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 Thoracoscopic Lung Cancer Staging With the Use of Intraoperative Ultrasound (NCT02218242), a na na study. The primary outcome is Detection of Occult Pathologic N2 Lymph Nodes.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02218242 |
| Phase | NA |
| Condition | Lung Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 9 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Joel Thompson, PhD |
| Results posted | Yes |
2. Clinical Question
Population
Participants were undergoing surgical resection of lung cancer, specifically non-small cell lung cancer in the study description. Standard surgery included lobectomy or sub-lobar resection and mediastinal lymph node dissection. The record reports enrollment of 9; it does not provide further participant characteristics in the results.
Intervention
After standard-of-care dissection, intraoperative ultrasound was used to examine lymph node stations for nodes that might have been missed, with particular attention to nodes appearing pathologic on ultrasound. The intervention is listed as a device called intraoperative ultrasound.
Comparator
There was no separate control group. The study is registered as single-group, with allocation listed as NA and masking as none. The procedure followed standard surgical care, but the registry does not present a parallel group receiving surgery without the ultrasound assessment.
Primary question
The study asked whether ultrasound performed after standard video-assisted thoracoscopic dissection could identify occult pathologic N2 lymph nodes at surgery. Its primary outcome was described as the ratio of lymph nodes identified as cancerous to the total number investigated with ultrasound. The registry reports that no pathologic lymph nodes were identified, so the stated percentage was zero.
3. Trial Design
This was a single-group, Phase II study of thoracoscopic lung cancer staging with intraoperative ultrasound at the time of definitive resection. The registry lists the phase as NA, so the phase label in the official title and the phase field do not match. Allocation is listed as NA, masking as none, and the model as single group. There is no randomized comparison or concurrent control arm.
Participants had elected to undergo surgical resection of non-small cell lung cancer as standard care. The study description says standard treatment included lobectomy or sub-lobar resection and mediastinal lymph node dissection. After that standard procedure, ultrasound was used to assess lymph node stations for potentially missed nodes. The intent was to evaluate pathologic upstaging and ultrasound sensitivity and specificity as an additional intraoperative diagnostic tool.
The registry lists enrollment of 9, a start date of 2015-07-01, and primary completion on 2018-06-27. The study status is terminated. The primary outcome was measured at the time of surgery. The registry does not report a separate control condition, a masking procedure, or a detailed account of how participants were selected beyond their planned surgical resection.
The record states that enrollment was insufficient to generate meaningful data and was less than 10% of what the study's power calculations suggested was needed. The target enrollment and the underlying power calculations are not reported in the registry record. Reasons for termination beyond the stated enrollment shortfall 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
| Stage | Ultrasound |
|---|---|
| STARTED | 9 |
| COMPLETED | 9 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: An insufficient number of participants were consented to generate meaningful data for this study. We reached an enrollment of less than 10% of what our power calculations suggested we needed. No pathologic lymph nodes were identified, thus the percent of pathologic lymph nodes is in fact zero
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 | Ultrasound |
|---|---|---|
| Participants analysed | 9 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 3 |
| Age, Categorical: >=65 years | Participants | 6 |
| Sex: Female, Male: Female | Participants | 4 |
| Sex: Female, Male: Male | Participants | 5 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 9 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 9 |
6. Primary Endpoint
The registry lists the primary outcome as Detection of Occult Pathologic N2 Lymph Nodes, measured over At time of surgery.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of pathologic lymph nodes |
| Endpoint classification | not reduced to a single comparison |
The primary outcome, Detection of Occult Pathologic N2 Lymph Nodes, was assessed at the time of surgery. The description says the outcome would be presented as the ratio of lymph nodes identified as cancerous to the total number investigated using ultrasound. The unit is described as a percentage of pathologic lymph nodes. In practical terms, the outcome concerns whether the ultrasound assessment finds cancerous N2 nodes among the nodes examined.
This kind of outcome is relevant to a staging study because it focuses on detection of disease that may not have been recognized during standard dissection. If ultrasound finds a pathologic node, that finding could affect the pathologic staging recorded for a participant. The registry describes assessment of pathologic upstaging as an additional study aim, but the primary outcome itself is framed around lymph-node findings rather than a patient-level staging percentage.
The registry reports that no pathologic lymph nodes were identified and states that the percentage was zero. It does not report the total number of lymph nodes examined with ultrasound, the number of participants with evaluable ultrasound examinations, or a participant-level distribution of findings. Those omissions prevent independent reconstruction of the stated ratio or assessment of how much information the outcome contains.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central result reported in the registry is that no pathologic lymph nodes were identified, and the stated percentage of pathologic lymph nodes was zero. This is a descriptive finding, not evidence that ultrasound has a particular sensitivity, specificity, or ability to change staging. The registry does not provide the total number of lymph nodes investigated, participant-level observations, or a diagnostic-accuracy analysis. Without those details, the result cannot be interpreted as a precise estimate of performance.
The study enrolled 9 participants and was terminated. The registry states that this was less than 10% of the number indicated by its power calculations and that the enrollment was insufficient to generate meaningful data. The number required by those calculations and the assumptions behind them are not reported in the registry record. A small enrollment limits the amount of clinical information available, but the record does not provide enough detail to quantify uncertainty for the endpoint.
There is no separate comparison group. Consequently, the study cannot directly estimate a between-group difference in detection or staging. It also cannot separate findings attributable to ultrasound from those arising through standard surgical assessment using a controlled comparison. The stated aim of evaluating sensitivity and specificity is not accompanied by those estimates in the registered results.
Zero identified pathologic nodes is not equivalent to proof that no occult pathologic nodes were present, nor does it establish that ultrasound would never detect such nodes in a larger or different group. It describes the observed finding recorded for this study. The registry does not report a confidence interval, a formal test, or an analysis that would show the precision of that finding.
The record includes sample-size planning assumptions for a two-arm illustration, including a two-sided significance level of 0.05, equal allocation, and a normal approximation. Those are planning assumptions, not the design of this single-group study and not an observed-power result. The record does not report a calculated planning estimate that can be interpreted as an appropriate sample size for this trial.
9. Statistical Methods Explained
The registered outcome is a count-based diagnostic finding expressed as a percentage or ratio: nodes identified as cancerous divided by the total nodes investigated with ultrasound. The registry reports the result as zero because no pathologic lymph nodes were identified. It does not provide the denominator or a detailed breakdown of the nodes examined, so readers cannot verify the ratio from the record. A reported percentage is most informative when its numerator and denominator are also clear.
What does a zero finding mean?
A zero observed count means that no instances of the target finding were recorded in the observed study data. It does not by itself establish that the underlying probability of the finding is zero. General statistical reasoning distinguishes the observed sample from the broader population: a sample can contain no events even when the population event probability is not zero. The uncertainty around a zero count depends in part on how much information was collected. Here, the registry does not report the number of nodes examined or an interval estimate, so the precision cannot be assessed from the record.
The endpoint is also described as a ratio at the lymph-node level, while the study enrolled participants. Nodes from the same participant may be related rather than statistically independent. General statistical methods for clustered data account for the possibility that observations within a participant resemble one another. The registry does not report whether any clustering approach was planned or used. Since node-level counts and participant-level data are absent, the implications of clustering cannot be evaluated.
Why are sensitivity and specificity not available?
Sensitivity and specificity are diagnostic-accuracy measures that compare a test result with a reference classification. They require information about test-positive and test-negative findings relative to the reference status. The study description says sensitivity and specificity would be evaluated, but the registry does not report estimates or the underlying classification counts. The statement that no pathologic nodes were identified is not enough to derive either measure: the record does not say how many nodes were judged nonpathologic, how ultrasound findings were cross-classified against pathology, or how discordant findings were handled.
Likewise, the aim of assessing pathologic upstaging is not accompanied by a reported count of participants whose stage changed after ultrasound. The record's primary outcome narrative focuses on lymph nodes and states that none were pathologic. It does not give participant-level staging results or detail how an upstaging event was defined for analysis.
How should sample-size planning be read?
The registry describes a planning illustration based on a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These assumptions describe a planning exercise; they do not turn this single-group study into a two-arm trial. They should not be read as evidence that the study enrolled enough participants, or as observed power. The record itself states that enrollment was less than 10% of what the power calculations suggested was needed.
The planning target, effect assumptions, and resulting participant counts are not reported in the registry record. The method used for the study's own power calculations is also not reported in the registry record. Because the endpoint is recorded as zero and the node denominator is absent, a planning exercise based on a fraction of an observed effect may not be readily interpretable from the information available. No new sample-size estimate can be inferred from the registered summary.
What can be inferred from the statistical reporting?
The registry provides a descriptive outcome statement but no analysis entries. It does not report a confidence interval, hypothesis test, adjustment method, or model estimate for the primary outcome. General statistical interpretation treats estimates and intervals as complementary: an estimate describes the observed result, while an interval communicates uncertainty under specified assumptions. Since no interval is reported, the precision of the zero finding remains unknown.
The outcome is a diagnostic count or proportion, not a time-to-event measure. The record does not report a time-to-event analysis or any other inferential method. It also does not specify whether analysis was planned by participant, by lymph node, or using both levels of data. These details matter because a participant can contribute multiple nodes, and the unit of analysis affects both the estimate and its uncertainty.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and no analysis entries. It does not report a multiplicity plan addressing the primary outcome alongside other diagnostic aims, including pathologic upstaging and evaluation of sensitivity and specificity. Without a prespecified testing hierarchy or adjustment plan, the record does not establish how multiple analyses would have been interpreted if results had been available. This limitation is particularly relevant because the study description mentions several related objectives, while the registered results provide only the primary outcome narrative.
Missing-data methods are not reported in the registry record. The record does not state how incomplete ultrasound examinations, missing pathology assessments, or unavailable lymph-node observations would have been handled. It also does not report the number of participants with complete endpoint data or whether any enrolled participant was excluded from the primary outcome assessment. The enrollment count alone does not establish how many had evaluable data.
Analysis populations are not described. The registry does not identify an intention-to-treat population, a per-protocol population, or another defined set for the primary analysis. In this single-group surgical study, clear definitions would help readers understand which participants and which nodes contributed to the outcome. The absence of analysis entries means there is no reported account of deviations, exclusions, or missing observations to assess against such definitions.
These reporting gaps do not demonstrate that missing data or multiplicity affected the result. They mean that readers cannot assess how either issue was handled. The record's statement that enrollment was insufficient to generate meaningful data is consistent with substantial limits on the available evidence, but it does not substitute for a description of analysis populations or missing-data procedures.
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 |
|---|---|---|---|
| Ultrasound | 0 | 9 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Ultrasound | 0 of 9 |
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 |
|---|---|
| Ultrasound | 0 of 9 |
The registry reports safety figures for the Ultrasound group. Serious adverse events affected 0 of the 9 participants listed as at risk, and other adverse events affected 0 of the 9 listed as at risk. Deaths are reported as 0. No serious adverse event terms are listed.
These figures describe events recorded in the registry; they do not show that no adverse events of any kind occurred outside the categories and reporting represented in the record. The registry does not define the scope or collection procedures for the other-adverse-event category in the information. It also does not provide event-level descriptions, severity details beyond the serious-event category, or follow-up duration for safety assessment.
With enrollment of 9 and a terminated study, the safety counts provide a limited description of the participants included in the registry record. The figures do not support a comparative safety assessment because there was no separate control group. They should be read as reported counts, not as a determination of the safety of the procedure in broader clinical use.
12. What the Result Does, and Does Not, Mean
The record documents a small, terminated, single-group study of intraoperative ultrasound after standard surgical lymph-node dissection. Its primary outcome concerned pathologic N2 lymph nodes detected at surgery. The registry reports no pathologic lymph nodes identified and states that the percentage was zero. That is the observed result recorded for this study.
The result does not establish the diagnostic accuracy of ultrasound. The registry does not report sensitivity, specificity, the total number of nodes investigated, or the underlying pathology cross-classification. It also does not report confidence intervals or another estimate of uncertainty. Therefore, the zero finding cannot be treated as a precise measure of how the approach would perform in other participants or settings.
The study also does not provide a controlled comparison of ultrasound with surgery alone. It cannot show from these results whether adding ultrasound changes detection relative to standard care, whether it changes the frequency of pathologic upstaging, or whether any observed difference would be attributable to ultrasound. Those questions require comparative information that is not reported in the registry record.
The study's enrollment shortfall is central to interpretation. The registry states that enrollment was less than 10% of what the power calculations suggested was needed and that meaningful data could not be generated. The calculation details and intended enrollment are not reported. This means that the observed absence of pathologic nodes is descriptive and should not be mistaken for a conclusive test of the study's hypothesis.
In short, the record shows what was reported among the participants studied, but it leaves the amount of information and the precision of the diagnostic finding unclear. It supports neither a claim that ultrasound is effective nor a claim that it is ineffective. The result is best understood alongside the missing diagnostic detail, absence of a comparator, and stated enrollment limitation.
13. Why This Trial Matters Statistically
This trial illustrates an important distinction between an observed result and a statistically informative estimate. A registry can report a zero finding, but readers also need the denominator and an account of the analysis to judge how much evidence that result contains. Here, no pathologic lymph nodes were identified, while the total number of nodes investigated and the participant-level distribution are not reported. The recorded percentage therefore cannot be independently examined for precision.
It also demonstrates why design and analysis must be interpreted together. The scientific question concerns whether ultrasound adds information after standard dissection, but the study is single-group and has no concurrent control arm. A diagnostic procedure may be assessed descriptively in such a design, yet a controlled estimate of incremental detection is not available from this record. The stated aims of evaluating upstaging, sensitivity, and specificity are not accompanied by corresponding estimates.
The enrollment shortfall further limits what the result can establish. The registry says enrollment was less than 10% of the amount suggested by power calculations, but does not report the calculation or target. This leaves readers unable to assess the original planning assumptions and reinforces that the recorded zero finding is not a definitive answer to the study question.
Finally, the record shows the value of complete outcome reporting. Counts, denominators, analysis populations, uncertainty estimates, and definitions of diagnostic classifications would allow a more transparent assessment. Their absence does not invalidate the descriptive result, but it limits the conclusions that can reasonably be drawn from it.
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 main trial-specific limitation is enrollment of 9, which the registry characterizes as less than 10% of what the power calculations suggested was needed. The study is marked terminated, and the registry states that the number consented was insufficient to generate meaningful data. The target enrollment, power calculation details, and reason for termination beyond the enrollment shortfall are not reported in the registry record.
The single-group design has no separate control arm. It therefore does not provide a direct comparison between ultrasound-assisted assessment and standard surgical assessment alone. The record also does not report a participant-level estimate of pathologic upstaging, or the sensitivity and specificity that the study description says would be evaluated.
The primary outcome has a reporting gap: the registry states that no pathologic lymph nodes were identified and that the percentage was zero, but it does not report the total number of nodes investigated. It also does not provide participant-level data, diagnostic cross-classifications, or an uncertainty interval. This makes it impossible to reconstruct the outcome ratio or assess its precision from the registry record.
Analysis details are limited. The record contains no analysis entries and does not report analysis populations, missing-data procedures, multiplicity handling, or methods for accounting for multiple lymph nodes from the same participant. Participant characteristics beyond the study population description are not reported in the registry record. Safety reporting is limited to the recorded counts and does not include event-level descriptions or a stated follow-up duration.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Thoracoscopic Lung Cancer Staging With the Use of Intraoperative Ultrasound — NCT02218242.
- Registry record last updated 2018-11-07; status last verified 2018-10.
- Results first posted 2018-11-07.
- 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
This registry record describes a terminated, single-group study of intraoperative ultrasound during surgical resection and staging of lung cancer. Enrollment was 9. The study aimed to identify occult pathologic N2 lymph nodes after standard dissection and to evaluate ultrasound as an additional diagnostic tool.
The primary outcome was described as the ratio of cancerous nodes identified to nodes investigated with ultrasound. The registry states that no pathologic lymph nodes were identified and that the percentage was zero. It does not report the total number of nodes investigated, diagnostic-accuracy estimates, confidence intervals, or analysis entries. The record says enrollment was less than 10% of what power calculations suggested was needed and that meaningful data could not be generated.
The design has no comparator group. Safety reporting lists 0 serious adverse events, 0 other adverse events, and 0 deaths among 9 participants at risk. Further details about the analysis, missing data, and safety follow-up are not reported in the registry record.