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 Respiratory-gated Stereotactic Body Radiation Therapy for Adenocarcinoma of the Pancreas or Periampullary Region (NCT02780648), a na na study. The primary outcome is Acute Toxicity Rates of Grade 3 or Greater Gastrointestinal and Hematologic Toxicities (as Raw Percentage).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02780648 |
| Phase | NA |
| Condition | Pancreatic Neoplasms |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 36 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Indiana University |
| Results posted | Yes |
2. Clinical Question
Population
Patients with borderline resectable, unresectable, or recurrent/residual adenocarcinoma of the pancreas or periampullary region who had previously received treatment. The study description includes prior chemotherapy, surgery, photodynamic therapy, conventionally fractionated radiation treatment, or a combination of these. The primary endpoint population is described as eligible patients in cohorts A and B.
Intervention
Linac-based stereotactic body radiation therapy (SBRT), described as respiratory-gated. The registry says patients would receive 5 fractions of 5 Gy or 6.6 Gy, with the dose depending on whether they had previously received radiation therapy to the pancreatic region.
Comparator
There was no separate control group. This was a single-arm, single-group study, so the registry record does not support a randomized or like-for-like treatment comparison.
Primary question
Among eligible patients treated with SBRT, what percentages experienced acute, treatment-related grade 3 or greater gastrointestinal or hematologic toxicity within the stated follow-up period? The primary outcome description considers toxicities attributed to SBRT and says patients were at risk if they started SBRT.
The study also set out to estimate late gastrointestinal toxicity and describe local progression, overall survival, metastasis-free survival, progression-free survival, pain ratings, and quality-of-life measures. These are additional questions, not substitutes for the primary acute-toxicity endpoint. The registry lists the study as completed, with enrollment of 36. However, it does not report the primary endpoint estimate or the stated 90% confidence interval. Consequently, the record identifies what the investigators intended to measure but does not establish the observed acute toxicity percentage or its precision.
3. Trial Design
This was a prospective, single-center, single-arm study sponsored by Indiana University. The registry lists the study as completed, with enrollment of 36. It records a start date of 2016-05-01 and a primary completion date of 2019-12-17. The phase is listed as NA. Allocation is also listed as NA, and masking is listed as none. With no control arm, the design is descriptive rather than a randomized comparison of treatments.
The intervention was stereotactic body radiation, described in the study information as Linac-based SBRT. Treatment was planned as 5 fractions delivered over a five-day period. The listed dose was 5 Gy or 6.6 Gy per fraction, depending on prior radiation therapy to the pancreatic region. The study included people with pancreatic or periampullary cancer who had previously undergone other treatment. The record does not provide enough detail to determine how participants were assigned to cohorts A and B or how all eligibility decisions were made.
The primary objective was to estimate acute grade 3 or greater gastrointestinal and hematologic toxicity within 3 months of treatment. Secondary objectives included late gastrointestinal toxicities and measures of disease progression, survival, pain, and quality of life. The registry lists nine outcome measures and 16 analyses. It does not report a complete statistical analysis plan, including the planned methods for each outcome, handling of repeated measurements, or any interim analyses.
The record describes a sample-size illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those assumptions do not describe the single-group study design itself. Such figures are planning illustrations, not evidence of the study's original design rationale and not observed power. The protocol's sample-size justification is 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 | Cohort A | Cohort B |
|---|---|---|
| STARTED | 3 | 33 |
| COMPLETED | 2 | 33 |
| NOT COMPLETED | 1 | 0 |
Reasons for not completing this period:
| Reason | Cohort A | Cohort B |
|---|---|---|
| Disease Progression | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Includes all patients in cohorts A and B who met eligibility criteria for primary outcome measure.
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 | Cohort A | Cohort B | Total |
|---|---|---|---|---|
| Participants analysed | 3 | 33 | 36 | |
| Age, Continuous | years | 64 (SD 7.2) | 66.5 (SD 9.6) | 66.3 (SD 9.3) |
| Sex: Female, Male: Female | Participants | 2 | 18 | 20 |
| Sex: Female, Male: Male | Participants | 1 | 15 | 16 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 | 0 | 1 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 2 | 31 | 33 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 2 | 2 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 4 | 4 |
| Race (NIH/OMB): White | Participants | 3 | 27 | 30 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 2 | 2 |
| Region of Enrollment: United States | Participants | 3 | 33 | 36 |
6. Primary Endpoint
The registry lists the primary outcome as Acute Toxicity Rates of Grade 3 or Greater Gastrointestinal and Hematologic Toxicities (as Raw Percentage), measured over Up to 90 days after treatment.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 90% Confidence Interval |
| Unit | percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants experiencing acute grade 3 or greater gastrointestinal or hematologic toxicity attributed to SBRT. The registry defines the acute period as up to 90 days after treatment and describes toxicity grading according to Common Terminology Criteria for Adverse Events (CTCAE) 4.0. It says patients were considered at risk for an adverse event if they started SBRT. The primary population is described as eligible patients in cohorts A and B.
A percentage is a way to express how often an event occurred in the population at risk. For a toxicity endpoint, the estimate is meaningful only alongside a clear definition of the event, the population included, the follow-up period, and the handling of participants whose toxicity status is unknown. The registry describes the event criteria and the at-risk definition, but does not report the primary percentage, its confidence interval, or details about missing outcome data.
The endpoint focuses on more severe acute toxicities rather than all symptoms or adverse events. This makes it relevant to the study's stated safety objective, but it does not capture every possible consequence of treatment. Nor does an acute endpoint answer the separate questions about late toxicity, disease control, survival, pain, or quality of life. The record specifies a 90% confidence interval for the primary estimate, but the interval itself is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a study designed to estimate acute toxicity after SBRT in a previously treated patient population. Its primary outcome is a percentage of participants with treatment-related grade 3 or greater gastrointestinal or hematologic toxicity during the stated period. However, the registry record does not report the primary outcome estimate or its 90% confidence interval. There is therefore no posted primary result from which to assess the observed frequency of these toxicities or the precision of that estimate.
The record lists enrollment of 36 and identifies cohorts A and B in the primary population description. In the adverse-event information, Cohort A has 3 participants at risk for serious adverse events and 3 affected; Cohort B has 33 at risk and 33 affected. For other adverse events, the corresponding entries are 3 at risk and 3 affected in Cohort A, and 33 at risk and 24 affected in Cohort B. These are adverse-event reporting fields, not the missing primary endpoint result. The record does not establish that these fields use the same event definitions, time window, attribution rules, or analysis population as the primary toxicity outcome.
The serious adverse-event terms listed include Anemia, Hepatobiliary disorders - Other, sp, and Pleural effusion, each with a listed percentage of 33.3%; Ascites is listed at 12.1%; Abdominal infection and Adrenal insufficiency are each listed at 6.1%. These entries should be read as registry-listed serious-event terms and percentages, not as the primary endpoint's combined gastrointestinal and hematologic toxicity estimate. The record does not explain all details needed to interpret the percentages, such as whether the terms represent participants, event occurrences, or a particular follow-up interval.
Because this is a single-group study, any observed outcomes would describe participants treated in this study. They would not, on their own, show what would have happened to comparable patients under another treatment or without SBRT. Prior therapies and disease status are part of the study population's context, but the registry does not provide a comparative analysis that separates their influence from the intervention.
The study also names survival, progression, pain, and quality-of-life outcomes. Their results and analysis details are not reported in the registry record in the registry record for this interpretation. No conclusions about those outcomes should be inferred from the study's objectives alone. Overall, the posted information supports understanding the design and intended safety question, while leaving the primary estimate and its uncertainty unavailable.
9. Statistical Methods Explained
What a percentage estimates. The primary outcome is a percentage of participants with a defined toxicity. In general, a percentage summarizes the observed frequency of an event in a specified population. Its interpretation depends on who is counted as at risk, which events qualify, and the period during which events are assessed. Here, the registry says a patient was at risk if SBRT was started and defines the primary period as up to 90 days after treatment. It also specifies treatment-related grade 3 or greater gastrointestinal and hematologic toxicities. The actual primary percentage is not reported in the registry record.
Why a confidence interval matters. A confidence interval communicates uncertainty around an estimated quantity. In general, a narrower interval indicates greater precision, while a wider interval indicates less precision. The registry specifies a 90% confidence interval for the primary percentage, but does not report its limits. Without both the estimate and interval, readers cannot judge the magnitude of the observed primary toxicity percentage or how precisely it was estimated. A confidence interval is not a guarantee that the true value lies within its limits; it is an inferential summary whose interpretation depends on the statistical method and assumptions.
Single-group design. In a single-group study, outcomes are observed in one treated group rather than compared with a concurrent control group. The design can describe what occurred among participants who received the intervention. It cannot directly estimate a between-group treatment effect. Differences between cohorts, if presented, would not automatically be treatment effects, especially when the record does not describe random allocation or a control arm. The registry identifies the study as single-group and single-arm and lists allocation as NA.
Outcome definitions and attribution. The primary description limits the endpoint to adverse events considered related to SBRT and specifies CTCAE 4.0 grading. These definitions matter because broad event counts and treatment-related, grade-specific endpoint counts are not interchangeable. The registry's separate serious and other adverse-event fields should therefore not be assumed to reproduce the primary endpoint. The record does not provide enough information to reconcile those fields with the primary endpoint definition or to determine whether they cover identical populations and follow-up.
Multiple outcomes. The registry lists a primary toxicity outcome and secondary outcomes concerning late toxicity, survival, progression, pain, and quality of life. When many outcomes or analyses are considered, the chance of finding an apparently notable result by chance can increase if each is tested separately. Statistical approaches to this issue include prespecifying a primary outcome, adjusting significance thresholds, or treating secondary analyses as exploratory. The registry lists nine outcome measures and 16 analyses, but a multiplicity strategy is not reported in the registry record. The number of listed outcomes alone does not establish whether adjustment was planned or appropriate.
Missing outcome information. An analysis of a percentage requires knowing which participants have evaluable outcome status and how missing observations are handled. In general, excluding participants with missing status can bias an estimate if missingness is related to toxicity or other factors. Other approaches may be used, but their suitability depends on the reasons for missingness and the analysis objective. The record's primary population description identifies eligible patients in cohorts A and B, but it does not report the number with evaluable primary outcomes or a method for handling missing data.
Planning illustrations. The record describes sample-size illustrations using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and a target effect expressed as a fraction of the observed effect. It states that time-to-event illustrations give a total number of events, while other illustrations give participants per arm. These are planning assumptions, not the trial's reported design rationale. They also describe a two-arm allocation, whereas this trial is listed as single-group. Such planning numbers, if displayed, are not observed power and do not provide evidence about the trial's primary result.
Methods not documented. The registry record does not report the primary endpoint estimate or confidence interval, the method used to construct that interval, a complete statistical analysis plan, interim analyses, or the approach to missing data. It also does not provide sufficient analysis details to assess how each secondary outcome was modeled. General statistical concepts can clarify what those methods would mean, but they cannot replace the unreported trial-specific choices or results.
10. Multiplicity, Missing Data and Analysis Populations
The study had one stated primary objective and several secondary objectives. Secondary outcomes include late toxicity, overall survival, progression-free survival, metastasis-free survival, pain ratings, and quality-of-life measures. The registry lists nine outcome measures and 16 analyses. Considering multiple outcomes can create a multiplicity issue: in general, examining many results separately can increase the chance of at least one apparently notable finding even when there is no underlying effect. The registry does not report whether the investigators adjusted for multiplicity, prioritized secondary analyses, or treated them as exploratory.
The primary analysis population is described as eligible patients in cohorts A and B. The registry also says patients were at risk for an adverse event if they started SBRT. It does not report how these definitions were applied to participants with incomplete follow-up, missing toxicity grades, or unavailable outcome assessments. A missing-data method and the number of participants with evaluable primary outcome data are not reported in the registry record.
The record does not report whether analyses followed an intention-to-treat principle or another specified analysis population. Because the study has no randomized control group, there is no randomized comparison population to interpret. The listed analysis information is insufficient to determine how the 16 analyses were defined, whether they were prespecified, or how repeated quality-of-life measurements were handled. These omissions limit assessment of the risk of selective reporting and the reproducibility of the analyses.
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 |
|---|---|---|---|
| Cohort A | 3 | 3 | 100.0% |
| Cohort B | 33 | 33 | 100.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Cohort A | 3 of 3 |
| Cohort B | 33 of 33 |
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 |
|---|---|
| Cohort A | 3 of 3 |
| Cohort B | 24 of 33 |
Most frequent serious adverse event terms
| Event term | Organ system | Cohort A | Cohort B |
|---|---|---|---|
| Ascites | Gastrointestinal disorders | 0 of 3 | 4 of 33 |
| Hepatobiliary disorders - Other, sp | Hepatobiliary disorders | 1 of 3 | 2 of 33 |
| Pleural effusion | Respiratory, thoracic and mediastinal disorders | 1 of 3 | 2 of 33 |
| Abdominal infection | Infections and infestations | 0 of 3 | 2 of 33 |
| Adrenal insufficiency | Endocrine disorders | 0 of 3 | 2 of 33 |
| Allergic reaction | Immune system disorders | 0 of 3 | 2 of 33 |
| Dehydration | Metabolism and nutrition disorders | 0 of 3 | 2 of 33 |
| Anemia | Blood and lymphatic system disorders | 1 of 3 | 0 of 33 |
| Abdominal pain | Gastrointestinal disorders | 0 of 3 | 1 of 33 |
| Biliary tract infection | Infections and infestations | 0 of 3 | 1 of 33 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cohort A | Cohort B |
|---|---|---|---|
| Abdominal pain | Gastrointestinal disorders | 2 of 3 | 20 of 33 |
| Fatigue | General disorders and administration site conditions | 2 of 3 | 17 of 33 |
| Lymphocyte count decreased | Investigations | 1 of 3 | 16 of 33 |
| Aspartate aminotransferase increased | Investigations | 0 of 3 | 15 of 33 |
| Nausea | Gastrointestinal disorders | 2 of 3 | 12 of 33 |
| Alanine aminotransferase increased | Investigations | 0 of 3 | 13 of 33 |
| Anemia | Blood and lymphatic system disorders | 0 of 3 | 12 of 33 |
| Blood bilirubin increased | Investigations | 0 of 3 | 10 of 33 |
| Diarrhea | Gastrointestinal disorders | 0 of 3 | 10 of 33 |
| Alkaline phosphatase increased | Investigations | 1 of 3 | 8 of 33 |
Serious events with the highest arm-level rate: anemia (33.3%), hepatobiliary disorders - other, sp (33.3%), pleural effusion (33.3%), ascites (12.1%), abdominal infection (6.1%).
The registry's adverse-event entries distinguish serious adverse events from other adverse events and report fields for participants at risk and affected. For serious adverse events, Cohort A is listed as 3 at risk and 3 affected; Cohort B is listed as 33 at risk and 33 affected. For other adverse events, Cohort A is listed as 3 at risk and 3 affected; Cohort B is listed as 33 at risk and 24 affected. These are the record's reported entries and should not be combined into a new total or treated as the primary endpoint estimate.
The listed serious-event terms and percentages are Anemia, 33.3%; Hepatobiliary disorders - Other, sp, 33.3%; Pleural effusion, 33.3%; Ascites, 12.1%; Abdominal infection, 6.1%; and Adrenal insufficiency, 6.1%. The record does not fully explain the denominator, event-counting rules, or follow-up period for these term-specific percentages. They should not be assumed to be percentages of all enrolled participants or to represent the acute treatment-related toxicity endpoint.
The primary endpoint has a distinct definition: treatment-related grade 3 or greater gastrointestinal and hematologic toxicity up to 90 days after treatment. The adverse-event entries alone do not supply that endpoint's percentage or 90% confidence interval. The record also contains death fields for both cohorts, but does not explain their meaning or context in the registry record; they should not be interpreted as a survival result.
12. What the Result Does, and Does Not, Mean
The study record is useful for identifying the clinical setting and the intended safety question: a prospective, single-arm evaluation of respiratory-gated SBRT in previously treated pancreatic or periampullary cancer. It specifies the primary toxicity categories, severity threshold, attribution to SBRT, and acute assessment period. It also provides some cohort-level adverse-event entries and lists serious-event terms. Those details describe the scope of the planned assessment and some of the safety information recorded.
The record does not report the primary acute-toxicity percentage or its 90% confidence interval. It therefore cannot establish the observed frequency or precision of the primary endpoint from the information available. The adverse-event entries are not interchangeable with that endpoint, because the registry does not show that they use the same event definition, timing, population, and attribution rules.
Even if a primary estimate were available, a single-group study would describe outcomes among treated participants rather than establish a comparative treatment effect. Without a concurrent control group, differences from an external expectation could reflect patient characteristics, prior treatment, disease course, follow-up, or other factors. The study's design does not support a randomized comparison.
The stated objectives include outcomes beyond acute toxicity, such as late toxicity, survival, progression, pain, and quality of life. The objectives do not themselves demonstrate a result on any of those outcomes, and the registry entries available do not report their estimates. The study's completed status likewise indicates completion in the registry, not the direction or size of any clinical outcome.
In general, a result's clinical meaning depends on its magnitude, uncertainty, definitions, and study context. Here, the missing primary estimate and analysis details prevent a full assessment of the primary safety question. The record supports describing what the trial set out to measure and what adverse-event entries it lists, but not a conclusion that SBRT did or did not cause a particular level of toxicity or produced a particular clinical benefit.
13. Why This Trial Matters Statistically
This trial is statistically notable for asking a focused safety question in a population with prior treatment and for specifying a severity threshold and assessment window. A clearly defined primary outcome can help distinguish a targeted safety estimate from a broad list of adverse events. The registry describes acute grade 3 or greater gastrointestinal and hematologic toxicity attributed to SBRT, assessed up to 90 days after treatment, and specifies a 90% confidence interval as the dispersion measure.
The single-group structure also makes the inferential boundary clear. The study can be understood as an effort to characterize outcomes among treated patients, not as a randomized estimate of the effect of SBRT relative to another approach. That distinction is important when reading safety results in a clinical context where participants had previously received other therapies.
The record also illustrates why complete reporting matters. The primary endpoint is defined, but its estimate and confidence interval are not reported in the registry record. Without them, readers cannot assess the magnitude or precision of the central safety result. Similarly, the presence of several secondary outcomes makes reporting of analysis priorities and multiplicity methods relevant; those methods are not reported.
For biostatistical interpretation, the distinction between endpoint-specific results and general adverse-event summaries is central. Serious-event terms and cohort-level event fields can provide context, but they do not automatically answer a prespecified toxicity question with different severity, attribution, and timing criteria. A transparent account of populations, denominators, missing data, and uncertainty would be needed to connect those data to the primary objective.
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 most important limitation in interpreting the registry record is that it does not report the primary toxicity percentage or its 90% confidence interval. The primary endpoint is described, but its result and precision cannot be assessed from the record. The registry also does not report the method used to calculate that interval or a complete statistical analysis plan.
The single-group, single-arm design has no concurrent control group. It can describe outcomes observed among participants who received SBRT, but cannot by itself separate outcomes associated with treatment from the influence of disease status, previous therapy, or other factors. The record identifies a population with prior treatment but does not provide comparative analyses to address those influences.
The cohort-level adverse-event entries require cautious interpretation. The registry reports at-risk and affected counts and lists serious-event terms with percentages, but does not fully explain the term-specific denominators, counting rules, or follow-up period in the registry record. These entries cannot be assumed to match the primary endpoint's eligibility, attribution, severity, and timing criteria. Death fields are also present, but their context is not reported in the registry record.
Important analysis details are not reported, including missing-data handling, the number of participants with evaluable primary outcomes, multiplicity procedures, and the analysis methods for secondary outcomes. The record lists nine outcome measures and 16 analyses without enough detail to assess whether all analyses were prespecified or how repeated measurements were handled. The sample-size description uses hypothetical two-arm planning assumptions despite the single-group design; the trial's own sample-size justification is not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Respiratory-gated Stereotactic Body Radiation Therapy for Adenocarcinoma of the Pancreas or Periampullary Region — NCT02780648.
- Registry record last updated 2025-11-03; status last verified 2025-10.
- Results first posted 2025-11-03.
- 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
NCT02780648 is a completed, single-center, prospective, single-arm study sponsored by Indiana University. It evaluated respiratory-gated Linac-based SBRT for previously treated pancreatic or periampullary adenocarcinoma. The registry lists enrollment of 36, a start date of 2016-05-01, and a primary completion date of 2019-12-17. Phase is listed as NA, allocation as NA, and masking as none.
The primary objective was to estimate treatment-related grade 3 or greater gastrointestinal and hematologic toxicity up to 90 days after treatment, with a 90% confidence interval specified. The primary endpoint estimate and interval are not reported in the registry record. Secondary objectives covered late toxicity, survival and progression outcomes, pain, and quality of life. The registry also lists cohort-level adverse-event entries and serious-event terms, which should not be treated as the missing primary endpoint result.
Because the study has no control group, its design supports description of outcomes in the treated group rather than a randomized treatment comparison. Key analysis details, including missing-data and multiplicity methods, are not reported in the registry record.