Abstract Modern radiation therapy (RT) technologies allow for improved sparing of normal tissues, decreasing the risk of both acute and long-term toxicities. Existing RT dose constraints for prospective trials within the National Clinical Trials Network (NCTN) were formulated in the context of solid malignancies. As patients with hematologic malignancies are often treated with lower RT doses and are usually younger with more favorable prognoses, customized dose constraints are needed. The NRG Oncology Hematologic Malignancies Working Group (NRG HEME) commissioned a review of existing organ-at-risk (OAR) constraints from published primary literature, the NRG Center for Innovation in Radiation Oncology (CIRO), and national guidelines. Customized constraints were developed by iterative review by NRG HEME. Final recommendations were approved by radiation oncology representatives from all the lymphoma NCTN groups (NRG Oncology, Children’s Oncology Group, Alliance, ECOG-ACRIN, SWOG, Canadian Cancer Trials Group). For 49 OARs, a strict recommended constraint was determined, of which 20 were not present in CIRO. Of the remaining 29 constraints, 20 were lower, 2 were the same, and 5 used different metrics; 2 were higher than at least 1 CIRO trial constraint. Acceptable variations were determined and unacceptable variations were added for select critical OARs for plan scoring. While doses to OARs without explicit unacceptable variations should not exceed acceptable variations, violations should not be considered for plan quality assessment on trials. This consensus list of standard OAR constraints should be incorporated for all future NCTN trials in hematologic malignancies. Strict dose constraints will minimize long-term toxicities in this patient population.
Meta‐analysis of randomized controlled trials of external‐beam radiation versus transarterial chemoembolization for hepatocellular carcinoma
AbstractBackgroundExternal‐beam radiation (EBRT) is a noninvasive therapeutic alternative to transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). The objective of this study was to conduct a systematic review and meta‐analysis of prospective randomized clinical trials to assess the clinical efficacy of EBRT versus TACE for HCC as either a definitive monotherapy or as a bridge to transplantation/surgery.MethodsA systematic review and meta‐analysis were performed to include prospective randomized trials comparing EBRT versus TACE. Data was analyzed with random and fixed‐effects models. The inconsistency index (I2) was chosen to assess heterogeneity. Three publications were included with a total of 142 patients. Outcomes included local control (LC), overall survival (OS), progression‐free survival (PFS), and occurrences of grade ≥3 toxicity. Comparisons are reported as hazard ratios (HRs) or risk ratios (RRs) with 95% confidence intervals (CIs).ResultsThere were three randomized trials that met inclusion criteria. The EBRT was delivered in three to 15 fractions with a total dose between 30 and 75 gray(Gy). EBRT was associated with significantly improved LC (HR, 0.16; 95% CI, 0.08–0.34; I2 = 0%) and PFS (HR, 0.37; 95% CI, 0.23–0.60; I2, 0%) compared with TACE. There was no significant difference between EBRT and TACE in OS (RR, 0.79; 95% CI, 0.51–1.22; I2 = 0%) or grade ≥3 toxicity (RR, 0.86; 95% CI, 0.31–2.37; I2 = 57%). None of the analyses had statistically significant heterogeneity.ConclusionsCompared with TACE, EBRT yields superior LC and PFS without providing a survival benefit in early and intermediate stage HCC. Additional larger prospective randomized controlled trials should be conducted to further investigate differences in clinical outcomes amongst patients with more advanced disease.