Late radiation toxicity in Hodgkin lymphoma patients: proton therapy's potential

Abstract

In 2010, all young patients treated for intrathoracic Hodgkin lymphoma (HL) at one of 10 radiotherapy centers in the province of Quebec received 3D conformal photon therapy. These patients may now be at risk for late effects of their treatment, notably secondary malignancies and cardiac toxicity. We hypothesized that more complex radiotherapy, including intensity‐modulated proton therapy (IMPT) and possibly IMRT (in the form of helical tomotherapy (HT)), could benefit these patients. With institutional review board approval at 10 institutions, all treatment plans for patients under the age of 30 treated for HL during a six‐month consecutive period of 2010 were retrieved. Twenty‐six patients were identified, and after excluding patients with extrathoracic radiation or treatment of recurrence, 20 patients were replanned for HT and IMPT. Neutron dose for IMPT plans was estimated from published measurements. The relative seriality model was used to predict excess risk of cardiac mortality. A modified linear quadratic model was used to predict the excess absolute risk for induction of lung cancer and, in female patients, breast cancer. Model parameters were derived from published data. Predicted risk for cardiac mortality was similar among the three treatment techniques (absolute excess risk of cardiac mortality was not reduced for HT or IMPT (p>0.05,p>0.05) as compared to 3D CRT). Predicted risks were increased for HT and reduced for IMPT for secondary lung cancer (p<0.001,p<0.001) and breast cancers (p<0.001,p<0.001) as compared to 3D CRT.PACS numbers: 87.55.dh, 87.55.dk

Proton therapy for adults with mediastinal lymphomas: the International Lymphoma Radiation Oncology Group guidelines

“…Several dosimetric studies comparing proton with photon plans [8][9][10][11][12][13][14][15][16][17][18][19][20][21] have been conducted in an effort to establish the benefit and indications for the use of proton therapy in lymphoma, with the vast majority focusing on mediastinal involvement. They showed that there is an individualized and potential benefit in patients with dose reduction to the heart, lungs, and breasts with proton therapy compared with 3D conformal radiotherapy or IMRT.…”

Evidence-based Review on the Use of Proton Therapy in Lymphoma From the Particle Therapy Cooperative Group (PTCOG) Lymphoma Subcommittee

“…Proton therapy has been compared with 3D RT in 10 studies, 8 of which also evaluated modern photon techniques (Table E2; available online at www.redjournal.org). Among the studies, one did not report actual dose to the breast tissue in Gy (RBE) but rather translated that dose into the risk of breast cancer development (65). In all of the studies, proton therapy lowered the mean radiation dose to the breast compared with 3D RT or mRT.…”

Cardiovascular complications after radiotherapy

“…The aims of cardiooncology include the prevention, diagnosis, and treatment of CVDs in the population of oncological patients [7,62,76]. For patients treated with radiation therapy, there is a need for accurate recommendations regarding the planning and extent of cardiac screening for early diagnosis and effective treatment of cardiovascular complications of radiotherapy [5,77,78].…”

“…Studies indicated that the patient survival rate after effective anticancer treatment depended on late complications of the therapy delivered [4]. In patients with Hodgkin lymphoma who underwent radiotherapy, the most common causes of death included a primary or secondary cancer and cardiovascular disease (CVD) [5,6].…”