A retrospective study of external beam radiation, neutron brachytherapy, and concurrent chemotherapy for patients with localized advanced carcinoma of the esophagus

Neutron brachytherapy in the modern era: Indications and evidence

Hadrontherapy is a form of radiation therapy (RT) that relies on heavy particles, such as proton, heavy ions, or neutrons, to enhance anti-tumoral efficacy based on their specific dosimetric and radio-biological properties. Neutrons are characterized by specific radiobiological properties that might deserve greater consideration, including the high linear energy transfer and the low oxygen enhancement ratio. Neutron brachytherapy, relying on interstitial or intracavitary neutron sources, has been developed since the 1950s using Californium-252 (252Cf) as a mixed emitter of fission fast neutrons and γ-photos. However, the place of NBT in the era of modern radiation therapy is yet to be precisely defined. In this systematic review, we aim to provide an up-to-date analysis of current experience and clinical evidence of NBT in the XXI ^th century, by answering the following clinical questions: How is NBT currently delivered? What are the current efficacy data and tolerance profiles of NBT?

Single-Agent Versus Double-Agent Chemotherapy in Concurrent Chemoradiotherapy for Esophageal Squamous Cell Carcinoma: Prospective, Randomized, Multicenter Phase II Clinical Trial

LESSONS LEARNED

The efficacy of single-agent chemotherapy was not significantly different from that of double-agent chemotherapy in concurrent chemoradiotherapy for inoperable esophageal squamous cell carcinoma. Single-agent concurrent chemoradiotherapy had lower gastrointestinal and hematologic toxicity. Overall survival and progression-free survival were not significantly different between single- and double-agent concurrent chemoradiotherapy.

BACKGROUND

This multicenter, randomized, phase II trial aimed to compare the efficacy and safety of single-agent concurrent chemoradiotherapy using the oral fluoropyrimidine S-1 with those of double-agent concurrent chemoradiotherapy using S-1 and cisplatin in patients with inoperable esophageal squamous cell carcinoma.

METHODS

Patients with inoperable esophageal squamous cell carcinoma (clinical stages I to III) were randomly allocated to the single-agent group (S-1) or the double-agent group (S-1/cisplatin). The concurrent intensity-modulated radiation therapy plan was similar for both groups: planning target volume 1.8 Gy/f*30-33f and planning gross target volume of 2 Gy/f*30-33f. The primary outcome measure was the endoscopic complete response rate.

RESULTS

Of the 105 patients randomized, 89 were assessable. The endoscopic complete response rate was 46.9% (23/49) in the single-agent group and 52.5% (21/40) in double-agent group. The median progression-free survival within a median follow-up of 23 months was 20 and 21 months, respectively. The median overall survival was 26 months and not reached, respectively. Grade 3 hematological toxicities occurred in 4.1% and 27.5% of the patients in the single- and the double-agent group, respectively.

CONCLUSION

Single-agent chemotherapy in concurrent chemoradiotherapy for inoperable esophageal squamous cell carcinoma has good efficacy and safety, thus warranting a phase III trial.

Comparison of the clinical efficacy between single-agent and dual-agent concurrent chemoradiotherapy in the treatment of unresectable esophageal squamous cell carcinoma: a multicenter retrospective analysis

BACKGROUND

Some Chinese patients with esophageal squamous cell carcinomaare often treated with single-agent concurrent chemoradiotherapy. However, no results have been reported from randomized controlled clinical trials comparing single-agent with double-agent concurrent chemoradiotherapy. It therefore remains unclear whether these regimens are equally clinically effective. In this study, we retrospectively analyzed and compared the therapeutic effects of single-agent and double-agent concurrent chemoradiotherapy in patients with unresectable esophageal squamous cell carcinoma.

METHODS

This study enrolled 168 patients who received definitive concurrent chemoradiotherapy for locally advanced unresectable esophageal squamous carcinoma at 10 hospitals between 2010 and 2015. We evaluated survival time and toxicity. The Kaplan-Meier method was used to estimate survival data. The log-rank test was used in univariate analysis A Cox proportional hazards regression model was used to conduct a multivariate analysis of the effects of prognostic factors on survival.

RESULTS

In this study, 100 (59.5%) and 68 patients (40.5%) received single-agent and dual-agent combination chemoradiotherapy, respectively. The estimate 5-year progression-free survival (PFS) rate and overall survival (OS) rate of dual-agent therapy was higher than that of single-agent therapy (52.5% and 40.9%, 78.2% and 60.7%, respectively), but there were no significant differences (P = 0.367 and 0.161, respectively). Multivariate analysis showed that sex, age,and radiotherapy dose had no significant effects on OS or PFS. Only disease stage was associated with OS and PFS in the multivariable analysis (P = 0.006 and 0.003, respectively). In dual-agent group, the incidence of acute toxicity and the incidence of 3 and4 grade toxicity were higher than single-agent group.

CONCLUSION

The 5-year PFS and OS rates of dual-agent therapy were higher than those of single-agent concurrent chemoradiotherapy for patients with unresectable esophageal squamous cell carcinoma; however, there were no significant differences in univariate analysis and multivariable analysis. Single-agent concurrent chemotherapy had less toxicity than a double-drug regimen. Therefore, we suggest that single therapis not inferior to dual therapy y. In the future, we aim to confirm our hypothesis through a prospective randomized study.