Confirmatory study of accelerated breast irradiation after breast conserving surgery.

A single center, prospective, single-arm, confirmatory study of accelerated partial breast irradiation using intensity modulated radiotherapy technique after breast conserving surgery.

Status

Recruiting

Phases

Phase 2

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT1032220561

Enrollment

Registered

2023-01-11

Start date

2023-02-09

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Breast cancer with ductal carcinoma in situ(DCIS) or invasive ductal carcinoma(IDC)

Interventions

Accelerated partial breast irradiation is performed after partial mastectomy. A dose of 30 Gy in 5 fractions is administered.

Eligibility

Sex/Gender

Female

Inclusion criteria

Inclusion criteria: 1. All of the following conditions were met prior to surgery. a Single tumor deteceted in MRI. b No lung metastasis detected in chest X-ray. c No neoadjuvant treatment. d No distant metastasis detected in all preoperative examinations. 2. Additional resection during partial mastectomy is allowed. 3. Eligibility criteria of histopathology, a DCIS/IDC, pTis-1N0M0, tumor size =< 2 cm. b pN0. c No cancer cells within 2 mm of resection margin. d Not multiple tumors. 4. Receiving appropriate adjuvant therapy (may not be necessary). 5. Female (Explanation and consent can be given in Japanese). 6. 50 years or older. 7. ECOG Performance status 0 or 1. 8. No history of radiation therapy to the chest for any disease. 9. Major organ function is preserved. 10. Written informed consent is obtained.

Exclusion criteria

Exclusion criteria: 1. Active collagen diseases. 2. Simultaneous or metachronous (within 2 years) multiple cancers. 3. Active infectious disease requiring systemic therapy. 4. Receiving continuous administration of steroids (> 10mg/day) or immunosuppressant treatments. 5. Diabetes mellitus uncontrollable under proper treatment. 6. Other conditions judged as inappropriate for the study by the investigator.

Design outcomes

Primary

Measure	Time frame
The incident rate of 3-year late adverse event (Grade 2 or more)	—

Secondary

Measure	Time frame
1) The 5-year ipsilateral breast tumor recurrence rate 2) The 5-year regional lymph node (ipsilateral axillary lymph node, supraclavicular lymph node, parasternal lymph node) recurrence rate 3) The 5-year distant metastasis free survival rate 4) The 5-year tumor recurrence free survival rate 5) The 5-year overall survival rate 6) The 5-year contralateral breast tumor recurrence rate 7) Acute period adverse event incident rate 8) The proportion of patients with worse breast cosmetic changes	—

Measure

Time frame

1) The 5-year ipsilateral breast tumor recurrence rate 2) The 5-year regional lymph node (ipsilateral axillary lymph node, supraclavicular lymph node, parasternal lymph node) recurrence rate 3) The 5-year distant metastasis free survival rate 4) The 5-year tumor recurrence free survival rate 5) The 5-year overall survival rate 6) The 5-year contralateral breast tumor recurrence rate 7) Acute period adverse event incident rate 8) The proportion of patients with worse breast cosmetic changes

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Contacts

Public ContactTakuya Shimizuguchi

Tokyo Metropolitan Komagome Hospital

JASTRO.cick@gmail.com+81-3-3823-2101

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026