Stereotactic Body Radiation Therapy (SBRT) vs Trans-Arterial Chemoembolization (TACE) as Bridge to Transplant: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Stereotactic Body Radiation Therapy (SBRT) vs Trans-Arterial Chemoembolization (TACE) as Bridge to Transplant (NCT03960008), a randomized phase 3 study. The primary outcome is To Compare the Duration of Disease Control in Treated Lesions When Utilizing SBRT Versus TACE as a Bridging Strategy for Patients With HCC Eligible for Liver Transplantation.

2. Clinical Question

The clinical question concerns local disease control in treated lesions during a strategy intended to bridge patients to liver transplantation. The registry summary also proposes comparing the time from initial treatment to the need for retreatment. However, the listed primary-outcome description focuses on disease presence at 1 year post treatment, and the registry record says data were not collected and the outcome was not analyzed. Thus, the record does not answer whether one strategy had better lesion control or a longer interval before retreatment.

The listed secondary outcomes broaden the questions to treatment-related adverse events, further interventions, pathological and radiological response, quality of life measured with the FACT-Hep questionnaire, overall survival, and post-transplant morbidity and mortality at 90 days. These aims describe what the study intended to assess; they are not reported findings. No comparative estimate for any of these outcomes is included in the registry record.

3. Trial Design

This was a randomized, multicenter, phase III study with a parallel-group design. Participants were assigned to SBRT or TACE, and the registry record describes masking as none. The open-label description means that masking was not used according to the record; the record does not give further details about who knew each assignment or how treatment was allocated.

The study was intended to compare the strategies as bridges to transplantation among patients with HCC eligible for liver transplantation. The record lists SBRT as radiation therapy and TACE as a procedure involving chemoembolization with doxorubin. Enrollment was 9. The study status is terminated. Its recorded start date is 2020-03-01 and its primary completion date is 2024-02-28. The reason for termination is not reported in the registry record.

Randomization is generally used to create treatment groups whose baseline characteristics are not systematically determined by treatment choice. With a small enrolled group, however, chance differences between arms can remain substantial, and estimates may be imprecise. This general consideration does not establish that any particular imbalance occurred in this trial: participant characteristics by arm are not reported in the registry record.

The registry lists 9 outcome measures and no analysis records. It identifies a primary outcome and several secondary outcomes, but it does not report the methods used to analyze them. The design label and planned outcomes therefore describe the intended comparison, while the small enrollment, termination, and lack of collected primary-outcome data limit what can be learned from the posted 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

Analysis population for the primary outcome, as defined in the registry: Data has not been collected and therefore not analyzed for this outcome.

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.

6. Primary Endpoint

The registry lists the primary outcome as To Compare the Duration of Disease Control in Treated Lesions When Utilizing SBRT Versus TACE as a Bridging Strategy for Patients With HCC Eligible for Liver Transplantation, measured over 1 year post treatment.

The primary outcome is described as a comparison of disease control in treated lesions for SBRT versus TACE, with assessment at 1 year post treatment. More specifically, the measurement description asks whether disease was present in treated lesions in each arm at that time point. The endpoint therefore concerns the status of treated lesions at a specified follow-up time, rather than a reported numerical estimate of time to retreatment.

Assessing disease in treated lesions is relevant to the stated bridge-to-transplant question because the registry summary proposes that a bridging strategy may differ in how long it maintains control before retreatment is needed. The primary-outcome title refers to duration of disease control, and the brief summary refers to the interval between initial treatment and need for retreatment. Those descriptions explain the clinical rationale, but the listed measurement description focuses on disease presence at 1 year. The record does not provide further operational details to reconcile these formulations.

According to the registry record, data were not collected and therefore were not analyzed for this outcome. No arm-specific disease-status count, treatment effect, confidence interval, or statistical test is reported. The endpoint is consequently a statement of the question the trial intended to address, not evidence favoring either strategy.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Interpreting a trial record requires separating the design, the outcome definition, the observed data, and the statistical analysis. The record describes a randomized parallel-group design and identifies a primary outcome, but it also states that primary-outcome data were not collected and gives no analysis records. The design can tell readers how the comparison was intended to be organized; it cannot substitute for the missing outcome data.

What randomization contributes

General statistical explanation: randomization assigns participants to treatment groups by a chance-based process. Its purpose is to reduce systematic differences in prognostic characteristics between groups, so that an outcome contrast can be interpreted as a treatment comparison rather than simply a comparison of people selected for different treatments. Randomization does not guarantee that groups will be identical, particularly when enrollment is small. Chance imbalances can occur, and they can affect estimates. The registry record does not report participant characteristics by arm or the sequence-generation and allocation-concealment procedures, so those implementation details cannot be assessed.

The study is described as having no masking. In general, masking can reduce the influence of treatment knowledge on outcome assessment, participant reports, or decisions made during follow-up. Its relevance depends on the outcome and on how it is measured. The registry record does not describe masked assessment or give details about outcome ascertainment. It is therefore not possible to determine how knowledge of assignment may have affected measurement or follow-up.

What the primary outcome measures

The primary outcome is framed as disease control in treated lesions and specifies assessment at 1 year post treatment. Its description asks whether disease was present in treated lesions in the two arms at that point. A comparison of binary status at a fixed follow-up time is conceptually different from directly estimating a time-to-event outcome such as time until retreatment. The registry wording also refers to duration of disease control and the interval before retreatment, but it does not report a detailed endpoint definition, rules for handling events before the assessment time, or a statistical method. These details are not reported in the registry record.

General statistical explanation: endpoint definition matters because the analysis must match what is measured. A fixed-time status comparison asks about outcome status at a particular assessment point, while a time-to-event analysis uses information about when an event occurs and can account for differing follow-up under specified assumptions. The registry description alone does not establish which analytic approach was planned. No method should be inferred from the endpoint title.

Why estimates need uncertainty measures

General statistical explanation: an effect estimate describes the observed contrast between groups on a defined outcome. A confidence interval communicates uncertainty around that estimate under the chosen model and analysis assumptions. A narrow interval generally indicates greater precision than a wide interval, but interpretation also depends on the outcome scale and clinical context. A p-value, when reported, addresses compatibility between data and a specified null hypothesis under a statistical model; it does not by itself convey the size or importance of an effect.

For this trial, no primary-outcome estimate, confidence interval, or p-value is reported. The record says the data were not collected and therefore not analyzed. Consequently, there is no trial-specific estimate whose magnitude, precision, or statistical significance can be interpreted. General explanations of these tools do not fill that gap.

Small enrollment and precision

General statistical explanation: when few participants contribute outcome information, estimates can be unstable and uncertainty can be large. For outcomes that are uncommon, observing no events in a small group can still be compatible with a range of underlying event risks. Small studies may also have limited ability to detect moderate group differences. These are general principles, not calculated conclusions about the true effects in this trial.

Enrollment was 9, but the record does not report the number with primary-outcome observations because it explicitly states that the outcome data were not collected. It also does not report a trial-specific sample-size justification. The registry record therefore does not permit a judgment about whether the intended enrollment was adequate for the planned primary comparison.

Over-dispersion and model choice

General statistical explanation: over-dispersion occurs when outcome variability is greater than a statistical model expects. If a model assumes less variability than the data contain, uncertainty can be understated and tests can become unreliable. Analysts may use a model that accommodates extra variability when the outcome and data support it. The registry record does not report an outcome distribution, an analysis model, or any indication that over-dispersion was assessed. This concept is therefore relevant as general background only; it is not a reported feature of this trial.

More broadly, analysis choices should follow the outcome scale, follow-up pattern, and prespecified estimand. An estimand clarifies which treatment effect is being targeted, for which participants, and under what handling of events such as discontinuation or additional treatment. The registry record does not report an estimand or an analysis plan. It also does not describe handling of protocol deviations, post-randomization treatment, or incomplete follow-up. These omissions prevent reconstruction of the intended statistical analysis.

The registry lists several secondary outcomes, but it does not report analyses for them. No multiplicity adjustment, hierarchy among secondary outcomes, or prespecified subgroup analysis is described. Since no results are posted, there are no secondary estimates to interpret or compare. Statistical methods can explain how an analysis might be designed in general, but the specific methods used or intended for this trial are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary outcome and lists secondary outcomes covering treatment-related adverse events assessed by CTCAE v5.0, further interventions, pathological and radiological response, quality of life by the FACT-Hep questionnaire, overall survival, and post-transplant morbidity and mortality at 90 days. It does not report a statistical plan for handling multiple outcomes. A hierarchy of tests, an adjustment procedure, or a rule for interpreting a collection of secondary comparisons is not reported in the registry record.

General statistical explanation: when many outcomes or comparisons are examined, the chance of obtaining an apparently notable result by chance can increase. Prespecified priorities and multiplicity procedures can help make interpretation more disciplined. That general issue cannot be evaluated through reported estimates because the registry provides no analysis records and no outcome results.

Missing-data handling is also not described. For the primary outcome, the record explicitly states that data were not collected and therefore not analyzed. This is more fundamental than a reported analysis with some missing observations: there is no primary-outcome result from which to assess the extent or consequences of incomplete data. The record does not explain why data were not collected or whether any related measurements exist outside the posted results.

The analysis populations are not reported. In particular, the registry record does not say which participants would have been included in a primary analysis or how treatment changes, withdrawal, or other post-randomization events would have been handled. Interim analyses, stopping rules, and a sample-size justification are also not reported in the registry record. No assumptions about these matters should be inferred from the randomized design or the phase designation.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry lists serious adverse event counts separately for the two arms. For SBRT, 4 participants were at risk and 0 were affected; for TACE, 5 participants were at risk and 0 were affected. The record also lists 4 and 5 participants at risk, respectively, for other adverse events, with 0 affected in each arm. Deaths are recorded as 0 in both groups. No serious adverse event terms are listed.

These are counts in the posted registry record, not a comparative estimate of safety. The record does not provide a statistical test, confidence interval, event-rate estimate, or detailed follow-up information for these safety counts. General statistical explanation: observing no recorded events in a group does not establish that the underlying risk is absent. With limited participant information, rare or later events may not be represented in the observed counts. The figures should therefore be read narrowly as the events recorded for the participants listed as at risk, not as proof of no adverse-event risk or evidence that the arms are equivalent in safety.

The listed secondary outcome describes treatment-related adverse events assessed by CTCAE v5.0, but the record does not provide a separate analyzed comparison for that outcome. The registry’s safety counts alone do not show how the intended adverse-event assessment was carried out.

12. What the Result Does, and Does Not, Mean

The record establishes that a randomized, multicenter phase III study was intended to compare SBRT with TACE as bridging strategies for patients with HCC eligible for liver transplantation. It also establishes that enrollment was 9, the study status is terminated, and primary-outcome data were not collected or analyzed. These details describe the study and the limits of its posted evidence; they do not establish a treatment effect.

The record does not show whether disease was present in treated lesions at 1 year post treatment, whether time to retreatment differed, or whether either strategy produced better lesion control. There is no reported primary-outcome estimate, precision measure, or statistical test. The planned secondary questions also have no posted comparative results in the registry record. Accordingly, the record cannot support a conclusion that SBRT is more effective, less effective, equivalent, or safer than TACE.

The safety counts report no affected participants for serious or other adverse events in the listed risk groups and no deaths. Those observations are limited to the registry counts and should not be interpreted as proof of no risk. The record does not provide enough outcome information to characterize comparative safety or to assess the uncertainty around the counts.

General statistical explanation: a trial’s planned design and its results answer different questions. A randomized design describes how a comparison was meant to reduce bias; collected outcomes and an appropriate analysis are needed to estimate the comparison. When outcome data are absent, the planned clinical question remains unanswered by the posted record. The trial’s termination does not, on its own, identify why the study ended or imply a favorable or unfavorable result. The reason for termination is not reported in the registry record.

13. Why This Trial Matters Statistically

This trial matters statistically because it illustrates the distinction between a randomized design and an informative comparative result. Randomization is an important design feature, but it cannot produce an estimate when the primary outcome was not collected. The registry record describes a clinically focused comparison of SBRT and TACE as bridges to transplantation, yet it reports no primary-outcome analysis.

The small enrollment of 9 and the terminated status make the absence of outcome information especially consequential for interpretation. Even when results are available, a small study may yield imprecise estimates, and uncertainty should be assessed through the estimates and their intervals rather than through a design label alone. In this record, those quantities are not available for the primary question. The reader cannot tell whether any observed group contrast would have been large, small, or consistent with a wide range of effects.

The record also highlights the value of clear endpoint specification. The primary outcome is titled as duration of disease control, while its description asks whether disease was present in treated lesions at 1 year post treatment. The brief summary additionally emphasizes the interval to retreatment. These concepts are related to the stated study purpose but are not interchangeable analytic targets. Precise definitions help readers understand what was measured and how a treatment contrast should be interpreted.

Finally, the listed safety counts show why descriptive event counts and comparative safety conclusions must be kept distinct. The registry reports no affected participants in the listed groups, but it does not report an analysis that establishes equivalence or rules out risk. The trial is therefore informative about what was planned and what the registry says was not analyzed, but it does not resolve the treatment comparison.

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 is explicit: primary-outcome data were not collected and therefore were not analyzed. No result is reported for disease in treated lesions at 1 year post treatment. This prevents assessment of the principal clinical question and leaves no estimate or uncertainty measure to interpret.

Enrollment was 9, and the study is listed as terminated. The registry record does not report the reason for termination or give enough detail to assess what happened to participants after enrollment. It does not describe follow-up completeness, participant flow, baseline characteristics, treatment adherence, or whether additional interventions occurred. These items are not reported in the registry record.

The primary-outcome wording combines duration of disease control with disease presence at a fixed follow-up time, while the study summary also describes time to retreatment. The record does not provide the operational definitions or analysis details needed to determine how these concepts were to be linked. Statistical analysis methods, the analysis populations, missing-data procedures, and multiplicity handling are also not reported.

The safety counts are limited descriptive information. No comparative safety analysis or uncertainty measure is reported, and the small enrollment limits the amount of safety information available in the record. Although the study lists several secondary outcomes, their results are not reported. The registry record also does not report a sample-size justification, interim analyses, or stopping rules. These limitations do not establish why the study ended; the reason is not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Stereotactic Body Radiation Therapy (SBRT) vs Trans-Arterial Chemoembolization (TACE) as Bridge to Transplant — NCT03960008.
• Registry record last updated 2024-08-28; status last verified 2024-08.
• Results first posted 2024-08-28.
• 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.

18. Record Summary

NCT03960008 is a randomized, multicenter, parallel-group phase III study comparing SBRT with TACE as a bridge to liver transplantation for patients with HCC. Masking is listed as none. Enrollment was 9, and the status is terminated. The recorded start date is 2020-03-01, and the primary completion date is 2024-02-28.

The primary outcome concerns disease in treated lesions at 1 year post treatment. The registry record states that data were not collected and therefore not analyzed. It lists 9 outcome measures and no analysis records. Safety counts list no serious or other adverse events and no deaths in either arm among the participants recorded as at risk. The reason for termination and the statistical analysis plan are not reported in the registry record.