Intensity modulated radiotherapy (IMRT) with concurrent chemotherapy as definitive treatment of locally advanced esophageal cancer

A Meta-Analysis and Review of Radiation Dose Escalation in Definitive Radiation Therapy between Squamous Cell Carcinoma and Adenocarcinoma of Esophageal Cancer

Esophageal cancer, ranked as the eighth most prevalent cancer globally, is characterized by a low survival rate and poor prognosis. Concurrent chemoradiation therapy (CCRT) is the standard therapy in the non-surgical treatment of localized carcinoma of the esophagus. Nevertheless, the radiation doses employed in CCRT remain notably lower compared to the curative definite chemoradiation therapy utilized in the management of other carcinomas. In order to increase the local control rates and enhance the treatment outcomes, several clinical trials have used high-dose radiation to analyze the effect of dose escalation. Despite the integration of technically advanced RT schemes such as intensity-modulated radiation therapy (IMRT), the results of these trials have failed to demonstrate a significant improvement in overall survival or local progression-free survival. In this review, we investigated previous clinical trials to determine the ineffectiveness of radiation dose escalation in the context of CCRT for esophageal cancer. We aim to clarify the factors contributing to the limited efficacy of escalated radiation doses in improving patient outcomes. Furthermore, we delve into recent research endeavors, exploring prospective radiation dose modifications being altered based on the histological characteristics of the carcinoma. The exploration of these recent studies not only sheds light on potential refinements to the existing treatment protocols but also seeks to identify novel approaches that may pave the way for more efficacious and personalized therapeutic strategies for esophageal cancer management.

American Society for Gastrointestinal Endoscopy guideline on endoscopic submucosal dissection for the management of early esophageal and gastric cancers: methodology and review of evidence

This document from the American Society for Gastrointestinal Endoscopy (ASGE) provides a full description of the methodology used in the review of the evidence used to inform the final guidance outlined in the accompanying Summary and Recommendations document regarding the role of endoscopic submucosal dissection (ESD) in the management of early esophageal and gastric cancers. This guideline used the Grading of Recommendations, Assessment, Development and Evaluation framework and specifically addresses the role of ESD versus EMR and/or surgery, where applicable, for the management of early esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), and gastric adenocarcinoma (GAC) and their corresponding precursor lesions. For ESCC, the ASGE suggests ESD over EMR for patients with early-stage, well-differentiated, nonulcerated cancer >15 mm, whereas in patients with similar lesions ≤15 mm, the ASGE suggests either ESD or EMR. The ASGE suggests against surgery for such patients with ESCC, whenever possible. For EAC, the ASGE suggests ESD over EMR for patients with early-stage, well-differentiated, nonulcerated cancer >20 mm, whereas in patients with similar lesions measuring ≤20 mm, the ASGE suggests either ESD or EMR. For GAC, the ASGE suggests ESD over EMR for patients with early-stage, well or moderately differentiated, nonulcerated intestinal type cancer measuring 20 to 30 mm, whereas for patients with similar lesions <20 mm, the ASGE suggests either ESD or EMR. The ASGE suggests against surgery for patients with such lesions measuring ≤30 mm, whereas for lesions that are poorly differentiated, regardless of size, the ASGE suggests surgical evaluation over endosic approaches.

Late Toxicity and Health-Related Quality of Life Following Definitive Chemoradiotherapy for Esophageal Cancer: A Systematic Review and Meta-analysis

PURPOSE

Definitive chemoradiotherapy (dCRT) is a treatment option with curative intent for patients with esophageal cancer that could result in late toxicities and affect health-related quality of life (HRQoL). This study aimed to review the literature and perform a meta-analysis to investigate the effect of dCRT on late toxicities and HRQoL in esophageal cancer.

METHODS AND MATERIALS

A systematic search was performed in MEDLINE, EMBASE, and PsychINFO. Prospective phase II and III clinical trials, population-based studies, and retrospective chart reviews investigating late toxicity or HRQoL after dCRT (≥50 Gy) were included. The HRQoL outcomes were analyzed using linear mixed-effect models with restricted cubic spline transformation. Any HRQoL changes of ≥10 points were considered clinically relevant. The risk of toxicities was calculated using the number of events and the total study population.

RESULTS

Among 41 included studies, 10 assessed HRQoL and 31 late toxicity. Global health status remained stable over time and improved after 36 months compared with baseline (mean change, +11). Several tumor-specific symptoms, including dysphagia, eating restrictions, and pain, improved after 6 months compared with baseline. Compared with baseline, dyspnea worsened after 6 months (mean change, +16 points). The risk of any late toxicity was 48% (95% CI, 33%-64%). Late toxicity risk of any grade for the esophagus was 17% (95% CI, 12%-21%), pulmonary 21% (95% CI, 11%-31%), cardiac 12% (95% CI, 6%-17%), and any other organ 24% (95% CI, 2%-45%).

CONCLUSIONS

Global health status remained stable over time, and tumor-specific symptoms improved within 6 months after dCRT compared with baseline, with the exception of dyspnea. In addition, substantial risks of late toxicity were observed.

Geriatric Radiation Oncology: What We Know and What Can We Do Better?

Elderly patients represent a growing subgroup of cancer patients for whom the role of radiation therapy is poorly defined. Older patients are still clearly underrepresented in clinical trials, resulting in very limited high-level evidence. Moreover, elderly patients are less likely to receive radiation therapy in similar clinical scenarios compared to younger patients. However, there is no clear evidence for a generally reduced radiation tolerance with increasing age. Modern radiation techniques have clearly reduced acute and late side effects, thus extending the boundaries of the possible regarding treatment intensity in elderly or frail patients. Hypofractionated regimens have further decreased the socioeconomic burden of radiation treatments by reducing the overall treatment time. The current review aims at summarizing the existing data for the use of radiation therapy or chemoradiation in elderly patients focusing on the main cancer types. It provides an overview of treatment tolerability and outcomes with current standard radiation therapy regimens, including possible predictive factors in the elderly population. Strategies for patient selection for standard or tailored radiation therapy approaches based on age, performance score or comorbidity, including the use of prediction tests or geriatric assessments, are discussed. Current and future possibilities for improvements of routine care and creation of high-level evidence in elderly patients receiving radiation therapy are highlighted.

The impact of lymphopenia during chemoradiotherapy using photons or protons on the clinical outcomes of esophageal cancer patients

We assessed the development of lymphopenia during concurrent chemoradiotherapy (CRT) using X-ray versus proton beams and the impact on survival in patients with esophageal cancer. Among patients with esophageal cancer who were administered concurrent CRT with a curative intent at our institute from 2014 to 2018, 69 (15 receiving X-ray radiotherapy (XRT) and 54 receiving proton beam therapy [PBT]) who underwent weekly blood testing during treatment were enrolled. The absolute lymphocyte counts (ALC) at 1, 5 and 6 weeks were significantly higher in the patients who received PBT than in those who received XRT (p = 0.002, p = 0.006 and p = 0.009, respectively), and a similar trend in the neutrophil-to-lymphocyte ratio (NLR) was observed (p = 0.003 at 5 weeks). The 2-year overall survival (OS) and progression-free survival (PFS) rates tended to be higher in the patients who maintained an ALC ≥200 compared with those who did not (p = 0.083 and p = 0.053, respectively), and similar trends were observed in the NLR (p = 0.061 and p = 0.038, respectively). Dose-volume analysis revealed significant correlations between volumes of the thoracic bones irradiated by 5-50 Gy and minimum ALCs and maximum NLR. These findings suggested that PBT prevented the development of lymphopenia during CRT by reducing the irradiated volume of the thoracic bone, and the maintained lymphocyte count is possibly one of the early predictors for survival in patients with esophageal cancer.

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.

[F18] FDG-PET/CT for manual or semiautomated GTV delineation of the primary tumor for radiation therapy planning in patients with esophageal cancer: is it useful?

Background

Target volume definition of the primary tumor in esophageal cancer is usually based on computed tomography (CT) supported by endoscopy and/or endoscopic ultrasound and can be difficult given the low soft-tissue contrast of CT resulting in large interobserver variability. We evaluated the value of a dedicated planning [F18] FDG-Positron emission tomography/computer tomography (PET/CT) for harmonization of gross tumor volume (GTV) delineation and the feasibility of semiautomated structures for planning purposes in a large cohort.

Methods

Patients receiving a dedicated planning [F18] FDG-PET/CT (06/2011–03/2016) were included. GTV was delineated on CT and on PET/CT (GTV_CT and GTV_PET/CT, respectively) by three independent radiation oncologists. Interobserver variability was evaluated by comparison of mean GTV and mean tumor lengths, and via Sørensen–Dice coefficients (DSC) for spatial overlap. Semiautomated volumes were constructed based on PET/CT using fixed standardized uptake values (SUV) thresholds (SUV30, 35, and 40) or background- and metabolically corrected PERCIST-TLG and Schaefer algorithms, and compared to manually delineated volumes.

Results

45 cases were evaluated. Mean GTV_CT and GTV_PET/CT were 59.2/58.0 ml, 65.4/64.1 ml, and 60.4/59.2 ml for observers A–C. No significant difference between CT- and PET/CT-based delineation was found comparing the mean volumes or lengths. Mean Dice coefficients on CT and PET/CT were 0.79/0.77, 0.81/0.78, and 0.8/0.78 for observer pairs AB, AC, and BC, respectively, with no significant differences. Mean GTV volumes delineated semiautomatically with SUV30/SUV35/SUV40/Schaefer’s and PERCIST-TLG threshold were 69.1/23.9/18.8/18.6 and 70.9 ml. The best concordance of a semiautomatically delineated structure with the manually delineated GTV_CT/GTV_PET/CT was observed for PERCIST-TLG.

Conclusion

We were not able to show that the integration of PET/CT for GTV delineation of the primary tumor resulted in reduced interobserver variability. The PERCIST-TLG algorithm seemed most promising compared to other thresholds for further evaluation of semiautomated delineation of esophageal cancer.

Death unrelated to cancer and death from aspiration pneumonia after definitive radiotherapy for head and neck cancer

BACKGROUND AND PURPOSE

The incidence of hypopharyngeal and supraglottic cancer (HSC) is high in Japan. This study aimed to retrospectively identify risk factors for death unrelated to cancer and death from aspiration pneumonia after definitive radiotherapy (RT) for HSC.

MATERIALS AND METHODS

Overall, 391 patients who began definitive RT for HSC between 2006 and 2014 were identified from the Osaka International Cancer Institute electronic database. Among 391 patients, 33 had a history of surgery for esophageal cancer (EC) and 19 received simultaneous RT for synchronous EC. The cause of death was divided into 3 main categories: "cancer under study," "other malignancy," and "unrelated to cancer." Cox proportional hazard model was used to estimate the hazard ratio (HR).

RESULTS

The median follow-up for survivors was 8 (range 3.6-14.1) years. At the last follow-up, 202 patients died. Death from "cancer under study," "other malignancy," and "unrelated to cancer" occurred in 92 (45.5%), 55 (27.2%), and 55 (27.2%) patients, respectively. Twelve patients died from aspiration pneumonia. In multivariate analysis for death unrelated to cancer and death from aspiration pneumonia, history of surgery for EC (HR: 3.87, p < 0.001; HR: 6.84, p = 0.007, respectively) and simultaneous RT for synchronous EC (HR: 3.74, p = 0.006; HR: 16.37, p < 0.001, respectively) were significant risk factors.

CONCLUSION

The laryngeal preservation approach by RT for HSC patients with a history of surgery for EC and simultaneous RT for synchronous EC should be used with caution.

Late-course accelerated Hyperfractionation vs. Conventional Fraction Radiotherapy under precise technology plus Concurrent Chemotherapy for Esophageal Squamous Cell Carcinoma: comparison of efficacy and side effects

Background: The accelerated reproliferation of esophageal squamous cell carcinoma (ESCC) after radiation contributes to conventional fraction radiotherapy (CFRT) failure. Late course accelerated hyperfractionated radiotherapy (LCAHFRT) can improve the long-term survival of esophageal cancer patients in China but is associated with a high rate of side effects due to the large exposure field of two-dimensional treatment and drug toxicity. Intensity-modulated radiotherapy (IMRT) can increase the tumor dose while decreasing the normal tissue dose. Therefore, we compared the outcomes and side effects of LCAHFIMRT plus concurrent chemotherapy (CT) and CFIMRT plus CT for ESCC.

Methods and Materials: Between 2013 and 2016, 114 eligible patients with ESCC were recruited and randomly assigned to receive LCAHFIMRT+CT (58 patients) or CFIMRT+CT (56 patients) by a linear accelerator (6-MV X-ray) under image guidance. Two cycles of CT with cisplatin and docetaxel were also administered.

Results: The complete response (CR) rates were 79.3% and 61.8% in the LCAHFIMRT+CT and CFIMRT+CT groups, respectively (P=0.041). The median duration of local control times was 31.0±1.9 months for the LCAHFIMRT+CT group and 24.0±3.3 months for the CFIMRT+CT groups,and the 1-, 2-, and 3-year local control rates were 86.2%, 63.8%, and 41.4% and 85.7%, 51.8%, and 32.1% for the LCAHFIMRT+CT and CFIMRT+CT groups (P=0.240), respectively. The median survival times were 34.0±1.1 months for the LCAHFIMRT+CT group and 28.0.0±3.7 months for the CFIMRT groups,and the 1-, 2-, and 3-year survival rates were 87.9%, 74.1%, and 44.8% and 87.5%, 60.7%, and 39.3% for the LCAHFIMRT+CT and CFIMRT+CT groups, respectively (P=0.405). The incidence of side effects was not significantly different between the two groups. Local recurrence and uncontrolled disease resulted in more deaths in the CFIMRT+CT group than in the LCAHFIMRT+CT group (58.9% vs. 39.7%) (P=0.040).

Conclusion: For ESCC patients, LCAHFRT delivered by image-guided intensity-modulated techniques Plus Concurrent Chemotherapy with cisplatin and docetaxel keeps safety and high CR rate, as well as local control and long-term survival rates.

Combination of checkpoint inhibitors with radiotherapy in esophageal squamous cell carcinoma treatment: A novel strategy

Despite the rapid development of numerous types of treatment, including radiotherapy (RT) as the main strategy, esophageal squamous cell carcinoma (ESCC) has a poor prognosis. Recent studies demonstrated that immunotherapy can improve the survival of patients with locally advanced and metastatic ESCC. Furthermore, previous studies reported that the expression of programmed death-ligand 1 is significantly associated with esophageal cancer prognosis. At present, several ongoing clinical trials have extended the use of immunotherapy from palliative and salvage treatments to neoadjuvant treatment with concurrent chemoradiation. The first- or second-line treatments were used to explore antitumor efficacy with reduced adverse events. The combination of RT and immunotherapy can exert a local therapeutic effect and improve the function of the immune system, enhancing antitumor efficacy. This review investigated the role of immunotherapy and radiotherapy in ESCC and described the potential efficacy of combining immunotherapy with radiotherapy in ESCC.

[Normal tissue: radiosensitivity, toxicity, consequences for planning]

Along with chemotherapy, surgery and immunotherapy, radiotherapy is a mainstay of cancer treatment. Considering the improving survival rates for various malignancies during the past decades, the importance of radiation-induced late normal tissue response is increasing. Quality of life is becoming an important issue in modern cancer treatment and is correlated with acute and late normal tissue response after radiotherapy. A profound understanding of radiation-induced normal tissue response is necessary to sufficiently diagnose and treat radiation-induced side effects and thereby increase the patients' quality of life. Here, the various normal tissue responses in consideration of the radiation biology are specified and prospective options to attenuate radiation-induced side effects are discussed.

Differential response of esophageal cancer cells to particle irradiation

Background

Radiation therapy is a mainstay in the treatment of esophageal cancer (EC) patients, and photon radiotherapy has proved beneficial both in the neoadjuvant and the definitive setting. However, regarding the still poor prognosis of many EC patients, particle radiation employing a higher biological effectiveness may help to further improve patient outcomes. However, the influence of clinically available particle radiation on EC cells remains largely unknown.

Methods

Patient-derived esophageal adenocarcinoma and squamous cell cancer lines were treated with photon and particle irradiation using clinically available proton (¹H), carbon (¹²C) or oxygen (¹⁶O) beams at the Heidelberg Ion Therapy Center. Histology-dependent clonogenic survival was calculated for increasing physical radiation doses, and resulting relative biological effectiveness (RBE) was calculated for each radiation modality. Cell cycle effects caused by photon and particle radiation were assessed, and radiation-induced apoptosis was measured in adenocarcinoma and squamous cell EC samples by activated caspase-3 and sub-G1 populations. Repair kinetics of DNA double strand breaks induced by photon and particle radiation were investigated.

Results

While both adenocarcinoma EC cell lines demonstrated increasing sensitivities for ¹H, ¹²C and ¹⁶O radiation, the two squamous cell carcinoma lines exhibited a more heterogeneous response to photon and particle treatment; average RBE values were calculated as 1.15 for ¹H, 2.3 for ¹²C and 2.5 for ¹⁶O irradiation. After particle irradiation, squamous cell EC samples reacted with an increased and prolonged block in G2 phase of the cell cycle compared to adenocarcinoma cells. Particle radiation resulted in an incomplete repair of radiation-induced DNA double strand breaks in both adenocarcinoma and squamous cell carcinoma samples, with the levels of initial strand break induction correlating well with the individual cellular survival after photon and particle radiation. Similarly, EC samples demonstrated heterogeneous levels of radiation-induced apoptosis that also corresponded to the observed cellular survival of individual cell lines.

Conclusions

Esophageal cancer cells exhibit differential responses to irradiation with photons and ¹H, ¹²C and ¹⁶O particles that were independent of tumor histology. Therefore, yet unknown molecular markers beyond histology may help to establish which esophageal cancer patients benefit from the biological effects of particle treatment.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1326-9) contains supplementary material, which is available to authorized users.

Subclinical Lesions of the Primary Clinical Target Volume Margin in Esophageal Squamous Cell Carcinoma and Association With FDG PET/CT

Background and Objectives: An accurate delineation of the primary clinical target volume (CTVp) in esophageal squamous cell carcinoma (ESCC) significantly affects the outcomes of radiotherapy. However, when basing the CTVp on the primary gross tumor volume, there are no consistent guidelines for the size of the margin. We compared preoperative ¹⁸F-fluorodeoxyglucose (FDG) PET/CT images and large slices of resected pathological ESCC specimens for evidence and prediction of subclinical lesions. We also investigated associations between the maximum standardized uptake value (SUVmax), metabolic tumor volumes (MTVs), and lesions to improve estimates of the CTVp.

Methods:55 patients underwent FDG PET/CT before surgery, and the SUVmax and MTVs were determined. To ensure that the in situ distances between the primary and secondary tumors were preserved, the esophageal specimens collected during radical surgery were processed to minimize shrinkage, and subclinical lesions were characterized by pathological examination. A 2-dimensional logistic regression model was used to assess the associations between clinicopathological features and microscopic spread of the lesions.

Results: Subclinical lesions in pathological specimens were characterized as direct invasion, multicentric occurrence lesions, intra-mural metastasis, vascular invasion, and perineural invasion in 56.4, 40.0, 30.9, 21.8, and 18.2% of patients, respectively. The mean distances of the subclinical lesions from the primary tumor were 0.79 ± 1.28 cm and 0.87 ± 1.00 cm in the cranial and caudal directions, respectively. Together the SUVmax and MTV values could predict the presence of subclinical lesions that were not detectable in PET/CT images.

Conclusions: To cover 94.5% of ESCC subclinical lesions in the CTVp, a 3-cm margin along the cranial-caudal axis should be added to the primary gross tumor volume as defined by FDG-PET/CT, as well as a cutoff SUVmax value of 2.5. Although preoperative FDG PET/CT images may not reveal lesions directly, the SUVmax and MTV measurements together could predict their presence.

miRNA‑30a‑3p inhibits metastasis and enhances radiosensitivity in esophageal carcinoma by targeting insulin‑like growth factor 1 receptor

It has been demonstrated that microRNAs (miRNAs) serve important roles in various biological processes, such as tumorigenesis. In the present study, the role of miR‑30a‑3p in the pathogenesis of esophageal carcinoma (EC) was investigated. Reverse transcription‑quantitative polymerase chain reaction was performed to determine the levels of miR‑30a‑3p expression in EC tissues and cell lines. Then, the effects of miR‑30a‑3p on the migration, invasion and radiosensitivity of EC cells were investigated using scratch‑wound, Transwell and radiosensitivity assays, respectively. A dual‑luciferase reporter assay was performed to determine potential interactions between miR‑30a‑3p and the 3'‑untranslated region (3'‑UTR) of insulin‑like growth factor 1 receptor (IGF‑1R). The results demonstrated that the levels of miR‑30a‑3p expression in EC tissues and cell lines were significantly decreased compared with those in paired healthy tissues and a human esophageal epithelial cell line. Upregulation of miR‑30a‑3p expression significantly suppressed migration, invasion and epithelial‑mesenchymal transition (EMT), and enhanced radiosensitivity in EC cells. Analysis of luciferase activity demonstrated that miR‑30a‑3p interacted with the 3'‑UTR of IGF‑1R, and knockdown of IGF‑1R induced similar effects on the migration, invasion, EMT and radiosensitivity of EC cells. The results indicated that miR‑30a‑3p suppressed metastasis and enhanced the radiosensitivity of EC cells via downregulation IGF‑1R, suggesting that miR‑30a‑3p may be a potential therapeutic target in the treatment of EC.

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.

Volumetric modulated arc therapy (VMAT) in the treatment of esophageal cancer patients

The aim of the study is to evaluate feasibility, safety, toxicity profile, and dosimetric results of volumetric modulated arc therapy (VMAT) to deliver definitive or pre-operative radiation in locally advanced esophageal cancer patients. A total of 68 patients were treated with VMAT between March 2014 and March 2018 (44% vs 56% for definitive and neoadjuvant settings, respectively). Dose prescription differed depending on the clinical scenario (54-60 Gy in 30 fractions for definitive treatments; 41.4/45 Gy in 23-25 fractions in the pre-operative setting). Most of the patients were given concurrent chemotherapy. Two coplanar and one non-coplanar arcs were employed for VMAT delivery. Treatment was generally well tolerated. Acute toxicity was generally mild. In patients treated with definitive intent, ≥ G3 toxicities were observed for esophagitis (30%), anorexia (26.7%), fatigue (26.7%), nausea (6.7%), and vomiting (3.3%). In patients treated within a neoadjuvant approach, ≥ G3 anorexia (21%), esophagitis (15.8%), fatigue (13.3%), nausea (5.3%), and vomiting (2.6%) were observed. Dosimetric results were consistent in term of both target coverage and normal tissue sparing. In conclusion, VMAT proved to be a feasible, safe, and effective strategy to deliver definitive or pre-operative radiation in locally advanced esophageal cancer patients.

Feasibility of using optical coherence tomography to detect radiation-induced fibrosis and residual cancer extent after neoadjuvant chemo-radiation therapy: an ex vivo study

Treatment of resectable esophageal cancer includes neoadjuvant chemo-radiation therapy (nCRT) followed by esophagectomy in operable patients. High-risk surgery may have been avoided in patients with a pathological complete response (pCR). We investigated the feasibility of optical coherence tomography (OCT) to detect residual cancer and radiation-induced fibrosis in 10 esophageal cancer patients that underwent nCRT followed by esophagectomy. We compared our OCT findings with histopathology. Overall, OCT was able to differentiate between healthy tissue, fibrotic tissue, and residual cancer with a sensitivity and specificity of 79% and 67%, respectively. Hence, OCT has the potential to add to the assessment of a pCR.

Surgery combined with radio-chemotherapy for esophageal mucoepidermoid carcinoma: A case report

RATIONALE

Primary mucoepidermoid carcinoma (MEC) of the esophagus is a rare type of malignant neoplasm. Its morphology resembles that of MEC of the salivary glands. It is characterized by a diffuse mixture of squamous and mucus-secreting glandular carcinoma cells. Due to the low incidence of esophageal MEC, the biological behavior and treatment of this tumor have not been well studied.

PATIENT CONCERNS

In this case report, we describe a case of a 59-year-old man who presented with difficulty in swallowing. Iohexol swallowing revealed a malignant-appearing structure in the inferior-thoracic region.

DIAGNOSES

Biopsy of the lesion under endoscopy demonstrated a mucoepidermoid carcinoma of the esophagus.

INTERVENTIONS

We performed esophagectomy, esophagogastrostomy through the esophageal bed and 2-field lymphadenectomy. Histopathological analysis of the tumor revealed histological characteristics typical of an esophageal MEC. Radio-chemotherapy was administered to this patient.

OUTCOMES

Seventeen months after surgery, an esophageal computed tomography (CT) scan revealed that the wall of esophagus was evenly thickened. However, endoscopic assessment revealed no evidence of recurrence. Further CT scans at 19 and 31 months after surgery also showed a thickened esophageal wall, although endoscopic assessment at 31 months still revealed no esophageal stricture and no evidence of recurrence. The patient is alive with no dysphagia and no evidence of recurrence for over 39 months.

LESSONS

There is little evidence of effective treatment nor guidelines for treatment of esophageal MEC. Although the general prognosis of esophageal MEC is poor, comprehensive treatment of surgery and radio-chemotherapy appeared to be effective in this case. Radio-chemotherapy is a possible treatment option that was shown to have acceptable short-term effects.

Comparison of intensity-modulated radiotherapy vs 3-dimensional conformal radiotherapy for patients with non-metastatic esophageal squamous cell carcinoma receiving definitive concurrent chemoradiotherapy: A population-based propensity-score-matched analysis

Whether the survival outcome of patients with non-metastatic esophageal squamous cell carcinoma (NM-ESCC) receiving definitive concurrent chemoradiotherapy (CCRT) is better with intensity-modulated radiotherapy (IMRT) or with 3-dimensional conformal radiotherapy (3DCRT) has been debated in the literature. We designed this population-based propensity-score (PS)-matched analysis to address this question. We identified eligible patients diagnosed between 2008 and 2015 from the Taiwan Cancer Registry and constructed a PS-matched cohort (1:1 for IMRT vs 3DCRT) to balance observable potential confounders. We compared the hazard ratio (HR) of death between IMRT and 3DCRT during the entire follow-up period. We also evaluated freedom from local regional recurrence (FFLRR) and esophageal cancer-specific survival (ECSS). Sensitivity analyses (SA) were performed to examine the robustness of our findings. Our study population constituted 558 patients who were well balanced with regard to the measured covariables. The HR of death with IMRT compared to 3DCRT was 0.43 (95% confidence interval 0.35-0.52, P < .001). The results remained significant for FFLRR and ECSS. In SA, our results remained significant when additional covariables were taken into consideration. The survival outcome of patients with NM-ESCC receiving CCRT might be better with IMRT vs 3DCRT. These study results should be interpreted with caution given some possible covariates lacking in the registry. Further studies are needed to clarify this issue.

Clinical outcome of elderly patients (≥ 70 years) with esophageal cancer undergoing definitive or neoadjuvant radio(chemo)therapy: a retrospective single center analysis

BACKGROUND

To analyse the outcome of elderly patients (≥70 years) with esophageal cancer treated with curative intent radio(chemo)therapy.

METHODS

Fifty five patients (median 75 years) receiving curative intent radio(chemo)therapy for esophageal cancer from 1999 to 2015 were retrospectively analyzed. Most patients showed locally advanced disease (T3/4:78%, N+:58%) with squamous cell histology (74%). Charlson comorbidity score was > 1 in 27%. 48 patients (87%) received definitive treatment while 7 patients were treated neoadjuvantly. RT was carried out as 3D-conformal treatment or IMRT. Concurrent chemotherapy was applied in 85%, mainly cisplatin/5-FU or mitomycin/5-FU. ¹⁸FDG-PET/CT staging was used in 65%.

RESULTS

Median follow-up was 11 months (1-68) and 21 months in survivors. 1- and 2-year rates of LRC, DC, FFTF and OS were 60%/45, 81%/72, 55%/41 and 46%/26% for the entire cohort. In univariate analysis, addition of surgery was associated with improved LRC and FFTF, nodal involvement with improved DC and lower T stage, lower Charlson score and use of PET-CT with improved OS. In multivariate analysis, lower T stage and lower Charlson score remained significant for OS. Patients treated after 2008 showed a significantly improved FFTF (1-year FFTF 64% vs 35%) and OS (1-year OS 66% vs 24%). Maximum (chemo)radiation related grade3+ toxicity was observed in 80% including 7 deaths (13%). Grade5 toxicity was significantly associated with Charlson score (CS > 1:33% vs CS ≤ 1:5%) and treatment period (24% before vs 3% after 2008). The patients treated after 2008 included significantly more SCCs, less T4 stages, had a higher percentage of PET-CT staging and were treated with smaller field lengths. Trends were also observed for lower Charlson scores and increased use of IMRT.

CONCLUSION

Curative intent (chemo)radiation of elderly patients with esophageal cancer may result in considerable toxicity and unfavorable outcome. However, a clear improvement over time was observed in our cohort, probably based on improved patient selection. In patients with less advanced stages and lower comorbidity similar results as in younger cohorts seem achievable with modern staging and treatment approaches. Age per se should not be a decisive factor, but careful attention should be paid regarding patient selection including a structured and tight follow-up strategy.

Efficacy of virtual block objects in reducing the lung dose in helical tomotherapy planning for cervical oesophageal cancer: a planning study

Background

Intensity-modulated radiotherapy is useful for cervical oesophageal carcinoma (CEC); however, increasing low-dose exposure to the lung may lead to radiation pneumonitis. Nevertheless, an irradiation technique that avoids the lungs has never been examined due to the high difficulty of dose optimization. In this study, we examined the efficacy of helical tomotherapy that can restrict beamlets passing virtual blocks during dose optimization computing (block plan) in reducing the lung dose.

Methods

Fifteen patients with CEC were analysed. The primary/nodal lesion and prophylactic nodal region with adequate margins were defined as the planning target volume (PTV)-60 Gy and PTV-48 Gy, respectively. Nineteen plans per patient were made and compared (total: 285 plans), including non-block and block plans with several shapes and sizes.

Results

The most appropriate block model was semi-circular, 8 cm outside of the tracheal bifurcation, with a significantly lower lung dose compared to that of non-block plans; the mean lung volumes receiving 5 Gy, 10 Gy, 20 Gy, and the mean lung dose were 31.3% vs. 48.0% (p <  0.001), 22.4% vs. 39.4% (p <  0.001), 13.2% vs. 16.0% (p = 0.028), and 7.1 Gy vs. 9.6 Gy (p <  0.001), respectively. Both the block and non-block plans were comparable in terms of the homogeneity and conformity indexes of PTV-60 Gy: 0.05 vs. 0.04 (p = 0.100) and 0.82 vs. 0.85 (p = 0.616), respectively. The maximum dose of the spinal cord planning risk volume increased slightly (49.4 Gy vs. 47.9 Gy, p = 0.002). There was no significant difference in the mean doses to the heart and the thyroid gland. Prolongation of the delivery time was less than 1 min (5.6 min vs. 4.9 min, p = 0.010).

Conclusions

The block plan for CEC could significantly reduce the lung dose, with acceptable increment in the spinal dose and a slightly prolonged delivery time.

Definite intensity-modulated radiotherapy with concurrent chemotherapy more than 4 cycles improved survival for patients with locally-advanced or inoperable esophageal squamous cell carcinoma

We investigated which prognostic factor could improve survival for esophageal cancer patients who received definite concurrent chemoradiation (CCRT). Eighty patients with age ≥18, Karnofsky Performance Scale (KPS) ≥ 60, and clinical stage T1-4N0-3M0 esophageal squamous cell carcinoma were enrolled from July 2004 to December 2015. They underwent definite intensity-modulated radiotherapy (IMRT) with or without simultaneous integrated boost to the primary tumor, and reception of concurrent chemotherapy ≥ 1 cycle. The primary endpoints were overall survival (OS), locoregional progression-free survival (LRPFS) and distant metastasis-free survival (DMFS). The median follow-up duration for alive patients was 21.5 months. The rates of 2-, 3- and 5-year OS/LRPFS/DMFS were 23.8%/53.5%/49.3%, 19.1%/44.6%/49.3%, and 13.0%/44.6%/43.9%, respectively. Only the non-clinical complete response (non-cCR) after CCRT was an independent poor prognostic factor in OS (HR 3.101, 95% CI 1.535-6.265, p = 0.0016). Radiation dose >50.4 Gy and chemotherapy ≥4 cycles significantly predicted better LRPFS (p = 0.0361 and 0.0163, respectively). Poorly differentiated tumor and stage III disease have poor DMFS (p = 0.0336 and 0.0411, respectively), and chemotherapy ≥ 4 cycles was a better predictor (p = 0.0004). In subgroup analysis, patients who received radiation dose ≤50.4 Gy with concurrent chemotherapy ≥4 cycles had the best survival outcome with 1-, 2-, 3- and 5-year survival rates of 73.7%, 39.4%, 31.5% and 17.5%, respectively. In conclusion, definite radiotherapy with concurrent chemotherapy ≥4 cycles improved the survival for patients with inoperable or locally-advanced esophageal squamous cell carcinoma.

Dosimetric comparison between modulated arc therapy and static intensity modulated radiotherapy in thoracic esophageal cancer: a single institutional experience

Purpose

The objective of this study was to compare dosimetric characteristics of three-dimensional conformal radiotherapy (3D-CRT) and two types of intensity-modulated radiotherapy (IMRT) which are step-and-shoot intensity modulated radiotherapy (s-IMRT) and modulated arc therapy (mARC) for thoracic esophageal cancer and analyze whether IMRT could reduce organ-at-risk (OAR) dose.

Materials and Methods

We performed 3D-CRT, s-IMRT, and mARC planning for ten patients with thoracic esophageal cancer. The dose-volume histogram for each plan was extracted and the mean dose and clinically significant parameters were analyzed.

Results

Analysis of target coverage showed that the conformity index (CI) and conformation number (CN) in mARC were superior to the other two plans (CI, p = 0.050; CN, p = 0.042). For the comparison of OAR, lung V₅ was lowest in s-IMRT, followed by 3D-CRT, and mARC (p = 0.033). s-IMRT and mARC had lower values than 3D-CRT for heart V₃₀ (p = 0.039), V₄₀ (p = 0.040), and V₅₀ (p = 0.032).

Conclusion

Effective conservation of the lung and heart in thoracic esophageal cancer could be expected when using s-IMRT. The mARC was lower in lung V₁₀, V₂₀, and V₃₀ than in 3D-CRT, but could not be proven superior in lung V₅. In conclusion, low-dose exposure to the lung and heart were expected to be lower in s-IMRT, reducing complications such as radiation pneumonitis or heart-related toxicities.

Dosimetric and clinical outcomes after volumetric modulated arc therapy for carcinoma of the thoracic esophagus

Purpose

The efficiency of radiation delivery via volumetric modulated arc therapy (VMAT) is indisputable, but outcomes after VMAT for thoracic esophageal carcinoma are largely unknown.

Methods and materials

We retrospectively analyzed 65 patients with thoracic esophageal cancer who received VMAT to 50.4 Gy (range, 45-50.4 Gy) with concurrent chemotherapy from November 2012 to March 2016 at a single tertiary cancer center. We then used propensity score matching to match these 65 patients with 130 other patients treated with step-and-shoot intensity modulated radiation therapy (ssIMRT) and concurrent chemotherapy. Differences in continuous and categorical variables were examined with independent-sample t or Wilcoxon tests and χ² tests.

Results

Dosimetrically, VMAT had a higher conformity index (87.75 ± 10.70 VMAT vs 83.20 ± 9.42 ssIMRT, P = .003), a higher heart V5, and a lower V50 than ssIMRT, but lung V5-20, heart V30, heart V40, cord_max, and homogeneity index were similar. At median follow-up intervals of 14.3 months (range, 3.8-34.5 months) for VMAT and 31.8 months (range, 1.8-117.2 months) for ssIMRT, overall survival rates were similar between the treatments (93.5% VMAT vs 91.5% ssIMRT at 1 year; 60.0% VMAT and 61.4% ssIMRT at 2 years; P = .868). Recurrence-free survival rates were similar (73.3% VMAT vs 79.5% ssIMRT at 1 year, 59.9% VMAT and 61.8% ssIMRT at 2 years; P = .614), as were pathologic complete response rates (31.2% VMAT vs 23.3% ssIMRT; P = .41) and toxicity and postoperative complications (radiation pneumonitis 9% VMAT vs 15.4% ssIMRT; pericardial effusion 2% VMAT vs 7% ssIMRT; esophageal fistula and stricture 9% VMAT vs 13% ssIMRT; all P > .05).

Conclusion

Compared with ssIMRT, VMAT had better target conformity with similar organ sparing and comparable rates of survival, recurrence, and toxicity. These results suggest that VMAT can be safe and effective for esophageal cancer.

Intensity-modulated versus 3-dimensional conformal radiotherapy in the definitive treatment of esophageal cancer: comparison of outcomes and acute toxicity

Background

Though the vast majority of seminal trials for locally advanced esophageal cancer (EC) utilized three-dimensional conformal radiotherapy (3DCRT), the advanced and highly conformal technology known as intensity-modulated radiotherapy (IMRT) can decrease doses to critical cardiopulmonary organs. To date, there have been no studies comparing both modalities as part of definitive chemoradiation (dCRT) for EC. Herein, we investigated local control and survival and evaluated clinical factors associated with these endpoints between cohorts.

Methods

We retrospectively analyzed 93 patients (3DCRT n = 49, IMRT n = 44) who received dCRT at our institution between 2000 and 2012 with the histologic diagnosis of nonmetastatic EC, a Karnofsky performance status of ≥70, curative treatment intent, and receipt of concomitant CRT. Patients were excluded if receiving <50 Gy. Kaplan-Meier analysis was used to evaluate the endpoints of local relapse rate (LR), progression-free survival (PFS), and overall survival (OS). Cox proportional hazards modeling addressed factors associated with outcomes with univariate and multivariate approaches. Rates of acute toxicities and basic dosimetric parameters were compared between 3DCRT and IMRT patients.

Results

Mean follow-up was 34.7 months. The 3-year LR was 28.6% in the 3DCRT group and 22.7% in the IMRT group (p = 0.620). Median PFS were 13.8 and 16.6 months, respectively (p = 0.448). Median OS were 18.4 and 42.0 months, respectively (p = 0.198). On univariate analysis, only cumulative radiation dose was associated with superior LR (hazard ratio (HR) 0.736; 95% confidence interval (CI) 0.635 – 0.916, p = 0.004). Factors clearly affecting survival were not observed.

Conclusions

When comparing 3DCRT- versus IMRT-based dCRT, no survival benefits were observed. However, we found a lower local recurrence rate in the IMRT group potentially owing to dose-escalation. Prospective data are needed to verify the presented results herein.

Recent advances in intensity modulated radiotherapy and proton therapy for esophageal cancer

INTRODUCTION

Radiotherapy is an important component of the standard of care for esophageal cancer. In the past decades, significant improvements in the planning and delivery of radiation techniques have led to better dose conformity to the target volume and improved normal tissue sparing. Areas covered: This review focuses on the advances in radiotherapy techniques and summarizes the availably dosimetric and clinical outcomes of intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy, proton therapy, and four-dimensional radiotherapy for esophageal cancer, and discusses the challenges and future development of proton therapy. Expert commentary: Although three-dimensional conformal radiotherapy is the standard radiotherapy technique in esophageal cancer, the retrospectively comparative studies strongly suggest that the dosimetric advantage of IMRT over three-dimensional conformal radiotherapy can translate into improved clinical outcomes, despite the lack of prospective randomized evidence. As a novel form of conventional IMRT technique, volumetric modulated arc therapy can produce equivalent or superior dosimetric quality with significantly higher treatment efficiency in esophageal cancer. Compared with photon therapy, proton therapy has the potential to achieve further clinical improvement due to their physical properties; however, prospective clinical data, long-term results, and cost-effectiveness are needed.

High dose radiation with chemotherapy followed by salvage esophagectomy among patients with locally advanced esophageal squamous cell carcinoma

Background

Locoregional failure is a major problem associated with chemoradiation treatment for squamous cell esophageal carcinoma. The aim of this study was to assess the feasibility, efficacy, and toxicity of preoperative radiation (dose > 50 Gy) with platinum‐based chemotherapy followed by esophagectomy in locally advanced squamous cell carcinoma.

Methods

Data of patients with cT2‐cT4 or node positive squamous cell carcinoma of the esophagus who received trimodality treatment between February 2006 and June 2015 were reviewed.

Results

Forty‐four patients were treated with intensity‐modulated radiation therapy, volumetric‐modulated arc therapy or three‐dimensional radiation therapy. The median radiation dose was 60 Gy. The average volume of the lungs receiving 10 Gy was 48.1%, 20 Gy was 24.5%, and the average mean lung dose was 14 Gy. After chemoradiation, R0 resection was achieved in 31 patients (71%). Patients who received >60 Gy had a higher pathologic complete remission rate than those in the lower dose group (59.1% vs. 36.4%). R0 resection and radiation dose >60 Gy were associated with better overall survival in Cox proportional hazards regression analysis. The median follow‐up duration was 22.4 months and median survival was 25.6 months. Two‐year overall, progression‐free survival and locoregional control rates were 55.9%, 28.6%, and 56%, respectively. The most common grade 3–4 toxicities were esophagitis (63.6%) and neutropenia (25%). Grade 3–4 postoperative morbidities included surgical wound infection (2.3%), acute renal failure (2.3%), and anastomosis stricture (2.3%).

Conclusion

Trimodality treatment with a high preoperative radiation dose and chemotherapy yielded a good pathologic complete response rate, and long‐term survival with low toxicities.

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.

Intrafractional dose variation and beam configuration in carbon ion radiotherapy for esophageal cancer

Background

In carbon ion radiotherapy (CIR) for esophageal cancer, organ and target motion is a major challenge for treatment planning due to potential range deviations. This study intends to analyze the impact of intrafractional variations on dosimetric parameters and to identify favourable settings for robust treatment plans.

Methods

We contoured esophageal boost volumes in different organ localizations for four patients and calculated CIR-plans with 13 different beam geometries on a free-breathing CT. Forward calculation of these plans was performed on 4D-CT datasets representing seven different phases of the breathing cycle. Plan quality was assessed for each patient and beam configuration.

Results

Target volume coverage was adequate for all settings in the baseline CIR-plans (V₉₅ > 98% for two-beam geometries, > 94% for one-beam geometries), but reduced on 4D-CT plans (V₉₅ range 50–95%). Sparing of the organs at risk (OAR) was adequate, but range deviations during the breathing cycle partly caused critical, maximum doses to spinal cord up to 3.5x higher than expected. There was at least one beam configuration for each patient with appropriate plan quality.

Conclusions

Despite intrafractional motion, CIR for esophageal cancer is possible with robust treatment plans when an individually optimized beam setup is selected depending on tumor size and localization.

Dosimetric predictors of acute haematological toxicity in oesophageal cancer patients treated with neoadjuvant chemoradiotherapy

OBJECTIVE

Haematological toxicity (HT) is common in patients with oesophageal cancer (EC) treated with chemoradiotherapy (CRT). The Quantitative Analysis of Normal Tissue Effects in the Clinic guidelines provide no dose constraints for the bone marrow (BM) to avoid HT. We aimed to determine dosimetric factors associated with HT during CRT for EC.

METHODS

41 patients with EC treated with neoadjuvant cisplatin and 5-fluorouracil-based CRT were retrospectively reviewed. Associations between the dose-volume histogram parameters of thoracic bones and blood cell count changes during CRT were assessed using logistic regression analyses. Receiver-operating characteristic curves were used to derive optimal dosimetric planning constraints. Vx indicates the total organ volume percentage exceeding a radiation dose of x (Gy).

RESULTS

Greater thoracic vertebrae and rib irradiation doses, including mean vertebral dose (MVD), thoracic vertebrae V5-30 (TVV5-30), mean rib dose and rib V5-20, were associated with increased leukopenia (grade ≥ 3) risk. Additional BM sites (sternum, scapulae and clavicles) did not influence HT. White blood cell and absolute neutrophil count nadirs were associated with increased irradiation doses to the thoracic vertebrae, ribs and sternum. Chemotherapy cycle number was not significantly associated with severe neutropenia or leukopenia. Cut-off values with the highest likelihood of avoiding leukopenia were MVD < 25.9 Gy, TVV20 < 70% and TVV10 < 77%.

CONCLUSION

Thoracic bone irradiation dose was significantly associated with HT after adjusting for chemotherapy effects. Efforts to maintain MVD < 25.9 Gy, TVV10 < 77% and TVV20 < 70% could reduce HT.

ADVANCES IN KNOWLEDGE

This is the first study addressing issues concerning HT in patients with neoadjuvant CRT-treated EC.

Radiation Dose Escalation in Esophageal Cancer Revisited: A Contemporary Analysis of the National Cancer Data Base, 2004 to 2012

PURPOSE

To evaluate the effect of radiation dose escalation on overall survival (OS) for patients with nonmetastatic esophageal cancer treated with concurrent radiation and chemotherapy.

METHODS AND MATERIALS

Patients diagnosed with stage I to III esophageal cancer treated from 2004 to 2012 were identified from the National Cancer Data Base. Patients who received concurrent radiation and chemotherapy with radiation doses of ≥50 Gy and did not undergo surgery were included. OS was compared using Cox proportional hazards regression and propensity score matching.

RESULTS

A total of 6854 patients were included; 3821 (55.7%) received 50 to 50.4 Gy and 3033 (44.3%) received doses >50.4 Gy. Univariate analysis revealed no significant difference in OS between patients receiving 50 to 50.4 Gy and those receiving >50.4 Gy (P=.53). The dose analysis, binned as 50 to 50.4, 51 to 54, 55 to 60, and >60 Gy, revealed no appreciable difference in OS within any group compared with 50 to 50.4 Gy. Subgroup analyses investigating the effect of dose escalation by histologic type and in the setting of intensity modulated radiation therapy also failed to reveal a benefit. Propensity score matching confirmed the absence of a statistically significant difference in OS among the dose levels. The factors associated with improved OS on multivariable analysis included female sex, lower Charlson-Deyo comorbidity score, private insurance, cervical/upper esophagus location, squamous cell histologic type, lower T stage, and node-negative status (P<.01 for all analyses).

CONCLUSIONS

In this large national cohort, dose escalation >50.4 Gy did not result in improved OS among patients with stage I to III esophageal cancer treated with definitive concurrent radiation and chemotherapy. These data suggest that despite advanced contemporary treatment techniques, OS for patients with esophageal cancer remains unaltered by escalation of radiation dose >50.4 Gy, consistent with the results of the INT-0123 trial. Furthermore, these data highlight that many radiation oncologists have not embraced the concept that dose escalation does not improve OS. Although local control, not investigated in the present study, might benefit from dose escalation, novel therapies are needed to improve the OS of patients with esophageal cancer.

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.

Bortezomib sensitizes esophageal squamous cancer cells to radiotherapy by suppressing the expression of HIF-1α and apoptosis proteins

Radiation therapy is a typical treatment for esophageal squamous cell carcinoma (ESCC), especially middle and upper segment esophagus, and inoperable patients. However, how to promote radiation sensitivity in radio-resistant cancer cells is a conundrum. Here, our study investigated the radiosensitizing effect of bortezomib, a specific and reversible dipeptide boronic acid analog, in ESCC cells. Human esophageal squamous carcinoma cell lines Eca109 and TE-13 were exposed to hypoxia and/or ionizing radiation (IR) with or without treatment of bortezomib. Cell proliferation assay was performed with CCK8. Cell apoptosis and cell cycle assay were performed with flow cytometry. The radiosensitization effect of was assessed by clonogenic survival and progression of tumor xenograft. The expression of HIF-1α, VEGF, and apoptosis proteins was evaluated by Western blot. Radiation-induced DNA double strand break and homologous recombination repair were assessed by immunofluorescence. Our results show that bortezomib efficiently radiosensitizes ESCC cells by decreasing the expression of HIF- 1α and VEGF, inducing apoptosis by activating caspase, and delaying DNA damage repair after radiation.

Long term results of postoperative Intensity-Modulated Radiation Therapy (IMRT) in the treatment of Squamous Cell Carcinoma (SCC) located in the oropharynx or oral cavity

BACKGROUND

To report our long-term results with postoperative intensity-modulated radiation therapy (IMRT) in patients suffering from squamous-cell carcinoma (SCC) of the oral cavity or oropharynx.

METHODS

Seventy five patients were retrospectively analyzed. Median age was 58 years and 84 % were male. 76 % of the primaries were located in the oropharynx. Surgery resulted in negative margins (R0) in 64 % of the patients while 36 % suffered from positive margins (R1). Postoperative stages were as follows: stage 1:4 %, stage 2:9 %, stage 3:17 %, stage 4a:69 % with positive nodes in 84 %. Perineural invasion (Pn+) and extracapsular extension (ECE) were present in 7 % and 29 %, respectively. All patients received IMRT using the step-and-shoot approach with a simultaneously integrated boost (SIB) in 84 %. Concurrent systemic therapy was applied to 53 patients, mainly cisplatin weekly.

RESULTS

Median follow-up was 55 months (5-150). 13 patients showed locoregional failures (4 isolated local, 4 isolated neck, 5 combined) transferring into 5-year-LRC rates of 85 %. Number of positive lymph nodes (n > 2) and presence of ECE were significantly associated with decreased LRC in univariate analysis, but only the number of nodes remained significant in multivariate analysis. Overall treatment failures occurred in 20 patients (9 locoregional only, 7 distant only, 4 combined), transferring into 3-and 5-year-FFTF rates of 77 % and 75 %, respectively. The 3-and 5-year-OS rates were 80 % and 72 %, respectively. High clinical stage, high N stage, number of positive nodes (n > 2), ECE and Pn1 were significantly associated with worse FFTF and OS in univariate analysis, but only number of nodes remained significant for FFTF in multivariate analysis. Maximum acute toxicity was grade 3 in 64 % and grade 4 in 1 %, mainly hematological or mucositis/dysphagia. Maximum late toxicity was grade 3 in 23 % of the patients, mainly long-term tube feeding dependency.

CONCLUSION

Postoperative IMRT achieved excellent LRC and good OS with acceptable acute and low late toxicity rates. The number of positive nodes (n > 2) was a strong prognostic factor for all endpoints in univariate and the only significant factor for LRC and FFTF in multivariate analysis. Patients with feeding tubes due to postoperative complications had an increased risk for long-term feeding tube dependency.

The effect of dose escalation on gastric toxicity when treating lower oesophageal tumours: a radiobiological investigation

PURPOSE

Using radiobiological modelling to estimate normal tissue toxicity, this study investigates the effects of dose escalation for concurrent chemoradiation therapy (CRT) in lower third oesophageal tumours on the stomach.

METHODS AND MATERIALS

10 patients with lower third oesophageal cancer were selected from the SCOPE 1 database (ISCRT47718479) with a mean planning target volume (PTV) of 348 cm(3). The original 3D conformal plans (50 Gy3D) were compared to newly created RapidArc plans of 50 GyRA and 60 GyRA, the latter using a simultaneous integrated boost (SIB) technique using a boost volume, PTV2. Dose-volume metrics and estimates of normal tissue complication probability (NTCP) were compared.

RESULTS

There was a significant increase in NTCP of the stomach wall when moving from the 50 GyRA to the 60 GyRA plans (11-17 %, Wilcoxon signed rank test, p = 0.01). There was a strong correlation between the NTCP values of the stomach wall and the volume of the stomach wall/PTV 1 and stomach wall/PTV2 overlap structures (R = 0.80 and R = 0.82 respectively) for the 60 GyRA plans.

CONCLUSION

Radiobiological modelling suggests that increasing the prescribed dose to 60 Gy may be associated with a significantly increased risk of toxicity to the stomach. It is recommended that stomach toxicity be closely monitored when treating patients with lower third oesophageal tumours with 60 Gy.

Thoracic Vertebral Body Irradiation Contributes to Acute Hematologic Toxicity During Chemoradiation Therapy for Non-Small Cell Lung Cancer

PURPOSE

To determine the relationships between radiation doses to the thoracic bone marrow and declines in blood cell counts in non-small cell lung cancer (NSCLC) patients treated with chemoradiation therapy (CRT).

METHODS AND MATERIALS

We included 52 patients with NSCLC treated with definitive concurrent carboplatin-paclitaxel and RT. Dose-volume histogram (DVH) parameters for the thoracic vertebrae (TV), sternum, scapulae, clavicles, and ribs were assessed for associations with changes in blood counts during the course of CRT. Linear and logistic regression analyses were performed to identify associations between hematologic nadirs and DVH parameters. A DVH parameter of Vx was the percentage of the total organ volume exceeding x radiation dose.

RESULTS

Grade ≥ 3 hematologic toxicity including neutropenia developed in 21% (n=11), leukopenia in 42% (n=22), anemia in 6% (n=3), and throbocytopenia in 2% (n=1) of patients. Greater RT dose to the TV was associated with higher risk of grade ≥ 3 leukopenia across multiple DVH parameters, including TV V20 (TVV) (odds ratio [OR] 1.06; P=.025), TVV30 (OR 1.07; P=.013), and mean vertebral dose (MVD) (OR 1.13; P=.026). On multiple regression analysis, TVV30 (β = -0.004; P=.018) and TVV20 (β = -0.003; P=.048) were associated with white blood cell nadir. Additional bone marrow sites (scapulae, clavicles, and ribs) did not affect hematologic toxicity. A 20% chance of grade ≥ 3 leukopenia was associated with a MVD of 13.5 Gy and a TTV30 of 28%. Cutoff values to avoid grade ≥ 3 leukopenia were MVD ≤ 23.9 Gy, TVV20 ≤ 56.0%, and TVV30 ≤ 52.1%.

CONCLUSIONS

Hematologic toxicity is associated with greater RT doses to the TV during CRT for NSCLC. Sparing of the TV using advanced radiation techniques may improve tolerance of CRT and result in improved tolerance of concurrent chemotherapy.

High-dose versus conventional-dose irradiation in cisplatin-based definitive concurrent chemoradiotherapy for esophageal cancer: a systematic review and pooled analysis

We investigate whether high-dose (HD, ≥60 Gy) radiotherapy in definitive concurrent chemoradiotherapy (CCRT) based on cisplatin could yield benefits compared to conventional-dose (CD) CCRT. PubMed, Embase and Google Scholar were searched and data were pooled and analyzed for response rate, survival, failure patterns and toxicity. Results showed advantages in response rate, 5-year overall survival rate, local regional recurrence and distant failure rate compared to the CD arm with no difference in Grade ≥3 acute and late esophagitis, other toxicities were rare with moderate tolerance, subgroup analysis of squamous cell carcinoma also showed advantages for HD arm. We concluded that ≥60 Gy CCRT improved clinical outcomes compared to the CD arm, especially for esophageal squamous cell carcinoma. Our findings may provide a basis for future trials.

Radiation dose does not influence anastomotic complications in patients with esophageal cancer treated with neoadjuvant chemoradiation and transhiatal esophagectomy

Background

Neoadjuvant chemoradiation might increase anastomotic leakage and stenosis in patients with esophageal cancer treated with neoadjuvant chemoradiation and esophagectomy. The aim of this study was to determine the influence of radiation dose on the incidence of leakage and stenosis.

Methods

Fifty-three patients with esophageal cancer received neoadjuvant chemoradiation (23 × 1.8 Gy) (combined with Paclitaxel and Carboplatin) followed by a transhiatal esophagectomy between 2009 and 2011. On planning CT, the future anastomotic region was determined and the mean radiation dose, V20, V25, V30, V35 and V40 were calculated. Logistic regression analysis was conducted to examine determinants of anastomotic leakage and stenosis.

Results

Anastomotic leaks occurred in 13 of 53 patients (25.5%) and anastomotic stenosis occurred in 24 of 53 patients (45.3%). Median follow-up was 20 months. Logistic regression analysis showed that mean dose, V20-V40, age, co-morbidity, method of anastomosis, operating time and interval between last radiotherapy treatment and surgery were not predictors of anastomotic leakage and stenosis.

Conclusions

A radiation dose of 23 × 1.8 Gy on the future anastomotic region has no influence on the occurrence of anastomotic leakage and stenosis in patients with esophageal cancer treated with neoadjuvant chemoradiation followed by transhiatal esophagectomy.