Resource implications of evolving breast cancer radiotherapy treatment protocols

Breast cancer remains one of the commonest cancers diagnosed [1] and the majority of women treated for breast cancer receive radiotherapy [2]. Treatment of this cohort represents a significant proportion of the overall workload in radiotherapy departments [3]. Changes in indications for adjuvant breast radiotherapy, increasing complexity of treatment techniques and altered fractionation schemes may impact on resources in busy radiotherapy departments in a myriad of ways.

Fractionation schemes have been the subject of extensive research. Moderate hypofractionation to a dose of 40Gy in 15 fractions over three weeks or 42.5Gy in 16 fractions has been widely adopted as standard for all women receiving adjuvant breast cancer treatment [4,5]. More recently the Fast Forward trial, which included over four thousand patients demonstrated that 26Gy in 5 fractions given over one week was non inferior to 40Gy in 15 fractions at 5 years for ipsilateral breast relapse in the treatment of early breast cancer [6]. The one week regimen also provided equivalent rates of moderate or marked toxicity. The addition of a boost to the tumour bed for women treated with breast conserving surgery has been used to further reduce the risk of recurrence for high-risk breast cancer [7]. However, in the modern setting, there may less benefit to the addition of a boost and its use is now individualised [8]. When indicated, the boost may be delivered by conventional fractionation [9], moderate hypofractionation [10] or by simultaneous integrated boost [11,12], all presenting varying challenges in resource management. A large randomised controlled trial has recently demonstrated a reduced risk of recurrence when a tumour bed boost is given for women with high-risk ductal carcinoma in situ (DCIS), an additional indication not previously a standard approach [13].

Prospective randomised data have shown similar outcomes for moderate hypofractionation when compared with standard fractionation in women receiving adjuvant radiotherapy after immediate implant-based reconstruction [14]. Various data including a large meta-analysis has demonstrated that modern radiotherapy to the locoregional nodes is associated with improved breast cancer and overall mortality leading to increased use of internal mammary node (IMN) radiotherapy [15]. This in turn will increase the use of more complex delivery techniques such as deep inspiration breath hold to minimize dose to organs at risk [16].

The resource impact of these various changes has been examined individually [17]. However, the combined resource impact of these changes will substantially depend on the patient cohort treated. We developed an activity-based costing model to examine the combined impact of these changes on staff time, linear accelerator time and cost in a clinical cohort.