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 Novel Optical Surface Image Guidance System for Beam-Gated Online Adaptive SBRT Delivery in Mobile Lower Lung and Upper Abdominal Malignancies (NCT05030454), a na na study. The primary outcome is Percentage of Scheduled Treatment Fractions Delivered Successfully Using the Surface Guidance System.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05030454 |
| Phase | NA |
| Condition | Any Solid Malignancies of Any Tissue Origin (Except for Small Cell Lung Cancer) Involving the Upper Abdomen and Thorax |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 10 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Washington University School of Medicine |
| Results posted | Yes |
2. Clinical Question
Population
People with solid malignancies of any tissue origin, except small cell lung cancer, involving the upper abdomen and thorax. The registry record lists an enrollment of 10.
Intervention
CT-guided stereotactic adaptive radiotherapy using ETHOS, with a novel optical surface-guidance system for beam gating during treatment delivery.
Comparator
There is no separate comparator group. The record describes a single-group study and does not list a randomized or like-for-like control comparison.
Primary question
What percentage of scheduled treatment fractions can be delivered successfully using the surface-guidance system, under the registry’s definition of success?
The clinical problem addressed is motion during radiation therapy. The study description distinguishes changes between treatment days from motion during the treatment-delivery window. Adaptive radiotherapy is intended to manage changes between fractions, while gating and related delivery approaches address motion during treatment. This pilot focuses on using surface guidance for intra-fraction gating alongside a cone-beam CT-guided adaptive radiotherapy platform.
The primary endpoint considers whether a scheduled fraction can be completed in one on-table attempt without switching to a backup motion-management system or another treatment machine. A fraction that cannot be delivered with reproducible positioning, breath-hold, or surface-guidance feedback and is abandoned is classified as unsuccessful. The endpoint therefore addresses operational feasibility as defined in the registry, rather than a comparison of tumor response or another clinical outcome.
The registry record does not report how many fractions met this definition. It also does not report a numerical estimate of the primary endpoint or its precision. Accordingly, the clinical question can be described, but the posted record does not establish the observed level of feasibility.
3. Trial Design
This is a completed, single-group pilot study sponsored by Washington University School of Medicine. The registry lists an enrollment of 10 and a phase of NA. Allocation is listed as NA, masking as none, and the model as single group. These design features mean the record does not describe a randomized comparison or a masked assessment against a control arm.
The intervention combines ETHOS with CT-guided stereotactic adaptive radiotherapy. The study description identifies a cone-beam CT platform for imaging target and organ-at-risk positions, an adaptive planning system, and an optical surface image-guidance system intended to manage motion during delivery. The particular feasibility question concerns using the surface system to gate the beam during treatment for mobile lower-lung and upper-abdominal malignancies.
The radiotherapy regimen is described as five fractions, delivered once daily or once every other day over one to two weeks. The primary endpoint timeframe is through completion of treatment, estimated to be two weeks. The registry lists the study as completed, with a start date of 2021-10-19 and primary completion date of 2022-03-17.
The endpoint is a fraction-level measure, while the listed enrollment is participant-level. The registry record does not report the total number of scheduled fractions contributing to the endpoint, the number successfully delivered, or how any repeated fractions or participants with incomplete treatment were handled in the analysis. It lists one outcome measure and zero analyses.
Because there is no separate comparator group, the design can describe experience with the system under the study conditions but cannot provide a like-for-like estimate of how outcomes would differ under another motion-management approach. The registry record does not report a sample-size justification or further details of the statistical analysis plan. The posted record therefore supports an account of the design and endpoint definition, but not a conclusion about the observed success rate.
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 | CT-guided Stereotactic Adaptive Radiotherapy |
|---|---|
| STARTED | 10 |
| COMPLETED | 10 |
| 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 | CT-guided Stereotactic Adaptive Radiotherapy |
|---|---|---|
| Participants analysed | 10 | |
| Age, Continuous | years | 72 (40 to 86) |
| Sex: Female, Male: Female | Participants | 7 |
| Sex: Female, Male: Male | Participants | 3 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 10 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 1 |
| 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 | 8 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 10 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Scheduled Treatment Fractions Delivered Successfully Using the Surface Guidance System, measured over Through completion of treatment (estimated to be 2 weeks).
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of treatment fractions |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the percentage of scheduled treatment fractions delivered successfully using the surface-guidance system, assessed through completion of treatment. The registry defines success as completing a given fraction in one on-table attempt without needing a secondary motion-management system or an alternative treatment machine. Failure includes repeated gating attempts without reproducible positioning, breath-hold, and/or surface-guidance feedback, leading to abandonment of that fraction.
This endpoint is used to assess operational feasibility: whether the proposed system can support delivery under the stated conditions. It captures more than whether the beam was gated; it incorporates whether the fraction could be completed as planned without recourse to the listed alternatives. Because the measure is based on fractions, a participant receiving multiple fractions may contribute more than one fraction to the overall endpoint. The registry record does not report the method used to account for that repeated contribution or the number of fractions included.
A percentage is a proportion expressed on a percentage scale. To interpret it, readers need both the observed number of successful fractions and the total number of scheduled fractions evaluated, as well as an understanding of how uncertainty was assessed. The registry record gives the endpoint definition but does not report the observed percentage, its numerator and denominator, or an interval estimate. The posted results therefore do not allow the degree of precision in the feasibility estimate to be assessed.
This endpoint is not a direct measure of tumor control, survival, or comparative effectiveness. Nor does a fraction-level success definition by itself summarize all aspects of safety or treatment experience. Those questions require distinct outcome information, and the registry record does not report a primary endpoint result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a pilot evaluation of surface-guided beam gating during CT-guided adaptive stereotactic radiotherapy. Its primary outcome is a treatment-delivery feasibility measure: the percentage of scheduled fractions completed in one on-table attempt without a backup motion-management system or alternative machine. That definition is clear enough to identify the intended operational question, but the record does not report the measured percentage.
Without the number of successful fractions and the number assessed, readers cannot determine the observed rate or its uncertainty. No confidence interval or other precision estimate for the primary endpoint is reported in the registry record. A confidence interval, in general, represents a range of values compatible with the observed data under a specified statistical procedure. It helps distinguish a precise estimate from one that remains uncertain. Here, the registry record supplies no primary result from which to interpret such precision.
The enrollment of 10 identifies the planned or recorded participant total, but it is not the denominator for the fraction-level endpoint. The regimen is described as five fractions per participant, yet the total number of scheduled fractions actually assessed is not reported. It would therefore be inappropriate to infer an endpoint denominator from the treatment schedule. The record also does not explain whether all enrolled participants completed treatment or how incomplete observations were handled.
The single-group design is suitable for describing experience with the system in the enrolled cohort, but it does not provide a control-group estimate. Any observed fraction-success percentage, if reported elsewhere, would describe performance in this study setting; it would not by itself quantify a difference from a backup system, another machine, or another treatment strategy. The registry record does not report such a comparative analysis.
The serious and other adverse-event fields provide limited safety information: the group lists 10 at risk for each category, 1 affected by a serious adverse event, 2 affected by other adverse events, and 0 deaths. Sepsis is listed among the serious adverse-event terms at 10.0%. These entries should be read as the registry’s reported safety counts, not as a complete characterization of the treatment’s safety profile. The record does not provide enough detail to connect these events to particular fractions or to interpret their causes.
Overall, the posted record documents the study question, intervention, endpoint definition, and some safety counts, but it does not provide the primary feasibility result or an inferential analysis. The absence of a reported result is not evidence that the system succeeded or failed. It means the central endpoint cannot be interpreted from this registry record alone.
9. Statistical Methods Explained
What does a fraction-level percentage represent?
In general, a percentage for this endpoint is formed by relating the number of fractions meeting the success definition to the number of scheduled fractions evaluated. The fraction is the unit specified in the primary outcome, not the participant. That distinction matters when each participant is scheduled to receive multiple fractions: a fraction-level percentage describes delivery opportunities, while a participant-level summary would describe people. The registry record does not report the endpoint numerator, denominator, or the procedure for accounting for multiple fractions from the same participant.
A fraction-level percentage can be useful for operational feasibility because the question is whether individual treatment sessions can be completed under the system’s stated conditions. However, fractions from the same person may not be statistically independent: they share participant and treatment-context characteristics. General statistical methods for repeated observations can account for such clustering, but the registry record does not report whether any such method was used. Without the analysis details and the number of fractions evaluated, the precision of the estimate cannot be assessed.
Why does precision matter?
In general, a point estimate alone does not show how much uncertainty surrounds it. A confidence interval communicates that uncertainty by giving a range of values compatible with the observed data under a specified method. The width depends on factors such as the amount of information and the statistical model. For a proportion based on a small cohort, uncertainty may remain substantial even when the observed proportion appears high or low. No primary endpoint estimate or confidence interval is reported in the registry record, so readers cannot judge precision for this study.
Different interval methods can behave differently, particularly when sample sizes are limited or proportions lie near the boundaries of their possible range. The method should therefore be stated rather than assumed. The registry record does not report an interval method for the primary outcome.
What can a single-group study estimate?
In general, a single-group study can describe outcomes observed under the intervention and study procedures. It cannot isolate a treatment contrast against a concurrent control group when no comparator is included. A comparison with historical experience would require an identified external source and suitable assumptions; neither is described in the registry record. The study is listed as single group, with allocation NA and masking none, and the record explicitly identifies no like-for-like control comparison.
The absence of a control does not prevent descriptive feasibility assessment. It does limit claims about how delivery would compare with another system or approach. Even if a successful-delivery percentage were available, it would answer the defined operational question for the observed study experience, rather than establish comparative performance.
How should planning illustrations be read?
General power calculations are prospective planning tools: they describe the sample size that might be needed under chosen assumptions to detect a specified effect with a chosen error rate. They are not a summary of the evidence collected and are not “observed power.” The registry record identifies a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect set as a stated fraction of the observed effect. It also specifies that non-time-to-event illustrations express participants per arm.
Those assumptions describe an illustration, not the design of this trial. This study is listed as single group, not as a two-arm trial, and the registry record does not report the primary endpoint result needed to evaluate an observed effect for this outcome. The illustration should therefore not be interpreted as the trial’s own sample-size justification, as evidence that the study had a particular power, or as a substitute for a reported outcome analysis. The registry record does not report the study’s sample-size justification.
Why can over-dispersion matter?
In general, a simple binomial model assumes that each observation follows the same success probability and that observations are independent. If outcomes vary more than that model allows, the data are over-dispersed relative to the model. Treating clustered or heterogeneous observations as independent can understate uncertainty. Methods that account for extra variation or within-participant clustering may be considered when appropriate, but their suitability depends on the data and analysis objective. The registry record does not report an approach to over-dispersion or clustering.
For this trial, interpreting any fraction-level result would require knowing how repeated fractions were analyzed and how uncertainty was calculated. Neither is reported in the registry record. No statistical significance test, adjusted analysis, or confidence interval for the primary outcome is reported.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary outcome measure and zero analyses. It does not report a statistical analysis plan specifying how the primary endpoint would be analyzed, what summary estimate would be presented, or how uncertainty would be quantified. It also does not report secondary outcome analyses or a strategy for handling multiple tests. With no reported inferential analyses, there is no reported multiplicity adjustment to interpret.
In general, multiplicity arises when several outcomes, time points, subgroups, or comparisons are tested. Repeated testing can increase the chance of at least one apparently unusual result, so a plan may specify which outcome is primary and how additional tests will be handled. The registry identifies one primary measure, but it does not report whether any additional analyses were planned or conducted. The record’s zero analyses entry should not be taken to establish that no analyses occurred outside the registry; it means analysis results are not reported in the registry record.
The record does not report how missing or incomplete fraction data were handled. It does not state whether all scheduled fractions were included, whether any fractions were excluded, or how a participant who did not complete the treatment schedule would contribute to the endpoint. These details matter because the outcome is defined as a percentage of scheduled fractions, and the denominator can affect the estimate.
Analysis populations are also not described. The registry does not state whether the primary analysis included every enrolled participant, only those who began treatment, or another defined group. Nor does it report whether the unit of analysis was the fraction, participant, or both. These omissions prevent assessment of how exclusions, missing observations, and repeated fractions may influence the primary result. No missing-data assumptions or sensitivity analyses are reported in the registry record.
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 |
|---|---|---|---|
| CT-guided Stereotactic Adaptive Radiotherapy | 1 | 10 | 10.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| CT-guided Stereotactic Adaptive Radiotherapy | 0 of 10 |
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 |
|---|---|
| CT-guided Stereotactic Adaptive Radiotherapy | 2 of 10 |
Most frequent serious adverse event terms
| Event term | Organ system | CT-guided Stereotactic Adaptive Radiotherapy |
|---|---|---|
| Sepsis | Infections and infestations | 1 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | CT-guided Stereotactic Adaptive Radiotherapy |
|---|---|---|
| Anorexia | Metabolism and nutrition disorders | 1 of 10 |
| Epigastric pain radiating to the back | Gastrointestinal disorders | 1 of 10 |
| Generalized muscle weakness | Musculoskeletal and connective tissue disorders | 1 of 10 |
| Diarrhea | Gastrointestinal disorders | 1 of 10 |
| Nausea | Gastrointestinal disorders | 1 of 10 |
| Body aches | General disorders | 1 of 10 |
| Syncope | Nervous system disorders | 1 of 10 |
Serious events with the highest arm-level rate: sepsis (10.0%).
The registry lists one treatment group, CT-guided Stereotactic Adaptive Radiotherapy, with 10 at risk for serious adverse events and 1 affected. For other adverse events, it lists 10 at risk and 2 affected. The death count is 0. Sepsis appears among the serious adverse-event terms with a reported value of 10.0%.
These are descriptive entries in the registry record. They do not by themselves establish whether an event was caused by the intervention, how severe or long-lasting it was, when it occurred, or whether it occurred in a participant who also experienced another event. The record does not provide detailed event narratives or a causal assessment. The serious-event term and its percentage should therefore be read as a reported safety entry, not as a complete clinical account.
Safety counts and the primary feasibility endpoint answer different questions. The adverse-event fields concern reported events among the group, whereas the primary outcome concerns successful delivery of scheduled treatment fractions. The registry record does not report the primary endpoint result, and the adverse-event counts cannot fill that gap. These limited safety figures also do not support a broad conclusion about safety beyond the information recorded.
12. What the Result Does, and Does Not, Mean
The record establishes that the investigators set out to evaluate the feasibility and safety of a novel surface-guidance beam-gating system integrated with CT-guided adaptive radiotherapy for respiratory motion management. It defines a successful fraction as one completed in a single on-table attempt without a backup motion-management system or alternative machine. That operational definition makes the intended primary question understandable.
The registry record does not report the number or percentage of fractions that met the definition. It does not report a confidence interval, other uncertainty measure, or analysis result for the primary endpoint. Consequently, the posted information cannot show how often delivery succeeded, how variable the experience was, or how precisely feasibility was estimated. The absence of a result should not be interpreted as either success or failure.
The single-group pilot design can provide descriptive experience in the enrolled cohort, if the outcome data are reported. It cannot establish a comparative advantage or disadvantage against a control group that is not part of the design. The record also does not report a comparison with another motion-management strategy. The study question is about delivery feasibility, not a direct test of tumor control, survival, or other clinical benefit.
The safety fields report adverse-event counts and a serious adverse-event term, but do not supply enough detail for a comprehensive safety assessment. Nor do those counts establish a causal relationship. The registry record does not report event-level context or an analysis relating safety events to treatment delivery.
In general, pilot studies can inform whether a procedure is workable and help identify what needs to be measured in later research. Such interpretation depends on clear outcome reporting, denominators, and uncertainty estimates. Here, the record describes the feasibility definition and treatment schedule but does not report the primary result or the methods needed to assess its precision. The most defensible interpretation is therefore limited to the study’s stated aim and design, rather than a claim about the performance or clinical effects of the system.
13. Why This Trial Matters Statistically
This trial raises a statistical issue that is easy to overlook: the primary outcome is measured across treatment fractions, while enrollment is counted across participants. Those are different units. Because the treatment plan describes multiple fractions for each participant, the analysis needs to make clear how repeated observations contribute and how their dependence is handled. The registry record does not report those details.
The endpoint also combines technical and procedural requirements. A fraction counts as successful only when it is completed in one on-table attempt without the specified fallback systems. That definition creates a concrete feasibility measure, but interpretation depends on a clear denominator and on knowing how abandoned or incomplete fractions were counted. The registry record does not report the observed fraction counts or the analysis rules.
Precision is especially important in a pilot with an enrollment of 10. In general, small studies can produce estimates with substantial uncertainty, and a point estimate alone may not convey that uncertainty. A confidence interval and transparent account of the analysis population would help readers judge how much the observed rate could vary. Neither the primary estimate nor its uncertainty is reported in the registry record.
The single-group design also clarifies the limits of the statistical question. It can describe the study’s experience with the system, but cannot provide a randomized or concurrent comparison with another approach. The record lists no like-for-like control comparison. Any planning calculation based on two-arm assumptions is an illustration rather than a description of this single-group design or evidence of observed power.
These features matter because feasibility results can guide further study only when the outcome, denominator, and uncertainty are transparent. The registry record gives the operational definition and broad treatment schedule, but its missing primary result prevents readers from evaluating the observed performance statistically.
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 most consequential limitation in interpreting the registry record is that it does not report the primary endpoint result. Although the success and failure definitions are described, the number of scheduled fractions evaluated, successful fractions, and resulting percentage are not reported. No interval estimate is reported either, so the precision of any feasibility estimate cannot be assessed.
The registry lists enrollment of 10 and describes a five-fraction treatment schedule, but does not report the number of participants who completed treatment or the number of fractions included in the endpoint analysis. The participant count cannot be substituted for the fraction denominator. The record also does not describe how incomplete, abandoned, or otherwise unevaluable fractions were handled.
The analysis details are limited. The registry lists one outcome measure and zero analyses, and does not report an analysis population, method for repeated fractions, treatment of clustering, or approach to missing data. It does not report whether confidence intervals, hypothesis tests, or sensitivity analyses were planned or performed. These omissions limit assessment of both the numerical result and the robustness of any estimate.
The single-group design has no like-for-like control comparison, so it cannot estimate a comparative effect against another motion-management system. Masking is listed as none, and the registry does not describe an independent outcome assessment. The record also does not report a sample-size justification for the trial.
Finally, the safety record is limited to aggregate counts and a serious-event term. It does not include detailed event descriptions, timing, or causal interpretation. These limitations are specific to what the registry record reports and do not establish what may or may not have been assessed outside that record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Novel Optical Surface Image Guidance System for Beam-Gated Online Adaptive SBRT Delivery in Mobile Lower Lung and Upper Abdominal Malignancies — NCT05030454.
- Registry record last updated 2023-04-18; status last verified 2023-03.
- Results first posted 2023-04-18.
- 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
NCT05030454 is a completed, single-group pilot study sponsored by Washington University School of Medicine. It evaluates ETHOS and CT-guided stereotactic adaptive radiotherapy with surface-guidance beam gating for mobile lower-lung and upper-abdominal malignancies. The registry lists an enrollment of 10, masking as none, and a phase of NA.
The primary outcome is the percentage of scheduled fractions delivered successfully through completion of treatment, estimated to take two weeks. Success requires completion in one on-table attempt without a backup motion-management system or alternative machine. Treatment is described as five fractions delivered once daily or once every other day over one to two weeks.
The registry record does not report the primary endpoint result or an analysis of it. It lists 1 serious adverse event affected among 10 at risk, 2 other adverse events affected among 10 at risk, 0 deaths, and sepsis at 10.0% among the serious-event terms. Those entries do not replace the missing feasibility result or provide a complete safety assessment.