{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=18F-FES",
    "query": {
      "intervention": "18F-FES"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 20,
    "total_pages": 2,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=18F-FES&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-06T01:06:25.725Z",
  "attribution": "Data derived from public ClinicalTrials.gov records. The official record at https://clinicaltrials.gov/ remains the source of truth for current availability, contacts, and full study details.",
  "notes": [
    "This endpoint exposes only public summary fields — no participant contact emails, phone numbers, or scraped investigator contact details.",
    "For contact information and full protocol detail, follow each trial's `official_url` to the ClinicalTrials.gov record.",
    "This API is a navigational aid. It does not provide medical advice, eligibility determinations, or compensation guarantees."
  ],
  "trials": [
    {
      "nct_id": "NCT04174352",
      "title": "FES Imaging to Optimize Tamoxifen for Metastatic Breast Cancer",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "EARLY_PHASE1"
      ],
      "conditions": [
        "ERα+ Breast Cancer",
        "ESR1 Gene Mutation"
      ],
      "interventions": [
        {
          "name": "Tamoxifen",
          "type": "DRUG"
        },
        {
          "name": "FES PET/CT",
          "type": "DIAGNOSTIC_TEST"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIAGNOSTIC_TEST"
      ],
      "sponsor": "University of Wisconsin, Madison",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "19 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "19 Years and older"
      },
      "enrollment_count": 12,
      "start_date": "2020-10-20",
      "completion_date": "2027-12",
      "has_results": false,
      "last_update_posted_date": "2026-07-21",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 2,
      "location_summary": "Madison, Wisconsin",
      "locations": [
        {
          "city": "Madison",
          "state": "Wisconsin"
        },
        {
          "city": "Madison",
          "state": "Wisconsin"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04174352"
    },
    {
      "nct_id": "NCT02409316",
      "title": "[18F]FES PET/CT in Endocrine Refractory Breast Cancer",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Estrogen Receptor Positive Breast Cancer",
        "Breast Neoplasm",
        "Metastatic Breast Cancer"
      ],
      "interventions": [
        {
          "name": "[18F]FES",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Pennsylvania",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 6,
      "start_date": "2015-10-15",
      "completion_date": "2025-08-01",
      "has_results": false,
      "last_update_posted_date": "2026-06-11",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 1,
      "location_summary": "Philadelphia, Pennsylvania",
      "locations": [
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02409316"
    },
    {
      "nct_id": "NCT04727632",
      "title": "[18F]Fluoroestradiol-PET/CT Companion Imaging Study to the FORESEE Trial",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "EARLY_PHASE1"
      ],
      "conditions": [
        "Estrogen Receptor Positive Breast Cancer"
      ],
      "interventions": [
        {
          "name": "[18F]Fluoroestradiol (FES) PET/CT",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Utah",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 2,
      "start_date": "2021-03-31",
      "completion_date": "2024-07-30",
      "has_results": false,
      "last_update_posted_date": "2024-10-28",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 1,
      "location_summary": "Salt Lake City, Utah",
      "locations": [
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04727632"
    },
    {
      "nct_id": "NCT00602043",
      "title": "F-18 16 Alpha-Fluoroestradiol-Labeled Positron Emission Tomography in Predicting Response to First-Line Hormone Therapy in Patients With Stage IV Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Estrogen Receptor-positive Breast Cancer",
        "Progesterone Receptor-negative Breast Cancer",
        "Progesterone Receptor-positive Breast Cancer",
        "Recurrent Breast Cancer",
        "Stage IV Breast Cancer"
      ],
      "interventions": [
        {
          "name": "F-18 16 alpha-fluoroestradiol",
          "type": "RADIATION"
        },
        {
          "name": "fludeoxyglucose F 18",
          "type": "RADIATION"
        },
        {
          "name": "positron emission tomography",
          "type": "PROCEDURE"
        },
        {
          "name": "computed tomography",
          "type": "PROCEDURE"
        },
        {
          "name": "laboratory biomarker analysis",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "RADIATION",
        "PROCEDURE",
        "OTHER"
      ],
      "sponsor": "National Cancer Institute (NCI)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 20,
      "start_date": "2008-09",
      "completion_date": "2014-09",
      "has_results": true,
      "last_update_posted_date": "2020-02-19",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 1,
      "location_summary": "Seattle, Washington",
      "locations": [
        {
          "city": "Seattle",
          "state": "Washington"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00602043"
    },
    {
      "nct_id": "NCT04382911",
      "title": "Evaluation of Endometriosis With 18F-fluoroestradiol PET / MRI",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Endometriosis"
      ],
      "interventions": [
        {
          "name": "18F-fluoroestradiol",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of North Carolina, Chapel Hill",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 8,
      "start_date": "2020-08-07",
      "completion_date": "2022-07-11",
      "has_results": true,
      "last_update_posted_date": "2023-05-30",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 1,
      "location_summary": "Chapel Hill, North Carolina",
      "locations": [
        {
          "city": "Chapel Hill",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04382911"
    },
    {
      "nct_id": "NCT01714128",
      "title": "FES-PET for Patients Treated on NCI Protocol 8762",
      "overall_status": "WITHDRAWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Diagnostic Imaging ( 6α-[18F]fluoro-17β-estradiol (FES))",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Washington University School of Medicine",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 0,
      "start_date": "2013-06",
      "completion_date": "2015-12",
      "has_results": false,
      "last_update_posted_date": "2021-10-25",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 1,
      "location_summary": "St Louis, Missouri",
      "locations": [
        {
          "city": "St Louis",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01714128"
    },
    {
      "nct_id": "NCT03065712",
      "title": "Test - Retest Reproducibility of 18F Fluoroestradiol (FES) PET",
      "overall_status": "WITHDRAWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "F-18 Fluoroestradiol",
          "type": "DRUG"
        },
        {
          "name": "Computed Tomography",
          "type": "PROCEDURE"
        },
        {
          "name": "Positron Emission Tomography",
          "type": "PROCEDURE"
        },
        {
          "name": "Laboratory Biomarker Analysis",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "PROCEDURE",
        "OTHER"
      ],
      "sponsor": "University of Texas Southwestern Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 0,
      "start_date": "2017-02-22",
      "completion_date": "2021-02-20",
      "has_results": false,
      "last_update_posted_date": "2020-05-12",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 1,
      "location_summary": "Dallas, Texas",
      "locations": [
        {
          "city": "Dallas",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03065712"
    },
    {
      "nct_id": "NCT04252859",
      "title": "[18F]Fluoroestradiol-PET/CT Imaging of Invasive Lobular Carcinoma",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Invasive Lobular Breast Carcinoma"
      ],
      "interventions": [
        {
          "name": "[18F]Fluoroestradiol (FES) PET/CT",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Utah",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 44,
      "start_date": "2020-12-11",
      "completion_date": "2024-12-07",
      "has_results": true,
      "last_update_posted_date": "2025-05-18",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 1,
      "location_summary": "Salt Lake City, Utah",
      "locations": [
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04252859"
    },
    {
      "nct_id": "NCT02398773",
      "title": "FES PET/CT in Predicting Response in Patients With Newly Diagnosed Metastatic Breast Cancer Receiving Endocrine Therapy",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "HER2/Neu Negative",
        "Progesterone Receptor Negative",
        "Progesterone Receptor Positive",
        "Stage IV Breast Cancer AJCC v6 and v7"
      ],
      "interventions": [
        {
          "name": "Computed Tomography",
          "type": "PROCEDURE"
        },
        {
          "name": "F-18 16 Alpha-Fluoroestradiol",
          "type": "DRUG"
        },
        {
          "name": "Laboratory Biomarker Analysis",
          "type": "OTHER"
        },
        {
          "name": "Positron Emission Tomography",
          "type": "PROCEDURE"
        }
      ],
      "intervention_types": [
        "PROCEDURE",
        "DRUG",
        "OTHER"
      ],
      "sponsor": "National Cancer Institute (NCI)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 99,
      "start_date": "2016-05-04",
      "completion_date": "2026-12-31",
      "has_results": false,
      "last_update_posted_date": "2026-06-29",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 25,
      "location_summary": "Birmingham, Alabama • Duarte, California • Los Angeles, California + 16 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Duarte",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Indianapolis",
          "state": "Indiana"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02398773"
    },
    {
      "nct_id": "NCT05068726",
      "title": "Clinical Utility of FES F18 PET/CT in Metastatic Breast Cancer Patients",
      "overall_status": "TERMINATED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Metastatic Breast Cancer"
      ],
      "interventions": [
        {
          "name": "18F Fluoroestradiol Radiopharmaceutical with PET/CT",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "GE Healthcare",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "99 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 99 Years · Female only"
      },
      "enrollment_count": 51,
      "start_date": "2023-01-05",
      "completion_date": "2024-06-01",
      "has_results": false,
      "last_update_posted_date": "2024-07-31",
      "last_synced_at": "2026-09-06T01:06:25.725Z",
      "location_count": 24,
      "location_summary": "Flagstaff, Arizona • Cerritos, California • Duarte, California + 20 more",
      "locations": [
        {
          "city": "Flagstaff",
          "state": "Arizona"
        },
        {
          "city": "Cerritos",
          "state": "California"
        },
        {
          "city": "Duarte",
          "state": "California"
        },
        {
          "city": "Long Beach",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05068726"
    }
  ]
}