# Radiotherapy in lymphoma: involved-site fields, 24 Gy, 4 Gy and total skin electron therapy

Source: https://onco.cc/terms/lymphoma-tx-radiotherapy/  
OnCo record `lymphoma-tx-radiotherapy` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Lymphoma is one of the most radiation-sensitive cancers there is, so the doses are low and the fields are small. Two doses of 2 Gy can shrink a painful node in a fortnight; 24 Gy can cure a stage I follicular lymphoma.

## Summary

Fields have shrunk twice in living memory: from mantle and inverted-Y fields covering whole regions, to involved-field radiotherapy covering a nodal region, to involved-site radiotherapy covering the pre-chemotherapy tumour volume with a margin. The change is the single largest reason late cardiac disease and second cancers after Hodgkin lymphoma are falling.

Doses, by purpose. Curative radiotherapy for stage I to II follicular or marginal zone lymphoma is 24 Gy in 12 fractions. The FoRT trial randomised 4 Gy in two fractions against 24 Gy in indolent lymphoma and found 4 Gy clearly inferior for local control (21 local progressions after 24 Gy against 70 after 4 Gy; hazard ratio 3.42), so 4 Gy is palliative, not curative. Palliative 4 Gy in two fractions, sometimes repeated, is remarkably effective for a symptomatic node, an orbital mass or a skin plaque and can be given to a frail patient in two visits. Consolidation after chemotherapy in Hodgkin lymphoma is 20 to 30 Gy to an involved site. Gastric MALT lymphoma that does not respond to antibiotics is treated with about 24 Gy to the stomach. Total skin electron beam therapy, at conventional 30 to 36 Gy or low-dose 10 to 12 Gy, treats the whole skin surface in mycosis fungoides.

When radiotherapy is left out. IELSG37 showed consolidation radiotherapy can be omitted in primary mediastinal B-cell lymphoma after a negative end-of-treatment PET (30-month progression-free survival 96.2 per cent observed against 98.5 per cent irradiated). In early Hodgkin lymphoma, HD16 and EORTC H10 both found that omitting radiotherapy from PET-negative patients costs some disease control without costing survival, which is why the decision differs by country and by patient age.

Proton therapy and deep-inspiration breath hold are used in young patients with mediastinal disease to keep dose off the heart, breasts and lungs.

## Fields

- Kind: Term
- Last checked: 2026-09-29
- Also known as: Involved-site radiotherapy; ISRT; Involved-field radiotherapy; Low-dose radiotherapy lymphoma; Boom-boom radiotherapy

## Sources

- HD16: PET-guided omission of radiotherapy in early favourable Hodgkin lymphoma, Journal of Clinical Oncology 2019: https://doi.org/10.1200/JCO.19.00964
- EORTC/LYSA/FIL H10 final results, Journal of Clinical Oncology 2017: https://doi.org/10.1200/JCO.2016.68.6394

## Connected records

- cancers: [Advanced-stage classical Hodgkin lymphoma (stage III to IV)](https://onco.cc/cancers/advanced-stage-classical-hodgkin-lymphoma/), [Cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome)](https://onco.cc/cancers/cutaneous-t-cell-lymphoma/), [Diffuse large B-cell lymphoma](https://onco.cc/cancers/dlbcl/), [Early-stage classical Hodgkin lymphoma (stage I to II)](https://onco.cc/cancers/early-stage-classical-hodgkin-lymphoma/), [Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)](https://onco.cc/cancers/malt-lymphoma/), [Follicular lymphoma](https://onco.cc/cancers/follicular-lymphoma/), [Hodgkin lymphoma](https://onco.cc/cancers/hodgkin-lymphoma/), [Marginal zone lymphoma](https://onco.cc/cancers/marginal-zone-lymphoma/), [Nodal marginal zone lymphoma](https://onco.cc/cancers/nodal-marginal-zone-lymphoma/), [Nodular lymphocyte-predominant Hodgkin lymphoma (nodular lymphocyte-predominant B-cell lymphoma)](https://onco.cc/cancers/nodular-lymphocyte-predominant-hodgkin-lymphoma/), [Non-Hodgkin lymphoma (all types)](https://onco.cc/cancers/non-hodgkin-lymphoma/), [Peripheral T-cell lymphomas (including cutaneous T-cell lymphoma)](https://onco.cc/cancers/peripheral-t-cell-lymphoma/), [Primary CNS lymphoma](https://onco.cc/cancers/primary-cns-lymphoma/), [Primary mediastinal (thymic) large B-cell lymphoma](https://onco.cc/cancers/primary-mediastinal-b-cell-lymphoma/), [Relapsed and refractory classical Hodgkin lymphoma](https://onco.cc/cancers/relapsed-refractory-hodgkin-lymphoma/)
- technologies: [Electron beam therapy systems (linac electrons, total skin electron units, mobile electron IORT)](https://onco.cc/technologies/electron-beam-therapy-systems/), [FDG PET](https://onco.cc/technologies/fdg-pet/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Palliative radiotherapy](https://onco.cc/technologies/palliative-radiotherapy/), [PET-adapted (response-adapted) therapy](https://onco.cc/technologies/pet-adapted-therapy/), [Proton therapy](https://onco.cc/technologies/proton-therapy/), [Total skin electron beam therapy](https://onco.cc/technologies/total-skin-electron-therapy/)
- terms: [Deauville score and PET-adapted therapy](https://onco.cc/terms/deauville/), [Helicobacter pylori eradication as cancer treatment in gastric MALT lymphoma](https://onco.cc/terms/lymphoma-tx-h-pylori-eradication/), [Lugano classification / Ann Arbor staging](https://onco.cc/terms/lugano-classification/), [Lymphoma treatments that did not work: the negative trials worth knowing](https://onco.cc/terms/lymphoma-tx-failed-and-negative/), [Skin-directed therapy in mycosis fungoides: creams, light and small radiotherapy fields](https://onco.cc/terms/lymphoma-tx-skin-directed-therapy/)
- key papers: [FoRT: 4 Gy versus 24 Gy radiotherapy for indolent lymphoma, a randomised phase 3 non-inferiority trial](https://onco.cc/key-papers/paper-fort-4gy-vs-24gy-indolent-lymphoma-hoskin-lancet-oncol-2014/), [IELSG37: omission of radiotherapy in primary mediastinal B-cell lymphoma after a negative PET scan](https://onco.cc/key-papers/paper-ielsg37-pmbcl-martelli-jco-2024/)

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