Concurrent Boost Radiotherapy
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.
|Study Design:||Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||A Feasibility Study to Evaluate Intensity Modulated Radiation Therapy (IMRT) for Concomitant Boost Breast Radiotherapy (CBRT)|
- 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 without major treatment deviation. [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]
- To evaluate acute and late morbidity related to treatment [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]
- To identify factors and parameters associated with increased risk of treatment morbidity [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]
- To evaluate local control rates [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]
- To develop treatment protocol outlining appropriate guidelines for planning and delivery [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]
|Study Start Date:||November 2008|
|Study Completion Date:||December 2011|
|Primary Completion Date:||December 2011 (Final data collection date for primary outcome measure)|
|Experimental: Concurrent Boost RT||
Radiation: Concurrent Boost RT
Patient will receive radiation to the tumour bed concurrently with whole breast radiation instead of receiving this treatment sequentially, that is, whole breast RT first then followed by RT directly to the tumour bed.
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.
|University Health Network, Princess Margaret Hospital|
|Toronto, Ontario, Canada, M5G 2M9|
|Principal Investigator:||Fei-Fei Liu, MD||University Health Network, Princess Margaret Hospital|