Accelerated Partial Breast Irradiation Using External Beam Volumetric Modulated Arc Therapy (VMAT): a Randomised Non-inferiority Trial of 30 Gy Versus 26 Gy in Five Fractions Investigating Patient-reported Outcomes

Not Applicable

Not yet recruiting

• Conditions: Breast Cancer

• Registration Number: NCT06909032
• Lead Sponsor: Integrated Community Oncology Network

Brief Summary

For women undergoing radiotherapy following surgery for early-stage breast cancer, breast-related quality of life (BrQoL) is an important consideration. Treating only the part of the breast by radiation where the cancer has been surgically removed (partial breast irradiation or "PBI") rather than the whole breast (whole breast irradiation) can reduce the toxic effects of radiotherapy. This trial aims to evaluate whether there is a difference in patient-reported BrQoL between two total doses of radiation given in five treatments using PBI. If BrQOL for the higher dose of PBI is no worse than the lower dose, using the higher dose would be advised as best practice, given that it is more likely to be more effective in reducing the chance of cancer coming back in the breast than the lower dose.

Detailed Description

Single-blind, phase III, multisite, randomised non-inferiority trial. PBI will be planned and treated as per the protocol using VMAT. The prescribed dose will be 30 Gy in 5 daily fractions (Arm A) or 26 Gy in 5 daily fractions (Arm B). Participants will be blinded to their treatment allocation.

Follow-up will be at the following time points:

* Eight weeks following the end of radiation

* Every six months post-randomisation for two years following randomisation

* Three years post-randomisation (final visit)

Assessments to be conducted at each time point are:

* Clinical assessment

* Completion of Patient-Reported Outcome Measures (PROMs)

* Mammogram and ultrasound (baseline and annually)

* Documentation of IBTR - classified as a true recurrence or Elsewhere

* Documentation of any other type of recurrence (regional, distant, opposite breast)

Recruitment is planned for three years with a three-year follow-up period for all patients.

Study Timeline

• Status Verified: 2025-03
• Study First Submitted: 2025-03-27
• Study First Submitted QC: 2025-03-27
• Last Update Submitted: 2025-03-27
• Study Start: 2025-04
• Study First Posted: 2025-04-03
• Last Update Posted: 2025-04-03
• Primary Completion: 2030-07
• Study Completion: 2032-12

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Female
• Target Recruitment: 168

Inclusion Criteria

• Aged greater than or equal to 50 years old
• Histologically confirmed Infiltrating ductal carcinoma (IDC) or pure DCIS, less than or equal to 20mm maximum size.
• Lobular carcinoma in situ (LCIS) is permitted.
• Histologic grade I or II
• Estrogen receptor (ER) +/- progesterone receptor (PR) positive in greater than or equal to 10% of cells and HER2 receptor-negative.
• Tumour bed identifiable on imaging via surgical clips
• Clear surgical margins
• Sentinel nodes negative (at least one node taken if invasive and no isolated tumour cells)
• No evidence of distant metastasis

Exclusion Criteria

• Ink on surgical margins or positive histological margins
• Lymphatic vessel invasion (LVI)
• Bilateral breast cancer
• Invasive lobular carcinoma
• Pleomorphic LCIS
• Multifocal or multicentric invasive cancer
• Invasive carcinoma with associated DCIS greater than or equal to 30mm.
• Patients receiving neoadjuvant chemotherapy, anti-HER2 agents or endocrine therapy
• Patients receiving adjuvant chemotherapy or anti-HER2 agents.
• Previous Hodgkin's lymphoma requiring mantle radiation
• Prior radiation therapy to the ipsilateral breast
• Triple-negative breast cancer
• Documented mutation of BRCA1, BRCA2 or TP53, or at high genetic risk of breast cancer
• Known inflammatory conditions associated with higher complications after RT, such as active scleroderma, systemic lupus erythematosus (requiring steroids or immune suppressive therapy)
• Oncoplastic surgery where the primary tumour site is difficult to delineate
• No previous cancer (except BCC or SCC of the skin) unless in remission beyond five years of diagnosis
• People who are pregnant or planning to become pregnant
• People who are unable or unwilling to comply with protocol requirements.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Patient-reported breast-related cosmetic outcome,	36 months post randomisation	Proportion of patients with a moderate or worse adverse cosmetic outcome, defined as a score of greater than or equal to 2.5 on the aesthetic sub-scale of the Breast Cancer Treatment Outcome Scale-12 (BCTOS-12).

Secondary Outcome Measures

Name	Time	Method
Patient-reported breast-related cosmetic outcome	Baseline, 8 weeks post-treatment, 6, 12, 18, 24 and 36-months post randomisation.	BCTOS-12 aesthetic sub-scale scores
Patient-reported breast-related functional outcome	Baseline, 8 weeks post-treatment, 6, 12, 18, 24 and 36-months post randomisation.	BCTOS-12 functional sub-scale scores
Patient-reported quality of life	Baseline, 8 weeks post-treatment, 6, 12, 18, 24 and 36-months post randomisation.	BREAST-Q (V2.0) questionnaire scores for the following Breast Conserving Therapy (Post-operative) modules: - Physical well-being: chest - Satisfaction with breasts - Adverse effects of radiation - Fatigue - Impact on work
Ipsilateral breast tumour recurrence (IBTR)	Up to 36 months post-randomisation	Cumulative incidence of local (true) recurrences of breast cancer within the index quadrant or newly diagnosed breast cancer within any other quadrant of the ipsilateral breast measured using results from standard of care imaging (mammogram, ultrasound, MRI).
Regional Recurrence	Up to 36 months post-randomisation	Cumulative incidence of any recurrence in the ipsilateral axillary, supraclavicular or internal mammary chain with or without recurrence in the breast or elsewhere measured using results from standard of care imaging (mammogram, ultrasound, MRI).
Locoregional disease recurrence	Up to 36 months post-randomisation	Cumulative incidence of IBTR plus any recurrence in the ipsilateral axillary, supraclavicular or internal mammary chain
Distant disease recurrence	Upto 36 months post-randomisation	Cumulative incidence of metastases to distant organs or bone sites measured using results from standard of care imaging (mammogram, ultrasound, MRI).
Patterns of care for treatment of disease recurrence (IBTR, locoregional, or metastatic)	Upto 36 months post-randomisation	Documented in patients' medical records
Patient satisfaction with treatment	At 8-weeks and 12 months post-treatment.	Assessed qualitatively via an open-ended question: "Please write about your experience with breast cancer treatment, specifically focusing on your treatment with accelerated partial breast irradiation (APBI). Think about how you felt physically and emotionally and what the greatest challenges were during this time."

Trial Locations

Locations (2)

Icon Cancer Centre Wahroonga; 🇦🇺 Wahroonga, New South Wales, Australia

Icon Cancer Centre Windsor Gardens; 🇦🇺 Windsor Gardens, South Australia, Australia