International journal of radiation oncology, biology, physics | 2021
Comparison of clinical efficacy of neoadjuvant chemoradiotherapy between lower and higher radiation dose for carcinoma of the esophagus and gastroesophageal junction: a systematic review.
Abstract
BACKGROUND\nNeoadjuvant concurrent chemoradiotherapy (nCRT) plus surgery has been a standard treatment for locoregionally advanced esophageal cancer and carcinoma of the gastroesophageal junction (EC/GEJ), but an optimal preoperative radiation dose is still unclear.\n\n\nPURPOSE\nWe performed this systematic review to explore the treatment efficacy and toxicity of different radiation dose levels and find an optimal dose-fractionation strategy in EC/GEJ patients receiving nCRT.\n\n\nMETHODS\nEmbase and Ovid Medline were searched for articles involving operable squamous and adenocarcinoma of the esophagus and GEJ receiving nCRT up to a dose of 50.4 Gy/28 fractions published until July 2019 when the search was performed. Physical dose distributions were converted to biologically equivalent dose (BED), which was described in units of Gy (alpha/beta). Pooled rates of overall survival (OS), progression-free survival (PFS), failure patterns, and toxicities were compared between lower-dose (BED ≤48.85 Gy10, LDRT) and higher-dose (BED >48.85 Gy10, HDRT) radiotherapy for patients treated with nCRT.\n\n\nRESULTS\nA total of 110 studies with 7,577 EC/GEJ patients receiving nCRT were included in this pooled analysis. Both the PFS and OS rates of patients receiving LDRT were significantly higher than those receiving HDRT. Patients receiving LDRT had improved safety regarding treatment-related adverse events and lower distant failure rates than patients receiving HDRT. Utilization of modern RT techniques including three-dimensional conformal radiation therapy and intensity-modulated radiation therapy was associated with improved oncologic outcomes compared to two-dimensional methods. Subgroup analysis showed that EC/GEJ patients receiving a conventionally fractionated radiation to a dose of 40.0-41.4 Gy/20-23 fractions showed improved OS compared with those receiving above this dose.\n\n\nCONCLUSIONS\nBased on the limited data, nCRT using BED≤48.85 Gy10 was suitable for locoregionally advanced, resectable EC/GEJ. A total dose of 40.0-41.4 Gy/20-23 fractions using modern RT techniques might provide the optimal therapeutic ratio.