Author of

• 10692

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  P1.08 - Poster Session 1 - Radiotherapy (ID 195)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Radiation Oncology + Radiotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10709

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    P1.08-017 - Factors Influencing Utilization of Prophylactic Cranial Irradiation in Limited-Stage Small Cell Lung Cancer (ID 1915)

    09:30 - 09:30  |  Author(s): L.T. Ong
    • Abstract

    Background
    Prophylactic cranial irradiation (PCI) improves survival in limited-stage small cell lung cancer (LS-SCLC). However, PCI is not always delivered to these patients, possibly due to concerns about neurocognitive effects. Efforts to reduce neurotoxicity of PCI, such as hippocampal-sparing radiation, may mitigate these concerns. Little is known about the utilization rate of PCI and the reasons it is not delivered. Therefore, we reviewed the experience with LS-SCLC at a large academic institution to determine the rate of PCI use and factors associated with the lack of use.

    Methods
    We retrospectively reviewed all patients with LS-SCLC treated at our institution between 2000 and 2012. Receipt of PCI was recorded, as well as information about clinical presentation and initial treatment. In patients who did not receive PCI, we reviewed clinical notes from both medical and radiation oncologists to determine the reason. Overall survival (OS) and brain metastasis-free survival (BMFS) were estimated using the Kaplan-Meier technique. Pearson’s chi-squared test was used to evaluate factors associated with PCI use.

    Results
    We identified 229 patients treated with thoracic radiotherapy (TRT) for LS-SCLC at our institution. Median followup was 15.1 months. Of these, 119 (52.0%) did not receive PCI. Thirty-three patients (27.7%) had progressive disease or concern for progression after initial therapy and therefore did not receive PCI. The next most common causes for no PCI were patient refusal (n=25, 21%) or deemed medically unfit by an oncologist (n=25, 21%). In 20 patients (16.8%), the reason for lack of PCI could not be ascertained. Other infrequent causes were patient death or lack of followup (n=8), age (n=3), and prior radiotherapy to the head (n=2). Patients who did not get PCI were significantly older (p<0.001) and had worse performance status at initial presentation (p<0.001). Patients who received sequential rather than concurrent chemoradiation, or who received once-daily rather than twice-daily TRT, were also significantly less likely to receive PCI (p<0.001). Patients who did not receive PCI had significantly worse OS (median 17 vs. 30 months, p=0.01) and BMFS (71% vs. 91% at 1 year, p=0.02) than those who did.

    Conclusion
    Even at a major academic center, fewer than half of patients with LS-SCLC ultimately receive PCI. Patients receiving PCI had better intracranial control. They also had better OS, but this is likely also attributable to other clinical and treatment characteristics. Younger and fitter patients, as well as those receiving optimal TRT, are significantly more likely to undergo PCI. The most common reason for lack of PCI is progression of disease after initial therapy, which is clinically appropriate. However, a significant number of patients are appropriate for PCI yet refuse therapy, generally due to concerns about toxicity. PCI is withheld from an equivalent number of patients due to oncologist concerns about ability to tolerate therapy. This indicates that efforts to reduce neurotoxicity of PCI, such as hippocampal-sparing radiation, may impact a significant number of patients with LS-SCLC and expand the application of this survival-enhancing intervention.