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 Stereotactic Body Radiotherapy for Prostate Cancer (NCT01352598), a na na study. The primary outcome is Biochemical Control Rate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01352598 |
| Phase | NA |
| Condition | Prostate Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 84 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Mercy Research |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with organ-confined prostate cancer. The registry records enrollment of 84 participants. It does not give further eligibility details or describe the characteristics of the participants included in the primary endpoint analysis; those details are not reported in the registry record.
Intervention
The intervention is stereotactic body radiotherapy (SBRT). The registry describes 30 - 40 Gy in 4 - 5 fractions. For high risk patients who also receive external beam radiotherapy, it describes SBRT at 19 - 21 Gy in 2 - 3 fractions. The record does not provide delivered-treatment details for individual participants.
Comparator
No separate comparator group is listed. The study is recorded as a single-group trial, with allocation listed as NA and no masking. The registry therefore does not provide a like-for-like control group for a comparative estimate of SBRT outcomes.
Primary question
The stated primary question is the one-year biochemical control rate after SBRT. The endpoint description defines control by tumor status and contrasts it with disease progression, using serial PSA tests and the Phoenix definition for biochemical recurrence. The registry record does not report the observed control count or rate, so it does not establish the endpoint result.
3. Trial Design
The registry identifies NCT01352598 as a Phase IV Trial Evaluating the Use of Stereotactic Body Radiotherapy for the Treatment of Prostate Cancer. Its listed phase is NA. The study is marked completed, with enrollment of 84. The recorded start is 2011-06 and primary completion is 2019-04. These are registry milestones; they do not by themselves describe the timing of follow-up or the completeness of outcome collection for each participant.
The design is recorded as single group, with no masking and allocation listed as NA. The listed intervention is stereotactic body radiotherapy, and the group is titled Stereotactic Body Radiotherapy. Because the record does not list a separate comparator arm, the design supports description of outcomes in the treated group, not a direct estimate of how those outcomes differ from another treatment or from no treatment. A comparative treatment effect is not reported in the registry record.
The intervention description gives a range of 30 - 40 Gy delivered in 4 - 5 fractions. For high risk patients who also receive external beam radiotherapy, the SBRT schedule is described as 19 - 21 Gy in 2 - 3 fractions. The registry does not explain how treatment schedules were selected, how many participants received each schedule, or whether treatment differed from the planned description.
The primary outcome is Biochemical Control Rate, measured in participants at one year. Late Toxicity Rate is listed as a secondary outcome. The registry lists 2 outcome measures and 0 analyses. It does not report a statistical analysis plan, sample-size justification, interim analyses, or outcome results. As a result, the stated design and endpoint definitions can be described, but the planned analysis details and the findings cannot be reconstructed from this 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
| Stage | Stereotactic Body Radiotherapy |
|---|---|
| STARTED | 84 |
| COMPLETED | 72 |
| NOT COMPLETED | 12 |
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 | Stereotactic Body Radiotherapy |
|---|---|---|
| Participants analysed | 84 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 23 |
| Age, Categorical: >=65 years | Participants | 61 |
| Age, Continuous | years | 68 (54 to 82) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 84 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 5 |
| Race (NIH/OMB): White | Participants | 66 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 11 |
| Region of Enrollment: United States | participants | 84 |
6. Primary Endpoint
The registry lists the primary outcome as Biochemical Control Rate, measured over one year.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the Biochemical Control Rate at one year, expressed in participants. The description says PSA blood tests are obtained at regular intervals every 3 months. It defines biochemical recurrence using the Phoenix definition: nadir + 2 ng/ml. The outcome is described as a comparison between participants experiencing tumor control—complete, partial, or stable—and participants experiencing disease progression.
Biochemical control is used as a way to characterize disease status after treatment through PSA monitoring. In general, a prespecified endpoint definition helps ensure that outcome classification follows a consistent rule rather than an informal judgment made after results are known. A fixed assessment timeframe also makes clear when the endpoint is intended to be evaluated. Those features make the definition interpretable, but they do not establish that all participants had an assessment at the specified time or that the endpoint was analyzed as planned.
The registry does not report how many participants met the control definition, how many experienced progression, or the resulting biochemical control rate. It also does not report the number assessed at one year, uncertainty intervals, or a statistical comparison. The endpoint description therefore tells readers what the study intended to measure, not what the observed outcome was.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record describes an intended assessment of one-year biochemical control after SBRT in patients with organ-confined prostate cancer. It reports the endpoint definition and the treatment schedules, but it does not report the observed biochemical control result. In particular, there is no posted numerator, denominator, rate, confidence interval, or analysis result for the primary endpoint. The registry record therefore does not allow readers to assess the frequency of biochemical control or the precision of an estimate.
The single-group design is central to interpreting the available information. Without a separate comparator group, the study can describe outcomes among participants who received the intervention, but it cannot directly estimate a difference between SBRT and another treatment using this record. Even if an outcome rate were present, the absence of a listed control group would limit conclusions about comparative effects. Here, the primary outcome rate itself is also not reported.
The record lists enrollment of 84, but that number should not be treated as the endpoint denominator. The number with evaluable one-year PSA results is not reported in the registry record. Nor is it stated how missing assessments, withdrawals, or participants without sufficient follow-up were handled. The endpoint description calls for regular PSA testing, but it does not establish that every participant completed those assessments.
The adverse-event summary is separate from the primary endpoint. It lists 1 participant affected by a serious adverse event among 74 at risk, 5 affected by other adverse events among 74 at risk, and 0 deaths. GU Bleeding is listed as a serious adverse event term at 1.4%. These figures describe the posted safety entries, but the registry does not provide additional context about event timing, duration, severity grading, attribution, or overlap between categories. They should not be used as a substitute for the unreported biochemical control result.
The completed status indicates that the trial is recorded as completed, not that all intended outcomes are present in the registry. The record lists 0 analyses. It does not provide a statistical plan, result estimates, or multiplicity procedures. Taken together, the registry supports a description of the question, design, endpoint definition, treatment schedules, and limited safety counts. It does not support a conclusion about the observed one-year biochemical control rate, its precision, or comparative benefit and harm.
9. Statistical Methods Explained
In general, a binary endpoint classifies each participant into one of two outcome states for the analysis, such as meeting or not meeting a specified criterion. The registry describes biochemical control in terms of control versus progression, with control encompassing complete, partial, or stable tumor status. A count of participants in each state can be used to estimate a proportion, provided the relevant denominator and the rules for classifying participants are clear. The registry labels the endpoint as a participant count, but does not post the observed counts or rate.
In general, the denominator is as important as the count of participants meeting an endpoint. The enrolled population, the treated population, and the population with an evaluable endpoint can differ. For a one-year outcome, a participant might lack an assessment at that time or have incomplete follow-up. The analysis would need to specify whether such a participant is excluded, classified in a particular way, or handled through another method. The record does not report the endpoint denominator or its approach to missing assessments, so neither the analyzed population nor the handling of incomplete follow-up can be determined.
In general, a confidence interval expresses the uncertainty around an estimate, taking account of the amount of information available and the method used. A point estimate alone can conceal substantial imprecision, especially when the number of observed outcomes is limited. The registry does not report a primary endpoint estimate or confidence interval, so there is no posted interval to interpret. The sample-size planning material cannot fill that gap: planning calculations describe hypothetical design performance under stated assumptions, not the precision of an observed result.
The registry describes a single-group design. In general, a single-group outcome rate can describe the observed experience of the participants included in an analysis. It does not isolate the effect of treatment from other explanations for the outcome, because there is no concurrent control group in the listed design. For comparative inference, random allocation can help balance measured and unmeasured factors on average; no randomized comparison is listed in this record. The absence of a comparator does not make a descriptive estimate meaningless, but it limits the questions that estimate can answer.
In general, the validity of an endpoint analysis also depends on a prespecified analysis population and consistent endpoint classification. An intention-to-treat approach, for example, generally analyzes participants according to their assigned groups, while a treated-population analysis uses participants who received treatment under a defined rule. Those approaches answer different questions. This record does not state an analysis population, and its single-group design does not describe a randomized assignment process. The analysis population is not reported in the registry record.
The endpoint definition refers to serial PSA measurements every 3 months and the Phoenix definition of biochemical recurrence, stated as nadir + 2 ng/ml. In general, operational definitions reduce ambiguity by specifying how an outcome is classified. Their application still depends on how measurements are collected and how cases with incomplete or irregular observations are handled. The registry does not explain those implementation details or provide participant-level trajectories, so the consistency of endpoint ascertainment cannot be evaluated from this record.
The record lists 2 outcome measures, including the primary biochemical control endpoint and the secondary Late Toxicity Rate, and 0 analyses. In general, when a study examines multiple outcomes, researchers should distinguish prespecified primary questions from secondary or exploratory questions and explain how multiple statistical tests are interpreted. The registry does not report multiplicity procedures, statistical tests, or an analysis plan. It is therefore not possible to determine whether any adjustment was planned or whether the posted outcomes were analyzed according to a prespecified hierarchy.
The accompanying sample-size framework is described as a planning illustration based on an observed effect, not as the trial's own design justification. Its stated assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those assumptions do not match the registry's single-group design as a description of the trial itself. A planning illustration under hypothetical two-arm assumptions should not be read as the actual allocation, the trial's original sample-size rationale, or observed power. No sample-size justification for the trial is reported in the registry record.
In general, over-dispersion matters when the observed variability exceeds what a chosen statistical model assumes; failing to account for it can make uncertainty appear too small. That concept is relevant only when the outcome model and data structure call for such a check. The record does not report a fitted model or analysis of the binary endpoint, and there is no basis in the registry to say that over-dispersion was assessed or was a concern. More broadly, the absence of analysis details means readers cannot evaluate model choice, assumptions, diagnostics, or sensitivity analyses for the primary endpoint.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists Biochemical Control Rate as the primary outcome and Late Toxicity Rate as a secondary outcome. It records 2 outcome measures and 0 analyses. It does not describe a hierarchy of hypotheses, a multiplicity adjustment, or a strategy for distinguishing confirmatory from exploratory findings. In general, testing several outcomes can increase the chance of a false-positive finding if each is treated as an independent confirmatory test without an appropriate plan. No conclusion about such testing can be drawn because the analyses and their results are not reported.
The endpoint is scheduled at one year, and the description refers to PSA testing every 3 months. The registry does not state how many participants had an evaluable one-year assessment, how missing PSA measurements were handled, or whether participants lost to follow-up were included in the endpoint analysis. Enrollment of 84 is not necessarily the denominator for the endpoint; the analyzed denominator is not reported in the registry record. No imputation method, censoring rule, sensitivity analysis, or missing-data assumption is described.
The record also does not identify an analysis population for the primary endpoint. It does not say whether outcome classification was based on all enrolled participants, participants who received SBRT, or those with sufficient follow-up. Without these details, readers cannot determine how missingness or exclusions may affect the endpoint estimate. The completed status and the presence of a defined outcome do not establish that all intended observations were collected or analyzed.
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 |
|---|---|---|---|
| Stereotactic Body Radiotherapy | 1 | 74 | 1.4% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Stereotactic Body Radiotherapy | 0 of 72 |
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 |
|---|---|
| Stereotactic Body Radiotherapy | 5 of 74 |
Most frequent serious adverse event terms
| Event term | Organ system | Stereotactic Body Radiotherapy |
|---|---|---|
| GU Bleeding | Renal and urinary disorders | 1 of 74 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Stereotactic Body Radiotherapy |
|---|---|---|
| Change in urinary frequency | Renal and urinary disorders | 4 of 74 |
| Impotence | Reproductive system and breast disorders | 1 of 74 |
| Dysuria | Renal and urinary disorders | 1 of 74 |
Serious events with the highest arm-level rate: gu bleeding (1.4%).
The registry lists the Stereotactic Body Radiotherapy group with 74 participants at risk for serious adverse events and 1 participant affected. It lists 74 at risk for other adverse events and 5 affected, with 0 deaths. GU Bleeding appears among the serious adverse event terms at 1.4%. These entries are the safety figures recorded for the group; they do not report a comparative safety estimate because no separate control group is listed.
In general, an at-risk count is the denominator used for interpreting the corresponding safety category, while an affected count describes participants recorded with an event. The record does not specify event timing, duration, severity grading beyond the serious classification, or attribution to treatment. It also does not state whether the serious and other adverse event categories overlap, or whether one participant could contribute to more than one term. The GU Bleeding percentage should be read as the registry's listed value, not as a basis for reconstructing unreported event details. These limited entries do not provide a complete account of safety monitoring or establish a treatment-related risk.
12. What the Result Does, and Does Not, Mean
The record establishes what the study set out to evaluate: one-year biochemical control after SBRT for organ-confined prostate cancer, alongside acute and late toxicity rates described in its summary. It also gives a biochemical recurrence definition, a PSA testing schedule, and treatment schedule ranges. Those details make the research question and intended endpoint understandable.
The record does not establish the observed biochemical control rate. It includes no reported primary outcome count, denominator, rate, confidence interval, or statistical analysis. Consequently, it is not possible to describe how often participants met the endpoint or how precisely that result was estimated. A completed trial status does not replace outcome reporting.
The single-group design also means the record cannot support a direct comparison of SBRT with another treatment. A descriptive outcome among treated participants, even if reported, would not by itself identify what would have happened to a comparable group under a different approach. This record supplies no control group and no comparative estimate. It therefore does not establish a causal treatment effect.
The safety entries offer limited counts: 1 participant affected by a serious adverse event among 74 at risk, 5 affected by other adverse events among 74 at risk, 0 deaths, and GU Bleeding listed at 1.4%. These data should be interpreted narrowly because the record does not report detailed event definitions, timing, attribution, or overlap. They do not show a comprehensive safety profile.
In general, a registry record is most useful for interpreting outcomes when it includes complete results, denominators, analysis methods, and missing-data handling. Several of those elements are not reported. The appropriate reading is therefore descriptive: the registry records a completed single-group study and defines its intended endpoint, but does not provide the primary endpoint result or enough analysis detail to support broader conclusions about efficacy, comparative effects, or precision.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of the distinction between a clear research question and a reportable result. The registry specifies a one-year biochemical control endpoint, a PSA monitoring schedule, and a rule for defining biochemical recurrence. Those elements define what the investigators intended to measure. They do not show the observed outcome or how uncertainty around it was assessed.
The design also makes the scope of inference important. A single-group study can describe outcomes among its participants, but a treatment comparison requires a credible comparator. The registry lists no separate control group, so readers should not interpret its design as a randomized comparison. This distinction remains important even when enrollment and treatment details are recorded.
Endpoint denominators and analysis populations are essential for binary outcomes. The enrolled count is not automatically the count with a complete one-year assessment. With no endpoint count, denominator, missing-data approach, or confidence interval, readers cannot assess the frequency or precision of biochemical control from this record. Reporting these components would make the outcome easier to evaluate and reproduce.
The safety entries illustrate a related issue: counts become more interpretable when the registry clarifies definitions, observation periods, severity, attribution, and whether categories overlap. The posted counts can be stated, but their context is limited. Overall, this record matters statistically because it shows how study design, endpoint definition, completeness of results, and limits on causal inference all shape what can responsibly be concluded.
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 primary limitation for interpreting the trial is that the registry record does not report the primary biochemical control result. Without an outcome count, analyzed denominator, rate, or uncertainty interval, the endpoint cannot be quantitatively interpreted. Although enrollment is recorded as 84, the number of participants assessed at one year is not reported in the registry record.
The single-group design has no listed comparator, and allocation is recorded as NA. No randomized comparison or control arm is described. Therefore, the record does not provide a direct estimate of how outcomes differ between SBRT and another approach. It also does not report enough information to assess how participant selection or other factors may relate to observed outcomes.
Important analysis details are absent. The registry does not report an analysis population, missing-data method, statistical test, confidence interval method, adjustment for multiplicity, interim analyses, or a statistical analysis plan. It does not state whether the PSA assessment schedule was completed consistently, how incomplete follow-up was handled, or how the endpoint components were classified in practice.
Intervention reporting is also limited to schedule ranges: 30 - 40 Gy in 4 - 5 fractions, with 19 - 21 Gy in 2 - 3 fractions for high risk patients who also receive external beam radiotherapy. The numbers receiving each schedule and treatment delivery details are not reported in the registry record. The safety summary gives limited counts but lacks details on event timing, grading, attribution, and overlap. These gaps constrain both outcome interpretation and assessment of how broadly the findings might apply.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Stereotactic Body Radiotherapy for Prostate Cancer — NCT01352598.
- Registry record last updated 2020-09-23; status last verified 2020-09.
- Results first posted 2020-09-23.
- 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
NCT01352598 is a completed, single-group study of stereotactic body radiotherapy for prostate cancer. The registry records enrollment of 84, no masking, and allocation listed as NA. The listed start is 2011-06 and primary completion is 2019-04. The primary outcome is Biochemical Control Rate at one year, using PSA testing and the Phoenix definition of biochemical recurrence. Late Toxicity Rate is listed as a secondary outcome.
The record describes SBRT schedules of 30 - 40 Gy in 4 - 5 fractions, and 19 - 21 Gy in 2 - 3 fractions for high risk patients who also receive external beam radiotherapy. It does not report the primary endpoint result or analysis details. Safety entries list 1 serious adverse event among 74 at risk, 5 other adverse events among 74 at risk, 0 deaths, and GU Bleeding at 1.4%. The registry supports description of the trial question and design, but not a conclusion about the observed biochemical control rate or comparative treatment effects.