Radiation Dose Optimization in Diffuse Large B- Cell Lymphoma.

Condition(s) studied

Investigational drug(s) / intervention(s)

Standard Arm: Radiation will be started within 3-4 weeks of completion of chemotherapy. Computed Tomography (CT)scan will be acquired for treatment planning, which will be done using External Beam Planning System. The target volumes will be defined by clinical examination, staging Positron Emission Tomography with CT (PET-CT) and response PET-CT. The staging PET-CT will be fused and co-registered with the planning CT scans for target volume delineation. For Involved Field Radiotherapy,Clinical target volume (CTV) will include the entire nodal region depending on the site involved. For Involved Site RT , CTV will include the involved nodal volume in the staging PET-CT. For extranodal sites, the CTV will include the involved extranodal region as per the staging PET-CT. The total dose will be prescribed to the Planning Target Volume based on dose uniformity guidelines. All patients will be treated with 3 Dimensional Conformal Radiotherapy or Intensity Modulated Radiotherapy where indicated.

Experimental Arm: Radiation will be started within 3-4 weeks of completion of chemotherapy. Computed Tomography (CT)scan will be acquired for treatment planning, which will be done using External Beam Planning System. The target volumes will be defined by clinical examination, staging Positron Emission Tomography with CT (PET-CT) and response PET-CT. The staging PET-CT will be fused and co-registered with the planning CT scans for target volume delineation. For Involved Field Radiotherapy,Clinical target volume (CTV) will include the entire nodal region depending on the site involved. For Involved Site RT,CTV will include the involved nodal volume in the staging PET-CT. For extranodal sites, the CTV will include the involved extranodal region as per the staging PET-CT. The total dose will be prescribed to the Planning Target Volume based on dose uniformity guidelines. All patients will be treated with 3 Dimensional Conformal Radiotherapy or Intensity Modulated Radiotherapy where indicated.

Study summary

The purpose of this study is to compare standard dose radiation of 45 Gray(Gy) in 25 fractions in Non Hodgkin's Lymphoma- Diffuse Large B cell Lymphoma (NHL-DLBCL) to that of 36 Gy in 20 fractions.

The role of radiation in NHL-DLBCL has been addressed in large cooperative trials showing improvement in overall survival and progression free survival with combined modality treatment. The doses of radiation used in these trials are heterogeneous ranging from 30-55 Gray(Gy). There is uncertainty about the optimal dose of radiation needed in aggressive lymphomas. A dose response phenomenon is known in Non- Hodgkin's Lymphoma. Late effects of higher dose radiation in the form of higher risk of stroke, myocardial infarction, thyroid abnormalities and secondary breast cancer are being increasingly identified. Hence it is essential to optimize the dose of radiotherapy for lower toxicity without compromising on efficacy.

Eligibility

Primary outcome measure(s)

• Event Free Survival — 2 years
  From the time of randomization till relapse or progression or death due to any cause or death due to disease. Assessment by physiological parameter

Trial sites (1)

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