ESTRO 2024 - Abstract Book

S1790

Clinical - Lung

ESTRO 2024

During the period 2020-2022 26 limited SCLC patients received twice-daily radiotherapy (45 Gy in 30 fractions) commencing from the second cycle of chemotherapy. A minimum 6-hour interval was maintained between the two fractions and a minimum six-month follow-up was collected. Treatments were delivered using either a Varian TrueBeam with daily kV-CBCT or Helical Tomotherapy on a Radixact platform with MV imaging capabilities. Patient characteristics are summarized in Table 1: 8 females and 18 males, with an age range from 52 to 82 years. Half of these patients subsequently underwent prophylactic cranial irradiation (PCI) in adherence to current guidelines, while the remaining patients opted against PCI due to concerns about potential cognitive impairment. A fisher exact test was calculated for the correlation between PCI and brain disease progression, and PCI and deaths.

Results:

All radiation treatments proceeded without interruptions, demonstrating the feasibility and tolerability of bi fractionation scheme. Patients deviated from the twice-daily treatment regimen solely during the initial day of chemotherapy, when the drug infusion extended allowed only for a single fraction in the afternoon. As a consequence, one fraction was administered on Saturday morning. Among these patients, only five experienced Grade 2 esophageal toxicity, effectively managed with PPI therapy and localized supplements. Additionally, two patients reported Grade 2 pulmonary toxicity, mitigated with corticosteroids and antitussive drugs, highlighting minimal side effects. It is essential to note that while bi-fractionation radiotherapy demonstrates promising local control, 12 patients experienced disease progression with distant metastases, including 7 cases of brain metastases. Notably, none of the patients with brain progression had undergone PCI. The protective effect of PCI against brain progression was confirmed by the Fisher exact test statistic (p-value=0.0149). Additionally, eight patients in our cohort have died from the disease since completing their radical treatment, with seven of them not having undergone PCI. The p value=0.0302 indicated that patients who underwnt PCI had a lower mortality risk.

This reaffirms the significance of Prophylactic Cranial Irradiation (PCI) within this patient cohort, particularly with regards to its potential to extend Overall Survival (OS) (3).

Conclusion:

In conclusion, bi-fractionation radiotherapy was confirmed as a feasible and well-tolerated treatment strategy for patients with limited SCLC, demonstrating an acceptable local disease control while incurring minimal side effects. Moreover, the inclusion of PCI in the treatment regimen proves to be protective against the development of brain metastases and has the potential to positively impact overall patient survival. These findings highlight the