Dr. Rico LiuConsultant, Department of Clinical Oncology, Queen Mary Hospital

Honorary Clinical Associate Professor, Department of Clinical Oncology, The University of Hong Kong

Deputy Hospital Chief Executive, Queen Mary Hospital

BTG 2013 Feb 2013

Points for discussionEffects of radiation Radiotherapy is not for everyone but for

whom and when The role of new technology

Effects of radiation

External Radiotherapy•High energy Xray

• Photon- •Gama ray- from radioactive decay, e.g. Colbert

•High energy particles• Electron• Proton

BrachytherapySystemic radiotherapy

apoptosis

Effects of therapeutic radiation

Normal tissue tolerance

Milano et al., Semin Radiat Oncol. 17 (2007): 131-140

Treatment improves survival Median survival (mo)

Untreated ~2

WBRT alone ~12

Chemotherapy follows by WBRT

~ 48

Henry JM et al. Cancer 34: 1293, 1974 Nelson DF et al. IJROBP Volume 23, Issue 1, 1992, Pages 9–17Ferreri AJ et al. Ann Oncol. 2000 Aug;11(8):927-37

PCNSL: Radiotherapy alone RTOG 8315

Phase II study of WBRT 40Gy + 20Gy boostN = 41Overall median survival 12.2 monthsBenefit of boost doubtful: disease recurrence

frequently occurred in the boosted field, survival nobetter than previous study without use of boost

Ocular involvement: 36Gy to both eyes (or Rxwith high dose MTX)

Nelson DF et al. IJROBP Volume 23, Issue 1, 1992, Pages 9–17

PCNSL: Chemo + radiotherapy

CR 58%, PR 36% (Overall RR 94%) Overall survival 37 months 15% ( 12 patients) developed severe delayed neurologic toxicity

8 out of 12 died ( 5/8 from the group > 60 years of age and 3/8 from < 60 years of age)

Delayed neurotoxicity is worse for elderly patients

Omuro AM et al. Arch Neurol. 2005 Oct;62(10):1595-600

G-PCNSL-SG-1 trial

Not enough evidence to forgo WBRTLimitations of the trial

Low statistical power High protocol violationsHigh rate of lost to follow upSmall sample size in the analysis of

neurotoxicity

Lower dose of RT for patients with CR

WBRT- set up

Therapeutic management of PCNSL

Ferreri A J M Blood 2011;118:510-522Role of radiotherapy

The role of new technology

Neuro Oncol (August 2009) 11 (4): 423-429

SummaryPCNSL is rareChemotherapy +/- radiotherapy offer the best

survival Delayed neurotoxicity is common and can

cause major disability and death Reduce risk of delayed neurotoxicity

lower consolidation dose for patients <60defer WBRT for those older patients >60

Radiotherapy remains an effective treatment for patients considered not suitable for chemotherapy

Thank You