TriangleHEALTH PROFESSIONAL · SOURCE READING
Radiation volume
Source: Childhood Hodgkin Lymphoma Treatment (PDQ®)–Health Professional Version, National Cancer Institute.
Source updated: April 16, 2025 · Captured 2026-09-09.
Selected source text with whitespace normalised. This Triangle page is not an NCI PDQ summary.
Context: Treatment of Newly Diagnosed Children and Adolescents With Hodgkin Lymphoma / Radiation Therapy
With advancements in systemic therapy, radiation therapy field definitions have become increasingly restricted. Radiation therapy is no longer needed to sterilize all disease. Advances in radiological imaging allow for a more precise radiation target definition. With effective chemotherapy and contemporary treatments using lower radiation doses (<21 Gy) and reduced volumes (ISRT), contralateral uninvolved sites are not irradiated.
General trends in radiation treatment volume are summarized as follows:
Historical regional radiation therapy fields (e.g., mantle, subtotal, or total nodal) have been replaced by involved-nodal radiation therapy (INRT) or ISRT. In select situations, such as adolescents and young adults treated with radiation alone for NLPHL, IFRT is used.
INRT defines the treatment volume using the prechemotherapy PET-CT scan that is obtained with the patient in a position similar to the position to be used at the time of radiation therapy. This volume is later contoured onto the postchemotherapy-planning CT scan. The final treatment volume only includes the initially involved nodes with a margin, typically 2 cm.[47-49] The subsequent EuroNet-PHL-C2 trial employs INRT.
ISRT, used in contemporary COG trials, is used when optimal prechemotherapy imaging (PET-CT in a position similar to the position to be used at the time of radiation therapy) is not available to the radiation oncologist. Because the delineation of the area of involvement is less precise, a somewhat larger treatment volume is contoured than for INRT, typically at least 2 cm around the nodes where the lymphoma was located before chemotherapy was given. The exact volume will depend on the individual case scenario.[45] There are several situations in which this definition is further modified, such as when inappropriately large volumes of sensitive normal tissues might be exposed.[50]
Modified involved-field radiation therapy is the term used in the EuroNet-PHL-C1 trial to describe treatment volumes that contain the involved lymph node(s) as seen before chemotherapy plus radiation planning margins of 1 cm to 2 cm, depending on the area of involvement. These volumes are comparable to ISRT fields, although the development preceded the widespread availability of CT-based planning.
Breast-sparing radiation therapy plans using proton therapy are under evaluation to determine whether there is a statistically significant reduction in dose.[51] Ongoing studies seek to determine whether doses to other critical organs, such as the heart and lungs, can be reduced with proton therapy, without compromising survival outcomes.[52][Level of evidence C1] Long-term results are pending.
Source links and citations
Continue within this section
Publication references
Read the original reference and check its publication notices.
Preserved source evidence · Not medical advice