ASHBY: Accelerated Super-Hypofractionated Breast Brachytherapy

Determine the incidence of accelerated partial breast irradiation (APBI) related toxicities, adverse events, of interest occurring at grade ≥3 within 1 year and 3 years after APBI. The APBI-related toxicities specified in Section 10.1 will be explicitly evaluated at all follow-up appointments. All APBI-related toxicities of interest will be captured, regardless of grade, beginning with the start of study treatment and continuing until the patient is off study utilizing study-specific grading criteria in place of Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

Cosmesis will be assessed utilizing the Breast Cancer Treatment Outcome Scale (BCTOS-12), a self-report instrument that evaluated the aesthetic outcome after breast conserving surgery (BCS). the Aesthetic Status, is composed of eight items referring to the breast. the new Aesthetic Status comprises eight items: (1) "breast shape", (2) "breast texture", (3) "nipple appearance", (4) "breast tenderness", (5) "scar tissue", (6) "breast swelling", (7) "fit of bra", and (8) "breast sensitivity".

Patients are instructed to rate each item of the BCTOS questionnaire on a four-point rating scale evaluating the differences between the treated and untreated breast (1 = no difference to 4 = large difference). The score for each subscale is calculated as the mean of its items, with the score ranging from 1.00 to 4.00. A higher score reflects a poorer status.

Cosmesis will be assessed utilizing the Breast Cancer Treatment Outcome Scale (BCTOS-12), a self-report instrument that evaluated the functional outcome after breast conserving surgery (BCS). The questionnaire comprises 12 items and assesses various aspects of patients' subjective perception of the surgical result. The new Functional Status comprises four items: (1) "arm heaviness", (2) "shoulder discomfort", (3) "arm discomfort", (4) "arm swelling". Patients are instructed to rate each item of the BCTOS questionnaire on a four-point rating scale evaluating the differences between the treated and untreated breast

(1 = no difference to 4 = large difference). The score for each subscale is calculated as the mean of its items, with the score ranging from 1.00 to 4.00. A higher score reflects a poorer status.

The radiation-specific module of this patient-reported outcome measure evaluates patient satisfaction with the cosmetic effects of radiation by utilizing the BREAST-Q© (intellectual property of Drs Andrea Pusic, Anne Klassen and Stefan Cano. The BREAST-Q© is owned by Memorial Sloan Kettering Cancer Center and The University of British Columbia (Copyright ©2012, Memorial Sloan Kettering Cancer Center and The University of British Columbia). There is no overall or total BREAST-Q© score, only scores for each independent scale. All BREAST-Q© scales are transformed into scores that range from 0-100. The scores are computed by adding the response items together and then converting the raw sum scale score to a score from 0-100. For all BREAST-Q© scales, a higher score means greater satisfaction or better QOL.

This physician-rated form will be used by the treating surgeon or radiation oncologist to score cosmesis at baseline and annually for 5 years, where Excellent= treated breast looks essentially the same as the contralateral breast as it relates to radiation effects. This includes patients with grade 1 punctate scarring. Good= minimal but identifiable radiation effects of the treated breast. This includes patients with grade 2 punctate scarring.

Fair= significant radiation effects readily observable. Poor= severe sequelae of breast tissue secondary to radiation effect

The number of participants that achieve complete responses, partial response, or relapse. Disease control will be assessed by physical examination and mammography.

The number of participants that have a reportable adverse event (AE) per protocol criteria.

Incidence and grade of punctate scarring. Punctate scarring, defined as scarring from catheter sites, is assigned according to the following grading criteria (Table 5):

• No toxicity: not clearly visible from 3 feet away
• Grade 1a: clearly visible from 3 feet away and no palpable scars
• Grade 1b: clearly visible from 3 feet away and palpable scars at <25% of catheter sites) OR clearly visible at 3-10 feet and no palpable scar tissue
• Grade 1c: clearly visible from ≥10 feet away and no palpable scars OR clearly visible at <10 feet and palpable scars at <25% of catheter sites)
• Grade 2: prominent (ie, visible at ≥10 feet away) and palpable scar tissue

Incidence of skin changes after APBI in African American and non-African American patients.