18. Hyperfraciionated and accelerated thoracic radiation therapy (HFXA/TRT) increased survival compared to daily TRT for limited small cell lung cancer (LSCLC) patients treated with concurrent chemotherapy (ChT)

Background: We renewed pts treated at UT M. D. Anderson Cancer Center by different Fx with ChT for LSCLC in regard to survival, LC and toxicities. Methods: All pts with LSCLC (disease in one thorax) treated between 1985 and 1998 were reviewed. All staged by CT of the chest, upper abdomen and brain. All treated wilh curative intent by ChT/RT. Complete responders received PCI. Restaging and determination of response done approximately 2 mos after end of treatment to the primär)'. Results: 324 pts were treated and followed from 3-140 mos (med 41 mos). Age ranged 29-94(med 60). Maleifemale ratio 173:151, med KPS 80-90, avg vrt loss 2.5%. Pleural fluid present in 24% of pts. TD of TRT ranged 30-66 Gy (med 45 Gy). PCI was given to complete or near-complete responders at 2.5 Gy X lOFx or 2.0 Gy X 15Fx. 169 pts received PCI. LR control was 60% at 2 yrs, med survival was 35 mo. Comparison between QD and BID is shown below. 2Yrs 5Yrs QD BID QD BID p Pts 217 107 OS (%) 42 57 15 26 0.04 DPS (%) 29 34 19 23 0.81 LC (%) 56 60 40 54 0.24 DMFS (%) 60 59 50 50 0.57 Other factors influencing outcome: concurrent vs sequential (P = 0.002), PCI vs no PCI (P = 0.0001), LR control (P = 0.006), DM failure (P = 0.0001), PE (P = 0.0001), KPS (P = 0.0001), total Fx RT (P = 0.0001), dyspnea (P = 0.002). Multivariate analysis showed factors influencing OS were concurrent ChT/RT (P = 0.05), PC (P = 0.03), LR control (P = 0.02), DM control (P = 0.00001) and PE (P = 0.003). Acute dysphagia Gr3 (P = 0.0001) and fibrosis (P = 0.0001) were significantly higher for the concurrent BID group. Conclusions: This study showed that survival was improved by concurrent ChT/RT and HFXA, and application of PCI. It is important to reduce normal tissue toxicities in the future.