Australia is one of the first countries in the world to publicly fund PET scanning in patients with indolent lymphoma.
It became effective from 1 November 2017 after the Medical Services Advisory Committee (MSAC) approved an application by Associate Professor Judith Trotman late last year.
Professor Trotman, Director of the Clinical Research Unit in Haematology at Concord Hospital, told the limbic that baseline PET was a more sensitive staging modality than standard contrast enhanced CT scanning
“But more importantly, a PET scan performed at the end of induction after first line therapy is highly predictive of outcome. It gives greater reassurance to the patients who become PET negative that their progression free survival is likely to last for several years.”
Conversely, she said the median progression free survival in PET positive patients was only about 18 months.
“Having indolent lymphoma included in the PET scanning MBS item numbers means we will be able to start participating in trials looking at PET adaptive therapy designed to improved the outcomes for these poor risk patients for whom follicular lymphoma is really no longer an indolent disease.”
“We will also now be able to assess the prognostic role of baseline total metabolic tumour volume in prospective studies.”
The initial evidence for PET scanning to predict outcome in follicular lymphoma included the PRIMA study and a pooled analysis of PRIMA data with the French (PET- FOLLICULAIRE) and Italian (FOLL05) studies.
Associate Professor Trotman said the same outcomes were demonstrated in 550 patients with follicular lymphoma in the prospective GALLIUM study. It demonstrated a five-fold risk for progression and five-fold risk for death in the 20% of patients who remained PET-positive – validating PET as the gold standard imaging modality for assessment of response to treatment.
“This is really important for indolent lymphoma patients because they will have the same access to PET that patients with Hodgkin’s and aggressive lymphomas have.”
She said it was important to have validated measures for assessing response across all the promising treatments now available for indolent lymphoma.
“Clearly, the advent of immunochemotherapy – whether rituximab and CHOP or bendamustine or obinutuzumab with chemotherapy – was a great step forward in prolonging survival for our patients with indolent lymphoma.”
She said idelalisib was also now PBS approved for double refractory patients with follicular lymphoma while immunomodulatory agents including lenalidomide were being studied.
“There is a lot of promise in the treatment of follicular lymphoma. There may also be a role for consolidation radiotherapy for patients with localised FDG-avid lesions although we don’t have prospective data on role of radiotherapy in the setting of patients remaining PET-positive after induction immunochemotherapy yet.”
Professor Trotman said many PET scans were already being performed in patients with indolent lymphoma for clinical concerns such as possible histological transformation.
She added there were social and economic benefits from the use of more sensitive PET scans.
“For a patient diagnosed with follicular lymphoma in their 60s who obtains PET negativity after first line treatment, they can be reassured of the high probability of prolonged progression free survival, with a median PFS likely beyond seven years. These patients are going to keep working and not necessarily retire.”
However PET scanning would have an impact on PBS costs by commonly upstaging the disease and leading to use of more systemic treatment.
Projected savings to the MBS were predicated on the fact that both CT and PET scanning would not be required at the end of induction.