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 Intra-operative Use of Indigo Carmine Dye for the Delineation of Ill Defined Tumor Borders Using Stereotactic Injection (NCT01767415), a na phase 1, phase 2 study. The primary outcome is Extent of Resection.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01767415 |
| Phase | Phase 1, Phase 2 |
| Condition | Brain Tumors With Ill-defined Margins |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 10 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Weill Medical College of Cornell University |
| Results posted | Yes |
2. Clinical Question
Population
People with brain tumors with ill-defined margins were the intended population. The registry describes the primary outcome population as undergoing intraoperative stereotactic injection of indigo carmine at the tumor margins. Enrollment was 10; further eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
The intervention was intraoperative stereotactic injection of indigo carmine. The study’s stated purpose was to investigate whether this approach could safely increase the extent of tumor resection. That purpose is a research question, not a finding that the intervention increased resection or was safe.
Comparator
The registry describes a single-group study, with allocation recorded as NA and no masking. It does not identify a comparison group or a control intervention. Consequently, the record does not support a like-for-like comparison between indigo carmine and another treatment or approach.
Primary question
The primary outcome was extent of resection, expressed as the percentage of tumor resected and assessed at 48 hours. The registry specifies a mean parameter and full-range dispersion, but does not report the observed outcome values. The posted information therefore does not establish what extent of resection was observed.
The central clinical question was whether indigo carmine injected stereotactically during surgery could help delineate ill-defined tumor borders, with extent of resection as the primary measure and complications after injection as a listed secondary outcome. The registry’s brief summary frames safety and increased resection as aims to investigate. A stated aim should not be read as a result: the available record does not give the primary outcome value or a statistical analysis of it.
The record identifies the intervention and intended tumor population, but does not report details such as participant-level tumor characteristics, the criteria used to define an ill-defined margin, or the surgical procedures apart from the stereotactic injection description. It also does not describe a comparator. Since the study is single-group, outcomes can be described for the enrolled group, but the registry does not provide a direct contrast with care without indigo carmine. Without such a contrast, the posted information cannot isolate the contribution of the dye from other influences on resection or complications.
The safety question also requires careful wording. The registry lists absence of complications after injection as a secondary outcome and records adverse-event counts. Those entries describe reported events within the study group; they do not, on their own, establish whether an event was caused by the injection. The record does not report the details needed to determine such attribution or to compare the observed safety experience with another group.
3. Trial Design
The registry identifies this as a phase 1/phase 2, single-group study with allocation recorded as NA and masking recorded as none. Enrollment was 10. The study status is completed; its recorded start was 2012-04 and its primary completion was 2014-04. The sponsor is Weill Medical College of Cornell University. The registered condition is brain tumors with ill-defined margins.
The listed intervention was indigo carmine, described as intraoperative stereotactic injection. Because the design is single-group, the registry does not describe random assignment between treatments or a concurrent control arm. Allocation marked NA should not be interpreted as evidence of randomization. The absence of masking means no masking is recorded; the record does not give additional details about who knew the intervention or how outcome assessments were conducted.
The primary outcome was extent of resection, expressed as a percentage of tumor resected, with an assessment timeframe of 48 hours. The registry specifies the mean as the parameter and the full range as the dispersion measure. A secondary outcome is listed as absence of complications after injection. The record identifies 2 outcome measures, but provides no numerical primary-outcome result in the available information. It also records 0 statistical analyses.
This design can describe what was observed among the enrolled group if outcome data are available, but the registry record does not present those primary outcome values. It does not identify a comparator from which to estimate a treatment contrast. The stated purpose of investigating whether injection could safely increase resection remains a research aim, not a conclusion demonstrated by the design description alone.
Other design details are not reported in the registry record. These include eligibility criteria beyond the broad condition, how participants were recruited, any planned or actual sample-size justification, the specific surgical protocol, the timing and method of outcome assessment beyond the stated 48-hour timeframe, and the statistical analysis plan. The fact that the registry labels the study phase 1/phase 2 does not fill in those missing details.
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 | Indigo Carmine |
|---|---|
| STARTED | 10 |
| COMPLETED | 10 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: intraoperative stereotactic injection of indigo carmine at the tumor margins
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.
Population: Information collected from all study participants.
| Characteristic | Unit | Indigo Carmine |
|---|---|---|
| Participants analysed | 10 | |
| Age, Continuous | years | 49 (25 to 74) |
| Sex: Female, Male: Female | Participants | 4 |
| Sex: Female, Male: Male | Participants | 6 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 10 |
| 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 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 10 |
| Region of Enrollment: United States | participants | 10 |
| Tumor Location: Lt Temporal | Participants | 1 |
| Tumor Location: Lt Frontal | Participants | 2 |
| Tumor Location: Rt frontal | Participants | 2 |
| Tumor Location: Lt Occipital | Participants | 2 |
| Tumor Location: Rt parietal | Participants | 1 |
| Tumor Location: Rt occipital | Participants | 1 |
| Tumor Location: Lt parietal | Participants | 1 |
| Tumor Diagnosis: Incidental finding | Participants | 3 |
| Tumor Diagnosis: Recurrent Disease | Participants | 3 |
| Tumor Diagnosis: Seizures | Participants | 1 |
| Tumor Diagnosis: Headache | Participants | 1 |
| Tumor Diagnosis: Neurological Defect | Participants | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Extent of Resection, measured over 48 hours.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Full Range |
| Unit | percentage of tumor resected |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is extent of resection, defined in the registry as the percentage of tumor resected following indigo carmine infusion to the tumor. The stated assessment timeframe is 48 hours. The registry identifies the outcome parameter as a mean and its dispersion as the full range. These labels describe how the result is intended to be characterized; they do not supply the observed mean or the observed range.
As a general statistical concept, extent of resection is a quantitative measure of how much of a tumor was removed. It is used to address the study’s stated question about whether stereotactic dye injection could increase resection. A percentage-based endpoint can communicate the amount resected relative to the tumor, but its interpretation depends on how tumor extent and resection were assessed. Those assessment procedures are not reported in the registry record beyond the stated description and timeframe.
A mean describes the central value of measured outcomes across observations. The full range describes the smallest and largest observed values, giving a view of the span of results but not indicating how observations are distributed within that span. General statistical interpretation of a mean and range requires the underlying observations or reported summary values. Neither the observed mean nor the full range is present in the available record, so the endpoint’s actual value and variability cannot be assessed from these registry entries.
The registry also does not report an estimate of uncertainty, such as a confidence interval, for the primary endpoint. In general, a confidence interval conveys the precision of an estimate under the assumptions of the analysis. Without a reported estimate and interval, the precision of the mean extent of resection cannot be evaluated. The listed endpoint definition should therefore be distinguished from evidence about the observed extent of resection.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes that the study investigated intraoperative stereotactic indigo carmine injection in brain tumors with ill-defined margins. It identifies extent of resection as the primary outcome, measured as a percentage of tumor resected at 48 hours. It does not report the observed value for that outcome. As a result, the primary clinical question cannot be answered from the outcome information in this record: no numerical estimate of resection extent, range, or uncertainty is available.
The study is recorded as single-group, with allocation NA and no masking. It therefore does not provide a like-for-like comparison with a control group in the information available. A within-group description, even if the primary values were present, would not by itself quantify what would have happened under a different approach. Differences among participants, surgical circumstances, and assessment practices could contribute to the observed outcomes, and the record does not report enough design or analysis detail to evaluate those influences.
The study’s brief summary says its purpose was to investigate whether injection could safely increase extent of resection. This language describes the motivation, not an outcome conclusion. The record’s completed status likewise indicates that the study is marked completed in the registry; it does not mean that all results are posted. The registry records 0 statistical analyses, and the registry entries do not include a primary-outcome estimate or inferential test.
For safety, the adverse-event information records 1 serious event among 10 at risk and 1 other event among 10 at risk. The listed leading serious-event term is Staphylococcus aureus infection (brain abscess), with 10.0% recorded. These are descriptive entries. The record does not establish event attribution, give enough information to determine whether the entries refer to overlapping participants or event episodes, or report a comparator rate. The death count is not reported in the registry record.
General statistical interpretation emphasizes that estimates need both a clear definition and information about uncertainty. A point estimate describes a result in the analyzed observations, while an interval can show how imprecisely that estimate is known under the chosen model. Neither the primary estimate nor an interval is reported. The small enrollment of 10 also means that any observed group-level summaries would need cautious interpretation, but no precision calculation should be inferred from enrollment alone. The analysis population, missing-data handling, and statistical model are not reported in the registry record.
Accordingly, the posted information supports a description of the study’s objective, design labels, endpoint definition, and recorded adverse-event counts. It does not support a quantitative claim about the amount of tumor resected, a comparative effect, or a definitive conclusion about safety. The planning illustrations associated with the record are not observed trial outcomes or observed power; their assumptions do not replace missing outcome estimates.
9. Statistical Methods Explained
What does a single-group design allow?
The registry classifies the study as single-group and records allocation as NA. In general, a single-group design collects observations in a group receiving the intervention without a concurrent comparison group specified in the design. It can describe what was observed among participants, provided outcome results are reported. It does not directly estimate a contrast against another treatment or against no intervention.
That distinction matters because a change or outcome within a treated group is not automatically attributable to the intervention. General sources of variation can include differences between participants, procedures, and outcome measurement. A comparison group can help address some questions about what would have happened under an alternative, although it does not automatically remove all bias. No such comparison is described in this record. The absence of a comparator limits interpretation of the stated aim to investigate whether injection could increase resection.
What do the endpoint summary labels mean?
The primary outcome is specified as a mean percentage of tumor resected, with full-range dispersion. In general, the mean is an average that summarizes the center of measured values. It can be affected by unusually high or low observations. The full range gives the lowest and highest observed values, indicating the spread between the extremes. It does not show whether most observations lie near the center or near one extreme, and it can be sensitive to extreme values.
The registry provides these summary labels but not the observed mean or range. Nor does it report a confidence interval. In general, a confidence interval expresses uncertainty around an estimate under a statistical model and its assumptions; a narrower interval usually indicates greater precision under those assumptions. Since no estimate or interval is posted in the registry entries, neither the magnitude nor precision of the primary result can be evaluated.
What does the absence of a listed analysis mean?
The record identifies 0 statistical analyses. This means no statistical analyses are listed in the registry information used for this description. It does not justify inferring which analyses were conducted outside the registry, whether analyses were planned, or why results are absent. The statistical methods, any adjustment, any hypothesis test, and any confidence-interval method are not reported in the registry record.
As a general principle, the analysis should match the outcome type and design. A quantitative endpoint such as percentage resected can be summarized with a center and measures of spread, but a suitable model also depends on the distribution of observations, data completeness, and the question being asked. For a single-group study, descriptive summaries may characterize the group; a claim about comparative effect would require an appropriate comparator or other clearly justified design and assumptions. The registry does not report enough detail to assess a model or its assumptions.
Why does over-dispersion matter in general?
Over-dispersion is a general issue for count outcomes when observed variability exceeds what a chosen model assumes. If a model underestimates variability, uncertainty estimates may be too small and inferential results may appear more precise than warranted. This concept is relevant to count-data methods generally, but the registry does not report a count-outcome model or any analysis of over-dispersion for this study. It should not be taken as a description of an analysis performed in this trial.
How should the planning illustrations be read?
The record describes planning illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. For time-to-event illustrations, the stated quantity is the total number of events; for other illustrations, it is participants per arm.
These assumptions are planning inputs, not features that establish the actual study design. In particular, the registered study is single-group, whereas the illustration assumes equal allocation between two arms. The illustration should not be read as evidence that the study randomized participants or had two treatment arms. It is not observed power. Sample-size planning calculations describe what might be needed under specified assumptions; they do not describe the precision achieved by this completed study. The numerical illustration values and the observed primary effect are not reported in the registry record.
General power calculations depend on a target effect, variability assumptions, significance level, allocation, and analysis method. If assumptions differ from the eventual data or design, planning calculations may not reflect actual precision. No trial-specific sample-size justification, planned effect, interim analysis, or statistical plan is reported in the registry record, so none should be inferred from the presence of a planning illustration.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists extent of resection as the primary outcome and absence of complications after injection as a secondary outcome. It records 2 outcome measures and 0 statistical analyses. A distinction between primary and secondary outcomes identifies their registered roles, but it does not reveal how hypotheses were tested or how uncertainty was quantified.
Multiplicity refers, in general, to the increased chance of at least one false-positive finding when several statistical tests or outcomes are considered. Researchers may address this through a prespecified hierarchy, adjustment, or other strategy. No multiplicity strategy, hypothesis-testing plan, or adjustment is reported in the registry record. Because no analyses are listed, there is no basis for describing whether multiplicity was addressed in an analysis.
The registry record does not report how missing endpoint values were handled, whether any primary outcome observations were missing, or what analysis population was used. It does not describe exclusions, protocol deviations, or whether participants were analyzed according to any prespecified rule. These details matter generally because excluding observations or handling missingness in different ways can alter summaries and their uncertainty. Their absence must not be interpreted as evidence that there were no missing data or exclusions.
The record also does not report a statistical analysis plan, interim analyses, or a sample-size justification. The planning illustrations described separately are not a substitute for those trial-specific details. Without the analysis plan and results, readers cannot determine which analyses were prespecified, whether analyses were adjusted, or how the primary and secondary outcomes were treated. These items are not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Indigo Carmine | 1 | 10 | 10.0% |
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 |
|---|---|
| Indigo Carmine | 1 of 10 |
Most frequent serious adverse event terms
| Event term | Organ system | Indigo Carmine |
|---|---|---|
| Staphylococcus aureus infection (brain abscess) | Infections and infestations | 1 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Indigo Carmine |
|---|---|---|
| hemiparesis | Nervous system disorders | 1 of 10 |
Serious events with the highest arm-level rate: staphylococcus aureus infection (brain abscess) (10.0%).
The registry records 1 serious adverse event among 10 at risk and 1 other adverse event among 10 at risk in the Indigo Carmine group. The listed leading serious-event term is Staphylococcus aureus infection (brain abscess), recorded as 10.0%. The registry also lists absence of complications after injection as a secondary outcome. These entries should be read as descriptive safety information recorded for the study group.
The record does not report enough detail to determine whether an adverse event was judged related to indigo carmine or the injection, how events were defined or collected, or whether the serious and other-event entries involved the same participant or overlapping episodes. The counts should not be added together to infer a number of affected participants. The death count is not reported in the registry record.
As a general statistical point, an event count in a small study can be informative as a description of what was recorded but gives limited information about the frequency of uncommon harms. A comparator can also help put observed event counts in context; no comparator group is reported for this single-group study. The registry counts therefore do not, by themselves, establish a causal relationship or a comparative safety profile.
12. What the Result Does, and Does Not, Mean
The record’s contribution is a registered description of a study investigating intraoperative stereotactic indigo carmine injection for delineating ill-defined tumor borders. It identifies extent of resection as the primary endpoint and absence of complications after injection as a secondary outcome. It also supplies design information and adverse-event counts. These details explain what the study set out to examine and what safety entries were recorded.
The registry entries do not report the observed mean percentage of tumor resected or its full range. They therefore do not show the amount of tumor resected in the study group or the variability of that outcome. No confidence interval or analysis is listed, so the precision and statistical evidence for the primary outcome cannot be assessed. The stated research purpose should not be mistaken for a positive finding.
The single-group design does not provide a like-for-like control comparison. Consequently, the registry entries do not establish that the intervention caused a particular extent of resection or changed resection relative to an alternative. They also do not establish that a recorded adverse event was caused by the dye or injection. The posted safety counts describe what is recorded, not a comparative risk estimate.
General interpretation of clinical research requires attention to both the observed results and the design that generated them. A quantitative result can be interpreted in light of its uncertainty, measurement process, and analysis population. Here, the primary estimate, uncertainty, measurement details, missing-data approach, and analysis population are not reported in the registry record. The study’s enrollment of 10 and its phase 1/phase 2 designation do not supply those missing elements.
The planning assumptions associated with the record are also not evidence of observed efficacy or observed power. They are described as planning illustrations, using assumptions that include equal allocation between two arms, while the registered design is single-group. They should not be treated as a report of how the participants were assigned or as a substitute for actual outcome results.
In short, the registry establishes the research question and some design and safety details, but it does not provide enough outcome or analysis information to support a conclusion about increased resection, comparative benefit, or definitive safety. The limitations are gaps in the posted record, not proof that outcomes were absent or that analyses were never conducted outside it.
13. Why This Trial Matters Statistically
This study is statistically notable because its stated clinical question concerns whether a technique can help delineate ill-defined tumor borders, while the registry identifies a single-group design and does not report the primary endpoint result. The contrast between a clearly defined research aim and missing outcome estimates illustrates why an endpoint description alone is not evidence of an effect. A reader needs the observed result and its uncertainty to judge what the data show.
The registry’s specification of a mean percentage resected and full-range dispersion identifies a possible descriptive summary, but each answers a different question. The mean gives a central summary; the range indicates the span of observations. Neither is present as a numerical result in the available record. Without the results, readers cannot assess central tendency or variation, and without an interval they cannot assess precision through an uncertainty estimate.
The single-group structure is also central. It can describe an intervention group but does not itself create the counterfactual comparison needed to estimate what would have happened under another approach. This is a general design issue, not a judgment about the study’s purpose. The record does not report a comparator, a random allocation scheme, or a statistical method that would support a comparative estimate.
The safety entries make a further statistical point: descriptive counts are not equivalent to causal attribution. The registry reports events within the group, but does not provide details sufficient to interpret causality or comparative frequency. With enrollment of 10, the counts should be presented as the recorded experience, rather than treated as a precise estimate of uncommon-event frequency.
Finally, the presence of planning illustrations should be distinguished from an analysis of observed outcomes. Planning calculations rest on assumptions and are not observed power. This distinction is especially important when the registered design is single-group but the illustration assumes two arms with equal allocation. Clear separation of design, planning assumptions, posted results, and unreported analysis details is essential to an accurate statistical reading.
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 principal limitation of the available record is that it defines the primary outcome but does not report its observed value. The mean percentage resected and full range are not available, and the record includes no reported uncertainty estimate. As a result, the primary outcome cannot be quantitatively interpreted from the posted information.
The single-group design and allocation recorded as NA mean that no like-for-like control comparison is described. This limits what can be inferred about a treatment effect, even if group outcome values were available. Masking is recorded as none, but further information about outcome assessment and awareness is not reported in the registry record.
The registry does not report the sample-size justification, eligibility criteria in detail, participant characteristics, surgical procedures beyond the intervention description, or methods for assessing the endpoint. It also does not report a statistical analysis plan, analysis population, missing-data handling, or multiplicity approach. The record lists 0 statistical analyses, so no inferential result is available in the registry record.
Safety interpretation is limited by the descriptive nature of the recorded counts and by the absence of reported details on event attribution, ascertainment, and overlap between entries. The death count is not reported in the registry record. A comparator safety rate is also not available in this single-group record.
These are limitations of the information reported in the registry record. They do not establish whether additional information exists elsewhere or whether unreported analyses were conducted. No conclusion about efficacy, comparative effect, or definitive safety should be inferred from the endpoint definition, study completion status, or planning assumptions alone.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Intra-operative Use of Indigo Carmine Dye for the Delineation of Ill Defined Tumor Borders Using Stereotactic Injection — NCT01767415.
- Registry record last updated 2018-12-11; status last verified 2018-11.
- Results first posted 2018-12-11.
- 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
The registry record identifies a completed phase 1/phase 2, single-group study of intraoperative stereotactic indigo carmine injection for brain tumors with ill-defined margins. Enrollment was 10, allocation was recorded as NA, and masking was recorded as none. The sponsor was Weill Medical College of Cornell University.
The primary outcome was extent of resection, defined as percentage of tumor resected at 48 hours, with a mean parameter and full-range dispersion. Absence of complications after injection was listed as a secondary outcome. The record lists 0 statistical analyses and does not report the primary outcome value.
For the Indigo Carmine group, the registry records 1 serious adverse event and 1 other adverse event among 10 at risk. Staphylococcus aureus infection (brain abscess) is listed as the leading serious-event term at 10.0%. The death count is not reported in the registry record. These details describe the posted registry information but do not provide a comparative estimate or establish event causation.