Volumetric Specimen Imager Device for the Intraoperative Imaging of Patients With Breast Carcinoma and Breast Ductal Carcinoma In Situ, The VIVID Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Volumetric Specimen Imager Device for the Intraoperative Imaging of Patients With Breast Carcinoma and Breast Ductal Carcinoma In Situ, The VIVID Study (NCT05545150), a na phase 2 study. The primary outcome is Positive Margins.

2. Clinical Question

The clinical question is therefore about the intraoperative use of volumetric specimen imaging and a specified margin outcome in patients having breast-conserving surgery. It is not a randomized comparison of imaging against no imaging. The study description explains that the device is intended to assist surgeons in identifying tissue that may need further removal while the patient is still in the operating room. The primary endpoint focuses on a margin that remains positive and was not excised through an intraoperative VSI-directed shave. It does not, by itself, summarize every aspect of surgery, later pathology, or subsequent care. Although the registry lists sensitivity, specificity, length of time, and volume of tissue excised as secondary outcomes, their measured values are not reported in the registry record. The registry also does not report how many participants had each listed condition, or whether the primary endpoint differed across those conditions.

3. Trial Design

This is a phase II, single-group study sponsored by Northwestern University. The registry reports an enrollment of 113 and a completed study. The listed start date is 2022-11-28, and the primary completion date is 2024-07-26. These are registry dates; the record does not describe the timing of individual participants’ procedures or follow-up assessments.

Patients undergo breast-conservation surgery, described as lumpectomy or partial mastectomy, per standard care. VSI imaging is captured on the day of surgery. The registry classifies the intervention as intraoperative imaging and lists lumpectomy as an intervention as well. No randomized allocation or masking is described: allocation is listed as not applicable and masking as none. The design is single-group, and the record explicitly notes that there is no randomized comparison and that arms are not a like-for-like control comparison.

The primary endpoint is defined around positive margins in the main specimen and whether these were excised intraoperatively by a VSI-directed shave. The endpoint uses a patient-level definition: a patient is counted if at least one main-specimen positive margin was not excised in that way. The registry gives separate definitions of a positive margin for invasive breast cancer and for ductal carcinoma in situ, including ductal carcinoma in situ with microinvasion.

The registry lists seven outcome measures and three analyses, but it does not describe their individual analysis methods, timing, or participant sets. A protocol-specific sample-size justification, a detailed statistical analysis plan, interim analyses, and analysis-population definitions are not reported in the registry record. The sample-size assumptions described for planning illustrations are not the trial’s own design rationale. Because there is no control group, results from this study would describe observed outcomes in the enrolled single group rather than a randomized treatment contrast.

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.

Before assignment: A total of 113 participants were enrolled into the study. For 13 of these, VSI was not used during surgery due to scheduling challenges. A total of 100 participants underwent the complete study protocol and had observed outcomes.

Overall Study

Reasons for not completing this period:

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 Positive Margins, measured over Intraoperative.

The primary endpoint measures the percentage of patients with at least one main-specimen positive margin that was not excised intraoperatively by a VSI-directed shave. It combines two features: the main specimen has a margin meeting the registry’s definition of positive, and that margin was not removed through the specified intraoperative response. The unit is participants, and the timeframe is intraoperative.

The registry defines a positive margin differently according to pathology context. For invasive breast cancer, including invasive breast cancer with a ductal carcinoma in situ component, a positive margin is ink on tumor, meaning one or more tumor cells touch the edge of the lumpectomy specimen. For ductal carcinoma in situ, including ductal carcinoma in situ with microinvasion, the definition uses ink within 2 mm of the edge of the specimen.

As a general statistical matter, a prespecified primary endpoint gives a study a principal outcome to describe and helps readers distinguish that central question from secondary outcomes. Here, the endpoint is focused on intraoperative margin management rather than being a broad measure of every surgical or later clinical outcome. Its patient-level definition means that the endpoint concerns whether a participant has at least one qualifying margin, not the total number of positive margins across specimens. The registry record does not report the observed percentage, its denominator, or an uncertainty interval. It is therefore not possible to quantify the observed frequency or its precision from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes a single-group study and names the primary endpoint, but it does not report a full statistical analysis plan or the numerical results for that endpoint. The methods below explain general statistical ideas relevant to interpreting a study of this type. They are not claims about analyses actually performed unless explicitly described in the registry record.

What does the endpoint count?

The primary outcome is a participant-level binary outcome: a patient either meets the endpoint definition or does not. Meeting it requires at least one main-specimen positive margin that was not excised intraoperatively by a VSI-directed shave. A binary endpoint is often summarized by the number of participants meeting the definition and the number evaluated, together with a proportion. The registry record does not report those observed counts or the proportion. It also does not report a confidence interval or another measure of uncertainty for this outcome.

The positive-margin definitions depend on the disease context. For invasive breast cancer, including invasive breast cancer with a ductal carcinoma in situ component, the definition is ink on tumor. For ductal carcinoma in situ, including ductal carcinoma in situ with microinvasion, it is ink within 2 mm of the specimen edge. These definitions determine which cases count toward the endpoint; they are not interchangeable across all participants.

What does a confidence interval convey?

As a general statistical concept, a confidence interval describes uncertainty around an estimated quantity under the assumptions of the method used to calculate it. For a participant proportion, an interval can show how much precision is supported by the observed number of participants and events. A narrower interval indicates greater precision under that method, while a wider interval indicates more uncertainty. A confidence interval does not guarantee that the estimate is free of bias, and it does not resolve limitations caused by study design or outcome measurement. No interval for the primary endpoint is reported in the registry record.

What can a single-group design estimate?

In general, a single-group study can describe outcomes observed among participants who received the study procedure or intervention. It does not include a concurrent randomized group to provide a direct comparison. Differences from an external benchmark, if considered, can be affected by differences in participant selection, clinical practice, outcome definitions, and follow-up. The registry record does not report an external comparison or a control group. Therefore, the study design as registered does not yield a randomized between-group estimate.

Allocation is listed as not applicable, masking as none, and the model as single group. These registry entries describe the design, but they do not give the detailed procedures for outcome assessment or adjudication. The record does not report whether the primary outcome was assessed independently of the imaging interpretation, or how disagreements about margin status were handled.

How should secondary measures be understood?

The registry lists sensitivity and specificity, as well as length of time and volume of tissue excised, among the secondary outcomes. In general, sensitivity and specificity are classification measures that depend on a reference standard and clear definitions of positive and negative findings. Their interpretation can also depend on which observations are included. The reference standard, thresholds, exact denominators, and results for these measures are not reported in the registry record. The record also does not provide the units, summary method, or results for time or tissue volume.

Different outcome types generally require different summaries. A binary participant outcome may be presented as a count and proportion, while a continuous measure such as time or volume may be described using a measure of central tendency and variability. This is a general explanation, not a statement about which summaries were used in this study. The registry record does not specify the statistical methods for the listed secondary outcomes.

What do the planning illustrations mean?

The registry’s sample-size assumptions describe a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation. The illustration considers an effect stated as a fraction of the observed effect. It is not the trial’s own design justification. The registry says that non-time-to-event illustrations are expressed as participants per arm for 80% power or other stated power levels, and time-to-event illustrations as a total number of events. No resulting sample-size values or observed effect are reported in the registry record.

As a general concept, power is a design-stage probability under specified assumptions, not a measure of how likely a study result is true. A planning illustration using an observed effect is not observed power and does not establish that the study was designed around that effect. Here, the illustration’s hypothetical two-arm allocation should not be confused with this study’s single-group design. The registry does not report a protocol sample-size justification or the assumptions used for the original trial design.

The record reports three analyses but does not describe them in enough detail to identify their models, adjustment methods, estimation procedures, or handling of repeated measurements. No recalculated results or discrepancy between a sponsor analysis and a recalculation are reported in the registry record. Statistical methods that were not specified should not be inferred from the endpoint type or the study phase.

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("Diagnostic (Volumetric Specimen Imager Device)")
n      <- c(100)
events <- c(9)
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  Diagnostic (Volumetric Specimen Imager Device)  100  9  9.0  4.2  16.4  4.8  16.2  4.9  16.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists seven outcome measures and three analyses. It does not report a detailed statistical analysis plan identifying which outcomes or analyses were prespecified, how they were prioritized, or whether any adjustment for multiple testing was planned. The primary endpoint is identified, but the registry does not state how statistical testing across the primary and secondary outcomes was handled.

As a general statistical matter, evaluating multiple outcomes or conducting multiple tests can increase the chance of at least one apparently unusual result when each test is considered separately. Methods for addressing this concern vary by study objective and analysis plan. Without the specified plan and results, it is not possible to determine whether multiplicity adjustment was used or how it would affect interpretation.

Missing-data methods and the extent of missing outcome information are not reported in the registry record. The record does not give the number of participants with evaluable primary endpoint data, the reasons data might be unavailable, or whether any imputation or sensitivity analyses were conducted. It also does not define the analysis populations, such as which participants were included in each outcome analysis. The enrollment count alone does not establish the denominator for any endpoint.

The safety listing gives 100 participants at risk in the diagnostic group, whereas the registry reports enrollment of 113. The record does not explain this difference or identify the analysis population underlying the safety count. It should not be assumed that the safety denominator applies to the primary endpoint or to the secondary outcomes. These omissions limit assessment of completeness and of how analyses relate to the enrolled group.

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.

The registry lists a diagnostic group with 100 participants at risk for serious adverse events and 0 participants affected. It also lists 100 at risk for other adverse events and 0 affected, with 0 deaths. No serious adverse event terms are listed. These are the recorded safety figures; the registry record does not provide further detail about event definitions or collection procedures.

The at-risk count for this safety listing is not the same as the reported enrollment of 113, and the registry does not explain the difference. The figures should therefore be read with their listed safety denominator rather than assumed to represent all enrolled participants. The record also does not state a safety follow-up timeframe, whether events were actively solicited, or how severity and relatedness were determined.

As a general statistical matter, observing zero recorded events does not establish that the true risk is zero. Interpretation depends on the number assessed, the observation period, and the completeness and method of event ascertainment. The registry record does not report enough detail to quantify uncertainty around these safety counts. The figures describe what is recorded, not a guarantee about safety outside the recorded group or observation period.

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

The registry record describes a phase II, single-group evaluation of intraoperative VSI imaging during breast-conservation surgery. It defines a primary endpoint involving main-specimen positive margins that were not excised intraoperatively by a VSI-directed shave. These details clarify what the study was intended to examine and how the main outcome was defined.

However, the registry record does not report the observed primary endpoint count or percentage, a confidence interval, or a statistical test result. It also does not report numerical results for the listed secondary outcomes. The record therefore does not support a quantitative conclusion about how often the primary endpoint occurred or how precisely it was estimated. It also does not establish whether the imaging changed outcomes compared with another approach.

The absence of a randomized comparator matters when interpreting effects. A single-group result describes outcomes among participants in that group; it cannot, by itself, separate the effect of imaging from other factors that may influence outcomes. This does not negate the descriptive value of a single-group study, but it limits the causal claims that can be made from its design.

These limitations do not mean that no outcome information exists outside the registry record. They mean that the registry record itself does not report the information needed to assess the primary result or make a comparative inference. The appropriate reading is to distinguish the stated research question and endpoint from results that are not reported. No conclusion about benefit or lack of benefit should be drawn from the design description or the absence of reported numerical outcomes alone.

14. Why This Trial Matters Statistically

The study raises a statistical question with a specific intraoperative focus: whether a margin-related outcome can be characterized when volumetric imaging is used during breast-conservation surgery. Its primary endpoint is defined at the participant level and depends on both a pathology-based margin definition and whether a qualifying margin was excised through an intraoperative VSI-directed shave. Clear definitions matter because they determine which observations count as endpoint events.

The design also illustrates why the form of evidence matters. A single-group study can describe what occurred among participants receiving the study approach, but it does not supply a randomized control contrast. Readers need to distinguish an observed frequency from an estimate of comparative effect. The registry identifies the single-group design and explicitly notes the absence of a like-for-like control comparison.

Another statistical consideration is whether the reported endpoint can be interpreted precisely. Counts, denominators, and uncertainty intervals are important for understanding a participant-level outcome. The registry record defines the primary endpoint but does not report its observed count, percentage, denominator, or uncertainty. It also names secondary measures with different statistical interpretations, including classification measures and measures of time or tissue volume, without reporting their results or methods.

The record therefore helps identify the question and some design features, while also demonstrating the limits of interpreting a registry entry without outcome estimates and analysis details. The distinction between a stated endpoint, a planning illustration, and an observed result is central: the sample-size illustration is not the original trial justification and is not a result. Transparent reporting of analysis populations, missing data, and statistical methods would be needed to evaluate the precision and robustness of reported estimates.

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 central limitation for interpreting this registry record is that it does not report the observed primary endpoint result. The endpoint definition is detailed, but its count, denominator, percentage, and uncertainty are not reported. Numerical results for the listed secondary outcomes are also not reported, so their magnitude and precision cannot be assessed.

The single-group design has no randomized comparator. It can describe the study group but does not provide a direct randomized estimate of the difference between VSI imaging and another approach. The registry does not report a detailed analysis plan, the methods used for the three analyses, or whether outcome assessment was masked. Masking is listed as none, but the record does not explain the assessment procedures.

Further information needed to evaluate the results is not reported in the registry record: participant characteristics, detailed eligibility criteria, outcome-specific denominators, missing-data handling, analysis populations, and the statistical methods for the primary and secondary outcomes. The relationship between the enrollment of 113 and the safety listing of 100 participants at risk is not explained. The registry also does not give a safety observation period or event-ascertainment details.

The planning assumptions are described as an illustration based on an observed effect, not as the trial’s own sample-size justification. The record does not report the original design rationale or the observed effect used for the illustration. These limitations restrict what can be concluded from the registry record; they are not evidence that unreported methods or results were absent from other records.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Volumetric Specimen Imager Device for the Intraoperative Imaging of Patients With Breast Carcinoma and Breast Ductal Carcinoma In Situ, The VIVID Study — NCT05545150.
• Registry record last updated 2026-08-19; status last verified 2026-07.
• Results first posted 2026-08-19.
• 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

NCT05545150 is a completed phase II, single-group study sponsored by Northwestern University. It enrolled 113 participants and evaluated intraoperative volumetric specimen imager use during breast-conservation surgery. The registry lists no randomized allocation and no masking.

The primary endpoint is the percentage of patients with at least one main-specimen positive margin that was not excised intraoperatively by a VSI-directed shave. The registry lists sensitivity, specificity, length of time, and volume of tissue excised among the secondary outcomes. It does not report the observed primary endpoint result or numerical results for those secondary outcomes.

The safety listing records 0 serious adverse events among 100 participants at risk, 0 other adverse events among 100 at risk, and 0 deaths. The record does not explain the safety denominator or provide further event follow-up details. The single-group design supports description of the enrolled group, not a randomized comparison.