Debate I, Sunday 4 May 2025
ESTRO 2025 Congress Report I RTT Track

By the ESTRO Positioning & Immobilisation Focus Group

The debate titled "This house believes that the need for robust positioning and immobilisation in radiotherapy practice is over!" brought together leading radiation therapists (RTTs) from across Europe and Australia. The discussion was focused on whether technological advances such as surface-guided radiotherapy (SGRT), adaptive radiotherapy (ART), and improved patient-centric workflows had rendered traditional rigid immobilisation obsolete, or whether application of such immobilisation remained essential for safety, precision, and consistency.

 

Let go of habitual restraint

Reijer Rutgers, RTT specialist from the Netherlands, opened the case for the motion. He challenged the habitual use of rigid immobilisation, suggesting that it stemmed more from routine and a desire for control than from clinical necessity. Highlighting the discomfort and psychological distress experienced by patients, he advocated modern alternatives that enhanced both comfort and precision.

Reijer underscored the transformative power of ART, real-time imaging, and motion tracking systems. These tools, he argued, allowed accurate treatment without the need for full physical restraint. He presented clinical examples in which the use of adaptive systems had led to smaller margins and improved intra-fraction stability, without the need for tattoos or rigid setups. Though he acknowledged that use of such systems led to lengthened treatment times and high initial costs, Reijer emphasised that these were outweighed by improved patient experiences and the ability to cut the number of overall sessions.

 

His conclusion was firm: with advancing technology and a patient-centred shift in care, robust immobilisation was no longer a necessity in radiotherapy.

 

Innovation should not replace essentials

Sophie Boisbouvier, a research RTT from France, strongly opposed the motion. She began by stating the limited global and national access to ART: for example, fewer than 1% of patients in France and Japan receive online adaptive treatments. The majority of departments worldwide still rely on conventional equipment, making robust immobilisation vital for safe and consistent care.

Sophie argued that even in high-tech environments, immobilisation tools remained crucial. Thermoplastic masks, breast boards, and limb supports were still used in ART to ensure reproducibility and comfort. She highlighted studies in which patients had reported high anxiety and instability without these tools, and she warned against oversimplification of the problem of discomfort.

 

Instead, she championed upright positioning as a complementary innovation, not a replacement, that had been proven to enhance comfort while maintaining precision. She concluded that although methods had evolved, the need for reliable, stabilising techniques remained fundamental to radiotherapy.

 

Precision over restraint

Melissa Burns, an RTT from Australia, echoed Reijer in supporting the motion, arguing that the profession must evolve with its technology. She acknowledged that robust immobilisation had once been critical. Still, she contended that with the rise of modern imaging, motion management, and planning algorithms, rigid restraints had become more of a limitation than a safeguard.

 

Melissa emphasised updated guidance from radiotherapy boards that now recommend comfort-driven stability in lung, breast, and head-and-neck treatments. She drew attention to the planning target volume concept, showing how current tools—daily imaging, robust optimisation, surface guidance, respiratory gating—enabled precision without physical constraint.

 

She presented clinical examples in which painful and complex setups had been replaced by more adaptable, comfortable approaches without compromising safety. Notably, her centre had removed the shoulder component of head-and-neck masks to reduce error and the need for imaging repetitions. She concluded that RTTs now had the knowledge and resources to move toward patient-centred, flexible positioning practices.

 

Confidence is not control

Dylan Callens, PhD researcher RTT and quality manager from Belgium, brought the debate back to safety, arguing emphatically against the motion. Using a compelling analogy of a broken shopping cart, he warned of the illusion of control that can occur when over-reliance on technology is combined with inadequate processes.

 

He identified robust immobilisation as one of several interlinked safety layers—which included SGRT, image-guided radiotherapy, and dosimetric verification—that should not be removed. Citing real-world incident data from Belgian clinics, Dylan showed how errors often stemmed from poor indexation or missing immobilisation in spinal and palliative cases. Over-reliance on SGRT, particularly in patients with darker skin or high body mass index, introduced risks.

 

He also highlighted human factors such as complacency and attention tunnelling, drawing on aviation disasters to illustrate how systems can fail when users are poorly integrated into automated workflows. Dylan emphasised that emerging paradigms—such as stereotactic radiotherapy, FLASH, and proton therapy—required more, not less, control. In each, robust immobilisation directly contributed to safety, reproducibility, and accurate dose delivery.

 

He concluded by likening immobilisation to aeroplane seatbelts: essential, even in the safest systems. Removing them, he warned, risked patient safety and undermined treatment quality.

 

Audience reflections and final vote

The audience discussion revealed important clinical and ethical considerations. On breast radiotherapy, Melissa emphasised that while arms-above-head positioning was typical, patient comfort should guide decisions, with techniques such as volumetric modulated arc therapy offering flexibility. In head-and-neck treatments, concerns about omitting masks had been addressed through reassurance about the safety of daily imaging and surface guidance for motion monitoring. Reijer and Dylan cautioned that departments without access to advanced technology had to adapt carefully and avoid overextending into workflows designed for more resource-rich settings. All speakers agreed on the need for improved patient education, with Sophie calling for a holistic, patient-centred approach to positioning choices.

 

When it came to the vote, the audience decisively rejected the motion. The result—“The need for robust positioning and immobilisation in radiotherapy is NOT over”—highlighted a prevailing sense of caution. While innovation is reshaping radiotherapy, the audience reaffirmed the importance of reliable and reproducible positioning methods, particularly in high-precision or low-resource contexts.

The debate ultimately underscored a profession in transition. Rather than elimination of immobilisation, the path forward lies in refining it—blending emerging tools with proven safety principles, and tailoring care to individual patients and clinical realities. As one moderator aptly put it, “safety never goes out of style”.

 

Siret Kivistik, MSc (RT advanced practice), doctoral researcher

Principal lecturer, Tartu Applied Health Sciences University

RTT, Tartu University Hospital
Member of the ESTRO Positioning & Immobilisation focus group