Trial Outcomes & Findings for Prospective Randomized Study of Accelerated Radiation Therapy (PRART) (NCT NCT04175210)

Prospective Randomized Study of Accelerated Radiation Therapy (PRART)

Proportion of grade ≥ 2 of acute toxicity defined according to the Common Terminology Criteria for Adverse Events (CTCAEs) - version 5.0, on the 10-fraction arm compared to the rate on the 15-fraction arm will be measured, up to 1-month post-radiation treatment.

Assess and compare local control at 2-3 years between the two arms. At each post treatment follow-up visit, a physical exam to detect breast clinical recurrence will be performed. Mammographic studies and/or breast MRI will be performed and reviewed on an annual basis, according to the standard care. Local control will be defined according to the findings from physical exam, mammographic studies and/or breast MRI.

Assess and compare local control at 5 years between the two arms. At each post treatment follow-up visit, a physical exam to detect breasts clinical disease recurrence will be performed. Mammographic studies and/or breast MRI will be performed and reviewed on an annual basis, according to the standard care. Local control will be defined according to the findings from physical exam, mammographic studies and/or breasts MRI.

Assess and compare fibrosis at 2-3 years between the two arms. At each post treatment follow-up visit, the fibrosis will be assessed by breasts palpation performed by the physician or nurse practitioner and will be measured as per LENT/SOMA fibrosis scoring system. According to this scoring system, fibrosis is categorized into three grades (Grade 1, Grade 2 and Grade 3), where Grade 1 is defined as "barely palpable, increased density" and Grade 3 is defined as "very marked density, retraction, and fixation".

Assess and compare breast cosmesis at 2-3 years between the two arms. At each post treatment follow-up visit, breast cosmesis will be self-assessed by the patient using Breast Cancer Treatment Outcome Scale (BCTOS) questionnaires. According to this scale, breast cosmesis is evaluated using a four-point system (Point 1, Point 2, Point 3, and Point 4), where Point 1 is defined as "no change compared to the untreated breast" and Point 4 as "large change compared to the untreated breast."

Assess and compare fibrosis at 5 years between the two arms. At each post treatment follow-up visit, the fibrosis will be assessed by breasts palpation performed by the physician or nurse practitioner and will be measured as per LENT/SOMA fibrosis scoring system. According to this scoring system, fibrosis is categorized into three grades (Grade 1, Grade 2 and Grade 3), where Grade 1 is defined as "barely palpable, increased density" and Grade 3 is defined as "very marked density, retraction, and fixation".

Assess and compare breast cosmesis at 5 years between the two arms. At each post treatment follow-up visit, breast cosmesis will be self-assessed by the patient using Breast Cancer Treatment Outcome Scale (BCTOS) questionnaires. According to this scale, breast cosmesis is evaluated using a four-point system (Point 1, Point 2, Point 3, and Point 4), where Point 1 is defined as "no change compared to the untreated breast" and Point 4 as "large change compared to the untreated breast."