Concurrent Boost Radiotherapy

Breast Cancer Clinical Trial

Official title: A Feasibility Study to Evaluate Intensity Modulated Radiation Therapy (IMRT) for Concomitant Boost Breast Radiotherapy (CBRT)

Status Completed

Clinical Trial Summary

The primary aim of this study is to evaluate the feasibility of delivering 42.5 Gy to the breast with a concomitant 10 Gy boost to the tumour bed in 16 fractions for a total duration of 3.5 weeks using intensity modulated radiotherapy (IMRT). The primary end-point is the proportion of patients treated without major treatment deviation.

Clinical Trial Description

Rather than a sequential boost, we propose delivering a concomitant boost using intensity modulated radiotherapy (IMRT). IMRT is a sophisticated technique deliberately using multiple non-uniform beams, resulting in complex, conformal dose distributions. This technique offers several advantages. A concomitant IMRT boost potentially offers improved dose distributions by allowing more conformal doses around the boost volume and increased sparing of the remaining breast and adjacent organs at risk. Several studies have shown better target dose homogeneity resulting in less toxicity with adjuvant breast IMRT . One study found a significant reduction in the rates of moist desquamation with IMRT compared to wedged tangential fields (31% vs. 48%, P=0.0014).

Longer treatment duration increases the inconvenience and decreases patient compliance. Furthermore, this places extra financial and emotional hardship on the patient and her family, particularly if they must travel long distances between home and the treatment centre. Studies have found 10-30% of patients do not receive adjuvant radiotherapy after lumpectomy,placing these patients at higher risk for local recurrence and death from disease. Radiobiologically, a boost increases the risk of late normal tissue effects. In the EORTC study, they found significantly higher but limited rates of severe fibrosis at 10 years of 4.4% vs. 1.6% (p<0.0001) with the boost. No age effect was noted on the incidence of fibrosis. One study compared a shorter hypofractionated schedule of 42.5 Gy/16 fractions over 3.5 weeks with the standard schedule of 50 Gy/25 fractions over 5 weeks and observed comparable 5 year local recurrence rates and cosmetic outcomes. ;

Study Design

Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Breast Cancer

• NCT number: NCT00981864
• Study type: Interventional
• Source: University Health Network, Toronto
• Status: Completed
• Phase: Phase 2
• Start date: November 2008
• Completion date: December 2011