Stereotactic Ablative Radiotherapy Fractionation for Hepatocellular Carcinoma in the United States

Introduction This study aims to analyze the patterns of care, including fractionation and utilization, of hypofractionated stereotactic ablative radiotherapy (SABR) in the treatment of hepatocellular carcinoma (HCC). Methods The National Cancer Database was queried for patients diagnosed with HCC from 2004 to 2014 and treated with SABR in three, four, or five fractions in 15-20Gy, 10-13Gy, or 6-12Gy per fraction, respectively. Patients with stage IV and Charlson-Deyo Comorbidity Index > 0 were excluded in order to avoid bias resulting from the selection of poorer prognosis patients. The patients were then stratified based on several characteristics including biologically equivalent doses (BEDs) of =/> 100 Gy and <100 Gy to determine whether there was an association with overall survival (OS) and a multivariable analysis (MVA) was performed to assess for potential confounding factors.  Results There were 462 patients identified in whom the most common SABR fractionation regimen was 10Gy x five fractions (25.3%), followed by 8Gy x five fractions (17.7%), and 15-16Gy x three fractions (26.4%). A total of 152 patients were treated to a BED < 100Gy, which was associated with a median OS of 20.8 months (95% CI 14.55-27.11). Three hundred and ten patients were treated to a BED =/> 100Gy, which was associated with a median OS of 30.8 months (95% CI 5.25-32.08). On MVA, BED =/> 100Gy was not significantly associated with improved OS (HR 0.85, 95% CI 0.64-1.14, p = 0.28). Factors that were associated with significantly worse survival were tumor size in the largest quartile (HR 2.197 CI 1.440-3.354, p < 0.0001) and T3a disease (HR 2.474 CI 1.472-4.158, p = 0.001 compared to T1).  Conclusion SABR fractionation schemes vary widely, but are most commonly 10Gy x five fractions followed by 8Gy x five fractions and 15Gy x three fractions. BED of at least 100Gy is not associated with improved OS. Further studies are needed to best identify the optimal SABR dose and fractionation.

Short Course Hypofractionated Radiotherapy for Frail or Elderly Patients With Meningioma

Purpose/Objective(s)

The incidence of intracranial meningiomas increases with age. The standard of care treatment is complete surgical excision, followed by radiation therapy (RT) if indicated. However, six weeks of RT can be challenging for elderly or frail patients. The purpose of this study was to determine if short course RT is safe and effective in elderly patients with meningioma.

Materials/Methods

We performed a retrospective analysis of patients with meningioma treated with short course beam RT (5-15 fractions) at a single institution. Seventeen patients (94%) received 4005 cGy over 15 fractions and one patient (6%) received 2500 cGy over five fractions. Study endpoints were treatment toxicity (edema), progression-free (PFS) and overall survival (OS).

Results

Eighteen patients with histologically proven (n = 12) or radiologically presumed meningioma (n = 6, presumed grade I) were identified. Median age at treatment was 85 years (66-95 years). There were eight, eight and two patients with grade I, II and III tumours, respectively. Eight patients (44%) had radiologic edema prior to RT. Six (33%) required dexamethasone treatment during RT and the dose was increased during RT for two patients. Fourteen patients had reduced or no edema post-RT and 13 patients had stable or improving symptoms post-RT. Six patients had disease progression (five in-field, one out-of-field). Median PFS was 3.3 and 0.9 years for grade I and II/III tumours, respectively (p = 0.014). Median OS was 3.3 and 2.5 years for grade I and II/III tumours, respectively (p = 0.12).

Conclusion

Short course RT for elderly patients with meningioma is well-tolerated and can offer disease control for some patients, particularly those with grade I tumours.