PRISM Trial: Partial Breast Versus Whole Breast Radiation in Early Breast Cancer

NCT07811635 | Not Yet Recruiting

• 1 other identifier: No. F.2-81/2026-GENL/247 /JPMC
• Study Type: interventional
• Target: 100
• Locations: 3 countries
• Sites: 3

Brief Summary

Breast-conserving surgery followed by radiotherapy is a standard treatment for women with early-stage breast cancer. Whole breast irradiation (WBI) is the current standard approach, but partial breast irradiation (PBI), which treats only the area surrounding the original tumor, may reduce radiation exposure to healthy tissues while maintaining similar treatment effectiveness. The PRISM Trial is a prospective, multicenter, phase II randomized controlled trial that will compare ultra-hypofractionated PBI and WBI using the same radiation schedule of 26 Gy delivered in five fractions with intensity-modulated radiotherapy (IMRT). One hundred eligible women with early-stage breast cancer will be randomly assigned to receive either PBI or WBI after breast-conserving surgery. The primary objective is to compare acute treatment-related skin toxicity between the two treatment approaches using both clinician-reported Common Terminology Criteria for Adverse Events (CTCAE v6.0) and patient-reported outcomes (PRO-CTCAE). Secondary objectives include evaluation of early and late toxicity, dosimetric parameters, normal tissue complication probability (NTCP), and the relationship between radiation dose distribution and clinical toxicity over 12 months of follow-up.

Conditions

Breast Cancer Early Stage Breast Cancer (Stage 1-3)

Keywords

Early-Stage Breast Cancer; Partial Breast Irradiation; Whole Breast Irradiation; Ultra-Hypofractionated Radiotherapy; Intensity-Modulated Radiotherapy; Radiation Toxicity

Outcome Measures

Primary Outcomes (1)

• Number of Participants With Acute Treatment-Related Adverse Events by CTCAE Grade and Acute Treatment-Related Symptoms Reported Using PRO-CTCAE

  Number of participants experiencing acute treatment-related adverse events, with severity graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 6.0, and number of participants reporting acute treatment-related symptoms using the Patient-Reported Outcomes version of the CTCAE (PRO-CTCAE).

  3 months after completion of radiotherapy

Secondary Outcomes (2)

• Number of Participants With Late Treatment-Related Adverse Events by CTCAE Grade and Late Treatment-Related Symptoms Reported Using PRO-CTCAE

  6 months and 12 months after completion of radiotherapy

• Dosimetric Parameters

  Baseline at the time of radiation treatment planning

Study Arms (2)

Partial Breast Irradiation (PBI)

EXPERIMENTAL

Radiation: Ultra-Hypofractionated Partial Breast Irradiation

Whole Breast Irradiation (WBI)

ACTIVE COMPARATOR

Radiation: Ultra-Hypofractionated Whole Breast Irradiation

Interventions

Ultra-Hypofractionated Whole Breast Irradiation RADIATION

Ultra-hypofractionated whole breast irradiation (WBI) delivered using intensity-modulated radiotherapy (IMRT). A total dose of 26 Gy in 5 once-daily fractions will be delivered over 5-7 days to the whole breast following breast-conserving surgery.

Whole Breast Irradiation (WBI)

Ultra-Hypofractionated Partial Breast Irradiation RADIATION

Ultra-hypofractionated partial breast irradiation (PBI) delivered using intensity-modulated radiotherapy (IMRT). A total dose of 26 Gy in 5 once-daily fractions will be delivered over 5-7 days to the protocol-defined partial breast target volume following breast-conserving surgery.

Partial Breast Irradiation (PBI)

Eligibility Criteria

• Age: 45 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Women aged ≥45 years.
• Newly diagnosed, histologically confirmed breast carcinoma, including Invasive Ductal Carcinoma (IDC), Invasive Lobular Carcinoma (ILC), or Ductal Carcinoma in Situ (DCIS).
• Early-stage disease (T1-T2, node-negative \[N0\]), with no evidence of distant metastasis.
• Hormone receptor-positive disease (ER and/or PR positive).
• HER2-positive disease, provided patients have received or are receiving appropriate HER2-targeted therapy, as per institutional practice.
• Patients who have undergone breast-conserving surgery with no tumor on inked margins or no residual disease following re-excision.

You may not qualify if:

• Age \<45 years.
• Multicentric disease.
• Locally advanced or node-positive disease (T3-T4 and/or N+) or evidence of distant metastasis.
• Lobular Carcinoma In Situ (LCIS).
• Triple-negative breast cancer.
• Positive surgical margins or incomplete breast-conserving surgery not suitable for re-excision.
• Prior ipsilateral breast irradiation.
• Non-breast malignancy within the past 5 years, except treated non-melanoma skin cancer or in-situ carcinoma.
• Pregnancy or lactation at enrollment.
• Inability to identify the tumor bed on planning Computed Tomography (CT), such as absence of surgical clips or seroma.
• Unacceptable radiotherapy planning feasibility for the experimental technique according to protocol constraints.

Sponsors & Collaborators

• Jinnah Postgraduate Medical Centre: lead

Study Sites (3)

Department of Radiation Oncology, Cyberknife and Tomotherapy Center, Jinnah Postgraduate Medical Centre (JPMC), Karachi, Pakistan

Karachi, Pakistan

Location

Department of Radiation Oncology, King Abdulaziz University, Jeddah, Saudi Arabia

Jeddah, Saudi Arabia

Location

Gulf International Cancer Centre City, Country: Abu Dhabi; UAE

Abu Dhabi, United Arab Emirates

Location

MeSH Terms

Conditions

Breast Neoplasms; Radiation Injuries

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases; Wounds and Injuries

Study Officials

• Fatima Shaukat

  Cyber knife & Tomotherapy center, JPMC

  PRINCIPAL INVESTIGATOR

• Yumna Ahmed

  Cyber knife & Tomotherapy center, JPMC

  STUDY DIRECTOR

• Rabia Tahseen

  Cyber knife & Tomotherapy center, JPMC

  STUDY DIRECTOR

• Nadeem Parvez

  Gulf International Cancer Centre, Abu Dhabi, UAE

  STUDY DIRECTOR

• Agha Hammad Khan

  Ziauddin Hospital, Karachi, Pakistan

  STUDY DIRECTOR

• Reem Khaled Ujaimi

  King Abdulaziz University, Jeddah, Saudi Arabia

  STUDY DIRECTOR

• Ayesha Nooruddin

  Cyber knife & Tomotherapy center, JPMC

  STUDY DIRECTOR

Central Study Contacts

Fatima Shaukat, MBBS, FCPS

CONTACT

03222528223; drfatimaali89@gmail.com

Yumna Ahmed, MBBS, FCPS

CONTACT

+92 321 3093115; yumnahmedali@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Due to the nature of the radiotherapy interventions, participants and treating clinicians cannot be blinded. Outcome assessors and, where feasible, data analysts will remain blinded to treatment allocation to minimize assessment bias. Standardized toxicity grading systems and validated patient-reported outcome measures will be used throughout the study.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Consultant Radiation Oncologist

Model Details: Participants will be randomized in a 1:1 ratio to receive either ultra-hypofractionated partial breast irradiation (PBI) or ultra-hypofractionated whole breast irradiation (WBI). Treatment will be delivered in parallel throughout the study, with each participant receiving only the assigned intervention.

Study Record Dates

• First Submitted: August 6, 2026
• First Posted: September 10, 2026
• Study Start: September 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2027
• Last Updated: September 10, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

PA (1); AE (1); SA (1)