Using FDG-PET During Radiation Therapy in Non-Small Cell Lung Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Using FDG-PET During Radiation Therapy in Non-Small Cell Lung Cancer (NCT01190527), a na na study. The primary outcome is 2 Year Rate of Overall Local-Regional Tumor Control Using FGD-PET-CT During Radiation Therapy(RT).

2. Clinical Question

3. Trial Design

This completed study, NCT01190527, is titled “Using FDG-PET During Radiation Therapy in Non-Small Cell Lung Cancer.” Its official title describes using FDG-PET acquired during radiation therapy to individualize adaptive radiation dose escalation. The sponsor is University of Michigan Rogel Cancer Center. The record gives a start date of 2008-08 and a primary completion date of 2014-07. Enrollment was 42.

The design is listed as single-group. The arm, Adaptive Radiation, is described as giving all subjects the same course of treatment, identified as the study treatment. Allocation is listed as NA and masking as NONE. These entries do not describe random assignment or blinding. The record lists the phase as NA.

The intervention is FDG-PET, categorized in the record as RADIATION. The study description discusses FDG-PET before treatment and again during treatment, with CT imaging used alongside PET. The adaptive plan was intended to use repeat imaging during radiation therapy to guide dose escalation according to tumor activity and the risk to healthy lung tissue. These are aims and design features; the registry entry does not give enough detail to reconstruct the treatment decisions made for each participant.

The lack of a separate control group matters when interpreting the study question. The record describes a goal of comparing outcomes with standard radiation therapy, but it does not report a concurrent standard-treatment arm. Therefore, results from this single group cannot, by themselves, establish how outcomes compare with outcomes under standard treatment. Detailed eligibility criteria, participant baseline characteristics, and the exact radiation protocols are not reported in the registry 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

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 2 Year Rate of Overall Local-Regional Tumor Control Using FGD-PET-CT During Radiation Therapy(RT), measured over 2 years.

The primary endpoint is titled “2 Year Rate of Overall Local-Regional Tumor Control Using FGD-PET-CT During Radiation Therapy(RT).” Its unit is the percentage of patients, its parameter is listed as NUMBER, and its dispersion is specified as a 95% confidence interval. The timeframe is 2 years. The endpoint is intended to describe local-regional tumor control at that time point among patients treated with the adaptive approach.

Local-regional control concerns whether cancer remains controlled in the local and regional areas addressed by the treatment. This endpoint is relevant to the study’s stated aim because the adaptive plan was designed to direct a higher total dose to active tumor while considering normal lung tissue. The endpoint description also mentions progression-free survival and normal tissue complication probability, but the primary endpoint title centers on local-regional tumor control. Those additional aims should not be mistaken for reported primary results.

In general, a percentage expresses the fraction of the analyzed population meeting an outcome definition. A confidence interval describes uncertainty around an estimate; it reflects the range of estimates compatible with the data under the method used. The registry record does not report the observed percentage, the confidence interval bounds, the outcome definition in operational detail, or the analysis population. The primary endpoint’s result and its precision therefore cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the confidence interval mean?

The primary endpoint specifies a 95% confidence interval around a percentage. In general, a confidence interval communicates statistical uncertainty in an estimated outcome. A narrow interval indicates greater precision than a wide interval, while an interval that spans a broad range leaves more uncertainty about the underlying value. The interval is not a guarantee that the true value lies within its particular limits, and it does not answer whether a treatment caused an outcome.

The registry record does not give the estimated local-regional control percentage or either confidence-interval limit. It also does not report the method used to calculate the interval. As a result, readers cannot judge the precision of the primary estimate or assess whether the interval method accounted for any features of the endpoint or follow-up.

How should the percentage endpoint be understood?

The primary endpoint is a percentage of patients with a specified outcome at 2 years. In general, percentage endpoints summarize the proportion of an analysis population meeting an outcome definition. Their interpretation depends on how the outcome is defined, which participants are included, and how participants without an observed outcome are handled. For a time-specific cancer-control outcome, the method used to account for follow-up and censoring can also affect interpretation.

The record does not give an operational definition of local-regional control, the analysis population, or details of follow-up and censoring. It does not state how deaths or missing assessments were treated for this endpoint. Those details are not reported in the registry record, so the endpoint cannot be independently reconstructed from the entry.

What can a single-group design establish?

This study is listed as single-group, and the arm description says all subjects received the same study treatment. In general, a single-group study can describe outcomes among participants receiving that approach. Without a separate comparison group, however, it cannot directly estimate the difference in outcomes between the approach and standard treatment. A historical or expected benchmark would not be equivalent to a concurrent, comparable control group, and no such benchmark is specified in the registry record.

The study description frames the goal as evaluating whether adaptive planning could improve tumor control while limiting normal-tissue complications. That goal does not itself define a statistical comparison. The registry record does not report a comparator, a statistical hypothesis, or an analysis plan for testing improvement. It would be inappropriate to infer these details from the stated research aim.

What do the sample-size planning assumptions describe?

The record describes a planning illustration based on the observed effect, not on the trial’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. These assumptions describe hypothetical planning, not observed power for this single-group study. Any planning illustration is not a substitute for the missing clinical outcome estimate and does not show the probability that this study detected an effect.

The sample-size description distinguishes between planning for participants per arm for 80% power and other planning targets, and notes that time-to-event illustrations use a total number of events under the Schoenfeld approach while other illustrations give participants per arm. The record does not include the resulting planning values or identify an effect estimate for reconstruction. No sample-size justification for the actual study is reported in the registry record. The two-arm planning assumptions should not be mistaken for evidence that the study enrolled two arms.

Why does over-dispersion matter in general?

For outcomes recorded as counts, statistical models often make assumptions about how variable the observations are. Over-dispersion means the observed variation is greater than the model expects. If it is ignored, uncertainty estimates can be too small and tests can appear more conclusive than warranted. This is a general statistical consideration for count outcomes; the registry record does not report a count model or an over-dispersion assessment for this study.

The primary endpoint is listed as a percentage, not a count model, and the record does not provide a statistical analysis description. It is therefore not possible to identify which estimation or modeling choices were used for the primary endpoint, or whether any checks of model assumptions were performed.

What analysis details are unavailable?

The record lists 0 analyses. That is a description of the analyses represented in the registry entry; it does not establish that no analyses were conducted outside the record. No primary endpoint estimate, confidence interval, hypothesis test, adjustment strategy, or detailed statistical plan is reported. The registry record also does not state whether analyses were adjusted for participant characteristics or how protocol deviations were handled.

For these reasons, the available design and endpoint descriptions permit a conceptual explanation of the planned question but not a reanalysis. The essential ingredients for checking an outcome estimate—reported results, the analyzed population, and the analysis method—are not reported in the registry record.

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("Adaptive Radiation")
n      <- c(42)
events <- c(29)
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  Adaptive Radiation  42  29  69.0  52.9  82.4  54.0  80.9  53.9  80.9

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 4 outcome measures. Besides the primary two-year local-regional tumor-control endpoint, the secondary outcomes include the number of patients able to receive dose escalation, the percentage of patients alive at 2 years, and the number of participants experiencing lung toxicity and esophagitis. Multiple outcomes can address different aspects of a study, but testing or interpreting several outcomes raises the general issue of multiplicity: the chance of highlighting an apparently notable finding can increase when many questions are examined.

The registry record does not report a multiplicity strategy, such as designating a hierarchy among secondary outcomes or adjusting interpretation for multiple statistical tests. It also lists 0 analyses, so there are no analysis details in the registry record from which to determine how outcomes were statistically evaluated. This absence should not be interpreted as evidence that the investigators did or did not use a particular strategy outside the registry.

Missing-data methods and analysis populations are also not reported in the registry record. The record does not specify who was included in each outcome analysis, how missing assessments were handled, or whether participants with incomplete follow-up were censored or otherwise treated in the analysis. These details matter because the denominator and handling of unavailable outcomes can affect a percentage estimate and its uncertainty.

The registry includes enrollment of 42, but does not state the number analyzed for the primary endpoint. Enrollment should therefore not be assumed to be the denominator for every outcome. The lack of reported analysis populations, missing-data methods, and multiplicity procedures limits the ability to assess the robustness and selectivity of any outcome interpretation.

12. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: disease progression (23.8%), dyspnea (11.9%), esophagitis (11.9%), infection, lung (pneumonia) (11.9%), hypoxia (9.5%).

For the Adaptive Radiation group, the registry record lists 42 participants at risk for serious adverse events and 29 affected. For other adverse events, it lists 42 at risk and 30 affected. These are distinct registry categories. The figures describe participants reported as affected; they should not be interpreted as counts of event episodes, since the record does not specify whether an affected participant could experience more than one event.

The listed serious adverse-event terms and percentages are Disease progression, 23.8%; Dyspnea, 11.9%; Esophagitis, 11.9%; Infection, Lung (pneumonia), 11.9%; Hypoxia, 9.5%; and Pneumonia, 9.5%. These percentages are reproduced as recorded. The denominator and method used to calculate each term’s percentage are not separately described in the registry entry.

Adverse-event reports are descriptive. They do not establish that treatment caused an event, and the registry record does not provide a comparison group for estimating relative safety. It also does not report event timing, severity grading details, or participant-level overlap among the listed terms. The serious and other affected counts should not be added together, since the entry does not establish whether the same participant could appear in both categories.

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

The record describes a completed study of adaptive radiation planning informed by FDG-PET during treatment for non-small cell lung cancer. Its primary question concerns local-regional tumor control at 2 years, with the stated aim of guiding dose escalation while considering normal lung tissue. This information is useful for understanding what the study was designed to examine.

It does not establish whether the adaptive approach improved local-regional control, progression-free survival, survival, or lung function. The registry record does not report the primary endpoint estimate or its 95% confidence interval. It also does not report the outcome results needed to judge whether the stated aims were achieved. A study objective is not itself an outcome finding.

The design further limits comparative interpretation. The study is single-group, and all participants are described as receiving the same study treatment. The entry does not include a concurrent standard-treatment group, even though the study description refers to comparison with standard radiation therapy. Consequently, the record cannot show a treatment effect relative to a like-for-like control group. Even a reported within-group percentage would describe outcomes in this group rather than directly quantify a difference against standard treatment.

The adverse-event entries provide counts and selected percentages, but they do not establish causality or comparative risk. Without additional information about definitions, timing, overlap, and analysis, they should be read as registry safety descriptions rather than a complete account of treatment-related harm.

Accordingly, the most defensible reading is that the registry documents the study’s design, intended endpoint, and some adverse-event reporting, while leaving the primary clinical outcome unavailable. It cannot support a claim that the treatment succeeds or fails, nor can it determine the magnitude or precision of any benefit or harm. Further outcome and analysis information is not reported in the registry record.

14. Why This Trial Matters Statistically

This study raises a statistically important challenge: an imaging measure collected during treatment is intended to guide a change in treatment intensity. The research question therefore connects an intermediate observation—FDG-PET activity during radiation therapy—with a patient outcome, local-regional tumor control. Describing this link clearly requires distinguishing the imaging strategy from the outcome it is meant to influence.

The record also illustrates why design and estimand matter. The stated aim refers to improvement compared with standard radiation therapy, but the registered study is single-group. A treatment contrast requires outcomes under both strategies to be compared in a way that supports interpretation. Without a concurrent control arm, the registry design can describe outcomes in the adaptive group but cannot directly estimate that comparative effect.

Precision is another central issue. A percentage accompanied by a 95% confidence interval would communicate both the estimated control rate and its uncertainty. The registry specifies that format but does not report the estimate or interval. Thus, the primary question cannot be answered from the available result information, regardless of how compelling the biological rationale may be.

The entry also lists secondary measures relating to dose escalation, survival, lung toxicity, and esophagitis. These outcomes represent distinct dimensions of feasibility, effectiveness, and safety. Their interpretation depends on definitions, analysis populations, missing-data handling, and a stated approach to multiplicity. Those analysis details are not reported in the registry record.

Statistically, the trial is informative as an example of why a promising study rationale, a registered endpoint, and an outcome result are not interchangeable. Its description sets out a meaningful clinical question, but evaluation of the answer requires comparative design or careful limits on causal claims, transparent outcome estimates, and the uncertainty and analysis details needed to interpret them.

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 primary limitation for interpreting clinical outcomes is that the registry record does not report the primary endpoint result or confidence interval. Although the endpoint is specified as the percentage of patients with local-regional tumor control at 2 years, there is no observed estimate to assess. Secondary outcome results are also not included in the record details.

The single-group design is a separate limitation. All subjects are described as receiving the study treatment, and there is no concurrent standard-treatment arm. The study description mentions comparison with standard radiation therapy, but the registered design does not supply a like-for-like control. This restricts causal and comparative interpretation.

Enrollment was 42, but the record does not report the primary analysis population or endpoint denominator. Participant characteristics, detailed eligibility criteria, outcome definitions, follow-up completeness, missing-data methods, and analysis procedures are also not reported in the registry record. These omissions prevent readers from evaluating representativeness, possible selection effects, and the robustness of endpoint estimation.

The adverse-event listing includes selected terms and percentages, but does not detail their timing, participant-level overlap, attribution, or percentage denominators. Nor does the record provide a control group for contextualizing these reports. The entry lists 0 analyses, which means analyses are not represented in the registry record; it does not establish whether analyses were conducted elsewhere.

Finally, sample-size planning assumptions describe a hypothetical two-arm illustration rather than the actual single-group design. The resulting planning values and the effect estimate used are not reported in the registry record, and these assumptions cannot be used to infer observed power. Taken together, these limitations mean the record is more informative about the intended study question than about its clinical findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Using FDG-PET During Radiation Therapy in Non-Small Cell Lung Cancer — NCT01190527.
• Registry record last updated 2017-06-02; status last verified 2017-05.
• Results first posted 2015-01-14.
• 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

NCT01190527 is a completed, single-group study sponsored by University of Michigan Rogel Cancer Center. It enrolled 42 participants with non-small cell lung cancer and examined FDG-PET-based adaptive radiation planning during treatment. The record lists allocation as NA, masking as NONE, and phase as NA.

The primary endpoint is the 2 Year Rate of Overall Local-Regional Tumor Control, expressed as a percentage with a 95% confidence interval. The study description also refers to progression-free survival and limiting normal lung complications. The primary endpoint result and its confidence interval are not reported in the registry record.

The registry lists secondary outcomes involving dose escalation, survival at 2 years, lung toxicity, and esophagitis. It also reports adverse-event counts and selected serious-event terms. With no separate control group and no reported outcome analysis, the entry documents the study’s intent and design but does not establish comparative effectiveness or causality.