For more than three decades, we have treated patients with multiple types of hematologic disorders, including but not limited to:
- Hodgkin Lymphoma (HL):Early stage and/or bulky tumors, usually in combination with chemotherapy
- Non-Hodgkin Lymphoma (NHL): While radiation therapy (RT) can be delivered to all subtypes of the NHL, in mainstream practice systemic chemotherapy is usually the recommended treatment except for certain clinical situations. However, local RT still has an important role for the following circumstances:
(A) Localized and low-grade NHL subtypes: For example, examine extranodal lymphomas of the mucosa-associated lymphoid tissue (abbreviation: MALT lymphoma) which are most commonly found in the eye, salivary glands, stomach, and so forth. If pathology confirms the lymphoma is low-grade and detected early, local RT alone is the initial treatment of choice unless clinically contraindicated, while systemic chemotherapy is reserved for cases of relapse.
(Ｂ) Diffused large B-cell lymphoma (DLBCL): The recommended treatment for this subtype should be CHOP-based systemic chemotherapy combined with rituximab. However, if the tumor is identified as bulky, in order to enhance the effects of chemotherapy, after drug therapy local RT would be applied to irradiate the site of the bulky tumor.
(Ｃ) NK/T cell lymphoma: Typically found in parts of the nasal cavity and paranasal sinuses, if the diagnosis is early, treatment should include aggressive local RT combined with systemic chemotherapy.
(Ｄ) Primary central nervous system lymphoma (PCNSL): Aggressive treatment relies on methotrexate (MTX)-based chemotherapy. Nevertheless, if the dose of MTX is not high enough (i.e., not higher than 3 g/m2), or the tumor response after MTX is not strong enough, cranial RT might be recommended.
With the advent of radiotherapy technology in recent years, RT-related adverse effects have been remarkably reduced by using new techniques such as intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), RapidArc – which is a technique of volume-modulated arc radiotherapy (VMAT) – and stereotactic body radiation therapy (SBRT). Proton therapy is considered the “target therapy” for radiotherapy, in which protons can administer concentrated irradiation doses in tumors, and avoid dosing normal tissues/organs. Additionally, the prescribed per fraction dose and cumulative RT dose ranges for most of the hematologic malignancies are not as high as that prescribed for other types of adult cancers. Therefore, the role of proton therapy in treating hematologic malignancies might be similar to that in treating pediatric cancers. Currently, several proton cancers in the US have conducted prospective clinical studies/trials to investigate the benefit of using proton therapy to treat patients with mediastinal HL, making great efforts to significantly minimize the potential RT-related long-term sequelae, such as chronic pulmonary/cardiovascular diseases and second malignant neoplasms (i.e. breast cancer, lung cancer).
Article author: Dr. Shinn-Yn Lin