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 Radiation Therapy in Treating Patients With Metastatic or Recurrent Kidney Cancer (NCT02542202), a na na study. The primary outcome is Number of Participants With Radiation Therapy (RT)-Related Grade >= 4 Toxicity.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02542202 |
| Phase | NA |
| Condition | Metastatic Renal Cell Cancer, Recurrent Renal Cell Carcinoma, Stage IV Renal Cell Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 25 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Chicago |
| Results posted | Yes |
2. Clinical Question
Population
Patients with metastatic or recurrent renal cell cancer were the intended population. The registry describes the study as a pilot in oligometastatic renal cell carcinoma and lists metastatic, recurrent, and stage IV renal cell cancer among its conditions. Eligibility details beyond those descriptions are not reported in the registry record.
Intervention
The intervention was stereotactic body radiation therapy (SBRT), a form of focused radiation. The registry describes treatment as occurring on day 1 and then 3 times a week for 28 days, in the absence of disease progression or unacceptable toxicity. The precise delivered schedule for individual participants is not reported in the registry record.
Comparator
There was no separate comparator group. The study used a single-group design, so its safety observations are not a randomized or like-for-like comparison against another treatment or a control condition. A comparator arm is not reported in the registry record.
Primary question
The primary endpoint asks how many participants had radiation therapy-related grade >= 4 toxicity, assessed up to 1 year. The registry says the study group would judge whether toxicity was related to radiation on a case-by-case basis, considering the treated region, timing, and nature of the event. The primary endpoint result is not reported in the registry record.
The study is registered as a pilot examining side effects and dose of SBRT in patients whose kidney cancer had spread or returned. Its stated primary question is about severe radiation-related toxicity, rather than a direct comparison of tumor response or survival between treatment strategies. The registry also names treated lesion control, progression-free survival, and toxicity according to normal-tissue dosimetric constraints as secondary outcomes.
The registry lists enrollment as 25, but does not report the primary endpoint result or analysis population. The posted adverse-event record separately lists 15 participants at risk in the SBRT group. Those are different registry entries and should not be treated as interchangeable measures of the study population. The record does not explain the relationship between these counts.
Because there is no control group, the study can describe outcomes observed among participants represented in its record but cannot, by design, estimate a randomized treatment contrast. The single-group structure also limits what can be concluded about whether outcomes reflect SBRT rather than patient characteristics, disease course, or other care. Details needed to determine which participants were eligible, treated, followed, or included in each analysis are not reported in the registry record.
3. Trial Design
NCT02542202 is listed as a single-group pilot study of SBRT in oligometastatic renal cell carcinoma. The registry identifies the sponsor as the University of Chicago and lists the study status as terminated. The phase is recorded as NA. Allocation is also recorded as NA, and masking is listed as none. A randomized allocation procedure or a masked assessment process is not reported in the registry record.
The registry records enrollment as 25. The recorded start date is 2015-05-01, and the primary completion date is 2023-03-23. These are registry entries; the record does not provide a fuller account of recruitment, treatment completion, follow-up, or the circumstances of termination. The reason for termination is not reported in the registry record.
The intervention is stereotactic body radiation therapy. The treatment description says patients undergo SBRT on day 1 over 3 times a week for 28 days, provided there is no disease progression or unacceptable toxicity. The record does not provide participant-level treatment details, such as the radiation dose actually received, the number completing treatment, or the number who stopped early.
The primary endpoint is the number of participants with radiation therapy-related grade >= 4 toxicity, with a timeframe of up to 1 year. The registry describes case-by-case attribution by the study group and says rates, time to toxicity, and freedom from toxicity would be recorded or determined using the Kaplan-Meier method. Secondary outcomes include treated lesion control, progression-free survival, and a toxicity profile based on normal-tissue dosimetric constraints by organ site.
The registry lists 4 outcome measures but 0 analyses. No posted primary outcome analysis is included in the record represented by these results. It is therefore not possible to assess the stated primary endpoint from a reported estimate, confidence interval, or analysis output. The study has no control arm, so there is no between-group treatment comparison to interpret. The record does not report the protocol’s sample-size justification, a detailed statistical analysis plan, or the analysis populations.
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 Radiation Therapy |
|---|---|
| STARTED | 15 |
| COMPLETED | 15 |
| 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 | Stereotactic Body Radiation Therapy |
|---|---|---|
| Participants analysed | 15 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 4 |
| Age, Categorical: >=65 years | Participants | 11 |
| Age, Continuous | years | 67.9 (SD 10.5) |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 10 |
| 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 | 1 |
| Race (NIH/OMB): White | Participants | 12 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 15 |
| Number of Baseline Lesions | number of lesions | 1 (1 to 4) |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Radiation Therapy (RT)-Related Grade >= 4 Toxicity, measured over Up to 1 year.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with radiation therapy-related grade >= 4 toxicity, assessed up to 1 year. It is a count-based safety outcome: it is intended to capture participants who experience toxicity meeting the stated severity threshold and judged related to radiation therapy. It is not a measure of tumor control or a direct estimate of comparative treatment benefit.
Attribution is not described as automatic. The registry says the study group determines whether toxicity is related to RT on a case-by-case basis, taking account of the region treated with SBRT, when the event occurred, and the nature of the toxicity. That approach makes clinical judgment part of the endpoint definition. The registry does not report adjudication procedures, whether reviewers were independent, or how disagreements would be handled.
The record says rates and time to RT-related grade >= 4 toxicity would be recorded, and freedom from such toxicity would be determined using the Kaplan-Meier method. In general, a time-to-event method uses both whether an event occurred and the time until it occurred, while accounting for participants whose event status is not observed through the full follow-up period under the method’s assumptions. The endpoint description does not provide the detailed censoring rules.
The primary endpoint result is not reported in the registry record. Without a posted count, rate, time-to-event estimate, or uncertainty interval, the endpoint cannot be quantified from this record. The adverse-event counts are separate registry entries and do not substitute for the specified primary result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record gives the study’s intended safety question but does not give a result for its primary endpoint. In particular, it does not report the number of participants with RT-related grade >= 4 toxicity, an estimated rate, a time-to-event result, or a confidence interval for that endpoint. The primary endpoint therefore cannot be interpreted as evidence for a particular frequency or timing of severe radiation-related toxicity.
The adverse-event entry for the SBRT group lists 15 participants at risk for serious adverse events and 0 with a serious adverse event. It also lists 15 participants at risk for other adverse events and 0 with another adverse event, alongside 3 deaths. These entries are descriptive counts in the registry record. The record does not say that the deaths were caused by SBRT, were related to the cancer, or were unrelated to treatment. It also does not explain how the adverse-event entries relate to the recorded enrollment of 25.
A zero count in a registry field does not by itself establish that the event could not occur or that the risk is zero. The precision of an estimate depends on details including the number followed, duration and completeness of follow-up, event definitions, and how missing observations were handled. Those details are not reported in the registry record for these adverse-event counts. Without an interval estimate and fuller follow-up information, the counts alone do not show how precisely the underlying event frequency is known.
The single-group design is central to interpretation. Observed outcomes in a single group cannot be contrasted with an independently assigned control group, so they do not isolate the effect of SBRT from other explanations. The posted adverse-event counts should not be read as a comparative safety estimate or as proof that treatment caused or prevented an event. The primary endpoint itself calls for a study-group judgment of radiation relatedness, but the result of that assessment is not reported.
The registry lists secondary outcomes, including treated lesion control and progression-free survival, but does not post analyses for them in this record. Consequently, the record does not support conclusions about tumor control or progression-free survival. The listed enrollment, termination status, and dates describe the study record; they do not resolve the missing outcome information. Overall, the posted information is insufficient to quantify the primary safety outcome or to make a comparative treatment claim.
9. Statistical Methods Explained
The study design determines which statistical questions can be answered. This is a single-group study, not a randomized comparison. A single-group design can describe event counts or follow-up outcomes among participants represented in the data, but it cannot estimate a randomized difference between SBRT and a control treatment. Differences from outcomes in other populations or studies would not provide the same protection against confounding as a concurrent randomized comparison.
What does a count-based endpoint represent?
The primary endpoint is defined as a number of participants with RT-related grade >= 4 toxicity. A count records how many participants meet the event definition; it is not automatically a rate or a probability. To interpret a count as a frequency, the relevant population and observation period must be clear. The registry gives a timeframe of up to 1 year, but does not post the primary count, the corresponding analysis population, or a rate estimate.
In general, an interval estimate communicates uncertainty around an estimated quantity. A narrow interval indicates greater precision under the method’s assumptions, while a wide interval indicates less precision. The registry record does not include an interval for the primary endpoint. Without an estimate and its uncertainty, readers cannot judge the precision of a primary endpoint result from this record.
How does the time-to-event method fit the endpoint?
The endpoint description names the Kaplan-Meier method for determining freedom from RT-related grade >= 4 toxicity. In general, Kaplan-Meier methods use the observed timing of events and account for participants whose follow-up ends before an event is observed. Such participants are typically treated as censored at the point their outcome is no longer observed; the method relies on assumptions about censoring and the available follow-up. The registry does not report the detailed censoring rules, the number of events, an estimate of freedom from toxicity, or an uncertainty interval.
Time-to-event analysis can add information beyond a simple event count because timing matters. However, an analysis requires adequate information about when participants entered observation, when events occurred, and when follow-up ended. Those participant-level details and the analysis output are not reported in the registry record. The method named in the endpoint description should not be mistaken for a reported result.
What do the adverse-event counts say?
The safety record lists 0 serious adverse events and 0 other adverse events among 15 at risk in each corresponding entry, as well as 3 deaths. These are posted counts, not a comparative statistical test. No uncertainty estimates, event timing, or participant-level details accompany them in the registry record. A zero observed count can occur even when the true event frequency is not known precisely, especially when the amount and completeness of follow-up are unclear. The death count is recorded separately, and attribution is not reported.
How should planning illustrations be read?
Sample-size illustrations are planning calculations, not observed trial results. The stated assumptions for those illustrations are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. The illustrations use participants per arm for non-time-to-event outcomes and total events for time-to-event outcomes. Those assumptions do not describe the actual single-group study design, which has no two-arm randomized comparison.
In general, a planning calculation asks how much information a hypothetical design might require to detect an assumed effect under stated statistical assumptions. It is not observed power and does not establish that the study had adequate power. The registry does not report a sample-size justification for the actual study. The primary endpoint result and its observed effect are not reported in the registry record, so the illustrations should not be treated as a way to recover the missing result.
What is not available for evaluating the analyses?
The registry records 4 outcome measures and 0 analyses. It does not report a detailed analysis plan, the analysis populations, handling of missing outcomes, or a multiplicity strategy for the primary and secondary outcomes. Those omissions constrain assessment of whether an analysis followed prespecified methods, how much data contributed to an outcome, and how uncertainty should be interpreted. The method description is useful for understanding the intended primary endpoint, but it does not replace the missing results and analysis details.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary toxicity endpoint and secondary outcomes for treated lesion control, progression-free survival, and toxicity according to normal-tissue dosimetric constraints. When a study examines multiple outcomes, multiplicity can arise because repeated statistical testing increases the chance of finding at least one apparently notable result by chance. In general, a prespecified strategy may address that issue, for example by prioritizing outcomes or adjusting interpretation across tests. A multiplicity strategy is not reported in the registry record.
The registry records 4 outcome measures and 0 analyses. It does not post results for the primary or secondary outcomes in this record. Without analysis outputs, there are no reported estimates or tests whose multiplicity-adjusted interpretation can be evaluated. The record also does not report whether analyses were prespecified, whether any outcome definitions changed, or whether additional analyses were conducted.
Missing-data methods and analysis populations are also not reported in the registry record. It is not stated how participants who did not complete treatment or follow-up were handled, whether all enrolled participants were included in each outcome analysis, or what rules were used for incomplete event information. The listed enrollment of 25 and the adverse-event entry’s 15 participants at risk are distinct registry entries; the record does not explain their relationship. They should not be combined to infer an analysis denominator or follow-up completeness.
For a time-to-event endpoint, general practice requires rules for censoring and a clear account of follow-up. The endpoint description names Kaplan-Meier estimation but does not provide those operational details. These gaps limit reproducibility and make it difficult to determine how representative the posted counts are of the intended study population.
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 Radiation Therapy | 0 | 15 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Stereotactic Body Radiation Therapy | 3 of 15 |
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 Radiation Therapy | 0 of 15 |
The registry’s adverse-event entry for the SBRT group lists 15 participants at risk for serious adverse events and 0 participants with a serious adverse event. It also lists 15 at risk for other adverse events and 0 participants with another adverse event. The same entry records 3 deaths. These are the posted counts; the registry record does not give event rates, confidence intervals, event timing, or additional detail about the events.
The death count should be kept separate from the adverse-event counts. The registry record does not state whether the deaths were related to SBRT, the cancer, another condition, or another cause. It would not be justified to attribute them to treatment or to assume they were unrelated.
The adverse-event counts also do not replace the primary endpoint. The primary endpoint specifically concerns RT-related grade >= 4 toxicity and requires case-by-case attribution by the study group. That endpoint result is not reported in the registry record. A zero count in the serious or other adverse-event fields does not establish that the risk is zero; interpretation depends on follow-up, event definitions, and completeness of outcome ascertainment, details not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The record establishes that a pilot study was registered to examine SBRT in oligometastatic renal cell carcinoma and that its primary safety endpoint concerned RT-related grade >= 4 toxicity. It also records the study as terminated and lists adverse-event counts for the SBRT group. These details describe the study and the registry entries, but they do not provide the missing primary endpoint estimate.
The serious and other adverse-event fields each show 0 events among 15 participants at risk, while 3 deaths are listed separately. These counts do not establish a zero underlying risk, and the record does not attribute the deaths. Without event timing, complete follow-up information, and uncertainty estimates, it is not possible to judge the precision of the safety counts. The record also does not explain how these at-risk counts relate to the enrollment entry of 25.
The single-group design does not provide a randomized comparison. Therefore, outcomes in the SBRT group cannot establish how those outcomes would differ under another treatment or no treatment. Nor can the record establish a treatment effect on lesion control or progression-free survival: those outcomes appear among the listed secondary measures, but analyses are not posted.
These limitations do not mean that the study had no value. A pilot can inform how an intervention is studied and what outcomes are tracked. However, the available registry record does not permit a quantitative conclusion about the primary safety endpoint, a comparative safety conclusion, or a claim about efficacy. The appropriate interpretation is limited to the registered design and the descriptive counts actually posted, with substantial uncertainty about the unreported results and analysis details.
13. Why This Trial Matters Statistically
This trial matters statistically because its question is clinically specific while its design and posted results sharply limit what can be concluded. A clearly defined primary endpoint focused on RT-related grade >= 4 toxicity gives the study a stated safety target. The endpoint description also makes clear that attribution depends on a study-group judgment considering the treated region, timing, and nature of toxicity. Those features matter when interpreting safety outcomes: an event count depends not only on observation but also on how the endpoint is defined and assigned.
The single-group design is equally important. It can describe outcomes among participants represented in the study, but it cannot provide the randomized contrast needed to separate treatment effects from other influences. This is not a defect that can be repaired by interpreting a count as a comparison. It defines the scope of inference available from the design.
The record also illustrates why outcome registration and outcome reporting are not the same thing. The registry names a primary endpoint, secondary outcomes, and a method for time-to-event estimation, yet records 0 analyses and does not post the primary endpoint result. The adverse-event counts offer limited descriptive information, but they do not answer the specified primary question or convey precision.
Finally, the record’s enrollment and at-risk entries are not explained in relation to one another, and the study is listed as terminated without a reported reason. Those gaps make transparency about analysis populations, follow-up, and missing data especially important. The statistical lesson is that a design, an endpoint definition, and a few event counts are not substitutes for complete results and methods. Clear estimates, uncertainty, denominators, and analysis details are essential to judge what a study can support.
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 are specific to this registry record. First, the primary endpoint result is not reported, even though the endpoint is described in detail and has a timeframe of up to 1 year. The record therefore does not provide the key count or time-to-event estimate needed to answer its stated primary safety question.
Second, the study is a single-group design with no comparator. Its observed outcomes cannot support a randomized estimate of how SBRT compares with another approach. The record does not report randomization or masking, and none should be inferred from the study description.
Third, the recorded enrollment is 25, while the adverse-event entry lists 15 at risk in each adverse-event category. The record does not explain the relationship between these entries. It also does not report how many participants received treatment, completed treatment, remained under observation, or contributed to each outcome analysis. These gaps prevent assessment of denominators and follow-up completeness.
Fourth, the study is listed as terminated, but the reason for termination is not reported in the registry record. The record does not report a detailed statistical analysis plan, the analysis populations, missing-data procedures, multiplicity handling, or detailed time-to-event censoring rules. The method named for the primary endpoint is not accompanied by an analysis result.
Finally, the posted adverse-event counts lack uncertainty estimates and event-level context, and the deaths are not attributed. Together, these limitations mean that the registry record supports only cautious description of the recorded design and counts, not a complete assessment of safety or treatment effect.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Stereotactic Body Radiation Therapy in Treating Patients With Metastatic or Recurrent Kidney Cancer — NCT02542202.
- Registry record last updated 2024-05-30; status last verified 2024-05.
- Results first posted 2024-05-30.
- 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
NCT02542202 is a terminated, single-group pilot study of stereotactic body radiation therapy in oligometastatic renal cell carcinoma, sponsored by the University of Chicago. The registry lists enrollment as 25, a start date of 2015-05-01, and a primary completion date of 2023-03-23. Phase and allocation are recorded as NA; masking is listed as none.
The primary endpoint is the number of participants with RT-related grade >= 4 toxicity up to 1 year, with case-by-case attribution and Kaplan-Meier estimation described. The primary result is not reported in the registry record. The adverse-event entry lists 0 serious adverse events and 0 other adverse events among 15 at risk for each category, and 3 deaths, without attribution or uncertainty estimates. The record lists 4 outcome measures and 0 analyses. It does not report the reason for termination, analysis populations, missing-data procedures, or a detailed statistical analysis plan.