What is a treatment protocol? — COG, SIOP & NCCN explained for parents

When a doctor says “we are following the COG protocol” or “this is a SIOP-based approach,” they are telling you something important: your child’s plan is not guesswork — it is built on decades of research involving tens of thousands of children worldwide.

A cancer treatment protocol is a detailed, step-by-step written plan that specifies which treatments will be given, in what sequence, at what schedule, and how the team will check whether those treatments are working. Think of it as a map that the oncology team follows — with built-in checkpoints where they review progress and, if needed, adjust the route.

Protocols are not written by a single doctor for a single patient. They are developed by large international bodies — the Children’s Oncology Group (COG), the International Society of Paediatric Oncology (SIOP), and the National Comprehensive Cancer Network (NCCN) — after analysing results from many clinical trials. This means the plan your child receives reflects what has worked for children with the same cancer type, the same subtype, and the same risk group all around the world.

Following a protocol does not mean your child is treated like a number. It means the big decisions — which treatment combination to use, in which order, and for how long — are backed by the strongest available evidence. The care team’s job is to deliver that protocol safely and adjust it to your child as an individual at every visit.

Different cancers use different protocols. A leukaemia protocol looks very different from a brain tumour protocol or a Wilms tumour protocol. Each one is designed for that specific cancer’s biology. The page below explains the three major international frameworks and how the tumour board at CION uses them to build your child’s personalised plan.

A protocol is not just a document — it is a rhythm that your family will live by. Understanding what the coming weeks and months will look like can reduce some of the fear of the unknown.

Treatment is given in phases or cycles. Most paediatric protocols divide treatment into distinct phases: an initial intensive phase, one or more consolidation phases, and often a longer maintenance phase. The names and number of phases vary by cancer type. Your care team will give you a written schedule before treatment begins so you know which appointments are coming and what they involve.

Clinic visits are frequent at the start. The early, more intensive parts of a protocol require more frequent visits for blood tests, infusions, or monitoring. As treatment moves into maintenance phases, visits often become less frequent. Blood count checks — to ensure your child is safe to receive the next part of the protocol — are a routine part of every visit.

The protocol has built-in rest periods. Between treatment cycles, the body is given time to recover. These gaps are part of the protocol, not delays. Some medicines work partly during the rest period as well as during active dosing. Sticking to the schedule — including the rest periods — is important. If you are concerned about a missed appointment or a delay, call the oncology team promptly; they will advise whether and how the schedule needs to be adjusted.

Side effects are anticipated and managed proactively. Protocols include supportive care measures — anti-nausea medicines, infection-prevention strategies, nutritional support — because the oncology community has learned over decades what side effects to expect at each phase. The goal is to keep side effects manageable so the protocol can be delivered safely and on schedule. You will receive a written guide to which symptoms need a same-day call and which are expected parts of the treatment process.

You are part of the team. Parents and caregivers are essential partners in delivering a protocol safely. You will be taught what to watch for at home, which temperatures or bleeding symptoms need an emergency call, and how to support your child’s nutrition and daily life. You deserve to understand everything that is happening — and at CION, no question is too small.