Page 166 - Hospital Authority Convention 2018

Masterclasses
HOSPITAL AUTHORITY CONVENTION 2018

M12.1 Management of Patients with Brain Metastases – 10:45 Room 423 & 424
A Paradigm Shift from Whole Brain Radiotherapy to
Stereotactic Radiosurgery

Development of the New Treatment Paradigm in Hospital Authority, Patient Profiles and Their Clinical Outcomes
Wong FCS
Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong

The incidence of brain metastasis, either isolated or associated with disseminated involvement, has increased over time with
the increase in the use of systemic treatment. Blood-brain-brain with poor drug concentration in central nervous system and
ultimate drug resistance are the reasons for the former and latter, respectively. In the past, prognosis of patients with cerebral
metastasis was extremely poor, with a median overall survival (OS) of 62 days in a local study performed in Tuen Mun Hospital
(Wong et al, 2005). Whole brain radiotherapy (WBRT) has been the standard treatment for more than 40 years, and most
patients were referred for best supportive care. With the progress in local treatment (including neurosurgery, and stereotactic
radiosurgery (SRS)/radiotherapy) and a newer generation of systemic treatments, the intracranial control rate and survival
have improved significantly. Median OS of patients treated with and without targeted therapies after SRS were 456 and 167
days respectively, according to a local review (Lam et al, 2015). Treatment decisions nowadays depend on prognostic factors.
Assessment of performance status is the first step, as patients with poor medical conditions (and no druggable mutations)
will not benefit from additional treatments besides best supportive care. The next step is staging or restaging, with biopsy
or re-biopsy for selected patients. Local treatment is indicated for isolated brain “oliogometastasis” or “oligo-progression”.
The decision of neurosurgery or radiotherapy depends on the location, number and size of brain metastases. WBRT with
systemic treatments is considered for disseminated involvement. The trend, however, is to avoid the former in order to reduce
late toxicities in good prognostic group. The demand for imaging (in particular MRI brain and PET scan), histological and
molecular tests, complicated neurosurgical and radiotherapeutic procedures, and systemic treatments to support the new
treatment paradigm will be significantly increasing.

M12.2 Management of Patients with Brain Metastases – 10:45 Room 423 & 424
A Paradigm Shift from Whole Brain Radiotherapy to
Stereotactic Radiosurgery

Is It Cost-effective to Treat Brain Metastasis with Advanced Technology? Cost-effectiveness
Analysis of Whole Brain Radiotherapy, Stereotactic Radiosurgery and Craniotomy in Hospital Authority Setting
Lam TC
Tuesday, 8 May 2018 Background
Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong

Brain metastasis is common among advanced cancer patients. Whole brain radiation therapy (WBRT) has been used as a
standard treatment for decades to control intracranial disease; however, it is associated with poor overall survival outcomes
and neurocognitive impairment. More aggressive focal therapies, including surgical resection or stereotactic radiosurgery
(SRS), have been proposed for patients with good prognosis with superior outcomes in various randomised controlled trials.
While these focal therapies are available in various Hospital Authority (HA) cancer centres, the complexity and high resources
requirement of these therapies had raised concern on the cost-effectiveness of such treatment approach.

Methodology
A Markov model will be employed to evaluate the cost effectiveness of SRS, WBRT, and SRS+WBRT in patients with 1
or 2–10 brain metastases. Transition probabilities will be based on the JLGK0901 study and modified according to the
recurrence rates observed in the Radiation Therapy Oncology Group (RTOG) 9508 and European Organization for Research
and Treatment of Cancer (EORTC) 22952– 26001 studies. The outcome of patients who received WBRT will be estimated on
the data of Medical Research Council (MRC) QUARTZ study and local audit data. Costs of treatment will be based on the
HA private patient charges which are on the gazette on 2013. Study end-points will include cost, quality-adjusted life years
(QALYs), and incremental cost-effectiveness ratios (ICERs). The willingness-to-pay (WTP) threshold will be set at $87,362
per QALY (two times of GDP per capita of Hong Kong in 2016). One-way and probabilistic sensitivity analyses will be used to
explored uncertainty with regard to the model assumptions.

Results
Study results will be reported at the Convention meeting. Cross comparison of QALYs and ICERs of other common cancer
treatment regimes will be presented. The results will have important implications in oncology service planning, resources
allocation and service efficiency audit.

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