Evidence Based Questions Flashcards
Can chemo replace RT in the Tx of pure germinomas?
No. In a large CNS GCT study (Balmaceda C et al., JCO 1996), 45 germinomas were treated with carboplatin/etoposide/bleomycin. 84% had CR, but 48% recurred in 13 mos and 10% of pts died d/t Tx toxicity. >90% were salvaged by RT (ifosfamide/carboplatin/etoposide [ICE] × 3 → involved-field radiation therapy [IFRT] of 24 Gy).
What hypothesis is being tested in the current germinoma study ACNS1123?
ACNS1123 is attempting to determine if neoadj chemo can help reduce RT doses and volumes in localized germinoma and NGGCT.
In ACNS1123, what chemo agents are being tested?
Carboplatin, etoposide and ifosfamide are being tested in ACNS1123.
With pre-RT chemo, what are the RT doses in the experimental arm of ACNS1123 for germinoma?
In ACNS1123, the RT doses depend on the chemo response.
Induction chemo, carbo/etoposide × 3 cycles + alternating ifosfamide × 3 cycles—for a total 6 cycles of chemo.
If CR, WVRT to 18 Gy + boost to 30 Gy with IFRT alone.
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What studies showed that even with CR to chemo, IFRT (without WVRT) may not be sufficient for localized germinoma?
SIOP CNS GCT96 (Calaminus G et al., Neurooncol 2013): M0 pts treated with CSI 24 Gy + 16-Gy boost (RT alone) vs. 2 × ICE → IFRT 40 Gy (CRT). 5-yr PFS was 88% for CRT vs. 97% with RT alone (p = 0.04); 5-yr OS was 92% vs. 94% (NS). All CRT failures were within the ventricular system. Conclusion: Suggest inclusion of ventricles in RT fields. In M+ Dz, they found reduced-dose CSI to 24 Gy was effective (98% EFS and OS).
What other evidence demonstrates that IFRT may not be sufficient for germinomas?
(Rogers SJ et al., Lancet Oncol 2005): literature review of 788 pts. There was a greater failure rate in focal RT vs. WBRT or WVRT + boost or CSI + boost (23% vs. 4%–8%). The pattern of relapse was mostly isolated spinal (11%), but there was no difference in WVRT vs. CSI in spinal relapse (3% vs. 1%). Conclusion: WVRT + boost should replace CSI. Similar findings were found in a Seoul study. (Eom KY et al., IJROBP 2008)
What early studies established the feasibility of RT dose reduction?
German MAKEI 83/86/89 studies (from 50 Gy to 34 Gy)
Which study showed that bifocal germinoma can be treated as localized Dz?
Canadian data (Lafay-Cousin L et al., IJROBP 2006): chemo and then limited-field RT (WVRT + boost) resulted in a CR.
Which recent study showed better QOL with CRT (dose/field reduction) than with RT alone?
Seoul study (Eom KY et al., IJROBP 2008), need for hormonal therapy: RT alone 69% vs. CRT 38% (however, all RT alone pts rcvd CSI)
