The Influence of Treatment Position (Prone vs. Supine) on Whole Breast Target

Chinese Academy of Medical Sciences & Peking Union Medical College

Status: Enrolling

Conditions: Breast Cancer

Treatments: Device: dedicated treatment board with no degree

Study type: Interventional

Funder types: Other

Identifiers

NCT05609058

BC-2019

Details and patient eligibility

About

Radiotherapy after breast conserving therapy plays an important role in early stage breast cancer patients. It not only results in a reduction in local and regional recurrence but also decrease the death rate effectively. For adjuvant radiotherapy, supine positioning is the most common approach and has multiple advantages. Due to deformability and softness of the breast, during simulation and treatment in supine position, the breast stretches over the chest wall, especially in patients with large and pendulous glands. Thus the organs at risk (OARs) received dose increased. The radiotherapeutic toxicity are unavoidable. Some present studies show that the prone positioning of patients can improve dose homogeneity and reduce the dose distribution in OARs in patients with large and pendulous glands. Chinese women have relatively small breasts, the advantages of those have not been established. Therefore, investigators compared the parameters between supine and prone positions for whole breast irradiation after conserving surgery.

Full description

Objective To investigate the difference of target volumes and dosimetric parameters between supine and prone positions for whole breast irradiation after conserving surgery.

Methods Breast cancer patients with T1-2N0M0 stage who underwent radiation therapy after conserving surgery were enrolled. Supine and Prone scan sets were acquired during free breathing for all patients. Target volumes and organs at risk (OARs) including heart, ipsilateral lung and bilateral breast were contoured by the same radiation oncologist. The tumor bed (TB) was determined based on surgical clips. The Clinical target volume (CTV)consisted of the whole breast. The planning target volume (PTV) was CTV plus 0.5cm. The boost of PTV (PTVboost) was TB plus 0.5cm. Dosimetric parameters of target volumes and OARs were compared between supine and prone position.

Enrollment: 300 estimated patients

Sex: Female

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Breast cancer patients with T1-T2N0M0 stage who underwent radiation therapy after conserving surgery
2. exhibited normal arm movement aſter surgery
3. had no chronic lung diseases
4. Written informed consent forms

Exclusion criteria

1. Breast cancer patients with radical surgery
2. could not exhibit normal arm movement after surgery
3. had chronic lung diseases
4. refused informed consent forms

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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300 participants in 1 patient group

Breast cancer underwent scanning in the supine position

Experimental group

Description:

Breast cancer patients with T1-2N0M0 stage who underwent radiation therapy after conserving surgery were enrolled. Supine scan sets were acquired during free breathing for all patients. Target volumes and organs at risk (OARs) including heart, ipsilateral lung and bilateral breast were contoured by the same radiation oncologist. The tumor bed (TB) was determined based on surgical clips. The Clinical target volume (CTV)consisted of the whole breast. The planning target volume (PTV) was CTV plus 0.5cm. The boost of PTV (PTVboost) was TB plus 0.5cm.

Treatment:

Device: dedicated treatment board with no degree