Every year, a growing number of patients hear the words every oncologist hopes to say: your lymphoma is in remission. It’s genuinely one of the better stories in modern oncology. Hodgkin lymphoma and many aggressive non-Hodgkin lymphomas are now treated with curative intent, and many patients go on to live for decades after treatment.
But in clinical practice, “cured” isn’t always the end of the conversation. For some patients, especially those who receive radiotherapy to the chest as part of their treatment, there’s a second, quieter conversation that unfolds years later, one about the heart, the lungs, and the long-term consequences of the very treatment that saved their life.
That is where proton therapy enters the conversation.
Why Radiation to the Chest Is Complicated
Not every lymphoma patient needs radiotherapy. Treatment decisions are individualized. But for some patients with lymphoma affecting the mediastinum, the central region of the chest between the lungs, radiotherapy can be an important part of a curative treatment plan.
The challenge is largely anatomical. The treatment target can lie close to the heart, lungs and, particularly in women, breast tissue. This makes limiting radiation exposure to surrounding healthy tissues an important consideration during treatment planning.
Here’s what makes this matter so much: lymphoma is often diagnosed in younger patients, many of whom go on to live for decades after treatment. Long-term follow-up studies of Hodgkin lymphoma survivors have found a two- to fourfold increased risk of second malignant neoplasms and cardiovascular disease compared with the general population. Radiotherapy has specifically been associated with a 1.5- to 15-fold increased risk of solid malignancies, with this risk remaining elevated for decades after treatment.
So the question for radiation oncology has been a fair one: is there a way to treat the lymphoma just as effectively, while reducing how much radiation reaches the heart, lungs, and breast tissue nearby?
Enter Proton Therapy
This is where the physics of radiation becomes directly relevant to patient care.
Conventional photon radiotherapy deposits dose along its path through the body. Even with modern, highly targeted techniques such as intensity-modulated radiotherapy (IMRT), some dose continues beyond the target.
Protons behave fundamentally differently. Because of a physical property called the Bragg peak, a proton beam can be planned to deposit most of its prescribed dose within the target, followed by a rapid reduction in dose beyond it. In simple terms: proton therapy can often “stop” where photon therapy “continues.”
For appropriately selected patients with mediastinal lymphoma, this difference can translate into a meaningful reduction in radiation reaching the heart, lungs, and breast tissue, while maintaining the prescribed dose to the lymphoma target.
What Does the Research Actually Show?
The potential benefit becomes clearer when we look at the comparative data.
A 2022 systematic review by Patel and colleagues examined eight comparative planning studies of proton therapy and photon-based IMRT for mediastinal lymphoma. Compared with IMRT, proton-based plans reduced mean heart dose in 7 of the 8 studies, mean lung dose in 8 of the 8 studies, and mean breast dose in 6 of the 8 studies. The magnitude of benefit, however, varied depending on individual anatomy, disease distribution, and treatment planning.
More recently, a 2026 study by Reiners and colleagues compared IMRT and pencil-beam scanning proton plans for 156 patients with Hodgkin lymphoma or aggressive non-Hodgkin lymphoma. The study found that proton plans reduced dose to several organs at risk compared with IMRT, although the magnitude of benefit varied according to disease location.
That last point matters clinically. Proton therapy isn’t automatically the best option for every patient with mediastinal lymphoma. The benefit depends on individual anatomy, where the disease sits, and how the treatment is planned. This is why careful patient selection is just as important as the technology itself.
The Access Reality in India
It’s worth being upfront about something the research alone doesn’t convey: particle therapy, including proton therapy, remains limited in availability relative to the potential need in India.
A 2024 health-economic analysis led by researchers at AIIMS New Delhi modelled the growing demand for particle therapy facilities in India through 2040. The analysis suggested that, despite high upfront implementation costs, particle therapy could be economically feasible at a system level, while also highlighting challenges around infrastructure, skilled workforce, referral systems and patient affordability.
For now, proton therapy remains one option among several. Whether it offers a meaningful advantage depends on the individual patient’s disease distribution, anatomy, treatment plan, access and cost.
Why This Matters Beyond the Numbers
For patients and caregivers, the part that matters most may not be the technology itself. It is the shift in thinking behind it.
For decades, survival has understandably been one of the primary measures of success in cancer treatment. Did the treatment work? Is the disease gone? That’s still the most important question, and it always will be.
But as more patients survive lymphoma long-term, a second question has become impossible to ignore: what will the next 40 or 50 years of that patient’s life look like, medically?
Reducing unnecessary radiation exposure today isn’t just a technical improvement to a treatment plan. For a patient in their twenties or thirties, it may be one meaningful factor in their cardiovascular and cancer risk profile decades from now, in their forties, fifties, and beyond. That’s a genuinely different way of measuring a “successful” outcome.
Where This Research Is Headed
This field is still evolving, and it’s worth saying so honestly. Prospective clinical trials, including PRO-Hodgkin (NCT06883604), are helping to further define the role of proton therapy in Hodgkin lymphoma.
The direction of the evidence is encouraging, but important questions remain: which patients are most likely to benefit, how large that benefit is, and whether reductions in radiation exposure ultimately translate into fewer clinically important late effects.
The Bottom Line
Lymphoma treatment has come a long way, and for many patients, cure is now a realistic and achievable outcome. Treating the disease and protecting the years that follow are increasingly being considered together. For appropriately selected patients with mediastinal lymphoma, proton therapy is one example of how the field is learning to hold both of those goals together, not as a trade-off, but as a shared objective.
Because when a patient has decades of life ahead of them, those decades deserve just as much attention as the diagnosis did.
If you or someone you know is navigating a lymphoma diagnosis involving the chest, this is a conversation worth having with your oncologist about what treatment options exist, and whether proton therapy is relevant to your specific situation.
References
- van Leeuwen FE, Ng AK. Long-term risk of second malignancy and cardiovascular disease after Hodgkin lymphoma treatment. Hematology Am Soc Hematol Educ Program. 2016;2016(1):323–330.
- Patel CG, et al. Systematic review for deep inspiration breath hold in proton therapy for mediastinal lymphoma: A PTCOG Lymphoma Subcommittee report and recommendations. Radiother Oncol. 2022;177:21–32.
- Reiners K, Viviers E, Getman N, et al. Comparing Organs at Risk Sparing Between Intensity-Modulated Radiotherapy and Pencil-Beam Scanning Plans Based on Disease Location for Hodgkin and Non-Hodgkin Lymphoma. Int J Part Ther. 2026;19:101307.
- PRO-Hodgkin. ClinicalTrials.gov Identifier: NCT06883604. Clinical Investigation of PBS Proton Treatment in Hodgkin Lymphoma Patients.
- Gupta A, Subramani V, Kumar R, Kareem R, Vishwanathan B, Sharma DN. Revolutionizing cancer treatment in India: Evaluating the unmet need, economics, and a roadmap for project implementation of particle therapy. 2024;130(14):2528–2537.
