1. Dr. Rico Liu
Consultant, 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
2. Points for discussion
Effects of radiation
Radiotherapy is not for everyone but for whom and
when
The role of new technology
3. Effects of radiation
External Radiotherapy
•High energy Xray
• Photon-
•Gama ray- from radioactive decay, e.g. Colbert
•High energy particles
• Electron
• Proton
Brachytherapy
Systemic radiotherapy
apoptosis
6. 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 9–17
Ferreri AJ et al. Ann Oncol. 2000 Aug;11(8):927-37
7. PCNSL: Radiotherapy alone
RTOG 8315
Phase II study of WBRT 40Gy + 20Gy boost
N = 41
Overall median survival 12.2 months
Benefit of boost doubtful: disease recurrence
frequently occurred in the boosted field, survival no
better than previous study without use of boost
Ocular involvement: 36Gy to both eyes (or Rx
with high dose MTX)
Nelson DF et al. IJROBP Volume 23, Issue 1, 1992, Pages 9–17
8. 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)
9.
10. Delayed neurotoxicity is worse for
elderly patients
Omuro AM et al. Arch Neurol. 2005 Oct;62(10):1595-600
13. Not enough evidence to forgo WBRT
Limitations of the trial
Low statistical power
High protocol violations
High rate of lost to follow up
Small sample size in the analysis of neurotoxicity
20. The role of new technology
Neuro Oncol (August 2009) 11 (4): 423-429
21. Summary
PCNSL is rare
Chemotherapy +/- 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 <60
defer WBRT for those older patients >60
Radiotherapy remains an effective treatment for
patients considered not suitable for chemotherapy
Flow chart of therapeutic management of PCNSL in everyday practice. (1) Mostly marginal zone B-cell lymphoma, small lymphocytic lymphoma, and lymphoplasmacytic lymphoma. (2) Mostly intravascular large B-cell lymphoma and neurolymphomatosis. (3) Conclusion from the IELSG no. 20 trial.40 (4) Several regimens are available (Table 3). (5) A higher amount of available evidence suggests WBRT. The discussion with selected patients about the pros and cons of the use of consolidation WBRT or HDC/ASCT is recommended. (6) Available literature suggesting that some elderly patients in CR after primary chemotherapy could be watchful waited without OS impairment is constituted by a few small retrospective series. However, to delay WBRT until relapse is an acceptable strategy considering the increased risk of disabling neurotoxicity in these patients. (7) Radiation field and dose should be chosen on the bases of response to primary chemotherapy. WBRT dose reduction to 23-30 Gy in patients in CR after chemotherapy is recommended. DLBCL indicates diffuse large B-cell lymphoma; HD-MTX, high-dose methotrexate; ara-C, cytarabine; WBRT, whole-brain radiotherapy; CR, complete remission; PR, partial response; SD, stable disease; PD, progressive disease; and HDC/ASCT, high-dose chemotherapy supported by autologous stem cell transplantation.
