Patient selection: malignant lymphoma, Hodgkin's or non-Hodgkin's disease
A partial response may be classified based on:
(1) PET-CT based response, also known as the metabolic response
(2) CT based response, also referred to as the radiologic response
The PET-CT scan would not be relevant if the lymphoma did not show FDG-avidity.
Criteria for a partial PET-CT based response - all of the following:
(1) FDG uptake with score 4 or 5 on 5-PS at the end of treatment but reduced compared to baseline
(2) none or residual FDG uptake in bone marrow but reduced compared to baseline
(3) no new lesions
where:
• FDG uptake before the end of treatment can be seen in responding tumor.
• Diffuse uptake in the bone marrow may reflect reactive change to chemotherapy.
Criteria for a partial CT based response - all of the following:
(1) >= 50% decrease in the sum of the perpendicular products (SPD) in up to 6 measurable nodal and/or extranodal sites
(2) smaller lesions (not measured for SPD) are regressed or absent AND not increased
(3) if spleen was enlarged then length must have decreased > 50%
(4) no new lesions
where:
• Assessment of bone marrow was designated not applicable to radiologic response.
