Stereotactic Body Radiation Therapy and FES PET/CT Imaging for the Treatment of Oligoprogressive Estrogen Receptor Positive Metastatic Breast Cancer

Description

PRIMARY OBJECTIVE:

I. To determine whether using SBRT to treat oligoprogressive lesions allows ER+ breast cancer patients to continue on their current systemic therapy for at least 24 weeks post SBRT treatment.

SECONDARY OBJECTIVES:

I. To evaluate adverse events (Common Terminology Criteria in Adverse Events [CTCAE] and Patient-Reported Outcomes PRO-CTCAE) in patients who receive SBRT.

II. To assess whether F-18 16 alpha-fluoroestradiol (FES)-PET increases the number of lesions found prior to SBRT.

III. To determine the impact of SBRT on patient quality of life using the European Organization for the Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 and QLQ-BR45.

IV. To estimate time to the next line of systemic therapy in patients who receive SBRT for oligoprogression.

V. To estimate progression-free survival time in patients who receive SBRT for oligoprogression.

EXPLORATORY OBJECTIVES:

I. To assess whether FES-PET increases the number of lesions found after SBRT. II. To describe circulating tumor deoxyribonucleic acid (ctDNA) levels over time after SBRT treatment.

III. To identify potential predictors of outcomes to treatment with SBRT.

OUTLINE:

Patients currently taking selective estrogen receptor modulators (SERMs)/selective estrogen receptor degraders (SERDs) immediately undergo 3 or 5 treatment fractions of SBRT within 3 weeks in the absence of unacceptable toxicity or evidence of > 4 sites of disease progression. Patients not currently taking SERMs/SERDs first receive F-FES intravenously (IV) and undergo PET/CT scans at baseline. After baseline FES PET/CT, patients with ≤ 4 sites of progressive disease then undergo 3 or 5 treatment fractions of SBRT within 3 weeks in the absence of unacceptable toxicity or evidence of > 4 sites of disease progression. All patients undergo FES PET/CT at 12 and 24 weeks. Patients with stable disease (SD) after 12 or 24 week FES PET/CT may continue standard systemic therapy. Patients with ≤ 4 sites of progressive disease after 12 or 24 week FES PET/CT may receive SBRT to additional sites in the absence of unacceptable toxicity or evidence of > 4 sites of disease progression. All patients also undergo CT, PET/CT, or bone scans, and blood samples collection during screening and on study.

After completion of study intervention, patients are followed up at 30 days.