Starting any cancer treatment brings uncertainty. When that treatment involves technology as sophisticated as proton therapy, the questions multiply quickly. What does the first appointment look like? How long will I be there each day? Will I feel anything?
At Tennessee Oncology Proton Center, we believe informed patients are empowered patients. This guide walks you through what a typical proton therapy course looks like — from your very first appointment through the final session and beyond.
Before Treatment Begins: Simulation and Planning
Before a single proton beam is delivered, your care team invests significant time in planning your treatment with precision. This phase typically takes one to two weeks and involves two key steps.
The Simulation Appointment
Your first major visit is the simulation, where our team creates an exact, reproducible setup used every day of your treatment. Depending on the area being treated, this may involve a custom immobilization device — a form-fitting mask for head and neck patients, or a body mold for thoracic or abdominal treatments. A CT scan is taken in your treatment position, creating the blueprint for everything that follows. Simulation typically lasts 60 to 90 minutes.
Treatment Planning
After simulation, your radiation oncologist works alongside a medical physicist and dosimetrist to design your treatment plan. Using specialized software, they define exactly where the proton beams will enter, at what angles, and how much dose each area will receive. This planning phase is one of the most important parts of your entire treatment — and you will not feel a thing during it.
Week 1: Getting Oriented
Your first week is often the most unfamiliar — but also when many patients are pleasantly surprised by how smooth the process feels. Each daily treatment session typically lasts 20 to 45 minutes from check-in to check-out, with the actual beam delivery taking only a few minutes. You will lie in the same position established at simulation. The gantry — a large rotating device that houses the proton delivery system — will move around you. You will not see or feel the proton beam itself.
Side effects in the first week are usually minimal. Fatigue may begin to develop, but for many patients, week one passes with few noticeable changes.
Weeks 2 and 3: Finding Your Rhythm
By the second and third weeks, most patients have settled into a routine. Side effects may begin to emerge during this phase, but because proton therapy deposits significantly less radiation in healthy tissue than conventional X-ray radiation, the severity is often lower than patients expect.
Common side effects during this phase depend on the treatment area. Head and neck patients may experience mild skin changes, dry mouth, or throat irritation. Chest and lung patients may notice some fatigue or occasional esophageal sensitivity. Prostate patients often report urinary frequency or mild irritation.
Mid-Treatment: The Check-In Appointment
Roughly halfway through your course, you will have a formal on-treatment visit with your radiation oncologist — a dedicated time to review how you are tolerating treatment, address any concerns, and confirm the plan is performing as expected. The American Society for Radiation Oncology (ASTRO) recommends these regular check-ins as a standard of care throughout radiation treatment.
Final Weeks: The Home Stretch
As you approach the end of treatment, cumulative effects may be at their peak. Fatigue is the most universally reported late-treatment side effect, and some patients notice skin changes in the treatment area. These are normal and expected — and they typically begin to resolve within days to weeks after your final session.
Your last treatment day is often a moment of genuine celebration in our center. You leave knowing you have completed one of the most precise cancer treatments available anywhere in the world.
After Treatment: Recovery and Follow-Up
Post-treatment follow-up is structured to monitor your recovery and watch for any signs of recurrence. Most side effects resolve within two to four weeks of your final session. Long-term effects from proton therapy — when they occur — are typically less severe than those associated with conventional radiation, one of the key reasons patients and physicians continue to choose protons for complex cases.
If you are considering proton therapy or have recently been referred, we encourage you to reach out to our team. We are happy to walk you through what treatment would look like for your specific diagnosis and answer every question you have before you begin.
