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Completed

NCT Number: NCT07590505

Ultrahypofractionated Versus Normofractionated Sequential Boost After Whole-breast Radiation Therapy in Patients Treated With Breast-conserving Surgery for Breast Cancer

The ULTIMO trial is a monocentric, prospective, randomised controlled, open-label, phase III interventional clinical trial, with a non-inferiority design, in patients with breast cancer undergoing breast conservative treatment (BCT). After giving informed consent and verifying eligibility, data collection starts and patients will be randomized in one of the following treatment arms:

* Standard treatment arm: Breast Conserving Surgery (BCS) takes place, followed by the SoC hypofractionated Whole Breast Radiation Therapy (WBRT) and SoC normofractioned sequential boost (normSEB) of 10Gy over 5 fractions. * Experimental treatment arm: Breast Conserving Surgery (BCS) takes place, followed by the SoC hypofractionated WBRT and experimental ultrahypofractionated sequential boost (ultSEB) of 6Gy in a single fraction.

The primary objective of the ULTIMO study is to assess whether the ultSEB RT boost protocol is non-inferior to the current SoC normSEB RT boost protocol. This assessment will be based on the cosmetic outcome of the breasts, while also taking into account quality of life (QoL), the frequency and intensity of (S)AEs of interest (breast pain and fibrosis), and oncological survival.

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Key information

Conditions

Breast Cancer Breast Diseases Breast Neoplasms Neoplasms Neoplasms by Site Skin Diseases Skin and Connective Tissue Diseases

Age range

18 year and older

Sex eligibility

Female

Study type

Interventional

Phase

Phase 3

Primary location

Ziekenhuis aan de stroom

Antwerp, Antwerpen, 2610, Belgium

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Breast cancer patients referred for WBRT + boost to the lumpectomy cavity
  • Patients ≥18y
  • Karnofsky Performance Score >70%, or ECOG <2
  • Life expectancy of more than 5 years
  • Invasive tumour free resection margins, defined as R0 resection on the pathology report
  • Written informed consent

Exclusion criteria

  • Previous contralateral breast cancer
  • Previous RT of the same breast or thorax.
  • Metastatic disease (M1)

Treatment and study plan

Standard of Care (SOC) - Normofractionated Sequential Boost Radiation Therapy

Radiation

Standard of care fractionation and dosage scheme of the sequential radiation therapy boost. This consists of 5 fractions of 2Gy each, adding up to a total dose of 10Gy.

Other names: normSEB

Experimental - UltraHypofractionated Sequential Boost Radiation Therapy

Radiation

The radiation therapy sequential boost is delivered in a ultrahypofractionated scheme. This consists of a single fraction of 6Gy.

Other names: ultSEB

Primary outcomes

  1. Cosmetic non-inferiority - BCCT.core scoring

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    BCCT.core is a software package for evaluating photographs of breasts after BCS. The 'Global cosmetic result' from the two frontal photos (arms up, and arms down) will be averaged and then used as the individual value of this measure. The results are scored on a 4-point Likert scale, coded as 0-3.

    Analysis metric:

    The change from baseline at 1 and 3YFU will be used. Negative values will be transformed to '1' to signal an inferiority event, positive or values of zero will be transformed to '0' to signal non-inferiority.

    For comparisons and estimands, please refer to the SAP.

    Method of aggregation:

    The results will be reported as a contingency table reporting both frequencies and proportions of non-inferior and inferior results in each treatment arm.

    Time point(s):

    A baseline assessment is performed during the screening visit, followed by repeated measurements during the 1 and 3YFU (primary endpoint) visits.

  2. Cosmetic outcome - Expert panel, AIS-TAS

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The AIS is a tool for scoring breast cosmesis based on standardized photos. It comprises of 5 items, each comprising of a 5 point Likert-scale, coded as 1 to 5. The score is given based on the group of photos taken at a single time point. The scores of all items are summed to produce the TAS, which consequently ranges from 5 to 25. The AIS is used in an expert panel setting, where all scores, from each assessor are averaged per item.

    A higher scores represents a more favourable cosmetic outcome.

    Analysis metric:

    AIS-TAS absolute values will be used for analysis.

    Method of aggregation:

    The mean, median, SD and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit, followed by repeated measurements during the 1 and 3YFU (primary endpoint) visits.

  3. Cosmetic outcome - Expert panel, AIS-Symmetry

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The AIS is a tool for scoring breast cosmesis based on standardized photographs. It comprises of 5 items, each comprising of a 5 point Likert-scale, coded as 1 to 5. The score is given based on the group of photos taken at a single time point. The AIS is used in an expert panel setting, where all scores, from each assessor are averaged per item.

    A higher scores represents a more favourable cosmetic outcome.

    Analysis metric:

    AIS-Symmetry score absolute values will be used for analysis.

    Method of aggregation:

    The mean, median, SD and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit, followed by repeated measurements during the 1 and 3YFU (primary endpoint) visits.

Secondary outcomes

  1. Cosmetic outcome - Physician scoring

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The physician scoring scale (questionnaire, cfr. protocol) will be used to assess cosmetic outcome. The normalised average score of all items will be summed and used as outcome measure. This will be calculated as the score of an item divided by the amount of answering options minus 1 (k-1), averaged over all items. Some questions have the option 'not evaluable', if this answer is selected, then that item is not used in deriving the average score.

    A higher scores represents a more favourable cosmetic outcome.

    Analysis metric:

    Absolute values will be used for analysis.

    Method of aggregation:

    The mean, median, SD and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit. It is then assessed again at 1 year, and 3 years of follow-up after the last study treatment (LST).

  2. Cosmetic outcome - Patient reported (PROM)

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The cosmetic evaluation questionnaire by Sneeuw at al. will be used to assess cosmetic outcome, as reported by the participant. The normalised average score of all items will be summed and used as outcome measure. This will be calculated as the score of an item divided by the amount of answering options minus 1 (k-1), averaged over all items.

    A higher scores represents a more favourable cosmetic outcome.

    Analysis metric:

    Absolute values (calculated score) will be used for analysis.

    Method of aggregation:

    The mean, median, variance and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit. It is then assessed again at 1 year, and 3 years of follow-up after the last study treatment (LST).

  3. Quality of life - EORTC QLQ C30 v3 - Global health status/QoL

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The QoL (QLQ-C30) outcome variable is operationalised through the QLQ-C30 questionnaire. The answers are transformed into 3 separate scores, which can all range from 0 to 100. These scores are: Global health status/QoL, Functional scales, Symptom scales. Where a higher score on the first 2 scales indicate a better health state and QoL, while on the symptom scale a higher score indicates a higher level of disturbance by symptoms.

    Analysis metric:

    The QLQ-C30 Global health status absolute values will be used for analysis.

    Method of aggregation:

    The mean, median, SD and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit. It is then assessed again at 1 year, and 3 years of follow-up after the last study treatment (LST).

  4. Quality of life - EORTC QLQ C30 v3 -Functional scales

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The QoL (QLQ-C30) outcome variable is operationalised through the QLQ-C30 questionnaire. The answers are transformed into 3 separate scores, which can all range from 0 to 100. These scores are: Global health status/QoL, Functional scales, Symptom scales. Where a higher score on the first 2 scales indicate a better health state and QoL, while on the symptom scale a higher score indicates a higher level of disturbance by symptoms.

    Analysis metric:

    The QLQ-C30 Functional scales score absolute values will be used for analysis.

    Method of aggregation:

    The mean, median, SD and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit. It is then assessed again at 1 year, and 3 years of follow-up after the last study treatment (LST).

  5. Quality of life - EORTC QLQ C30 v3 -Symptom scales

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The QoL (QLQ-C30) outcome variable is operationalised through the QLQ-C30 questionnaire. The answers are transformed into 3 separate scores, which can all range from 0 to 100. These scores are: Global health status/QoL, Functional scales, Symptom scales. Where a higher score on the first 2 scales indicate a better health state and QoL, while on the symptom scale a higher score indicates a higher level of disturbance by symptoms.

    Analysis metric:

    The QLQ-C30 Symptom scales score absolute values will be used for analysis.

    Method of aggregation:

    The mean, median, SD and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit. It is then assessed again at 1 year, and 3 years of follow-up after the last study treatment (LST).

  6. Quality of life - EORTC QLQ BR23 v1 - Functional scales

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The QoL (QLQ-BR23) outcome variable is operationalised through the QLQ-BR23 questionnaire. The answers are transformed into 2 separate scores, which can both range from 0 to 100. These scores are: Functional scales; Symptom scales. Where a higher score on the functional scale indicate a better health state and QoL, while on the symptom scale a higher score indicates a higher level of disturbance by symptoms.

    Analysis metric:

    The QLQ-BR23 Functional scales score absolute values will be used for analysis.

    Method of aggregation:

    The mean, median, SD and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit. It is then assessed again at 1 year, and 3 years of follow-up after the last study treatment (LST).

  7. Quality of life - EORTC QLQ BR23 v1 - Symptom scales

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    The QoL (QLQ-BR23) outcome variable is operationalised through the QLQ-BR23 questionnaire. The answers are transformed into 2 separate scores, which can both range from 0 to 100. These scores are: Functional scales; Symptom scales. Where a higher score on the functional scale indicate a better health state and QoL, while on the symptom scale a higher score indicates a higher level of disturbance by symptoms.

    Analysis metric:

    The QLQ-BR23 Symptom scales score absolute values will be used for analysis.

    Method of aggregation:

    The mean, median, SD and IQR will be reported. For comparisons and estimands, please refer to the SAP.

    Time point(s):

    A baseline assessment is performed during the screening visit. It is then assessed again at 1 year, and 3 years of follow-up after the last study treatment (LST).

  8. Fibrosis

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    During the 1Y and 3Y Follow-Up study visits the overall and tumour bed fibrosis will be scored according to the 'National Cancer Institute Common Terminology Criteria for Adverse Events' (NCI-CTCAE) v5.0 AE reporting system. This scoring will be performed by either the principal- or sub-investigators.

    Analysis metric:

    Tabulation of absence vs. presence and severity of fibrosis will be used for analysis.

    Method of aggregation:

    The proportion of participants experiencing no 'Fibrosis' vs. any 'Fibrosis' will be used. As well as the frequency of all grades, including 0 (absence).

    For comparisons and estimands, please refer to the SAP.

    Time point(s):

    Fibrosis will be assessed and recorded during the 1YFU and 3YFU study visits.

  9. Breast pain

    Time frame: From enrollment to the end of follow-up at 3 years of follow-up, counting from the last study visit.

    Operationalisation:

    During the 1Y and 3Y Follow-Up study visits the occurrence of 'Breast pain' will be scored according to the 'National Cancer Institute Common Terminology Criteria for Adverse Events' (NCI-CTCAE) v5.0 AE reporting system. This scoring will be performed by either the principal- or sub-investigators.

    Analysis metric:

    Tabulation of absence vs. presence and severity of 'Breast pain' will be used for analysis.

    Method of aggregation:

    The proportion of participants experiencing no 'Breast pain' vs. any 'Breast pain' will be used. As well as the frequency of all grades, including 0 (absence).

    For comparisons and estimands, please refer to the SAP.

    Time point(s):

    Fibrosis will be assessed and recorded during the 1YFU and 3YFU study visits.

  10. Oncological survival and time-to-event data - Overall Survival (OS)

    Time frame: Oncological TTE data will be registered at 1 and 3 years of follow-up after the last study treatment (LST). However, the exact dates of diagnosis/death will be used.

    Operationalisation:

    The oncological survival and TTE data are operationalised as time-to-event intervals for the events of interest listed below.

    The 'OS' TTE/survival outcome will be reported according to the 2015 DATECAN consensus, including time-to-event data for the following events of interest: 'Death from any cause'.

    Analysis metric:

    The TTE data is registered in days from randomisation (Rz). Censoring will be used for participants without events at the end of their follow up.

    Method of aggregation:

    KM-estimates, as well as proportions free from events at follow-up visit timepoints will be reported. The non-aggregated data will be used for survival analysis. For comparisons and estimands, please refer to the SAP.

  11. Oncological survival and time-to-event data - Breast Cancer-Specific Survival (BCSS)

    Time frame: Oncological TTE data will be registered at 1 and 3 years of follow-up after the last study treatment (LST). However, the exact dates of diagnosis/death will be used.

    Operationalisation:

    The oncological survival and TTE data are operationalised as time-to-event intervals for the events of interest listed below.

    The 'BCSS' TTE/survival outcome will be reported according to the 2015 DATECAN consensus, including time-to-event data for the following events of interest: 'Death from breast cancer'.

    Analysis metric:

    The TTE data is registered in days from randomisation (Rz). Censoring will be used for participants without events at the end of their follow up.

    Method of aggregation:

    KM-estimates, as well as proportions free from events at follow-up visit timepoints will be reported. The non-aggregated data will be used for survival analysis. For comparisons and estimands, please refer to the SAP.

  12. Oncological survival and time-to-event data - Relapse-Free Survival (RFS)

    Time frame: Oncological TTE data will be registered at 1 and 3 years of follow-up after the last study treatment (LST). However, the exact dates of diagnosis/death will be used.

    Operationalisation:

    The oncological survival and TTE data are operationalised as time-to-event intervals for the events of interest listed below.

    The 'RFS' TTE/survival outcome will be reported according to the 2015 DATECAN consensus, including time-to-event data for the following events of interest: 'Death from any cause', 'Invasive ipsilateral breast tumor recurrence', 'Local Invasive recurrence', 'Regional Invasive recurrence', 'occurrence of metastases', or 'Ipsilateral DCIS'.

    Analysis metric:

    The TTE data is registered in days from randomisation (Rz). Censoring will be used for participants without events at the end of their follow up.

    Method of aggregation:

    KM-estimates, as well as proportions free from events at follow-up visit timepoints will be reported. The non-aggregated data will be used for survival analysis. For comparisons and estimands, please refer to the SAP.

  13. Oncological survival and time-to-event data - Locoregional Relapse-Free Survival (L-RFS)

    Time frame: Oncological TTE data will be registered at 1 and 3 years of follow-up after the last study treatment (LST). However, the exact dates of diagnosis/death will be used.

    Operationalisation:

    The oncological survival and TTE data are operationalised as time-to-event intervals for the events of interest listed below.

    The 'L-RFS' TTE/survival outcome will be reported according to the 2015 DATECAN consensus, including time-to-event data for the following events of interest: 'Death from any cause', 'Invasive ipsilateral breast tumor recurrence', 'Local Invasive recurrence', 'Regional Invasive recurrence', or 'Ipsilateral DCIS'.

    Analysis metric:

    The TTE data is registered in days from randomisation (Rz). Censoring will be used for participants without events at the end of their follow up.

    Method of aggregation:

    KM-estimates, as well as proportions free from events at follow-up visit timepoints will be reported. The non-aggregated data will be used for survival analysis. For comparisons and estimands, please refer to the SAP.

  14. Oncological survival and time-to-event data - Distant-Relapse Free Survival (D-RFS)

    Time frame: Oncological TTE data will be registered at 1 and 3 years of follow-up after the last study treatment (LST). However, the exact dates of diagnosis/death will be used.

    Operationalisation:

    The oncological survival and TTE data are operationalised as time-to-event intervals for the events of interest listed below.

    The 'D-RFS' TTE/survival outcome will be reported according to the 2015 DATECAN consensus, including time-to-event data for the following events of interest: 'Death from any cause', or 'occurrence of metastases'.

    Analysis metric:

    The TTE data is registered in days from randomisation (Rz). Censoring will be used for participants without events at the end of their follow up.

    Method of aggregation:

    KM-estimates, as well as proportions free from events at follow-up visit timepoints will be reported. The non-aggregated data will be used for survival analysis. For comparisons and estimands, please refer to the SAP.

Sponsors and collaborators

Lead sponsor

Cancer Research Antwerp

Other

Collaborators

  • Gasthuis Zusters Antwerpen
  • Iridium netwerk
  • Ziekenhuis aan de Stroom

Registry information

Acronym: ULTIMO

Important dates

Study start
2022
Primary completion
2025
Study completion
2026
First posted
May 15, 2026
Registry last updated
May 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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