter. The title and description refer to sites, while the registry lists participants as the unit. Depending on whether the target is a participant-level count or a site-level count, the analysis and interpretation can differ. Clarification would be necessary to understand what a reported value represents and how repeated sites within a participant contribute.
The single-group design also matters. A diagnostic pilot can characterize findings, but it does not provide a randomized control comparison. Associations with other tests may be informative, yet they require clear definitions and cannot alone establish diagnostic accuracy. Results, uncertainty estimates, and a description of reference standards would be important for assessing those associations.
Finally, a completed study record without a reported primary result leaves a gap between the research question and what can be interpreted statistically. The record lists outcomes but no analyses, and it does not describe missing-data handling or multiplicity. These reporting details are essential for understanding whether estimates are precise, complete, and consistent with planned questions. The study is therefore statistically notable as an example of how design and endpoint definitions frame interpretation—and how missing results constrain it.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The principal limitation for interpretation is that the registry record does not report the primary endpoint result. It also does not report estimates or uncertainty for the secondary outcomes. As a result, the stated diagnostic questions cannot be answered from this record.
The endpoint’s measurement unit is unclear: the title and description concern putative sites, while the listed unit is participants. The record does not specify the imaging criteria for classifying uptake, the handling of multiple sites, or the treatment of indeterminate findings. It also does not describe how imaging findings were matched to tissue specimens or how the reference standard was defined.
The single-group design has no randomized control arm, and masking is listed as none. The record does not provide further details about image interpretation, reader procedures, or whether interpretations were independently assessed. It therefore does not support evaluation of reader agreement or the possibility of assessment bias.
The registry lists enrollment as 50, while the safety summary lists 31 at risk. The difference is not explained, and there is no participant-flow description or endpoint-specific denominator. Missing-data procedures, analysis populations, and reasons for any exclusions are not reported in the registry record.
Although 7 outcome measures are listed, the registry records 0 analyses and does not describe a multiplicity plan, statistical analysis plan, or sample-size justification for this study. The sample-size planning illustration uses two-arm assumptions and is not a description of this single-group pilot’s design. These limitations leave the completeness, precision, and analytic basis of the study’s findings unassessable from the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Pilot Study of 18F-DCFPyL PET/CT in the Evaluation of Men With an Elevated PSA Following Radical Prostatectomy — NCT02523924.
- Registry record last updated 2020-01-31; status last verified 2020-01.
- Results first posted 2020-01-31.
- 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.
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18. Record Summary
This completed pilot study evaluated 18F-DCFPyL PET/CT in men with an elevated PSA following radical prostatectomy. It is listed as single-group, with no masking, and enrollment of 50. The registry dates are 2015-06-02 for study start and 2016-11-04 for primary completion.
The primary outcome concerns putative sites of metastatic disease identified by uptake considered consistent with prostate cancer, with a 6-month timeframe. Secondary outcomes concern correlations with PSA, conventional imaging, and tissue histology and PSMA expression. The registry lists 7 outcome measures and 0 analyses.
The primary result, secondary results, statistical analysis plan, and missing-data methods are not reported in the registry record. The safety summary lists 0 serious adverse events, 0 other adverse events, and 0 deaths among 31 at risk; the record does not explain how this safety denominator relates to enrollment.