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Background: Adjuvant breast cancer radiotherapy has seen great change in the past decade with respect to the treatment targets indicated, and RT technique capabilities.  For example, regional lymph node irradiation encompassing the internal mammary nodes (IMN) in high-risk node positive patients is routine practice in many clinics; with deep inspiration breath hold (DIBH), intensity modulated arc therapy (IMAT), and partial breast RT also widely utilised.  Complex volume delineation and highly conformal dosimetric treatment plans demand more from our immobilisation systems and verification protocols than what previous simple breast radiotherapy techniques required.  However, the translation of 3D corrective verification protocols used for other treatment sites has not been straightforward when applied to breast radiotherapy, with significant disparity existing between centres.

Aim: To present the common challenges and barriers to developing a standardised verification protocol for breast radiotherapy, and identify the advances in immobilisation and available resources to support the implementation of best practice.  

Discussion: Many factors impact the ability to have a standardised immobilisation and verification protocol for breast cancer radiotherapy.  These include: the large deformative target(s); collision risk associated with a latero-anterior isocentre/arm-up technique; resource impact of a large patient cohort; and the library of techniques required within a single clinic to treat this heterogenous patient group with respect to disease stage and subtype.  Manufacturers have responded to some of these challenges; acknowledging the need to reduce collision risk and improve reproducibility, by developing partial arc cone beam CT (CBCT) and designing breast immobilisation devices that facilitate low-incline positioning with indexed wing-boards and vac-bags.  Patient alignment is also evolving in response to patient dignity and quality of life: tattoo-less surface guidance; specialist radiotherapy bra’s; and alternatives to permanent skin marks are amongst those being investigated.  There are various resources available to support the development and implementation of best practice, such as the newly launched ESTRO-ACROP guideline for positioning, immobilisation and set-up verification for breast radiotherapy; and international networks such as the Breast Radiotherapy Interest Group (BRIG).