Why Interruptions in Radiotherapy Must Be Avoided: Lessons from International Clinical Guidelines

In curative radiotherapy, every treatment session is part of a carefully planned schedule aimed at destroying cancer cells while protecting healthy tissues. The 2019 Clinical Guidelines from the Royal College of Radiologists (RCR) emphasize that continuity of treatment is essential for the success of cancer therapy.

Based on over four decades of radiobiological evidence, the RCR guidelines show that tumor cells can start to regrow quickly if radiotherapy is extended beyond the planned overall treatment time, especially in fast-proliferating cancers such as those of the head and neck, lung, or cervix. Studies reviewed by the RCR estimate that each additional day of delay may reduce tumor control by 1–2%.

To prevent this, the guidelines recommend that every radiotherapy department should have a clear policy for managing and compensating missed treatment days, tailored to each patient’s condition. Depending on the situation, compensation may include adding weekend sessions, providing two treatments in one day (with at least six hours between them), or slightly adjusting the dose per session. These measures must always be guided by the treating radiation oncologist and medical physicist to ensure safety and effectiveness.

Importantly, the document also highlights the value of good communication and planning. In countries like Costa Rica, where many patients travel long distances to receive treatment at specialized centers such as Hospital México, San Vicente de Paúl, or Centro Médico de Radioterapia Siglo XXI, anticipating logistical issues—like holidays, machine maintenance, or transportation difficulties—is vital.

The RCR’s message is clear and timeless:

“There is no substitute for timely radiotherapy.”

Every session matters. If a patient cannot attend, they should inform their oncology team immediately so that compensation can be safely arranged.

Consistency, teamwork, and trust between patients and their radiation oncology team remain the cornerstones of effective and compassionate cancer care.