Esophageal cancer dose escalation using a simultaneous integrated boost technique

High versus standard radiation dose of definitive concurrent chemoradiotherapy for esophageal cancer: A systematic review and meta-analysis of randomized clinical trials

OBJECTIVES

Compare the efficacy and safety of high vs standard radiation dose of definitive concurrent chemoradiotherapy (dCCRT) for esophageal cancer (EC).

METHODS AND MATERIALS

This meta-analysis is registered in PROSPERO, and it was followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Eligible randomized clinical trials (RCTs) comparing high dose (HD;≥59.4 Gy/1.8 Gy) and standard doses (SD; 50 Gy/2Gy or 50.4 Gy/1.8 Gy) were identified on electronic databases. STATA16.0 was used for statistical analysis. A meta-analysis was performed to compare treatment effect and toxicity.

RESULTS

Four articles with a total of 1014 patients were finally included. The results showed that the two groups had similar 1-, 2-, and 3-year OS rates (RR = 1.08, 95 % CI = 0.90-1.30, P = 0.395; RR = 1.07, 95 % CI = 0.95-1.20, P = 0.272; RR = 1.06, 95 % CI = 0.97-1.17, P = 0.184; respectively) and 2-, and 3-year locoregional progression-free survival (LRPFS) (RR = 0.95, 95 % CI = 0.81-1.10, P = 0.478; RR = 0.97, 95 % CI = 0.85-1.11, P = 0.674; respectively). The HD-RT group had higher grade ≥ 3 treatment-related toxicities (OR = 1.35, 95 % CI = 1.03-1.77, P = 0.029) and treatment-related deaths rates (OR = 1.85, 95 % CI = 1.04-3.28, P = 0.036) compared with the SD-RT group. Results of subgroup analysis also indicated that HD could not bring benefit compared to SD, even with modern radiotherapy techniques.

CONCLUSION

SD-RT had similar treatment effect but lower Grade ≥ 3 treatment-related toxicities rates compared with the HD-RT. Therefore, SD (50 Gy/2Gy or 50.4 Gy/1.8 Gy) should be considered as the recommended dose in dCCRT for EC. Further RCTs are needed to verify our conclusions.

Validation of esophageal cancer treatment methods from 3D-CRT, IMRT, and Rapid Arc plans using custom Python software to compare radiobiological plans to normal tissue integral dosage

Background

The aim was to develop in-house software that is able to calculate and generate the biological plan evaluation of the esophagus treatment plan using the Niemierko model for normal tissue complication probability and tumor control probability. The Niemierko model can be applied for esophagus cancer treatment plan to estimate the tumor control probability (TCP) and the normal tissue complication probability (NTCP) using different planning techniques. The equivalent uniform dose (EUD) and effective volume parameters were compared with organ at risk. Subsequently, EUD and TCP parameter were compared with tumor volume for all five different planning techniques.

Materials and methods

Ten cases for esophageal cancer were included in this study. For each patient, five treatment plans were generated. The Anisotropic analytical algorithms (AAA) were used for dose calculation for the three-dimensional conformal radiation therapy (3D-CRT), intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques. The in-house developed radiobiological plan evaluation software using python programming is used for this study which takes a dose volume histogram (DVH) text file as an input file for biological plan evaluation.

Results and Conclusion

EUD, NTCP, TCP and effective volume were calculated from the Niemierko model using the in-house developed python based software and compared with treatment monitor units (MU) with all five different treatment plan. The best technique is quantified as benchmarked out of other different qualities of treatment. The four field 3D-CRT treatment plan is found to be the best suited from the perspective of biological plan index evaluation among the other planning techniques.

Combined modality therapy for patients with esophageal squamous cell carcinoma: Radiation dose and survival analyses

BACKGROUND

We aimed to analyze the radiation dose and compare survival among combined modality therapy using modern radiation techniques for patients with esophageal squamous cell carcinoma (ESCC).

METHODS

This retrospective study included patients with clinically staged T1-4N0-3M0 ESCC from 2014 to 2018. Patients who received combined modality therapies with curative intent were enrolled. The overall survival (OS) rates among combined modality therapy were compared. The clinical variables and impacts of radiation dose on survival were analyzed by the Kaplan-Meier method and Cox regression model.

RESULTS

Of the 259 patients, 141 (54.4%) received definitive concurrent chemoradiotherapy (DCCRT); 67 (25.9%) underwent neoadjuvant chemoradiotherapy followed by surgery (NCRT+S); 51 (19.7%) obtained surgery followed by adjuvant chemoradiotherapy (S+ACRT). Two-year OS rates of the DCCRT, NCRT+S and S+ACRT group were 48.9, 61.5 and 51.2%. In the subgroup analysis of DCCRT group, the 2-year OS of patients receiving radiation dose 55-60 Gy was 57.1%. Multivariate analyses showed that clinical stage (p = 0.004), DCCRT with 55-60 Gy (p = 0.043) and NCRT+S with pathological complete response (pCR) (p = 0.014) were significant prognostic factors for better OS. The radiation dose-survival curve demonstrated a highly positive correlation between higher radiation dose and better survival.

CONCLUSION

Our results suggest that NCRT+S can provide a favorable survival for patients with ESCC, especially in patients who achieved pCR. The optimal radiation dose might be 55-60 Gy for patients receiving DCCRT via modern radiation techniques. Further randomized clinical studies are required to confirm the survival benefits between NCRT+S and DCCRT with escalated dose.

[Dose-escalated radiotherapy in esophageal cancer: A review of the literature]

For non-operable, localized esophageal cancer, definitive concurrent chemoradiotherapy is the standard treatment. Currently, the radiation dose recommended is 50 to 50,4Gy. However, the optimal radiation dose remains controversial. Many studies have demonstrated that locoregional failure remains a common failure pattern, most likely to occur within the original gross tumor volume. Several retrospective studies have indicated that higher radiation dose may improve local control and survival while others failed to demonstrate improved oucomes. In three randomized trials (INT0123, ARTDECO, and CONCORDE), dose escalation did not improve locoregional control nor survival, establishing 50Gy as the standard chemoradiation dose for patients who will not undergo surgery. Here, we reviewed the results of dose escalation in the literature in the neoadjuvant and definitive settings.

A Prospective Phase II Study of Simultaneous Modulated Accelerated Radiotherapy Concurrently With CDDP/S1 for Esophageal Squamous Cell Carcinoma in the Elderly

Background

To explore the efficacy and toxicity of simultaneous modulated accelerated radiotherapy (SMART) concurrently with cisplatin (CDDP) and S1 (tegafur/gimeracil/oteracil) in elderly patients with esophageal squamous cell carcinoma (ESCC).

Methods

This single-arm, phase II study enrolled pathologically confirmed, stage II-IVa ESCC of 70-80 years old and Eastern Cooperative Oncology Group performance status (ECOG PS) 0-2. Patients received SMART (64 Gy to gross tumor volume and 48 Gy to clinical target volume in 30 fractions) with concurrent CDDP (day 1 of each week) and S1 (days 1-14, 22-35). The primary endpoint was objective response rate (ORR). The secondary endpoints included progression-free survival (PFS), overall survival (OS) and toxicities.

Results

Thirty-seven eligible patients were analyzed with median follow-up of 25.7 months for all and 46.1 months for survivors. The ORR was 88.9%. Patients with baseline weight loss <5% (p=0.050) and nutritional risk index (NRI) ≥105.2 (p=0.023) had better tumor response. Median PFS was 13.8 months with 2-year PFS of 37.5%. Median OS was 27.7 months with 2-year OS of 57.5%. OS was significantly associated with ECOG PS (p=0.005), stage (p=0.014), gross tumor volume (p=0.004), baseline NRI (p=0.036), baseline C-reactive protein (CRP) level (p=0.003) and tumor response (p=0.000). CRP level (p=0.016) and tumor response (p=0.021) were independently prognostic of OS. ≥grade 3 anemia, neutropenia and thrombocytopenia occurred in 2.7%, 10.8% and 13.5% of patients; ≥grade 3 esophagitis and pneumonitis occurred in 18.9% and 2.7% of patient, respectively.

Conclusion

SMART concurrently with CDDP/S1 yielded satisfactory response rate, survival outcome and tolerable treatment-related toxicities in elderly patients with ESCC. Further studies are warranted to validate the results.

Isotoxic investigation of 18F-FDG PET/CT-guided dose escalation with intensity-modulated radiotherapy for LA-NSCLC

PURPOSE

This research compared differences of dosimetric and biological parameters between PET/CT-guided isotoxic SIB-IMRT plans and conventional radiotherapy plans for patients with LA-NSCLC, and it also evaluated the factors that affect dose escalation.

MATERIALS AND METHODS

This study consisted of a retrospective cohort of thirty patients with IIIA-IIIB NSCLC. SIB-IMRT (Plan_iso) and conventional radiotherapy (Plan_primary) plans were generated using auto-planning. Dosimetric parameters such as mean lung dose (MLD) and other indicators were compared. Tumor control probability (TCP) of PTV and normal tissue complication probability (NTCP) of total lung, heart, esophagus, and spinal cord were calculated. The relationships between dose escalation and 3 D length of PTV and other factors were analyzed. Paired-samples t-test, Mann-Whitney U test, and Chi-Square test were performed for comparisons between datasets. A P < .05 was considered statistically significant.

RESULTS

The dosimetric parameters of PTV in Plan_iso were higher than those of PTV in Plan_primary, and there were significant differences (p < .05). Compared with Plan_primary, Plan_iso slightly increased dosimetric parameters of the total lung, heart, spinal cord, esophagus, and MUs. The absolute differences were small. TCPs of PTV in Plan_iso were significantly higher than those in Plan_primary. NTCPs of the total lung, esophagus, and spinal cord in Plan_iso were higher than those in Plan_primary. There were significant differences, but the absolute differences were small. NTCP of heart in Plan_iso was slightly higher than that in Plan_primary, but there was no statistical difference.

CONCLUSIONS

For LA-NSCLC, the SIB based on isotoxic radiotherapy can significantly increase TCP under the premise that the toxicity of OARs is comparable.

Efficacy and Prognostic Analysis of 315 Stage I-IVa Esophageal Cancer Patients Treated with Simultaneous Integrated Boost-Intensity-Modulated Radiation Therapy

Purpose

Use of simulated integrated boost-intensity-modulated radiation therapy (SIB-IMRT) is rarely reported in the treatment of esophageal cancer. This study was performed to observe the curative effect and prognostic factors associated with concurrent chemoradiotherapy for esophageal cancer using modern radiotherapy (RT) techniques.

Patients and Methods

In total, 315 patients with esophageal squamous cell carcinoma who received SIB-IMRT between 2015 and 2018 were included in this retrospective study. Median doses were planning target volume (PTV) 5400 cGy, 30 times (180cGy/fraction); planning gross tumor volume (PGTV) 6000 cGy, 30 times (200 cGy/fraction), once a day and 5 times a week. The entire period of RT was 6 weeks. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse reactions were observed. Univariate analysis was performed, and factors with P<0.15 were included in multivariate analysis. Cox regression analysis was used for multivariate prognostic analysis. P<0.05 was considered statistically significant. The incidence of adverse reactions under single chemotherapy concurrent chemoradiotherapy (sCCRT) and double chemotherapy concurrent chemoradiotherapy (dCCRT) was analyzed.

Results

Two-year, 3-year OS and PFS of the entire group were 49.5%, 40.2% and 40.3%, 34.0%, and the median survival time was 23.5 months. Univariate and multivariate analyses showed that T-stage (P=0.049), N-stage (P=0.024), clinical stage (P=0.041), short-term efficacy (P<0.001), and use of concurrent chemotherapy (P<0.001) were the influencing factors for OS. ORR was 87.6%. Adverse reactions were significantly increased with increasing chemotherapy dose.

Conclusion

The adverse reactions of SIB-IMRT in esophageal cancer can be tolerated. T-stage, N-stage, clinical stage, short-term curative effect, and concurrent chemotherapy are the prognostic factors affecting survival. Because it has lower toxicity and is as effective as dCCRT, sCCRT should be considered in the management of esophageal cancer.

Dysfunction of apoptosis and autophagy correlates with local recurrence in esophageal squamous cell carcinoma after definitive chemoradiation

OBJECTIVE

Definitive chemoradiotherapy (dCRT) is one of the standard treatments for esophageal squamous cell carcinoma (ESCC), but local recurrence is the main cause of treatment failure. The changes in apoptosis and autophagy in recurrent tumors of patients with ESCC following dCRT have been poorly estimated. Thus, this study aimed to investigate the expressions of key regulators of apoptosis and autophagy in matched paired samples of primary and recurrent ESCC.

METHODS

The medical records of patients with locally advanced ESCC who developed local recurrence after dCRT were reviewed, and the expression profiling of apoptosis-related genes, cell apoptosis, autophagy and autophagy-related proteins were detected in normal esophageal squamous epithelium and paired samples of primary and recurrent ESCC.

RESULTS

A total of 126 patients were enrolled, and 52.4% of them had stage III disease. The 1-, 3- and 5-year local recurrence-free survival (LRFS) rates were 54.8, 19.8 and 14.3%, respectively, with a median LRFS of 13.0 months. Patients with T2 tumor or stage II disease showed a significantly prolonged LRFS compared with that of patients with T3-4 tumor or stage III disease. The Apoptotic Machinery key genes expression profiling identified 5 upregulated and 7 downregulated apoptosis-related genes in recurrent tumors compared with their expression levels in the matched primary ESCC tumors. High expression of CD40, TRAF4 and BCL2A1, and low expression of CARD6 and TNFRSF21 were associated with increased risk of early local recurrence after dCRT. No differences in apoptotic index between primary and recurrent samples were detected. However, typical morphological features of autophagosomes and elevated LC3-II protein expression were detected in recurrent tumor samples, and positive LC3-II expression was correlated with increased risk of early local recurrence.

CONCLUSION

Our findings indicated that apoptosis and autophagy dysfunction correlated with early local recurrence in patients with locally advanced ESCC receiving dCRT. Further studies are necessary to understand the biology of tumor recurrence in esophageal cancer.

Computed Tomography-Based Evaluation of Volume and Position Changes of the Target Region and Organs at Risk During Radiotherapy for Esophageal Cancer: A Pilot Study

Objective

To analyze changes in volume and position of target regions and organs at risk (OARs) during radiotherapy for esophageal cancer patients.

Methods

Overall, 16 esophageal cancer patients who underwent radiotherapy, including 10 cases of intensity-modulated radiation therapy (IMRT) and six of three-dimensional conformal radiotherapy (3D-CRT), were enrolled. The prescription doses for the planning target volumes (PTVs) were as follows: PTV1, 64 Gy/32 fractions; and PTV2, 46 Gy/23 fractions. Repeat computed tomography (CT) was performed for patients after the 5th, 10th, 15th, 20th, and 25th fractions. Delineation of the gross tumor volume (GTV) and OAR volume was determined using five repeat CTs performed by the same physician. The target and OAR volumes and centroid positions were recorded and used to analyze volume change ratio (VCR), center displacement (ΔD), and changes in the distance from the OAR centroid positions to the planned radiotherapy isocenter (distance to isocenter, DTI) during treatment.

Results

No patient showed significant changes in target volume (TV) after the first week of radiotherapy (five fractions). However, TV gradually decreased over the following weeks, with the rate slowing after the fourth week (40 Gy). The comparison of TV from baseline to 40 Gy (20 fractions) showed that average GTVs decreased from 130.7 ± 63.1 cc to 92.1 ± 47.2 cc, with a VCR of −29.21 ± 13.96% (p<0.01), while the clinical target volume (CTV1) decreased from 276.7 ± 98.2 cc to 246.7 ± 87.2 cc, with a VCR of −10.34 ± 7.58% (p<0.01). As TVs decreased, ΔD increased and DTI decreased. After the fourth week of radiotherapy (40 Gy), centroids of GTV, CTV1, and prophylactic CTV (CTV2) showed average deviations in ΔD of 7.6 ± 4.0, 6.9 ± 3.4, and 6.0 ± 3.0 mm, respectively. The average DTI of the heart decreased by 4.53 mm (from 15.61 ± 2.96 cm to 15.16 ± 2.27 cm).

Conclusion

During radiotherapy for esophageal cancer, Targets and OARs change significantly in volume and position during the 2^nd–4^th weeks. Image-guidance and evaluation of dosimetric changes are recommended for these fractions of treatment to appropriate adjust treatment plans.

Definitive Simultaneous Integrated Boost Versus Conventional-Fractionated Intensity Modulated Radiotherapy for Patients With Advanced Esophageal Squamous Cell Carcinoma: A Propensity Score-Matched Analysis

BACKGROUND

The aim of this study was to compare the effects of simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) and conventional fractionated-IMRT (CF-IMRT) for patients with esophageal squamous cell carcinoma (ESCC).

METHODS

The data of 1173 patients treated with either CF-IMRT or SIB-IMRT for a curative intent from 2005 to 2016 were retrospectively reviewed. Propensity score matching (PSM) was used to create a well-balanced cohort of 687 patients at 1:2 ratio (237 patients in SIB-IMRT group and 450 patients in CF-IMRT group). Overall survival (OS), progression-free survival (PFS), recurrence pattern, and toxicity profiles were evaluated and compared between the two groups after PSM.

RESULTS

After a median follow-up time of 42.3 months (range, 3.0-153.2 months) for surviving patients, survival results were comparable in the two groups. After PSM, the 1-year, 2-year and 4-year OS rates in the SIB-IMRT and CF-IMRT groups were 70.0% vs. 66.4%, 41.9% vs. 41.7% and 30.2% vs. 27.6%, respectively (p = 0.87). The 1-year, 2-year and 4-year PFS rates were 48.4% vs. 49.1%, 31.2% vs. 29.4%, and 26.1% vs. 17.9%, respectively (p = 0.64). Locoregional recurrence (p = 0.32) and distant metastasis (p = 0.54) rates were also comparable between two groups. The toxicity profile was similar in the two groups. Multivariate analyses in the matched samples showed that female, concurrent chemotherapy and earlier clinical stage were independently associated with longer OS and PFS.

CONCLUSIONS

SIB-IMRT appears to be equivalent to CF-IMRT in treatment efficacy and safety, and could become an alternative option for definitive radiotherapy of ESCC.

Results of a Phase 1/2 Trial of Chemoradiotherapy With Simultaneous Integrated Boost of Radiotherapy Dose in Unresectable Locally Advanced Esophageal Cancer

Importance

Effective treatment options for locally advanced esophageal cancer are limited, and rates of local recurrence after standard chemoradiotherapy remain high.

Objective

To evaluate toxic effects, local control, and overall survival rates after chemoradiotherapy with a simultaneous integrated boost of radiotherapy dose to the gross tumor and nodal disease for patients with unresectable locally advanced esophageal cancer.

Design, Setting, and Participants

A phase 1/2, single-arm trial was conducted in 46 patients from April 28, 2010, to April 9, 2015 (median follow-up, 52 months [range, 2-86 months]), at a tertiary academic cancer center. Outcomes of the study patients were compared with those of 97 similar patients treated at the same institution from January 10, 2010, to December 5, 2014, as part of the interim analysis. Statistical analysis was performed from December 15, 2018, to February 12, 2019.

Interventions

Chemoradiotherapy with a simultaneous integrated boost of radiotherapy dose (50.4 Gy to subclinical areas at risk and 63.0 Gy to the gross tumor and involved nodes, all given in 28 fractions) with concurrent docetaxel and capecitabine or fluorouracil.

Main Outcomes and Measures

Toxic effects, local (in-field) control, and overall survival rates.

Results

All 46 patients (11 women and 35 men; median age, 65.5 years [range, 37.3-84.4 years]) received per-protocol therapy, as intensity-modulated photon therapy (39 [85%]) or intensity-modulated proton therapy (7 [15%]); 11 patients (24%) ultimately underwent resection. No patients experienced grade 4 or 5 toxic effects; the 10 acute grade 3 toxic events were esophagitis (4), dysphagia (3), and anorexia (3) and the 3 late grade 3 toxic events were all esophageal strictures. The actuarial local recurrence rates were 22% (95% CI, 11%-35%) at 6 months, 30% (95% CI, 18%-44%) at 1 year, and 33% (95% CI, 20%-46%) at 2 years. Overall, 15 patients (33%) experienced local failure, at a median interval of 5 months (range, 1-24 months). The median overall survival time was 21.5 months (range, 2.3-86.4 months). Exploratory comparison with a 97-patient contemporaneous institutional cohort receiving standard-dose (non-simultaneous integrated boost) chemoradiotherapy showed superior local control (hazard ratio, 0.49; 95% CI, 0.26-0.92; P = .03) and overall survival (hazard ratio, 0.66; 95% CI, 0.47-0.94; P = .02) in the group that received chemoradiotherapy with a simultaneous integrated boost.

Conclusions and Relevance

These findings suggest that chemoradiotherapy with a simultaneous integrated boost of radiotherapy dose for locally advanced esophageal cancer is well tolerated, with encouraging local control, and thus warrants further study.

Trial Registration

ClinicalTrials.gov identifier: NCT01102088.

Interobserver variability in target volume delineation in definitive radiotherapy for thoracic esophageal cancer: a multi-center study from China

Purpose

To investigate the interobserver variability (IOV) in target volume delineation of definitive radiotherapy for thoracic esophageal cancer (TEC) among cancer centers in China, and ultimately improve contouring consistency as much as possible to lay the foundation for multi-center prospective studies.

Methods

Sixteen cancer centers throughout China participated in this study. In Phase 1, three suitable cases with upper, middle, and lower TEC were chosen, and participants were asked to contour a group of gross tumor volume (GTV-T), nodal gross tumor volume (GTV-N) and clinical target volume (CTV) for each case based on their routine experience. In Phase 2, the same clinicians were instructed to follow a contouring protocol to re-contour another group of target volume. The variation of the target volume was analyzed and quantified using dice similarity coefficient (DSC).

Results

Sixteen clinicians provided routine volumes, whereas ten provided both routine and protocol volumes for each case. The IOV of routine GTV-N was the most striking in all cases, with the smallest DSC of 0.37 (95% CI 0.32–0.42), followed by CTV, whereas GTV-T showed high consistency. After following the protocol, the smallest DSC of GTV-N was improved to 0.64 (95% CI 0.45–0.83, P = 0.005) but the DSC of GTV-T and CTV remained constant in most cases.

Conclusion

Variability in target volume delineation was observed, but it could be significantly reduced and controlled using mandatory interventions.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13014-020-01691-4.

Randomized Study on Dose Escalation in Definitive Chemoradiation for Patients With Locally Advanced Esophageal Cancer (ARTDECO Study)

PURPOSE

To analyze the effect of radiation dose escalation to the primary tumor on local tumor control in definitive chemoradiation (dCRT) for patients with esophageal cancer.

PATIENTS AND METHODS

Patients with medically inoperable and/or irresectable esophageal carcinoma, referred for dCRT, were randomly assigned between a standard dose (SD) of 50.4 Gy/1.8 Gy for 5.5 weeks to the tumor and regional lymph nodes and a high dose (HD) up to a total dose of 61.6 Gy to the primary tumor. Chemotherapy consisted of courses of concurrent carboplatin (area under the curve 2) and paclitaxel (50 mg/m²) in both arms once a week for 6 weeks. The primary end point was local progression-free survival.

RESULTS

Between September 2012 and June 2018, 260 patients were included. Squamous cell carcinoma (SCC) was present in 61% of patients, and 39% had adenocarcinoma (AC). Radiation treatment was completed by 94%, and 85% had at least five courses of chemotherapy. The median follow-up time for all patients was 50 months. The 3-year local progression-free survival (LPFS) was 70% in the SD arm versus 73% in the HD arm (not significant). The LPFS for SCC and AC was 75% versus 79% and 61% versus 61% for SD and HD, respectively (not significant). The 3-year locoregional progression-free survival was 52% and 59% for the SD and HD arms, respectively (P = .08). Overall, grade 4 and 5 common toxicity criteria were 12% and 5% in the SD arm versus 14% and 10% in the HD arm, respectively (P = .15).

CONCLUSION

In dCRT for esophageal cancer, radiation dose escalation up to 61.6 Gy to the primary tumor did not result in a significant increase in local control over 50.4 Gy. The absence of a dose effect was observed in both AC and SCC.

Effect of SIB-IMRT-based selective dose escalation of local tumor on the prognosis of patients with esophageal cancer

BACKGROUND

To investigate the effect of SIB-IMRT-based selective dose escalation to local tumor on the prognosis of patients with esophageal cancer (EC).

METHODS

A total of 302 EC patients were enrolled. The prognostic factors of the entire group were initially analyzed, and the composition ratios of the two groups and the different doses of each fraction for PTV were compared. The propensity-score matching (PSM) was carried out (1:1 ratio), and the prognostic factors for the two groups were analyzed according to the results of COX.

RESULTS

The median overall survival (OS) for all patients was 30.0 months (23.495-36.505 months), and the median disease-free survival (DFS) was 21.3 months (7.698-24.902 months). In multivariate analysis, chemotherapy, cTNM stage and dose-per-fraction for the PTV were independent prognostic factors for OS (P = 0.013, 0.000, 0.028) and DFS (P = 0.033, 0.000, 0.047). Multivariate analysis of patients after PSM revealed that cTNM staging and dose-per-fraction were the independent prognostic factors for OS (P = 0.000, 0.015). Chemotherapy, cTNM staging and dose-per-fraction for the PTV were the independent prognostic factors for DFS (P = 0.025, 0.010, 0.015). There was no significant difference in grade ≥ 2 acute toxicities between the two groups. A subgroup analysis of patients with a single dose of 2 Gy and > 2 Gy in the SIB-IMRT group showed that OS and DFS of the latter were significantly better than those of the former.

CONCLUSION

The selective dose escalation to local tumors based on SIB-IMRT technique can improve the survival of patients received radical radiotherapy without increasing toxicities.

Concurrent chemoradiotherapy versus radiotherapy alone for patients with locally advanced esophageal squamous cell carcinoma in the era of intensity modulated radiotherapy: a propensity score-matched analysis

Background

To investigate the survival benefit of concurrent chemoradiotherapy (CCRT) for patients with locally advanced esophageal squamous cell carcinoma (ESCC) during the years of intensity‐modulated radiotherapy (IMRT).

Methods

Medical records of 1089 patients with ESCC who received IMRT from January 2005 to December 2017 were retrospectively reviewed. A total of 617 patients received CCRT, 472 patients received radiotherapy (RT) alone. Propensity score matching (PSM) method was used to eliminate baseline differences between the two groups. Survival and toxicity profile were evaluated afterward.

Results

After a median follow‐up time of 47.9 months (3.2–149.8 months), both overall survival (OS) and progression‐free survival (PFS) of the CCRT group were better than those of the RT alone group, either before or after PSM. After PSM, the 1‐, 3‐, and 5‐year OS of RT alone and CCRT groups were 59.0% versus 70.2%, 27.7% versus 40.5% and 20.3% versus 33.1%, respectively (p < 0.001). The 1‐, 3‐, and 5‐year PFS were 39.4% versus 49.0%, 18.3% versus 30.4% and 10.5% versus 25.0%, respectively (p < 0.001). The rates of ≥ grade 3 leukopenia and radiation esophagitis in the CCRT group were higher than that of RT alone group (p < 0.05). There was no significant difference in the probability of radiation pneumonitis between the two groups (p = 0.167). Multivariate Cox analysis indicated that female, EQD2 ≥60 Gy and concurrent chemotherapy were favorable prognostic factors for both OS and PFS.

Conclusions

Concurrent chemotherapy can bring survival benefits to patients with locally advanced ESCC receiving IMRT. For patients who cannot tolerate concurrent chemotherapy, RT alone is an effective alternative with promising results.

The Promise of Proton Beam Therapy for Oesophageal Cancer: A Systematic Review of Dosimetric and Clinical Outcomes

AIMS

Due to its physical advantages over photon radiotherapy, proton beam therapy (PBT) has the potential to improve outcomes from oesophageal cancer. However, for many tumour sites, high-quality evidence supporting PBT use is limited. We carried out a systematic review of published literature of PBT in oesophageal cancer to ascertain potential benefits of this technology and to gauge the current state-of-the-art. We considered if further evaluation of this technology in oesophageal cancer is desirable.

MATERIALS AND METHODS

A systematic literature search of Medline, Embase, Cochrane Library and Web of Science using structured search terms was carried out. Inclusion criteria included non-metastatic cancer, full articles and English language studies only. Articles deliberating technical aspects of PBT planning or delivery were excluded to maintain a clinical focus. Studies were divided into two sections: dosimetric and clinical studies; qualitatively synthesised.

RESULTS

In total, 467 records were screened, with 32 included for final qualitative synthesis. This included two prospective studies with the rest based on retrospective data. There was heterogeneity in treatment protocols, including treatment intent (neoadjuvant or definitive), dose, fractionation and chemotherapy used. Compared with photon radiotherapy, PBT seemed to reduce dose to organs at risk, especially lung and heart, although not for all reported parameters. Toxicity outcomes, including postoperative complications, were reduced compared with photon radiotherapy. Survival outcomes were reported to be at least comparable with photon radiotherapy.

CONCLUSION

There is a paucity of high-quality evidence supporting PBT use in oesophageal cancer. Wide variation in intent and treatment protocols means that the role and 'gold-standard' treatment protocol are yet to be defined. Current literature suggests significant benefit in terms of toxicity reduction, especially in the postoperative period, with comparable survival outcomes. PBT in oesophageal cancer holds significant promise for improving patient outcomes but requires robust systematic evaluation in prospective studies.

Patterns of Dose Escalation Among Patients With Esophageal Cancer Undergoing Definitive Radiation Therapy: 2006-2016

PURPOSE

Although single-institution series suggest potential benefit to dose escalation in definitive radiation therapy for esophageal cancer, randomized trials including intergroup-0123 and the recently presented A Randomized Trial of Dose Escalation in definitive Chemoradiotherapy for patients with Oesophageal cancer (ARTDECO) trial showed no improvement in outcomes with higher radiation therapy dose. As such, there may be significant variation in radiation dose for definitive treatment of esophageal cancer.

METHODS AND MATERIALS

The National Cancer Database was used to identify patients who received a diagnosis of nonmetastatic T2+ esophageal cancer between 2006 and 2016 who did not receive definitive surgery and were treated with chemotherapy and radiation therapy doses between 41.4 and 74 Gy. Multivariable logistic regression defined adjusted odds ratios (AORs) of receipt of >50.4 Gy, including year of diagnosis (2006-2013 vs 2014-2016) ∗ histology (squamous cell carcinoma [SCC] vs adenocarcinoma) and year of diagnosis (2006-2013 vs 2014-2016) ∗ disease site (cervical esophagus vs noncervical esophagus) interaction terms, to assess whether the effect of diagnosis year on dose varied by histology and disease site, respectively.

RESULTS

Among 14,517 patients, the most common dose was 50.4 Gy, used for 6955 (47.9%) patients. Dose escalation above 50.4 Gy was observed in 4440 (30.6%) patients and declined by year, from 42.2% in 2006 to 23.5% in 2016. Patients with SCC versus adenocarcinoma had higher odds of dose escalation (39.3% vs 23.8%; AOR 1.46; P < .001), as did those with cervical esophageal primaries versus other primary sites (54.9% vs 27.4%; AOR 2.51; P < .001). The effect of later diagnosis year was greater for adenocarcinoma than for SCC (pint = 0.001, AOR 0.54, P < .001 vs AOR 0.71, P < .001) and significant for noncervical esophagus but not cervical esophagus (pint <0.001, AOR 0.56, P < .001 vs AOR 0.95, P = .616).

CONCLUSIONS

Dose escalation in definitive chemoradiotherapy for esophageal cancer declined over time, particularly for adenocarcinoma histology and noncervical primary site. Given the recent results of ARTDECO, our findings can serve as a benchmark from which to measure future shifts in practice patterns.

Simultaneous integrated boost concepts in definitive radiation therapy for esophageal cancer: outcomes and toxicity

BACKGROUND

Radiation therapy and chemoradiation therapy play a major role in the definitive management of esophageal cancer. Survival in esophageal cancer patients is still relatively poor, mostly due to high rates of local recurrence and distant metastases. It is hypothesized that dose escalation in radiotherapy could improve outcomes. Therefore, this retrospective analysis aimed to investigate the outcomes and toxicity in patients treated with local dose escalation by means of using simultaneous integrated boost concepts.

METHODS

Between 2012 and 2018, 101 patients with esophageal carcinoma were analyzed in this monocentric, retrospective study. All patients received definitive chemoradiation or radiation therapy alone as intensity modulated radiotherapy. The prescribed dose was 50.4 Gy in 28 fractions to the primary tumor and the elective lymph nodes as well as a simultaneous integrated boost (SIB) with 58.8 Gy to macroscopic tumor and lymph node metastases. Endpoints were overall survival (OS), progression free survival (PFS), local control rate (LCR) and toxicity.

RESULTS

60 patients (59.4%) received chemoradiation, 41 patients (40.6%) radiotherapy alone. The median follow up was 17 months (range 0-75 months). OS, PFS and LCR were at 63.9%, 53.9% and 59.9% after 1 year and 37.6%, 34.5% and 36.1%, respectively after 3 years. 16 patients (15.8%) in total developed a locoregional recurrence within the field of radiation. In 48 patients (47.5%) at least one grade III° (CTCAE) toxicity was documented during radiotherapy, mostly dysphagia (36 pat., 75%). One patient suffered from a grade IV° pneumonia.

CONCLUSION

This retrospective analysis demonstrates that a SIB concept in definitive (chemo)radiation therapy is safe and feasible, showing acceptable outcomes in this patient cohort. Considering that this cohort mainly consists of elderly patients not eligible for chemotherapy in many cases, we emphasize the aspect of SIB radiation therapy as potential partial compensation for omitted simultaneous chemotherapy. Prospective studies are needed for validation.

Late Toxicities, Failure Patterns, Local Tumor Control, and Survival of Esophageal Squamous Cell Carcinoma Patients After Chemoradiotherapy With a Simultaneous Integrated Boost: A 5-Year Phase II Study

PURPOSE

We aimed to evaluate the long-term outcomes of concurrent chemoradiotherapy (CCRT) with a simultaneous integrated boost (SIB) of radiotherapy for esophageal squamous cell carcinoma (ESCC).

METHODS AND MATERIALS

Eighty-seven patients with primary ESCC enrolled in this phase II trial. The majority (92.0%) had locoregionally advanced disease. They underwent definitive chemoradiotherapy. The radiotherapy doses were 66 Gy for the gross tumor and 54 Gy for the subclinical disease. Doses were simultaneously administered in 30 fractions over 6 weeks. The patients also underwent concurrent and adjuvant chemotherapy, which comprised cisplatin and fluorouracil. The study end points were acute and late toxicities, first site of failure, locoregional tumor control, and overall survival rates.

RESULTS

The median follow-up time was 65.7 (range, 2.2-97.5) months for all patients and 81.5 (range, 19.4-97.5) months for those alive. There were 17 cases (19.5%) of severe late toxicities, including four cases (4.6%) of grade 5 and seven (8.0%) of grade 3 esophageal ulceration, four (4.6%) of grade 3 esophageal stricture, and two (2.3%) of grade 3 radiation-induced pneumonia. Twenty-three (26.4%) patients had locoregional disease progression. Most (86.7%) locally progressive lesions were within the dose-escalation region in the initial radiation plan, while majority of the recurrent lymph nodes were found out-of-field (83.3%) and in the supraclavicular region (75.0%). The 1-, 2-, 3-, and 5-year locoregional tumor control and overall survival rates were 79.2%, 72.4%, 72.4%, 70.8%, and 82.8%, 66.6%, 61.9%, 58.4%, respectively. Incomplete tumor response, which was assessed immediately after CCRT was an independent risk predictor of disease progression and death in ESCC patients.

CONCLUSIONS

CCRT with SIB was well tolerated in ESCC patients during treatment and long-term follow-up. Moreover, patients who underwent CCRT with SIB exhibited improved local tumor control and had better survival outcomes compared to historical data of those who had standard-dose radiotherapy.

Simultaneous Integrated Boost Intensity-Modulated Radiotherapy for Locally Advanced Drug-Resistant Gastrointestinal Stromal Tumors: A Feasibility Study

Background

As an emerging clinical problem, locally advanced drug-resistant gastrointestinal stromal tumors (LADRGISTs) has relatively few therapeutic schemes. Although radiotherapy is not often considered for GISTs, it could be a valuable contributing modality. The aim of our study is to explore a safe and effective radiation regimen for LADR-GISTs.

Methods

Three patients with LADR-GISTs were treated with simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) plans. In the SIB-IMRT plans, gross target volume (GTV) was divided into GTV-outer, GTV-mid, and GTV-center. And the prescribed dose of planning gross target volume (PGTV) and GTV-outer were both set to 50.4 Gy in 28 fractions. GTV-mid and GTV-center were simultaneously boosted to 60–62 Gy and 62–64 Gy respectively. For comparison purposes, conventional IMRT (Con-IMRT) plans with uniform dose distribution were generated for same optimization objectives without a dose boost to GTV-mid and GTV-center. All plans were optimized to make sure that deliver at least 95% of the prescription dose was delivered to PGTV. Isodose distribution, dose profiles, conformity indexes (CIs), monitor units (MUs), and dose volume histogram (DVH) was evaluated for each individual patient. After the three patients were treated with SIB-IMRT plans, the relative changes in the tumor size and CT values by CT scanning were also tracked.

Results

Compared with Con-IMRT plans, SIB-IMRT plans saw a significant increase from D₉₅ to D₂ of the GTV. With steeper dose gradients in the dose profiles, SIB-IMRT plans had GTV-mid and GTV-center accumulated with higher dose mainly by delivering extra 93 MUs in average. However, there was no significant difference in CIs and organs at risks (OARs) DVH. The relative changes in tumor size and CT values of the three patients in follow up were up to the Choi criteria and the three patients were all assessed as partial response.

Conclusions

The proposed SIB-IMRT may be a potential technique for achieving objective response and prolonging survival of selected GISTs patients.

A multicenter prospective phase III clinical randomized study of simultaneous integrated boost intensity-modulated radiotherapy with or without concurrent chemotherapy in patients with esophageal cancer: 3JECROG P-02 study protocol

BACKGROUND

Since the development of three-dimensional conformal radiotherapy and intensity-modulated radiotherapy (IMRT), no prospective study has investigated whether concurrent chemoradiotherapy (SIB-IMRT with 60 Gy) remains superior to radiotherapy (SIB-IMRT) alone for unresectable esophageal cancer (EC). Furthermore, the optimal therapeutic regimen for patients who cannot tolerate concurrent chemoradiotherapy is unclear. We recently completed a phase I/II radiation dose-escalation trial using simultaneous integrated boost (SIB), elective nodal irradiation, and concurrent chemotherapy for unresectable EC. We now intend to conduct a prospective, phase III, randomized study of SIB-IMRT with or without concurrent chemotherapy. We aim to find a safe, practical, and effective therapeutic regimen to replace the conventional segmentation (1.8-2.0 Gy) treatment mode (radiotherapy ± chemotherapy) for unresectable EC.

METHODS

This two-arm, open, randomized, multicenter, phase III trial will recruit esophageal squamous cell carcinoma patients (stage IIA-IVB [UICC 2002]; IVB only with metastasis to the supraclavicular or celiac lymph nodes). In all, 164 patients will be randomized using a 1:1 allocation ratio, and stratified by study site and disease stage, especially the extent of lymph node metastasis. Patients in the SIB arm will receive definitive SIB radiotherapy (95% planning target volume/planning gross tumor volume, 50.4 Gy/59.92 Gy/28 f, equivalent dose in 2-Gy fractions = 60.62 Gy). Patients in the SIB + concurrent chemotherapy arm will receive definitive SIB radiotherapy with weekly paclitaxel and a platinum-based drug (5-6 weeks). Four cycles of consolidated chemoradiotherapy will also be recommended. The primary objective is to compare the 1-year, 2-year, and 3-year overall survival of the SIB + chemotherapy group and SIB groups. Secondary objectives include progression-free survival, local recurrence-free rate, completion rate, and adverse events. Detailed radiotherapy protocol and quality-assurance procedures have been incorporated into this trial.

DISCUSSION

In unresectable, locally advanced EC, a safe and effective total radiotherapy dose and reasonable segmentation doses are required for the clinical application of SIB-IMRT + two-drug chemotherapy. Whether this protocol will replace the standard treatment regimen will be prospectively investigated. The effects of SIB-IMRT in patients with poor physical condition who cannot tolerate definitive chemoradiotherapy will also be investigated.

TRIAL REGISTRATION

clinicaltrials.gov ( NCT03308552 , November 1, 2017).

The efficacy and safety of simultaneous integrated dose reduction in clinical target volume with intensity-modulated radiotherapy for patients with locally advanced esophageal squamous cell carcinoma

Background

Compelling research to explore the effectiveness of simultaneous integrated dose reduction in clinical target volume (CTV) with intensity-modulated radiotherapy (SIR-IMRT) for locally advanced esophageal squamous cell carcinoma (ESCC) are limited. This study aimed to compare the clinical efficacy and treatment-related toxicity between SIR-IMRT and conventional IMRT (C-IMRT) in the treatment of ESCC.

Methods

From March 2010 to September 2016, the clinical data of 257 patients with ESCC who received definitive IMRT in the Tianjin Medical University Cancer Institute and Hospital were collected and retrospectively analyzed. Among these patients, 137 patients received C-IMRT with a prescribed dose of 60 Gy in 30 fractions for planning target volume (PTV), while 120 patients received SIR-IMRT with a prescribed dose of 60 Gy in 30 fractions for the planning gross tumor volume (PGTV) and a prescribed dose of 54 Gy in 30 fractions for PTV. All of the patients received definitive IMRT with elective nodal irradiation. Locoregional control, survival, treatment toxicity and dose to organs at risk (OAR) were compared between the groups.

Results

Patients who received SIR-IMRT showed a similar locoregional failure rate compared to the C-IMRT group (27.5% versus 29.9%, P=0.668). The 1-, 2- and 3-year overall survival (OS) rates were 71.5%, 44.3%, 44.3% vs. 77.9%, 52.1%, 32.9% in the C-IMRT and SIR-IMRT groups, respectively (P=0.825). No significant differences were observed in PFS and LRRFS between the two groups (P=0.880 and P=0.216, respectively). The dose of lung V30 and the maximum dose of spinal cord in the C-IMRT group were significantly higher than those in the SIR-IMRT group (P=0.013, P=0.047). The incidence of acute radiation esophagitis was significantly lower in the SIR-IMRT group (P=0.046), although no statistical difference was observed in the incidence of acute severe adverse events between the two groups.

Conclusions

SIR-IMRT offers an effective and safe option for patients with unresectable ESCC who receive definitive RT. Further prospective and larger sample size studies are warranted to confirm our results.

Radiation Dose-escalated Chemoradiotherapy Using Simultaneous Integrated Boost Intensity-Modulated Radiotherapy for Locally Advanced Unresectable Thoracic Oesophageal Squamous Cell Carcinoma: A Single-institution Phase I Study

AIMS

About 80% of cases of locally advanced unresectable thoracic oesophageal squamous cell carcinoma recur within the irradiation fields after chemoradiotherapy. Radiation dose escalation using advanced radiotherapy techniques is expected to improve clinical outcomes by reducing local and regional recurrence. The current study aimed to determine the recommended escalated radiation dose for these patients.

MATERIALS AND METHODS

Patients with locally advanced unresectable thoracic oesophageal squamous cell carcinoma with good performance status underwent chemoradiotherapy using simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) with elective nodal irradiation. SIB-IMRT was delivered in five fractions per week. The radiation dose to the unresectable gross tumour was escalated from 66 Gy to a planned maximum dose of 72 Gy in 3 Gy increments in a standard 3 + 3 design. The doses to the resectable component, superficial tumours and elective nodal regions were fixed as 60, 51 and 48 Gy, respectively. Cisplatin and 5-fluorouracil were concurrently administered. Dose-limiting toxicity (DLT) was defined as acute grade 3 oesophagitis, grade 2 pneumonitis, grade 2 cardiac toxicity and a failure to complete planned radiotherapy within 60 days. Locoregional control and overall survival were estimated using the Kaplan-Meier method. Nine patients were enrolled.

RESULTS

DLTs occurred in one of six and two of three patients at doses of 66 and 69 Gy, respectively. All DLTs were grade 3 oesophagitis. The recommended dose was determined as 66 Gy delivered in 30 fractions based on the predefined criteria. With a median follow-up period of 23 months, the 1-year locoregional control and overall survival rates were 67 (95% confidence interval = 19-90) and 78% (95% confidence interval = 36-94), respectively.

CONCLUSION

The recommended radiation dose in chemoradiotherapy using SIB-IMRT with elective nodal irradiation was 66 Gy delivered in 30 fractions.

High vs. Low Radiation Dose of Concurrent Chemoradiotherapy for Esophageal Carcinoma With Modern Radiotherapy Techniques: A Meta-Analysis

Purpose: The aim of this study was to evaluate the clinical benefit of different radiation doses in concurrent chemoradiotherapy (CCRT) for esophageal carcinoma using modern radiotherapy techniques. Methods: A systematic review was conducted by screening PubMed, EMBASE, Cochrane Central Register of Controlled Trials, SCOPUS, Wanfang, and Chinese National Knowledge Infrastructure (CNKI) databases with prespecified searching strategy. Studies which compared high radiation dose group with low-dose radiation group using modern radiotherapy techniques for esophageal cancer patients in CCRT were identified. The hazard ratios (HR) for overall survival (OS) and the odds ratios (OR) for local-regional failure (LRF), distant metastasis (DM), and toxicities were considered as the outcomes of interest. R 3.6.2 software was used for statistical analysis. Results: Twelve studies involving 10,896 patients were included for analyses. The results showed that the high-dose group had better OS (HR = 0.79, 95% CI = 0.70-0.90, P = 0.0004) and the local-regional control (OR = 0.59, 95% CI = 0.46-0.76, P < 0.0001), especially for patients who were diagnosed with squamous cell carcinoma (SCC). The subgroup analyses further indicated that ≥ circa 60 Gy can significantly improve the OS (HR = 0.73, 95% CI = 0.68-0.80, P < 0.0001) as well as the local-regional control (OR = 0.54, 95% CI = 0.40-0.74, P < 0.0001) as compared with < circa 60 Gy. Another subgroup analysis comparing ≤ 50.4 Gy with > 50.4 Gy showed no substantial difference in OS (HR = 0.98, 95% CI = 0.93-1.03, P = 0.43). In addition, there are no significant differences between the two groups in grade 3-5 radiation pneumonitis (OR = 1.05, 95% CI = 0.54-2.05, P = 0.89), grade 3-5 radiation esophagitis (OR = 1.40, 95% CI = 0.93-2.11, P = 0.11), treatment-related death (OR = 1.60, 95% CI = 0.70-3.66, P = 0.27), and DM (OR = 1.21, 95% CI = 0.92-1.59, P = 0.17). Conclusions: For esophageal carcinoma receiving CCRT with modern radiation techniques, evidence suggested that high-dose radiotherapy, especially ≥circa 60 Gy, had potentials to improve the OS and local-regional control without increase in severe toxicities when compared with low-dose radiotherapy. The result needs to be confirmed by randomized clinical trials.

Tolerance and efficacy of dose escalation using IMRT combined with chemotherapy for unresectable esophageal carcinoma: Long-term results of 51 patients

PURPOSE

The optimal dose in esophageal cancer patients treated with definitive chemoradiation (CRT) remains debated. We herein report on the dosimetric results, treatment-related toxicities and long-term outcomes of escalated dose up to 60Gy delivered with intensity-modulated radiotherapy (IMRT).

MATERIALS AND METHODS

All consecutive patients that received a definitive CRT>50Gy for an unresectable esophageal carcinoma between 2010 and 2015 were retrospectively evaluated for this study. Methodology included data base search, delayed toxicity grading, statistical testing including frequency analysis and survival analysis.

RESULTS

A total of 51 patients were irradiated for a squamous cell carcinoma (86.3%) or an adenocarcinoma (13.7%). The median age at diagnosis was 62 years. Seven patients were simultaneously irradiated for another synchronous primary tumor. Forty-six patients (90.2%) received concurrent platin-based chemotherapy. The median prescribed doses were 60Gy (54-66) and 48Gy (44.8-56) delivered in 30 (27-35) fractions to the high and the low risks PTV respectively. The mean dose delivered to the lungs was 11.4Gy (IC 95%: 4.8-19.8), the median volumes receiving up to 20Gy (V20) and 30Gy (V30) were 13.5% (3.0-46.0) and 4.6% (0.7-19.8) respectively. The mean dose delivered to the heart was 13.9Gy (IC 95%:0.3-31.3) with a median V40 of 3.3% (0.0-25.0). One treatment-related death occurred within days after RT completion (neutropenic aplasia). After a median follow-up of 2.7 years (95% CI: 1.9-4.3), the 2-year overall survival, disease free survival and loco-regional control rates were 53.6%, 42.0% and 72.8% respectively. Delayed treatment related-toxicities ≤grade 3 occurred among 25 patients (62.5%) mostly esophageal stricture (79.2%).

CONCLUSION

We demonstrated in this study that dose escalation using IMRT in combination with platin-based chemotherapy as a definitive treatment for esophageal carcinoma is safe and results in higher loco-regional and control survival when compared to previously reported data.

Sequential boost of intensity-modulated radiotherapy with chemotherapy for inoperable esophageal squamous cell carcinoma: A prospective phase II study

Purpose

This prospective phase II study aimed to determine the efficacy and tolerability of sequential boost of intensity‐modulated radiation therapy (IMRT) with chemotherapy for patients with inoperable esophageal squamous cell carcinoma (ESCC).

Methods

Patients with histologically or cytologically proven inoperable ESCC were enrolled in this study (ChiCTR‐OIC‐17010485). A larger target volume for subclinical lesion was irradiated with 50 Gy, and then, a smaller target volume only including gross tumor was boosted to 66 Gy. The fraction dose was 2 Gy, and no elective node was irradiated. Concurrent and consolidation chemotherapy of fluorouracil (600 mg/m², days 1‐3) plus cisplatin (25 mg/m², days 1‐3) was administered every 4 weeks, for 4 cycles in total. The primary endpoint was 2‐year progression‐free survival (PFS).

Results

Eighty‐eight patients were enrolled in this study. The median age was 65 years (range: 45‐75 years), and 69 patients (78.4%) were men. With the median follow‐up of 26 (range: 3‐95) months, the 2‐ and 5‐year PFS were 39.3% and 36.9%, respectively, and overall survival (OS) were 57.1% and 39.2%, respectively. Tumor stage and concurrent chemotherapy were independent OS predictors. Major acute adverse events were myelosuppression and esophagitis, most of which were grades 1‐2. Nine percent and 2.3% of patients had grade 3 acute esophagitis and late esophageal strictures, respectively.

Conclusions

Sequential boost to 66 Gy by IMRT with chemotherapy was safe and effective for inoperable ESCC. A randomized phase III study to compare with standard dose of 50 Gy is warranted.

[Definitive or neo-adjuvant chemoradiation in esophageal carcinoma?]

Management of resectable esophageal carcinoma is based on a multimodal treatment associating neo-adjuvant chemoradiation before surgery. This therapeutic sequence allows a disease-free survival rate at 2 years around 45% but remains associated with a high post-operative morbidity. In case of definitive chemoradiotherapy, the dose delivered to the macroscopic disease is a controversial topic since decades and the prognosis of patients treated in this setting at the dose of 50Gy remains poor. This article proposes a review of the main published data and the ongoing studies related to the management of these patients.

Intensity-modulated radiotherapy at high-volume centers improves survival in patients with esophageal adenocarcinoma receiving trimodality therapy

The standard of care trimodality therapy for resectable locally advanced esophageal adenocarcinoma is complex and necessitates multidisciplinary care and expertise. In this work, it is hypothesized that facility clinical volume and utilization of intensity-modulated radiotherapy (IMRT) may influence outcomes. The National Cancer Data Base was queried for patients with cT1-4-N0-3 M0 esophageal adenocarcinoma undergoing trimodality therapy from 2004 to 2013 (n = 2445). All patients received chemoradiation followed by esophagectomy at a Commission on Cancer facility. The facility volume was categorized into tertiles: high-volume centers (HVCs) in the highest 25th percentile of cases per year, intermediate-volume centers (IVCs) with the next highest 25th percentile of cases, and low- and very low-volume centers (LVCs) in the lowest 50th percentile. Overall survival (OS) was estimated using Kaplan-Meier methods and Cox proportional hazard regression. Propensity score matching to balance patient characteristics between volume centers was performed. Subgroup analysis was done comparing IMRT versus 3D conformal radiotherapy. The median follow-up was 26 months. Treatment at an HVC (hazard ratio 0.63, 95% CI 0.49-0.81, P < 0.001) was found to be independently associated with improved overall survival in multivariable analysis. Three-year OS was 58.4%, 46.2%, and 47.5% for HVCs, IVCs, and LVCs, respectively (P < 0.001). Patients at HVCs were more likely to receive IMRT over 3D chemoradiation (CRT; OR 3.45, 95% CI 2.4-5.0, P < 0.001). Patients treated using IMRT at HVCs had improved OS compared to those treated at IVCs or LVCs (HR 0.68, 95% CI 0.52-0.90, P < 0.01), while patients treated with 3D CRT at HVCs had no survival advantage over those at IVCs or LVCs (P = 0.28). Patients with locally advanced esophageal adenocarcinoma treated with IMRT and at HVCs appear to have improved survival.

Dosimetric and Radiobiological Comparison of External Beam Radiotherapy Using Simultaneous Integrated Boost Technique for Esophageal Cancer in Different Location

Objectives: To compare treatment plans of intensity modulated radiotherapy (IMRT), volumetric modulated arc radiotherapy (VMAT), and helical tomotherapy (HT) with simultaneous integrated boost (SIB) technique for esophageal cancer (EC) of different locations using dosimetry and radiobiology. Methods: Forty EC patients were planned for IMRT, VMAT, and HT plans, including 10 cases located in the cervix, upper, middle, and lower thorax, respectively. Dose-volume metrics, conformity index (CI), homogeneity index (HI), tumor control probability (TCP), and normal tissue complication probability (NTCP) were analyzed to evaluate treatment plans. Results: HT showed significant improvement over IMRT and VMAT in terms of CI (p = 0.007), HI (p < 0.001), and TCP (p < 0.001) in cervical EC. IMRT yielded more superior CI, HI and TCP compared with VMAT and HT in upper and middle thoracic EC (all p < 0.05). Additionally, V30 (27.72 ± 8.67%), mean dose (1801.47 ± 989.58cGy), and NTCP (Niemierko model: 0.44 ± 0.55%; Lyman-Kutcher-Burman model: 0.61 ± 0.59%) of heart in IMRT were sharply reduced than VMAT and HT in middle thoracic EC. For lower thoracic EC, the three techniques offered similar CI and HI (all p > 0.05). But VMAT dramatically lowered liver V30 (9.97 ± 2.84%), and reduced NTCP of lungs (Niemierko model: 0.47 ± 0.48%; Lyman-Kutcher-Burman model: 1.41 ± 1.07%) and liver (Niemierko model: 0.10 ± 0.08%; Lyman-Kutcher-Burman model: 0.17 ± 0.17%). Conclusions: HT was a good option for cervical EC with complex target coverage but little lungs and heart involvement as it achieved superior dose conformity and uniformity. Due to potentially improving tumor control and reducing heart dose with acceptable lungs sparing, IMRT was a preferred choice for upper and middle thoracic EC with large lungs involvement. VMAT could ameliorate therapeutic ratio and lower lungs and liver toxicity, which was beneficial for lower thoracic EC with little thoracic involvement but being closer to heart and liver. Individually choosing optimal technique for EC in different location will be warranted.

A multicenter phase III study comparing Simultaneous Integrated Boost (SIB) radiotherapy concurrent and consolidated with S-1 versus SIB alone in elderly patients with esophageal and esophagogastric cancer - the 3JECROG P-01 study protocol

BACKGROUND

The importance of definitive radiotherapy for elderly patients with esophageal and esophagogastric-junction cancer is pronounced. However, little is known in terms of the best way to combine radiotherapy with other treatment options. This study aims to compare the efficiency of SIB radiotherapy alone with SIB radiotherapy concurrent and consolidated with S-1 for elderly patients. Comprehensive geriatric assessment is also incorporated in the procedure of treatment.

METHODS/DESIGN

The study is a two arm, open, randomized multicenter Phase III trial with patients over 70 years old with stage IIA-IVB (UICC 2002, IVB only with metastasis to supraclavicular or celiac lymph nodes) squamous cell carcinoma or adenocarcinoma of esophagus or gastroesophageal junction. A total of 300 patients will be randomized using a 1:1 allocation ratio stratified by disease stage and study site. Patients allocated to the SIB arm will receive definitive SIB radiotherapy (95%PTV/PGTV 50.4Gy/59.92Gy/28f) while those randomized to SIB + S-1 arm will receive definitive SIB radiotherapy concurrent and consolidated with S-1. The primary endpoint of the trial is 1-year overall survival. Secondary objectives include progression-free survival, recurrence-free survival (local-regional and distant), disease failure pattern, toxicity profile as well as quality of life. Besides, detailed radiotherapy protocol and quality assurance procedure have been incorporated into this trial.

DISCUSSION

The proportion of elderly patients in esophageal cancer is now growing, but there is a lack of evidence in term of treatment standard for this group of patients, which is what we aim to obtain through this prospective phase III study.

TRIAL REGISTRATION

clinicaltrials.gov NCT02979691 . Registered November 22, 2016.

A phase I/II radiation dose escalation trial using simultaneous integrated boost technique with elective nodal irradiation and concurrent chemotherapy for unresectable esophageal Cancer

Background

To investigate the safety and tolerability of simultaneous integrated boost (SIB) technique concurrent with elective nodal irradiation (ENI) and dual-drug chemotherapy for patients with unresectable esophageal cancer.

Methods

In phase I, the prophylactic PTV received a stable dose of 50.40Gy/1.80Gy/28f while the boost area was planned with 3 consecutive dose levels: the first dose level was 60.76Gy/2.17Gy/28f, and then escalated approximately every 2 Gy. ENI was incorporated in Clinical Target Volume (CTV), and paclitaxel and nedaplatin were given concurrently for at least 5 weeks. In phase II, enrolled patients were treated with Maximum Tolerated Dose (MTD) obtained in phase I and the compliance rate, survival results and toxicities were evaluated.

Results

From December 2014 to April 2017, 53 patients were enrolled. In phase I, 2 out of 6 patients developed Dose-Limiting Toxicity (DLT) at dose level 1. Due to excessive treatment-related toxicities, the escalation process was suspended and de-escalated to 59.92Gy /2.14Gy /28 f. Three patients were treated at this dose level, all of whom completed at least 5 weeks of chemotherapy and none of whom reached a DLT, determining the newly added dose level to be the MTD.

In phase II, 44 patients were treated with MTD, 31 of them (70.0%) completed at least 5 weeks of chemotherapy. The most common Grade 3 or 4 toxicities in phase II included leukopenia (21%) and esophagitis (15%). With a median follow-up time of 16.9 months, 1-y OS, DFS and local failure-free survival were 76.9, 63.6 and 78.8% respectively.

Conclusion

The SIB technique was feasible and safe at the MTD (95% PGTV/PTV 59.92/50.40Gy/28f) concurrent with ENI and dual-drug chemotherapy for patients with unresectable esophageal cancer.

Trial registration

clinicaltrials.govNCT02429622. Retrospectively registered on April 24, 2015.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1249-5) contains supplementary material, which is available to authorized users.

Radiation Pneumonitis after Intensity-Modulated Radiotherapy for Esophageal Cancer: Institutional Data and a Systematic Review

Radiation pneumonitis (RP) is a serious complication that can occur after thoracic radiotherapy. The goal of this study is to investigate the incidence of RP after radiochemotherapy with intensity modulated radiotherapy (IMRT) in patients with esophageal cancer and correlate this with dose volume histogram (DVH) related parameters. For this purpose, the clinical course of 73 patients was evaluated and irradiation doses to the lungs were extracted from radiotherapy treatment plans. Furthermore, a systematic review on this topic was conducted across PubMed. In our institutional cohort, Common Terminology Criteria for Adverse Events (CTCAE) grade II or higher RP occurred in four patients (5.5%). The systematic review identified 493 titles of which 19 studies reporting 874 patients qualified for the final analysis. No grade IV or V RP after radiochemotherapy with IMRT for esophageal cancer was reported in the screened literature. Grade II or higher RP is reported in 6.6% of the patients. A higher incidence can be seen with increasing values for lung V20. In conclusion, our institutional data and the literature consistently show a low incidence of symptomatic RP after radiochemotherapy in patients with esophageal cancer treated with IMRT. However, efforts should be made to keep the lung V20 below 23% and specific caution is warranted in patients with pre-existing lung conditions.

Dosimetric Benefits of Midposition Compared With Internal Target Volume Strategy for Esophageal Cancer Radiation Therapy

PURPOSE

Both midposition (MidP) and internal target volume (ITV) strategies can take the respiration-induced target motion into account. This study aimed to compare these 2 strategies in terms of clinical target volume (CTV) coverage and dose to organs at risk (OARs) for esophageal cancer radiation therapy (RT).

METHODS AND MATERIALS

Fifteen patients with esophageal cancer were included retrospectively for neoadjuvant RT planning. Per patient, a 10-phase, 4-dimensional (4D) computed tomography (CT) scan (4D-CT) was acquired with CTV and OARs delineated on the 20% phase. The MidP-CT scan was reconstructed based on deformable image registration between the 20% phase and the other 9 phases; thereby, the CTV and OARs delineations were propagated and an ITV was constructed. Both MidP and ITV strategies were used for treatment planning, yielding the planned dose. Next, these plans were applied to the 10-phase 4D-CT to calculate the dose distribution for each phase of the 4D-CT. On the basis of the deformable image registration, these calculated dose distributions were warped and averaged to yield the accumulated 4D dose. Subsequently, we compared, in terms of CTV coverage and dose to OARs, the planned dose with the accumulated 4D dose and the MidP strategy with the ITV strategy.

RESULTS

The differences between the planned dose and the accumulated 4D dose were limited and clinically irrelevant. In 14 patients, both MidP and ITV strategies showed V_95% > 98% for the CTV. Compared with the ITV strategy, the MidP strategy showed a significant reduction of approximately 10% in the dose-volume histogram parameters for the lungs, heart, and liver (P < .001, Wilcoxon signed-rank test).

CONCLUSIONS

Compared with the ITV strategy, the MidP strategy in treatment planning can lead to a reduction of approximately 10% in the dose to OARs, with an adequate CTV coverage for esophageal cancer RT.

18F-fluorodeoxyglucose positron emission tomography predicts lymph node responses to definitive chemoradiotherapy in esophageal squamous cell carcinoma patients

Purpose

To evaluate the capability of ¹⁸F-fluorodeoxyglucose positron emission tomography/ computed tomography (¹⁸F-FDG-PET/CT) to predict the clinical response of metastatic lymph node (mLN) to definitive chemoradiotherapy (dCRT) and guide personalized radiation dose in esophageal squamous cell carcinoma (ESCC) patients.

Patients and methods

One hundred and forty-three mLNs from 59 patients with ESCC treated with dCRT and who had undergone a pretreatment ¹⁸F-FDG-PET/CT scan were included in the study. All defined mLNs were contoured by nuclear medicine radiologists. Response was evaluated by contrast-enhanced computed tomography and ¹⁸F-FDG-PET/CT.

Results

Sixty-nine mLNs showed complete response (CR), and 74 mLNs showed non-complete response. The 143 mLNs were divided into 4 groups (Groups 1–4) based on the quartiles of maximum standardized uptake value (SUVmax-G1, SUVmax-G2, SUVmax-G3, and SUVmax-G4) and metabolic tumor volume (MTV-G1, MTV-G2, MTV-G3, and MTV-G4). The CR rate of SUVmax-G2 was significantly higher than the other 3 groups. The escalated radiation dose improved the CR rate of lymph nodes in SUVmax-G3 (55 Gy) and SUVmax-G4 (61 Gy). The lowest CR rate was found in MTV-G4 (the group with the largest MTV). The escalated radiation dose (59.7 Gy) improved the CR rate of lymph node in MTV-Groups 3 and 4.

Conclusion

Pretreatment metabolic parameters can predict the response of mLNs to dCRT for patients with ESCC. The parameters could also be used to guide personalized dose to mLNs.

Dosimetric comparison of TomoDirect, helical tomotherapy, VMAT, and ff-IMRT for upper thoracic esophageal carcinoma

BACKGROUND

The new TomoDirect (TD) modality offers a nonrotational option with discrete beam angles. We aim to compare dosimetric parameters of TD, helical tomotherapy (HT), volumetric-modulated arc therapy (VMAT), and fixed-field intensity-modulated radiotherapy (ff-IMRT) for upper thoracic esophageal carcinoma (EC).

METHODS

Twenty patients with cT2-4N0-1M0 upper thoracic esophageal squamous cell carcinoma (ESCC) were enrolled. Four plans were generated using the same dose objectives for each patient: TD, HT, VMAT with a single arc, and ff-IMRT with 5 fields (5F). The prescribed doses were used to deliver 50.4 Gy/28F to the planning target volume (PTV50.4) and then provided a 9 Gy/5F boost to PTV59.4. Dose-volume histogram (DVH) statistics, dose uniformity, and dose homogeneity were analyzed to compare treatment plans.

RESULTS

For PTV59.4, the D₂, D₉₈, D_mean, and V_100% values in HT were significantly lower than other plans (all p < 0.05), and those in TD were significantly lower than VMAT and ff-IMRT (all p < 0.05). However, there was no significant difference in the D₂ and D_mean values between VMAT and ff-IMRT techniques (p > 0.05). The homogeneity index (HI) differed significantly for the 4 techniques of TD, HT, VMAT, and ff-IMRT (0.03 ± 0.01, 0.02 ± 0.01, 0.06 ± 0.02, and 0.05 ± 0.01, respectively; p  < 0.001). The HI for TD was similar to HT (p = 0.166), and had statistically significant improvement compared to VMAT (p < 0.001) and ff-IMRT (p = 0.003). In comparison with the 4 conformity indices (CIs), there was no significant difference (p > 0.05). For PTV50.4, the D₂ and D_mean values in HT were significantly lower than other plans (all p < 0.05), and those in TD were significantly lower than VMAT and ff-IMRT (all p < 0.05). However, there was no significant difference in the D₂ and D_mean values between VMAT and ff-IMRT techniques (p > 0.05). No D₉₈ and V_100% parameters differed significantly among the 4 treatment types (p > 0.05). HT plans were provided for statistically significant improvement in HI (0.03 ± 0.01) compared to TD plans (0.05 ± 0.01, p = 0.003), VMAT (0.08 ± 0.03, p < 0.001), ff-IMRT (0.08 ± 0.01, p < 0.001). The HI revealed that TD was superior to VMAT and ff-IMRT (p < 0.05). The CI differed significantly for the 4 techniques of TD, HT, VMAT, and ff-IMRT (0.59 ± 0.10, 0.69 ± 0.11, 0.64 ± 0.09, and 0.64 ± 0.11, respectively; p = 0.035). The best CI was yielded by HT. We found no significant difference for the V₅, V₁₀, V₁₅, V₃₀, and the mean lung dose (MLD) among the 4 techniques (all p > 0.05). However, the V₂₀ differed significantly among TD, HT, VMAT, and ff-IMRT (21.50 ± 7.20%, 19.50 ± 5.55%, 17.65 ± 5.45%, and 16.35 ± 5.70%, respectively; p = 0.047). Average V₂₀ for the lungs was significantly improved by the TD plans compared to VMAT (p = 0.047), and ff-IMRT (p = 0.008). The V₅ value of the lung in TD was 49.30 ± 13.01%, lower than other plans, but there was no significant difference (p > 0.05). The D₁ of the spinal cord showed no significant difference among the 4 techniques (p = 0.056).

CONCLUSIONS

All techniques are able to provide a homogeneous and highly conformal dose distribution. The TD technique is a good option for treating upper thoracic EC involvement. It could achieve optimal low dose to the lungs and spinal cord with acceptable PTV coverage. HT is a good option as it could achieve quality dose conformality and uniformity, while TD generated superior conformality.

Advances in radiotherapy for esophageal cancer

Esophageal cancer is a common type of malignancy worldwide and usually requires multidisciplinary care. Radiotherapy plays an important part in management of the disease. During the past few years, researchers have made much progress about radiotherapy for esophageal cancer, which was revealed in every aspect of clinical practice. Neoadjuvant chemoradiotherapy remains the standard treatment for locally advanced esophageal cancer, whereas neoadjuvant chemotherapy appears to show less toxicities and non-inferior prognosis. What's more, definitive chemoradiotherapy could be an option for non-surgical candidates and good responders to chemoradiotherapy. Advances in radiation techniques result in higher conformity, homogeneity, more normal tissue sparing and less treatment time. Promising prognoses and less toxicities were also seen in advanced techniques. As radiation dose higher than 50 Gy obtains better local control and survival, simultaneously integrated boost is designed to increase primary tumor dosage and keep prophylactic dose to subclinical areas. Elective nodal irradiation brings about better local control but do not show advantages in survival compared with involved field irradiation (IFI). As a trend, more tolerable chemoradiotherapy regimen would be taken into account in dealing with elderly patients.

Radiation dose escalation by simultaneous modulated accelerated radiotherapy combined with chemotherapy for esophageal cancer: a phase II study

The outcomes for patients with esophageal cancer (EC) underwent standard-dose radical radiotherapy were still disappointing. This phase II study investigated the feasibility, safety and efficacy of radiation dose escalation using simultaneous modulated accelerated radiotherapy (SMART) combined with chemotherapy in 60 EC patients. Radiotherapy consisted of 66Gy at 2.2 Gy/fraction to the gross tumor and 54Gy at 1.8 Gy/fraction to subclinical diseases simultaneously. Chemotherapy including cisplatin and 5fluorouracil were administered to all patients during and after radiotherapy. The data showed that the majority of patients (98.3%) completed the whole course of radiotherapy and concurrent chemotherapy. The most common ≥ grade 3 acute toxicities were neutropenia (16.7%), followed by esophagitis (6.7%) and thrombopenia (5.0%). With a median follow-up of 24 months (5-38) for all patients and 30 months (18-38) for those still alive, 11 patients (18.3%) developed ≥ Grade 3 late toxicities and 2 (3.3%) of them died subsequently due to esophageal hemorrhage. The 1- and 2-year local-regional control, distant metastasis-free survival, disease-free survival and overall survival rates were 87.6% and 78.6%, 86.0% and 80.5%, 75.6% and 64.4%, 86.7% and 72.7%, respectively. SMART combined with concurrent chemotherapy is feasible in EC patients with tolerable acute toxicities. They showed a trend of significant improvements in local-regional control and overall survival. Further follow-up is needed to evaluate the late toxicities.

Simultaneous Integrated Boost for Radiation Dose Escalation to the Gross Tumor Volume With Intensity Modulated (Photon) Radiation Therapy or Intensity Modulated Proton Therapy and Concurrent Chemotherapy for Stage II to III Non-Small Cell Lung Cancer: A Phase 1 Study

PURPOSE

To establish, in the phase 1 portion of a prospective phase 1/2 study, the maximum tolerated dose of image guided intensity modulated radiation therapy (IMRT) or proton therapy (IMPT), both with a simultaneous integrated boost (SIB), for patients with stage II to IIIB non-small cell lung cancer receiving concurrent chemoradiation therapy.

METHODS AND MATERIALS

Patients had pathologically proven non-small cell lung cancer, either unresectable stage II to IIIB disease or recurrent disease after surgical resection, and could tolerate concurrent chemoradiation. Radiation doses were selectively escalated to the SIB volume (internal gross tumor volume + 5-mm margin), and the dose to the planning target volume (internal gross tumor volume + 8-mm margin for clinical target volume + 5 mm) was kept at 60 Gy [cobalt gray equivalent (CGE)] over 30 fractions. Patients were randomized between the IMRT and IMPT groups if slots were available on the treatment machines for both groups. Otherwise, patients were allocated to IMRT or IMPT, whichever had an open treatment slot on the machine without randomization.

RESULTS

Fifteen patients (6 IMRT, 9 IMPT) were enrolled. The highest doses to the SIB were 72 Gy in the IMRT group and 78 Gy(CGE) in the IMPT group. Nine patients (6 IMRT, 3 IMPT) received an SIB dose of 72 Gy(CGE) [biologically effective dose = 89.3 Gy(CGE)], and 6 patients (IMPT) received an SIB dose of 78 Gy(CGE) [biologically effective dose = 98.3 Gy(CGE)]. Dose-limiting (grade ≥3) toxicity (esophagitis) developed in 1 of the 9 patients given 72 Gy(CGE) SIB. Grade ≥3 pneumonitis developed in 2 of the 6 patients treated to 78 Gy(CGE) IMPT SIB: 1 (grade 3) at 3 months after treatment and the other (grade 5, possibly related to treatment) at 2 months after treatment. Only 1 patient developed a marginal tumor recurrence with a median follow-up of 25 months (range, 4.3-47.4 months).

CONCLUSIONS

We recommend that an SIB dose of 72 Gy(CGE) be used as the highest SIB dose for the planned randomized phase 2 study.

Automatic treatment planning facilitates fast generation of high-quality treatment plans for esophageal cancer

BACKGROUND

The quality of radiotherapy planning has improved substantially in the last decade with the introduction of intensity modulated radiotherapy. The purpose of this study was to analyze the plan quality and efficacy of automatically (AU) generated VMAT plans for inoperable esophageal cancer patients.

MATERIAL AND METHODS

Thirty-two consecutive inoperable patients with esophageal cancer originally treated with manually (MA) generated volumetric modulated arc therapy (VMAT) plans were retrospectively replanned using an auto-planning engine. All plans were optimized with one full 6MV VMAT arc giving 60 Gy to the primary target and 50 Gy to the elective target. The planning techniques were blinded before clinical evaluation by three specialized oncologists. To supplement the clinical evaluation, the optimization time for the AU plan was recorded along with DVH parameters for all plans.

RESULTS

Upon clinical evaluation, the AU plan was preferred for 31/32 patients, and for one patient, there was no difference in the plans. In terms of DVH parameters, similar target coverage was obtained between the two planning methods. The mean dose for the spinal cord increased by 1.8 Gy using AU (p = .002), whereas the mean lung dose decreased by 1.9 Gy (p < .001). The AU plans were more modulated as seen by the increase of 12% in mean MUs (p = .001). The median optimization time for AU plans was 117 min.

CONCLUSIONS

The AU plans were in general preferred and showed a lower mean dose to the lungs. The automation of the planning process generated esophageal cancer treatment plans quickly and with high quality.

Different definitions of esophagus influence esophageal toxicity prediction for esophageal cancer patients administered simultaneous integrated boost versus standard-dose radiation therapy

We aim to evaluate whether different definitions of esophagus (DEs) impact on the esophageal toxicity prediction for esophageal cancer (EC) patients administered intensity-modulated radiation therapy with simultaneous integrated boost (SIB-IMRT) vs. standard-dose IMRT (SD-IMRT). The esophagus for 21 patients diagnosed with primary EC were defined in the following four ways: the whole esophagus, including the tumor (ESO_whole); ESO_whole within the treatment field (ESO_infield); ESO_infield, excluding the tumor (ESO_{infield-tumor}) and ESO_whole, excluding the tumor (ESO_whole-tumor). The difference in the dose variation, acute esophageal toxicity (AET) and late esophageal toxicity (LET) of four DEs were compared. We found that the mean esophageal dose for ESO_whole, ESO_infield, ESO_{infield-tumor} and ESO_whole-tumor were increased by 7.2 Gy, 10.9 Gy, 4.6 Gy and 2.0 Gy, respectively, in the SIB-IMRT plans. Radiobiological models indicated that a grade ≥ 2 AET was 2.9%, 3.1%, 2.2% and 1.6% higher on average with the Kwint model and 14.6%, 13.2%, 7.2% and 3.4% higher with the Wijsman model for the four DEs. A grade ≥ 3 AET increased by 4.3%, 7.2%, 4.2% and 1.2%, respectively. Additionally, the predicted LET increased by 0.15%, 0.39%, 1.2 × 10⁻²% and 1.5 × 10⁻³%. Our study demonstrates that different DEs influence the esophageal toxicity prediction for EC patients administered SIB-IMRT vs. SD-IMRT treatment.

Radiobiological evaluation of simultaneously dose-escalated versus non-escalated intensity-modulated radiation therapy for patients with upper thoracic esophageal cancer

OBJECTIVE

To compare the radiobiological response between simultaneously dose-escalated and non-escalated intensity-modulated radiation therapy (DE-IMRT and NE-IMRT) for patients with upper thoracic esophageal cancer (UTEC) using radiobiological evaluation.

METHODS

Computed tomography simulation data sets for 25 patients pathologically diagnosed with primary UTEC were used in this study. DE-IMRT plan with an escalated dose of 64.8 Gy/28 fractions to the gross tumor volume (GTV) and involved lymph nodes from 25 patients pathologically diagnosed with primary UTEC, was compared to an NE-IMRT plan of 50.4 Gy/28 fractions. Dose-volume metrics, tumor control probability (TCP), and normal tissue complication probability for the lung and spinal cord were compared. In addition, the risk of acute esophageal toxicity (AET) and late esophageal toxicity (LET) were also analyzed.

RESULTS

Compared with NE-IMRT plan, we found the DE-IMRT plan resulted in a 14.6 Gy dose escalation to the GTV. The tumor control was predicted to increase by 31.8%, 39.1%, and 40.9% for three independent TCP models. The predicted incidence of radiation pneumonitis was similar (3.9% versus 3.6%), and the estimated risk of radiation-induced spinal cord injury was extremely low (<0.13%) in both groups. Regarding the esophageal toxicities, the estimated grade ≥2 and grade ≥3 AET predicted by the Kwint model were increased by 2.5% and 3.8%. Grade ≥2 AET predicted using the Wijsman model was increased by 14.9%. The predicted incidence of LET was low (<0.51%) in both groups.

CONCLUSION

Radiobiological evaluation reveals that the DE-IMRT dosing strategy is feasible for patients with UTEC, with significant gains in tumor control and minor or clinically acceptable increases in radiation-induced toxicities.

Local Control and Toxicity of a Simultaneous Integrated Boost for Dose Escalation in Locally Advanced Esophageal Cancer: Interim Results from a Prospective Phase I/II Trial

INTRODUCTION

Approximately 50% of recurrences after standard-dose chemoradiation for locally advanced esophageal cancer occur within the gross tumor volume (GTV). In this prospective phase I/II clinical trial, we explored the use of a simultaneous integrated boost (SIB) dose to the GTV.

METHODS

Forty-four patients with unresectable esophageal cancer received chemoradiation with an SIB of 58.8 to 63 Gy to the GTV and 50.4 Gy to the planning target volume, all in 28 fractions, with 5 weeks of concurrent docetaxel and fluorouracil or capecitabine. The end points were maximum tolerated dose, time to local failure, and clinical response.

RESULTS

Excluding those with less than 6 months of follow-up, 38 patients were evaluated at the time of analysis. The median age was 65 years (range 37-84). Most patients (71%) were men; 84% had T3 disease, 37% had N1 disease, 26% had N2 disease, 13% had M1 disease, and 50% had adenocarcinoma. The maximum tolerated SIB dose was 63 Gy. None experienced Common Terminology Criteria for Adverse Events grade 4 or 5 toxicity. At a median follow-up time of 13.3 months (range 1.2-36.2), 11 (29%) had local failure (median time to local failure 2.5 months [range 1.5-23.9]). A comparison with 97 similar patients who received 50.4 Gy without an SIB showed that the SIB reduced the local failure rate for patients with node-positive disease (13% versus 56%, p = 0.04), adenocarcinoma (26% versus 59%, p = 0.02), or stage III-IV disease (29% versus 55%, p = 0.04).

CONCLUSIONS

SIB intensity-modulated radiation therapy to gross primary disease may improve local control for patients with unresectable locally advanced esophageal cancer, especially those with adenocarcinoma.

Radiation field size and dose determine oncologic outcome in esophageal cancer

Background

Locoregional recurrence is a major problem in esophageal cancer patients treated with definitive concomitant chemoradiotherapy. Approximately half of the patients fail locoregionally. We analyzed the impact of enlarged radiation field size and higher radiation dose incorporated to chemoradiotherapy on oncologic outcome.

Methods

Seventy-four consecutive patients with histologically proven nonmetastatic squamous or adenocarcinoma of the esophagus were included in this retrospective analysis. All patients were locally advanced cT3–T4 and/or cN0-1. Treatment consisted of either definitive concomitant chemoradiotherapy (Def-CRT) (n = 49, 66 %) or preoperative concomitant chemoradiotherapy (Pre-CRT) followed by surgical resection (n = 25, 34 %). Patients were treated with longer radiation fields. Clinical target volume (CTV) was obtained by giving 8–10 cm margins to the craniocaudal borders of gross tumor volume (GTV) instead of 4–5 cm globally accepted margins, and some patients in Def-CRT group received radiation doses higher than 50 Gy.

Results

Isolated locoregional recurrences were observed in 9 out of 49 patients (18 %) in the Def-CRT group and in 1 out of 25 patients (3.8 %) in the Pre-CRT group (p = 0.15). The 5-year survival rate was 59 % in the Def-CRT group and 50 % in the Pre-CRT group (p = 0.72). Radiation dose was important in the Def-CRT group. Patients treated with >50 Gy (11 out of 49 patients) had better survival with respect to patients treated with 50 Gy (38 out of 49 patients). Five-year survivals were 91 and 50 %, respectively (p = 0.013).

Conclusions

Radiation treatment planning by enlarged radiation fields in esophageal cancer decreases locoregional recurrences considerably with respect to the results reported in the literature by standard radiation fields (18 vs >50 %). Radiation dose is as important as radiation field size; patients in the Def-CRT group treated with ≥50 Gy had better survival in comparison to patients treated with 50 Gy.

Comparison of planning target volumes based on three-dimensional and four-dimensional CT imaging of thoracic esophageal cancer

Background and purpose

To investigate the definition of planning target volumes (PTVs) based on four-dimensional computed tomography (4DCT) compared with conventional PTV definition and PTV definition using asymmetrical margins for thoracic primary esophageal cancer.

Materials and methods

Forty-three patients with esophageal cancer underwent 3DCT and 4DCT simulation scans during free breathing. The motions of primary tumors located in the proximal (group A), middle (group B), and distal (group C) thoracic esophagus were obtained from the 4DCT scans. PTV_3D was defined on 3DCT using the tumor motion measured based on 4DCT, PTV conventional (PTV_conv) was defined on 3DCT by adding a 1.0 cm margin to the clinical target volume, and PTV_4D was defined as the union of the target volumes contoured on the ten phases of the 4DCT images. The centroid positions, volumetric differences, and dice similarity coefficients were evaluated for all PTVs.

Results

The median centroid shifts between PTV_3D and PTV_4D and between PTV_conv and PTV_4D in all three dimensions were <0.3 cm for the three groups. The median size ratios of PTV_4D to PTV_3D were 0.80, 0.88, and 0.71, and PTV_4D to PTV_conv were 0.67, 0.73, and 0.76 (χ²=−3.18, −2.98, and −3.06; P=0.001, 0.003, and 0.002) for groups A, B, and C, respectively. The dice similarity coefficients were 0.87, 0.90, and 0.81 between PTV_4D and PTV_3D and 0.80, 0.84, and 0.83 between PTV_4D and PTV_conv (χ² =−3.18, −2.98, and −3.06; P=0.001, 0.003, and 0.002) for groups A, B, and C, respectively. The difference between the degree of inclusion of PTV_4D in PTV_3D and that of PTV_4D in PTV_conv was <2% for all groups. Compared with PTV_conv, the amount of irradiated normal tissue for PTV_3D was decreased by 11.81% and 11.86% in groups A and B, respectively, but was increased by 2.93% in group C.

Conclusion

For proximal and middle esophageal cancer, 3DCT-based PTV using asymmetrical margins provides good coverage of PTV_4D; however, for distal esophageal cancer, 3DCT-based PTV using conventional margins provides ideal conformity with PTV_4D.

An Analysis of Plan Robustness for Esophageal Tumors: Comparing Volumetric Modulated Arc Therapy Plans and Spot Scanning Proton Planning

PURPOSE

Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans.

METHODS AND MATERIALS

For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV)50Gy or PTV62.5Gy (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose-volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant.

RESULTS

SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D98 was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D98 was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D98 was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D98 was lower by 0.3% to 2.2% of the prescribed GTV dose.

CONCLUSIONS

The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup errors and might be unacceptable for certain patients. Robust optimization to ensure adequate target coverage of SIB proton plans might be beneficial.

Identification of a predictive factor for distant metastasis in esophageal squamous cell carcinoma after definitive chemoradiotherapy

BACKGROUND AND PURPOSE

Distant metastasis (DM) after definitive chemoradiotherapy has not been a focus of research in esophageal carcinoma. At present, local-regional control is improving following advances in salvage treatments after definitive chemoradiotherapy. There is a need to focus on suppressing the development of DM. The aim of this study was to identify pre-treatment factors associated with DM after definitive chemoradiotherapy.

MATERIALS AND METHODS

This study included 144 patients with thoracic esophageal squamous cell carcinoma (Stage I/II/III/IV; 35/17/69/23) (TNM 7th) who underwent definitive chemoradiotherapy; >50 Gy was prescribed to all gross tumors with concurrent administration of 5-fluorouracil ± platinum. Pre-treatment factors included age, gender, performance status, tumor location, T/N/M status, tumor length, size of metastatic lymph nodes (LN size), and the presence of intramural metastasis or multiple primary tumors. The effects of pre-treatment factors on overall survival (OS) and DM were evaluated.

RESULTS

The median follow-up period was 48 months. DM occurred as an initial progression in 21 % of patients, and LN size correlated with DM development (hazard ratio [HR] = 5.12; p = 0.0013) and poor OS (HR = 2.20; p = 0.0076) in univariate and multivariate analyses.

CONCLUSIONS

LN size is a quantitative pre-treatment prognostic factor that should be assessed prior to definitive chemoradiotherapy. Patients with large metastatic lymph nodes are at high risk of DM and should be monitored.