Timing of prophylactic cranial irradiation in small cell lung cancer – pro
Prophylactic cranial irradiation can be delivered after completion of chmotherapy (delayed) or during chemotherapy (early).Prophylactic cranial irradiation (PCI) has been demonstrated to reduce the risk of brain metastases from 58.6 to 33.3% 3 years subsequent to combined therapy, and in addition, meta-analyses have revealed that PCI results in a 16% reduction in mortality rate, which modestly increases the 3-year survival rate between 15.3 and 20.7%.
The benefit of PCI has been determined, but the optimal timing of PCI intervention has not been examined. Auperin et al demonstrated by meta-analysis that PCI had a significantly greater effect on the incidence of brain metastasis in patients that received PCI within 6 months following induction therapy compared with patients that received PCI after 6 months (P=0.01) (6). However, the results from Auperin et al were from a subgroup analysis and should be interpreted with caution. Two prospective randomized studies comparing the optimal timing of PCI revealed conflicting conclusions; an early randomized study revealed no difference in the frequency of brain metastases between PCI performed at the start of induction treatment and PCI delivered 6 weeks later, whereas a later study demonstrated a statistically significant decrease in intracranial recurrence when PCI was performed during chemoradiotherapy as opposed to following chemoradiotherapy.
GUOQIN QIU, XIANGHUI DU, XIA ZHOU, WUAN BAO, LEI CHEN, JIANXIANG CHEN, YONGLING JI, and SHENGYE WANG, Prophylactic cranial irradiation in 399 patients with limited-stage small cell lung cancer. Oncol Lett. 2016 Apr; 11(4): 26542660.