Breast CancerSOLISNCT07844759
SOLIS: Single-Dose Radiotherapy With Omission of Lumpectomy for Intact Small Breast Cancers
A study testing Stereotactic Radiation Therapy and Endocrine Therapy in people with Breast Cancer and Early-Stage Breast Carcinoma, run by Renaissance Institute of Precision Oncology and Radiosurgery at 1 site in United States.
Trial summary
SOLIS is a prospective, single-arm, single-institution pilot trial evaluating single-fraction stereotactic radiotherapy (24 Gy to the planning target volume with a simultaneous integrated boost of 30 Gy to the clinical target volume) delivered with a cleared linear accelerator as definitive non-operative local… Read more about this study
- Who is it for?
- Ages 50 years and older
- Conditions the study is for
- Breast Cancer, Early-Stage Breast Carcinoma, Hormone Receptor-Positive Breast Cancer
- What is being tested?
- Stereotactic Radiation Therapy and Endocrine Therapy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2027to 1 Jan 2032
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Invasive ductal carcinoma or favorable special histology confirmed by core biopsy.
- Unifocal tumor ≤2 cm; estrogen receptor-positive and HER2-negative; grade 1-2; clinically node-negative (cN0).
- Age ≥65, or age 50-64 when surgery is unsuitable or declined (capped at 10 of 30 participants).
- Tumor ≥5 mm from skin and pectoralis; willing to receive adjuvant endocrine therapy.
- Zubrod performance status 0-2; able to undergo MRI and FDG PET/CT; informed consent.
Who cannot join
- Multifocal or multicentric disease; pure DCIS; invasive lobular carcinoma >10%; extensive intraductal component or diffuse calcifications.
- Grade 3, triple-negative, or HER2-positive disease; nodal or distant metastases.
- Prior ipsilateral breast radiation or excisional biopsy/lumpectomy; neoadjuvant chemotherapy.
- Tumor <5 mm from skin or pectoralis; inability to meet dose constraints or PTV >60 cm³.
- Connective tissue disease; prohibited other malignancy; pregnancy or lactation.
- Pathogenic BRCA1, BRCA2, PALB2, or TP53 variant; investigator judgment that participation is inappropriate.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Renaissance Institute for Precision Oncology & Radiosurgery
Winter Park, Florida, 32789
Julia Pierson, 321-972-1102, jpierson@therenaissanceinstitute.org
Evan Thomas, MD, PhD
About this study
Official title: Single-Dose Stereotactic Radiosurgery (SDRT) as Definitive Non-Operative Treatment for Early-Stage Breast Cancer: A Prospective Single-Arm Pilot Trial With Bayesian Safety Monitoring (SOLIS / Protocol RAD 2024)
SOLIS is a prospective, single-arm, single-institution pilot trial evaluating single-fraction stereotactic radiotherapy (24 Gy to the planning target volume with a simultaneous integrated boost of 30 Gy to the clinical target volume) delivered with a cleared linear accelerator as definitive non-operative local treatment for early-stage, hormone receptor-positive, HER2-negative breast cancer with planned omission of lumpectomy. Adjuvant endocrine therapy is prescribed on-label. The primary endpoint is the incidence of CTCAE v5.0 Grade ≥2 skin adverse events within 90 days of treatment, monitored with a pre-specified Bayesian safety stopping rule. Secondary endpoints include biopsy-confirmed absence of residual invasive carcinoma at 12 months, imaging response on multiparametric MRI and FDG PET/CT, late toxicity, cosmesis, patient-reported outcomes, salvage surgery, and disease control through 36 months.
- Conditions
- Breast Cancer, Early-Stage Breast Carcinoma, Hormone Receptor-Positive Breast Cancer, HER2-Negative Breast Cancer
- Being tested
- Stereotactic Radiation Therapy, Endocrine Therapy
- Keywords
- SOLIS, single-fraction SDRT, stereotactic radiosurgery, lumpectomy omission, non-operative, HR-positive, HER2-negative
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Stereotactic Radiation TherapyRadiation
Single fraction 24 Gy to PTV with SIB 30 Gy to CTV on Varian Edge with image guidance.
Endocrine TherapyDrug
Adjuvant aromatase inhibitor or tamoxifen initiated within 30 days of SDRT; on-label; recommended 5 years.
| Study group | Role | What they receive |
|---|---|---|
| Single-fraction SDRT plus adjuvant endocrine therapy | Experimental | Single-fraction SDRT plus adjuvant endocrine therapy. Receives: Radiation: Stereotactic Radiation Therapy; Drug: Endocrine Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of CTCAE v5.0 Grade ≥2 skin adverse events
Proportion of treated patients with at least one Grade ≥2 skin AE within 90 days, graded per protocol by study research nurse practitioner.
Measured: 90 days after SDRT
Secondary outcomes (7)
Absence of residual invasive carcinoma on protocol-mandated tissue sampling
Proportion with no residual invasive carcinoma on mandated sampling.
Measured: 12 months
Modified RECIST 1.1 response on multiparametric breast MRI
MRI response by modified RECIST 1.1.
Measured: Up to 36 months
PERCIST 1.0 metabolic response on FDG PET/CT
Metabolic response assessed by PERCIST 1.0.
Measured: 6 and 12 months
Late Grade ≥2 skin adverse events
Incidence of late Grade ≥2 skin adverse events after treatment.
Measured: From 90 days through 36 months
Rate of salvage surgery
Proportion of participants undergoing salvage surgery.
Measured: Through 36 months
Ipsilateral breast tumor recurrence
Incidence of ipsilateral breast tumor recurrence.
Measured: 12, 24, and 36 months
BREAST-Q Breast Conserving Therapy module scores
Change in BREAST-Q Breast Conserving Therapy module scores.
Measured: Baseline through 36 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Sep 2026
- Study start1 Jan 2027 (estimated)
- Primary completion1 Jan 2029 (estimated)
- Study completion1 Jan 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Renaissance Institute of Precision Oncology and Radiosurgery
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Evan Thomas, Renaissance Institute of Precision Oncology and Radiosurgery
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07844759
- Sponsor's protocol ID
- RAD 2024
- Other IDs
- RAD 2024
- Acronym
- SOLIS
- Status last verified
- Sep 2026
- First submitted
- 21 Sep 2026
- Last updated
- 28 Sep 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No