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 Validation of FACBC for Detection of Metastasis Among High-risk Prostate Cancer Patients With Presumed Localized Disease (NCT03081884), a na phase 2 study. The primary outcome is Cancer Detection Performance of FACBC PET/CT.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03081884 |
| Phase | Phase 2 |
| Condition | Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 61 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Emory University |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people with newly diagnosed, high-risk prostate cancer presumed to be localized. They were scheduled for radical prostatectomy and did not have definitive evidence of systemic metastasis on conventional imaging. The registry description names computed tomography and magnetic resonance imaging, as well as bone scan and sodium fluoride PET, as examples of conventional imaging. The record does not specify further eligibility criteria or describe the characteristics of the enrolled participants.
Intervention
Participants underwent whole-body FACBC PET-CT imaging. FACBC is also called fluciclovine in the registry description. The stated purpose was to assess whether the imaging could identify metastatic disease in people whose conventional imaging did not show definitive systemic metastasis. The record also describes comparisons between FACBC uptake in the prostate and uptake in metastases, and analyses involving prostate tissue, serum, and urine parameters.
Comparator
This was a single-group study, not a randomized comparison between treatment arms. Conventional imaging was part of the clinical context and the diagnostic question, but the primary endpoint description identifies histological analysis of lymph nodes as the basis for confirming FACBC PET-CT findings. The registry does not report a separate control group or provide numerical results comparing imaging methods.
Primary question
The primary question was whether FACBC PET-CT could detect metastatic cancer, with findings assessed against lymph-node histology. The endpoint is described as cancer detection performance and is recorded in participants at Day 1. The registry record does not report the numerical primary endpoint result, nor does it provide estimates of diagnostic performance such as sensitivity or specificity. Therefore, the stated question can be described, but its answer cannot be quantified from the posted results.
3. Trial Design
This was a phase 2, completed, single-group study sponsored by Emory University. The registry lists an enrollment of 61. The study began on 2017-03-01, and primary completion was recorded as 2019-12-31. These dates and the completed status describe the trial record; they do not establish that every planned analysis or outcome result was posted.
Participants were people with primary prostate carcinoma and no definitive findings of systemic metastasis on conventional imaging. The intervention was whole-body FACBC PET-CT imaging. The brief description places the study in the setting of high-risk prostate cancer and radical prostatectomy. The registry identifies no randomized allocation and no masking. The design is therefore not a blinded, randomized comparison of FACBC against another imaging strategy.
The primary outcome is titled “Cancer Detection Performance of FACBC PET/CT.” Its description says that findings for diagnosing metastatic cancer were confirmed against histological analysis of lymph nodes. The recorded timeframe is Day 1. A secondary outcome is listed as diagnostic performance of FACBC PET/CT and conventional imaging, but no numerical secondary outcome results are reported in the registry record.
The registry lists two outcome measures and zero analyses. That listing should not be read as evidence that the study had no analyses outside the registry; it means the record does not post analyses in that entry. Likewise, the enrollment figure is not a substitute for the number of participants contributing to a particular endpoint. The record does not report an endpoint-specific analysis population or explain the difference between enrollment and the safety population.
The record does not report a protocol-level sample-size justification, a detailed statistical analysis plan, interim analyses, or planned handling of missing observations. Its sample-size assumptions describe a planning illustration based on an observed effect, with equal allocation between two arms, a two-sided significance level of 0.05, and a normal approximation. Those assumptions do not describe this single-group study and should not be mistaken for its design or for an observed-power calculation.
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 | FACBC PET-CT Imaging |
|---|---|
| STARTED | 61 |
| COMPLETED | 57 |
| NOT COMPLETED | 4 |
Reasons for not completing this period:
| Reason | FACBC PET-CT Imaging |
|---|---|
| deferred prostate cancer treatment | 1 |
| metastasis managed with systemic therapy | 3 |
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: The baseline analysis population includes participants who completed the study.
| Characteristic | Unit | FACBC PET-CT Imaging |
|---|---|---|
| Participants analysed | 57 | |
| Age, Continuous | years | 61.7 (SD 7.0) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 57 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: United States | Participants | 57 |
| Type of Standard of Care Imaging: Computerized tomography (CT) | Participants | 20 |
| Type of Standard of Care Imaging: Magnetic resonance imaging (MRI) | Participants | 37 |
6. Primary Endpoint
The registry lists the primary outcome as Cancer Detection Performance of FACBC PET/CT, measured over Day 1.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is described as cancer detection performance of FACBC PET-CT, measured in participants at Day 1. The registry says that imaging findings for metastatic cancer were confirmed against histological analysis of lymph nodes. Histology is therefore the stated reference standard for evaluating whether imaging findings corresponded to evidence of cancer in the lymph nodes.
In general, diagnostic studies use a reference standard to distinguish imaging classifications from the condition they are intended to identify. The choice and completeness of that reference standard matter: estimates of diagnostic performance depend on which participants receive verification and how the reference assessment is conducted. The registry record names lymph-node histology, but does not describe the specific verification procedures, whether all participants had evaluable histology, or how indeterminate imaging findings were handled.
The endpoint title does not itself provide a result. Although the registry describes the intended assessment, it does not report a numerical count or an estimate of diagnostic performance. Sensitivity, specificity, predictive values, and confidence intervals are not reported in the registry record. The endpoint therefore identifies what the study aimed to assess, but the posted information does not allow readers to quantify how often FACBC PET-CT findings agreed with the histological reference standard.
Using a reference standard is useful for interpreting a diagnostic test, but it does not make the study a randomized comparison. This endpoint addresses diagnostic classification in the studied group; it does not estimate a treatment effect or establish that imaging changes subsequent outcomes.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record presents a focused diagnostic question: whether FACBC PET-CT detects metastatic disease among people with high-risk prostate cancer whose conventional imaging did not show definitive systemic metastasis. It identifies lymph-node histology as the confirmation method for the primary diagnostic endpoint. However, the record does not report a numerical primary result. There is consequently no posted estimate to interpret for detection performance, agreement with histology, or precision.
The trial is listed as completed and reports enrollment of 61, but completion status and enrollment do not establish how many participants had evaluable imaging, histology, or paired data. The record does not report those analysis denominators. It also does not report the number of participants classified as having metastatic disease, the number of positive or negative imaging findings, or any uncertainty interval. No sensitivity, specificity, predictive value, or other diagnostic accuracy estimate is available in the registry record.
The study has a single group and no randomized allocation. This is compatible with an evaluation of diagnostic performance, but it does not provide a like-for-like randomized control comparison. Conventional imaging is part of the clinical context and a named secondary outcome, but numerical results comparing FACBC PET-CT with conventional imaging are not reported. The record therefore cannot establish the size or precision of any difference between imaging approaches.
As a general statistical principle, a point estimate describes the observed result in the analysed participants, while a confidence interval describes the range of values compatible with the data under the method used. Neither can be interpreted without a reported estimate, denominator, and analysis method. Here, the posted registry information does not give those elements for the primary endpoint. Any numerical claims about diagnostic accuracy would go beyond the record.
The listed secondary outcome concerns diagnostic performance of FACBC PET/CT and conventional imaging. The brief description also mentions comparisons of uptake in the prostate and metastases and analyses of tissue, serum, and urine parameters. These are descriptions of intended questions, not posted findings. The registry record does not provide numerical results for those comparisons or analyses. Readers should distinguish a planned or described objective from an outcome estimate.
The safety entry reports 57 participants at risk in the FACBC PET-CT Imaging group and zero serious adverse events. That is a descriptive count in the safety record. It should not be read as a full assessment of every possible harm or as proof that no adverse events occurred: the entry gives serious adverse event counts, while other adverse event details and the reasons for the safety population size are not reported in the registry record.
Overall, the posted information supports describing the study question, design, endpoint reference standard, enrollment, and limited safety counts. It does not support a quantitative conclusion about the diagnostic performance of FACBC PET-CT. The absence of a posted result is not evidence for either high or low accuracy.
9. Statistical Methods Explained
What does a single-group diagnostic study assess?
In general, a single-group diagnostic study evaluates how a test classifies participants relative to a reference standard. It is not the same as a randomized trial comparing treatments. For this study, the registry identifies FACBC PET-CT as the test and lymph-node histology as the reference for confirming the primary diagnostic findings. That description establishes the intended comparison, but the record does not provide the participant-level classifications or a numerical performance estimate.
Diagnostic measures answer different questions. Sensitivity describes how often a test is positive among people who have the condition according to the reference standard. Specificity describes how often the test is negative among people who do not have the condition according to that standard. Predictive values describe the probability of the condition given a test result, and depend in part on how common the condition is in the group being assessed. These are general definitions, not reported results from this trial. None of these numerical measures is reported in the registry record.
Why does the reference standard matter?
General diagnostic-study methods depend on the quality and availability of the reference assessment. If some participants do not have an evaluable reference standard, or if verification differs according to imaging findings, the analysed group may not represent everyone who entered the study. This can affect estimated performance. The registry names histological analysis of lymph nodes but does not report how many participants underwent that assessment, whether all had usable results, or how unavailable or inconclusive results were handled.
Agreement with a reference standard also needs a clear rule for classifying both the imaging test and the reference assessment. The record does not report thresholds, interpretation procedures, handling of equivocal scans, or whether image readers were blinded to other information. Masking is listed as none. The registry does not explain how that design feature related to imaging interpretation or histological assessment, so its practical influence cannot be determined from the record.
What does precision mean?
In general, a confidence interval expresses statistical uncertainty around an estimate under the assumptions of the method used. A narrower interval indicates greater precision, while a wider interval indicates greater uncertainty. Precision depends on the amount of usable information and on the statistical method, among other factors. No primary endpoint estimate or confidence interval is reported in the registry record, and the endpoint-specific denominator is not stated. Thus, the precision of the diagnostic result cannot be assessed.
For binary outcomes, counts and denominators are essential. A count without its relevant denominator cannot establish a rate, and a denominator for the overall study cannot automatically be used as the endpoint denominator. The record lists enrollment of 61 but does not report the number contributing to the primary endpoint or the underlying positive and negative classifications. No derived proportions should be inferred from the available entry.
How should the sample-size assumptions be read?
The registry includes planning assumptions describing 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. These are described as a planning illustration, not as the trial's own design. The study itself is listed as single-group, with no randomized allocation. The listed two-arm assumptions therefore do not describe the observed trial structure. The record does not report a trial-specific sample-size justification, and the assumptions do not provide an observed-power result.
In general, sample-size planning asks how much information would be needed to assess a specified effect under chosen statistical assumptions. A planning illustration is not evidence that an effect was observed, and it does not replace a confidence interval around the trial's actual result. No sample-size result or trial-specific power calculation is reported in the registry record. Any planning values should be interpreted only in the context stated in the record, not as evidence about diagnostic performance.
What can be inferred from the posted analysis information?
The registry lists two outcome measures and zero analyses. This indicates that no analyses are posted in that record entry; it does not establish what analyses were conducted elsewhere. The primary outcome description supplies a timeframe and reference standard, but no result value. The secondary diagnostic comparison is also named without numerical findings. Without posted counts, estimates, uncertainty intervals, and analysis details, readers cannot evaluate the magnitude, precision, or robustness of the diagnostic findings.
General statistical interpretation also depends on prespecified analytic choices, such as the definition of a positive test, the analysis population, and how missing results are handled. Those details are not reported in the registry record. They cannot be reconstructed from the outcome title or the brief study description. The appropriate interpretation is therefore limited to the study's stated diagnostic aim and the information actually recorded, rather than an assumed analysis plan or an unreported performance estimate.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary diagnostic endpoint and a secondary outcome concerning diagnostic performance of FACBC PET/CT and conventional imaging. The brief description also mentions comparisons of prostate and metastatic uptake and analyses of tissue, serum, and urine parameters. These multiple questions could involve multiple statistical comparisons, but the registry record does not report a multiplicity plan, such as whether any adjustment or hierarchy was specified. Without such information, the risk of interpreting chance findings across several analyses cannot be assessed.
The record lists two outcome measures and zero analyses. Numerical results for the primary and secondary outcomes are not reported in the registry record. It also does not report an analysis population for either outcome, the number with usable imaging and histology, or how participants with missing or indeterminate assessments were treated. Enrollment of 61 should not be assumed to be the denominator for each endpoint.
In general, missing diagnostic information can affect estimates if the participants with complete assessments differ from those without them. The direction and extent of any such effect depend on why data are unavailable and how the analysis handles them. No missing-data method or account of endpoint completeness is reported in the registry record. The information is therefore insufficient to assess potential bias from missing or unevaluable results.
The registry does not report a detailed statistical analysis plan, prespecified subgroup methods, or interim analyses. These omissions do not show that such procedures were absent from study documents; they mean they are not described in the registry entry. No post hoc or prespecified status can be assigned to particular analyses from the posted information.
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 |
|---|---|---|---|
| FACBC PET-CT Imaging | 0 | 57 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| FACBC PET-CT Imaging | 0 of 57 |
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 |
|---|---|
| FACBC PET-CT Imaging | 0 of 57 |
The safety entry lists the FACBC PET-CT Imaging group with 57 participants at risk and zero serious adverse events. It also records zero participants with other adverse events in the corresponding count fields, and zero deaths. These are registry counts for the safety entry; they do not provide a complete narrative account of all events, event severity, timing, or attribution.
The enrollment figure is 61, whereas the safety entry lists 57 participants at risk. The registry record does not explain this difference. The safety population should therefore be read using the risk count recorded for that entry, without assuming why some enrolled participants are not included in it. The record also does not report exposure duration or additional safety analyses.
In general, a count of zero serious adverse events in a recorded group means that none were entered in that category for the listed risk population. It does not establish that an intervention has no risks, and it does not rule out events not captured or reported in that category. These figures are descriptive and do not support a comparison of safety between groups, because this is a single-group study with no like-for-like control arm.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed phase 2, single-group study evaluated FACBC PET-CT in the setting of high-risk prostate cancer with no definitive systemic metastasis on conventional imaging. It identifies the primary diagnostic question and names lymph-node histology as the confirmation method. It also records enrollment of 61 and a safety entry for the FACBC PET-CT Imaging group.
What the record does not establish is the numerical accuracy of FACBC PET-CT. The primary endpoint result is not reported in the registry record. There are no posted counts of imaging classifications matched to histology, no diagnostic accuracy estimates, and no confidence intervals. The secondary comparison with conventional imaging is named but lacks numerical results. Consequently, the registry entry cannot show how often the imaging findings agreed with histology or how precise any estimate might be.
The design does not include random allocation to a comparator group. The study therefore cannot be interpreted as a randomized comparison of imaging strategies. Its stated diagnostic aim is distinct from questions about whether imaging changes treatment decisions, improves outcomes, or affects survival; those outcomes are not reported as results in this record.
In general, a missing registry result should not be interpreted as a positive or negative finding. It indicates that the information needed for that interpretation is not reported in the registry record. The study's completed status does not supply the missing numerical endpoint data, and enrollment does not establish the number of participants with complete diagnostic assessments.
The safety record reports zero serious adverse events among 57 participants listed at risk, along with zero in the other recorded event and death counts. Those figures are descriptive, not proof that no harms occurred or that the imaging strategy is risk-free. They also do not provide a controlled safety comparison. The most defensible reading is to separate the study's stated diagnostic purpose from the limited outcome information actually posted.
13. Why This Trial Matters Statistically
This study addresses a diagnostic problem in a defined clinical setting: identifying possible metastatic disease among people with high-risk prostate cancer whose conventional imaging did not show definitive systemic metastasis. The registry's stated use of lymph-node histology as a reference standard is statistically important because diagnostic performance depends on comparing test classifications with an independent assessment of disease status.
The single-group design is also important. Diagnostic accuracy can be studied without randomized treatment allocation, but the resulting question differs from a comparative-effectiveness question. The record does not provide a randomized control group, nor does it report numerical comparisons between FACBC PET-CT and conventional imaging. Readers should not treat the study as if it estimated the effect of assigning one imaging strategy rather than another.
Statistical interpretation depends not only on the question and reference standard, but also on endpoint denominators, classification rules, and uncertainty. The registry describes the endpoint but does not post the diagnostic counts, estimates, confidence intervals, or analysis population. This illustrates why a study title and outcome definition cannot substitute for results. Without those elements, the direction, magnitude, and precision of the diagnostic findings remain unknown from the registry record.
The entry also demonstrates the importance of distinguishing enrollment from endpoint-specific information. It lists enrollment of 61 and a safety population of 57, but does not explain the difference or give the primary endpoint denominator. Those figures describe different recorded aspects of the study and should not be combined or treated as interchangeable.
For biostatisticians and clinical researchers, the record is useful for identifying the intended diagnostic framework and the information needed for a full assessment. It also makes clear what remains unavailable: result estimates, uncertainty, missing-data handling, multiplicity procedures, and detailed analysis methods. Those are central to judging the strength and generalizability of diagnostic evidence.
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 main limitation of interpreting this record is that it does not report a numerical primary endpoint result. The study aim and reference standard are described, but the diagnostic findings needed to estimate performance are absent. There are no posted sensitivity, specificity, predictive values, confidence intervals, or underlying classification counts.
The record does not report the number of participants with evaluable FACBC PET-CT findings or lymph-node histology. It lists enrollment of 61, while the safety entry lists 57 at risk; the reason for this difference is not reported in the registry record. The endpoint-specific analysis population and completeness of verification are also not reported, so the extent to which the analysed group might differ from the enrolled group cannot be assessed.
The registry does not provide details about imaging thresholds, interpretation procedures, handling of equivocal results, or histological assessment procedures. Masking is listed as none, but the record does not explain how that fact related to test interpretation or the reference assessment. The statistical analysis plan, missing-data methods, and multiplicity procedures are not reported.
The single-group design does not provide a randomized comparison with another imaging strategy. Although conventional imaging appears in the stated secondary outcome, numerical comparative results are not reported. The record also does not establish whether diagnostic findings changed clinical decisions or affected later outcomes.
These limitations concern what can be learned from the registry record; they do not establish that the study lacked procedures or analyses outside the record. They restrict the conclusions that can be drawn from the posted information, particularly about performance estimates and their precision.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Validation of FACBC for Detection of Metastasis Among High-risk Prostate Cancer Patients With Presumed Localized Disease — NCT03081884.
- Registry record last updated 2021-01-25; status last verified 2021-01.
- Results first posted 2021-01-25.
- 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
The registry describes a completed phase 2, single-group study sponsored by Emory University, with enrollment of 61. The study evaluated whole-body FACBC PET-CT imaging in people with high-risk prostate cancer and no definitive systemic metastasis on conventional imaging. The primary endpoint concerns cancer detection performance, with FACBC findings assessed against lymph-node histology at Day 1.
The registry lists a secondary diagnostic-performance outcome involving FACBC PET/CT and conventional imaging, but does not report numerical results for either outcome. The primary endpoint estimate, endpoint denominator, diagnostic accuracy measures, confidence intervals, and detailed analysis methods are not reported in the registry record. The safety entry records 57 participants at risk in the FACBC PET-CT Imaging group and zero serious adverse events. The record does not explain the difference between enrollment and the safety risk count.
The posted information defines the diagnostic question and some features of the study design, but does not allow quantitative interpretation of diagnostic performance.