Ablative SBRT in Elderly BC Patients
NCT Number: NCT06523894
Acronym: EASE
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Breast Cancer
Interventions: RADIATION: SBRT
Sponsor: University Hospital, Geneva
Sex: FEMALE
Age: OLDER_ADULT
Enrollment: 36
Study Design: Allocation: NON_RANDOMIZED|Intervention Model: PARALLEL|Masking: NONE|Primary Purpose: TREATMENT
Start Date: 2024-10
Completion Date: 2027-05
Locations: Radiation Oncology Department, Geneva University Hospital, Geneva, 1205, Switzerland

Summary:
Stereotactic body radiotherapy (SBRT) is a modern radiotherapy technique, through which extremely high doses of irradiation are delivered in a very precise manner, within a few fractions. SBRT is increasingly used into clinical practice because it can provide excellent local control, comparable to surgery, in many tumor locations, such as lung, liver or bone. Efforts to develop it for BC treatment are promising, as it is safe, convenient, and effective. To date, SBRT for BC has been developed as an alternative method of partial-breast irradiation (PBI) in the pre- or post-operative setting. Therefore, the doses tested are comparable to the conventional doses used with surgery although its potential as sole local treatment for BC remains unknown. Higher SBRT doses are expected to permit obtaining an ablative effect on tumor and be suitable as an alternative to surgery, but this hypothesis has yet to be tested.

The aim of the present study is to prove the feasibility of SBRT as an ablative treatment in early breast cancer (BC). The primary objective is to find the maximum tolerated dose of SBRT that can be safely administered in inoperable patients with BC, the majority of whom are elderly or oldest old.

The overall objective is to determine whether high precision, dose- and fractionation- adapted SBRT is feasible and safe in inoperable patients with BC. The dose and fractionation-adapted SBRT regimen permits to test feasibility in different tumor sizes.

The primary objective of this study is to establish the maximum tolerated dose (MTD) that can be delivered with a single or few (up to 5) fractions of SBRT in inoperable patients with BC.

Primary Outcome Measures: Maximum Tolerated Dose (MTD), Dose before the dose-level at which one or more dose-limiting toxicity (DLT) (any treatment-related toxicity equal or superior to Grade 3, according to CTCAE v5) occurs within 4 weeks after end of study treatment (EOT)., 4 weeks
Secondary Outcome Measures: Early and late toxicities, • Early (up to 3 months after treatment start) and late (over 3 months and up to 2 years after treatment start) rates of toxicities, as graded by CTCAE v5, other than a dose-limiting toxicity (DLT), possibly, probably or definitely related to delivered treatment., 2 years|Differential safety profile between arms, Toxicity rates, as graded by CTCAE v5, will be compared between the fractionation regimens., 2 years|Explorative: clinically relevant technical parameters of SBRT, Technical parameters of treatment planning/ dose delivery and dose-volume histogram (DVH) parameters will be associated to toxicity in order to identify potential associations and constraints' thresholds., 2 years|Efficacy o SBRT on local control, Non progression, described as: stable local disease (SD), shrinkage of treated tumor (partial response (PR)) in imaging, as classified by RECIST v1.1 criteria, will be considered as response to treatment. Imaging should be consistent within study for a given patient. Progressive disease (PD) by RECIST v1.1 will be considered as disease progression, therefore non-response., 2 years|Explorative: Time to local, regional and distant progression, Time from enrolment until any objective tumor progression locally (within breast), regionally (supraclavicular, axillary or internal mammary chain area) or distantly (anywhere in the body beyond regional)., 2 years|Quality of life (QoL) before and after SBRT, QoL parameters in the treatment population before and after treatment delivery and at follow-up, using appropriate questionnaires (EORTC QLQ-C30, EORTC QLQ-B23)., 2 years|Explorative: Association between QoL and SBRT arm, Delivered treatment, in particular the risk-adapted dose and fractionation regimen used with QoL parameters after treatment delivery and at follow-up, using appropriate questionnaires (EORTC QLQ-C30, EORTC QLQ-B23) will be evaluated for the adapted regimens.

Esthetic outcomes will be evaluated a. clinically, by the radiation oncologist and b. by the patient. Photos will be taken before treatment start and at follow-up visits., 2 years