Early outcomes of proton therapy after chemotherapy

This study examined outcomes for patients with Hodgkin lymphoma receiving chemotherapy followed by proton therapy. Researchers reported good disease control and a low rate of side effects at 3 years. However, continued follow-up is needed.

The combination of chemotherapy and radiation therapy provides the best outcomes for patients with Hodgkin lymphoma. The risk of a disease relapse is low. However, survivors of Hodgkin lymphoma are at high risk of developing late side effects within 30 years of treatment. Some of these can be very serious including heart complications and secondary cancers. Late side effects are often in line with the radiation dose received. Lower radiation doses or a less intensive treatment schedule can reduce the risk of late side effects. Another alternative is proton therapy. This is a type of radiation therapy that uses beams of special particles called protons, instead of x-rays, to destroy cancer cells.

138 Hodgkin lymphoma patients receiving chemotherapy were included in this study. 115 patients showed complete response (no sign of active disease) to chemotherapy (based on imaging tests such as PET/CT scans). 15 patients showed a partial response. 8 patients had an unknown response.

All patients received proton therapy after chemotherapy. Adult patients received proton therapy at an average dose of 30.6 Gy. 42% of patients were aged under 18. Pediatric patients received proton therapy at an average dose of 21 Gy. Treatment outcomes were followed for an average of 32 months.

92% of patients were relapse-free at 3 years. This was 96% for adults and 87% for pediatric patients. 78% of patients with a partial response to chemotherapy were progression-free at 3 years. This was significantly lower compared to those with a complete response or unknown response (94%).

No serious radiation-related side effects were observed during the study period. Mild side effects included skin damage caused by radiation, fatigue, coughing, an inflamed esophagus, shortness of breath, anxiety, nausea, and dry mouth.

Researchers concluded that proton therapy is a suitable alternative for Hodgkin lymphoma patients at high risk of developing late side effects. Proton therapy after chemotherapy was safe and effective at 3 years. However, continued follow-up is needed.

Since late effects can occur for up to 30 years after treatment, further studies are needed to examine the long-term benefits of proton therapy.