Feasibility Study of Enhanced MRI for Early Stage Non Small Cell Lung Cancer (NSCLC): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Feasibility Study of Enhanced MRI for Early Stage Non Small Cell Lung Cancer (NSCLC) (NCT01799135), a na na study. The primary outcome is Feasibility Rate at 1-2 Days After the First SBRT Treatment and 1-2 Weeks and 3-4 Months After SBRT Treatment..

2. Clinical Question

The study asks whether pulmonary dynamic contrast-enhanced MRI (DCE-MRI) can characterize changes in tumor perfusion and normal lung injury around stereotactic body radiation therapy (SBRT) for early-stage non-small cell lung cancer. It also considers whether DCE-MRI and 4-dimensional computed tomography (4D-CT) ventilation imaging can help characterize lung function or identify functional lung regions for treatment planning.

The primary feasibility measure is based on a change in tumor perfusion from baseline. A participant meets the defined criterion if the change is at least 20% at each of the specified post-treatment assessments; success requires meeting it at all three timepoints. The record does not report the measured feasibility rate, so it does not establish how often this criterion was met.

3. Trial Design

This is a pilot, single-group study with enrollment listed as 6. The registry identifies the phase as NA, allocation as NA, and masking as none. It is not a randomized comparison, so the record does not support a like-for-like treatment comparison between arms. The study status is terminated; the reason for termination is not reported in the registry record.

The experimental arm is described as receiving SBRT, with either 54 Gy in 3 fractions or 50-60 Gy in 5 fractions over a span of at most 15 days. The arm description also specifies DCE-MRI assessments at baseline before SBRT, 1-2 days after the first treatment fraction, and 1-2 weeks after the end of the SBRT course. The primary endpoint additionally specifies an assessment 3-4 months after treatment. The complete schedule and any deviations from it are not reported in the registry record.

The study includes DCE-MRI, SBRT, and 4D-CT as interventions. Its stated aims include assessing tumor response and radiation-related lung injury, comparing DCE-MRI with 4D-CT ventilation imaging, and exploring functional-lung information for SBRT planning. These are imaging and feasibility aims; the single-group design does not offer a randomized treatment comparison.

The study start is listed as 2012-11 and primary completion as 2019-01. The record does not report a statistical analysis plan, a sample-size justification, or details explaining the terminated status. Its pilot framing indicates an investigation of feasibility, but it does not by itself establish the precision or generalizability of any estimate.

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

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 Feasibility Rate at 1-2 Days After the First SBRT Treatment and 1-2 Weeks and 3-4 Months After SBRT Treatment., measured over Measured 1-2 days, 1-2 weeks, and 3-4 months from baseline..

The primary endpoint is a feasibility rate, expressed as a percentage of participants. The registry defines feasibility by whether tumor perfusion changes by 20% or greater from baseline at 1-2 days, 1-2 weeks, and 3-4 months after SBRT. The criterion must be met at all three timepoints for a participant to count as a success. Perfusion is measured using DCE-MRI.

This definition makes the endpoint a binary participant-level outcome: each participant either meets the stated all-timepoint criterion or does not. The percentage would describe the proportion meeting that definition in the study population. Requiring success at every assessment makes the endpoint more demanding than counting a change at only one timepoint, and it combines information across the treatment course and follow-up.

A feasibility endpoint is used to evaluate whether an imaging approach can produce the specified measurements in the intended setting. It is not, by itself, a measure of clinical benefit or proof that an imaging-guided planning strategy improves outcomes. The registry lists a 90% confidence interval as the dispersion measure, but the numerical endpoint estimate and its interval are not reported in the registry record. The method used to construct the interval is also not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a binary feasibility measure summarized as a percentage. Each participant is classified according to the registry definition: tumor perfusion must change by 20% or greater from baseline at each of the specified follow-up assessments. The resulting percentage is intended to describe the share meeting the complete criterion. The numerical estimate is not reported in the registry record, so its magnitude cannot be interpreted.

What does the confidence interval represent?

A confidence interval expresses uncertainty around an estimate. A narrower interval indicates greater precision, while a wider interval indicates less precision. In general, an interval around a percentage helps readers judge how compatible the observed study result may be with a range of underlying feasibility rates. The registry lists a 90% confidence interval for the primary measure, but does not report its bounds or the method used to calculate it. Without the estimate and interval, neither the observed rate nor its precision can be assessed.

Confidence intervals are especially important for feasibility studies because a percentage from a small pilot can vary substantially with the outcome of individual participants. This is a general statistical point, not a conclusion about the unreported result of this study. A point estimate alone would not convey its uncertainty; the interval would be needed to describe precision. Conversely, an interval cannot repair limitations in the design or make an unreported result available.

Why does the all-timepoint rule matter?

The outcome uses a joint success rule: the change criterion must be reached at all three stated follow-up timepoints. This differs from reporting the percentage meeting a threshold at each timepoint separately. A participant who meets the threshold at some assessments but not all would not meet the stated overall definition. The endpoint therefore addresses sustained or repeated feasibility across the specified schedule, rather than success at a single selected assessment.

That rule also makes missing measurements consequential. If an assessment is absent, the record would need to explain how the participant is classified for the all-timepoint endpoint. The handling of missing measurements is not reported in the registry record. It is therefore not possible to determine whether incomplete assessment schedules were counted as failures, excluded, or handled in another way.

What can a single-group design establish?

A single-group study can describe observed measurements in the group receiving the study procedures. It does not provide a concurrent randomized comparison with a separate control group. Here, 4D-CT is included as another imaging method, but the registry does not describe it as a control treatment arm. Without a control group, comparative treatment effects and causal contrasts are not available from the design as registered.

Repeated imaging before and after SBRT can describe measurements at different times, but a change over time is not automatically attributable to one cause. Interpretation depends on the assessment schedule, measurement quality, participant follow-up, and analysis methods. Details of statistical models, adjustment, and handling of repeated measures are not reported in the registry record. No additional assumptions about these methods should be made.

How should planning calculations be read?

Any sample-size figures accompanying the posted material are planning illustrations, not observed power. The stated illustration assumptions 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 record's general planning note says time-to-event illustrations give total events and other illustrations give participants per arm. These are hypothetical design calculations, not findings from this single-group study. The registry does not report that these assumptions formed the original study design, and the record does not report a sample-size justification.

The study has no randomized two-arm allocation, so an illustration framed around equal allocation between arms should not be mistaken for the design actually registered. A planning calculation also cannot establish that a study had adequate precision or that a result would be reproducible. For this record, the outcome estimate and analysis results are absent, limiting any assessment beyond the stated endpoint and design.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Experimental Arm")
n      <- c(6)
events <- c(4)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Experimental Arm  6  4  66.7  22.3  95.7  30.0  90.3  29.0  90.1

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures, including the primary feasibility measure and secondary feasibility aims related to DCE-MRI, 4D-CT ventilation imaging, radiation-induced lung injury, and functional-lung regions for SBRT planning. When several outcomes or timepoints are considered, multiplicity can arise: repeated statistical testing increases the chance that at least one finding appears noteworthy by chance. A prespecified hierarchy or adjustment strategy can help readers understand how multiple questions were handled.

The registry does not report a multiplicity strategy, a statistical analysis plan, or analysis results. It is therefore not possible to determine whether the outcomes were tested inferentially, whether any adjustment was planned, or how results across timepoints were interpreted. The primary endpoint's all-timepoint success rule is part of its outcome definition; it does not itself establish how any additional analyses were handled.

Missing-data methods and analysis populations are not reported in the registry record. In particular, the record does not explain how missed scans, unusable images, or incomplete follow-up would affect the primary classification. No details are reported about an intention-to-treat, per-protocol, or evaluable-imaging population. These omissions matter because the primary outcome requires measurements at all specified assessments, and the denominator used for a percentage depends on how participants with incomplete data are handled.

The record reports zero analyses. This describes what is posted in the registry and should not be interpreted as proof that no analyses were performed elsewhere. With no numerical outcome results or analysis descriptions, the handling of multiplicity, missing data, and analysis populations cannot be evaluated.

12. 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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: death nos (16.7%).

The adverse-event record lists 1 serious adverse event affected among 6 at risk in the experimental arm. It lists 2 participants affected by other adverse events among 6 at risk. The record also lists 1 death and identifies “Death NOS” among the serious-event terms, with 16.7% shown for that term. These figures should be read as registry-reported counts and percentage, not as evidence about cause.

The record does not report whether the death or other listed events were judged related to DCE-MRI, gadolinium, SBRT, or another aspect of care. It also does not give event timing or additional clinical context. The category “Death NOS” does not provide a specific cause in the posted record. No causal attribution should be inferred from the event listing alone.

Adverse-event counts are not a comparative safety estimate in this single-group study. The registry does not present a randomized control group for comparison, and the safety figures do not establish how risks would differ under another approach. The record also does not provide enough detail to interpret the range or severity of events beyond the listed serious-event information. These entries describe what is recorded, not a complete account of clinical circumstances.

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

This record is useful for identifying a pilot study designed to examine pulmonary DCE-MRI around SBRT for early-stage non-small cell lung cancer. It defines a specific imaging feasibility endpoint based on tumor-perfusion change from baseline and lists related aims involving lung injury, 4D-CT ventilation imaging, and functional-lung information for planning. It also documents that the study was single-group and is now marked terminated.

The record does not report the numerical primary result, its confidence interval, or numerical results for the secondary outcomes. It therefore does not show whether the feasibility criterion was met, how precisely a feasibility rate was estimated, or whether the imaging aims were achieved. The absence of posted results is not evidence that the technique failed, just as the study's stated aims are not evidence that it succeeded.

The design also limits what could be learned even if descriptive imaging results were available. A single group does not provide a randomized treatment comparison, and 4D-CT is described as an imaging method rather than a control arm. Changes in imaging measurements over time would not, by themselves, establish that an imaging strategy improves treatment planning or clinical outcomes.

The adverse-event entries report counts and a listed death term, but the registry does not report causal attribution or clinical context. The terminated status does not explain why the study ended. Taken together, the record supports a cautious account of the intended feasibility research and its reporting gaps. It does not support a conclusion about treatment effectiveness, comparative safety, or the value of DCE-MRI for patient care.

14. Why This Trial Matters Statistically

Feasibility studies address whether a measurement strategy can be carried out and yield information relevant to a later research question. This study's endpoint makes that statistical question concrete: the perfusion-change criterion must be met at every specified follow-up assessment for a participant to count as a success. Defining the rule in advance is important because a clear threshold and assessment schedule reduce ambiguity about what the outcome is intended to represent.

The study also illustrates why precision and reporting matter. A feasibility percentage without its uncertainty can be difficult to interpret, particularly in a pilot. The registry lists a 90% confidence interval but does not report the estimate or interval. Without those results, readers cannot judge whether the observed rate was precise or whether the data were compatible with a wide range of underlying rates.

Statistically, the single-group structure sets limits on inference. It can describe measurements in the enrolled group, but it does not create a randomized comparison for treatment effects. The inclusion of 4D-CT addresses an imaging question, not a control-arm comparison. Distinguishing descriptive feasibility from comparative effectiveness prevents an endpoint from being asked to answer a question the design was not built to resolve.

The record further shows how outcome definitions, repeated assessments, missing data, and multiple aims are connected. Requiring success at each timepoint makes completeness and missing-measurement rules central, while several outcomes raise questions about multiplicity. Those analysis details are not reported. Transparent reporting of results and methods would be needed to assess the strength and precision of the evidence from this pilot.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation of the posted record is the absence of numerical efficacy or feasibility results. The primary endpoint is defined and a 90% confidence interval is specified, but neither the result nor interval is reported in the registry record. Secondary outcome results and analysis details are also absent, preventing assessment of observed imaging performance.

The single-group design has no randomized control arm, so it cannot provide a randomized comparison. Enrollment is listed as 6, and the record does not provide the information needed to assess the precision of the intended feasibility estimate. The method used to calculate the confidence interval is not reported in the registry record.

The endpoint requires meeting a perfusion-change criterion at all three post-baseline timepoints, but the handling of missing or unusable scans is not reported. The record also does not describe analysis populations, multiplicity handling, or a statistical analysis plan. These gaps make it difficult to evaluate how incomplete follow-up or several related outcomes might affect interpretation.

The study status is terminated, but the reason is not reported in the registry record. The adverse-event listing lacks reported causal assessments and clinical context. The arm description available in the record gives the stated SBRT regimens and some MRI timing, but the complete imaging schedule is not reported in the registry record. These limitations constrain interpretation of both the feasibility question and safety entries.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Feasibility Study of Enhanced MRI for Early Stage Non Small Cell Lung Cancer (NSCLC) — NCT01799135.
• Registry record last updated 2021-10-12; status last verified 2021-09.
• Results first posted 2021-10-12.
• 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.

19. Record Summary

NCT01799135 is a pilot, single-group study of pulmonary DCE-MRI in early-stage non-small cell lung cancer treated with SBRT. Enrollment is listed as 6; the study is marked terminated. Its primary outcome is a feasibility rate based on at least 20% change in tumor perfusion at each of three specified post-baseline assessments, with success requiring the criterion at all timepoints.

The registry lists a 90% confidence interval for the primary measure but does not report its numerical result or interval. It also lists secondary feasibility aims involving lung injury, 4D-CT ventilation imaging, and functional-lung regions for planning. The posted record contains zero analyses. Serious and other adverse-event counts are listed, including a death term, but causal attribution is not reported.

The record describes the study's intended questions and design, but does not provide the outcome results or analysis details needed to evaluate the observed feasibility rate, its precision, or comparative effects.