Clinical and dosimetric factors of radiation-induced esophageal injury: Radiation-induced esophageal toxicity

Obtaining organ-specific radiobiological parameters from clinical data for radiation therapy planning of head and neck cancers

Objective.Different radiation therapy (RT) strategies, e.g. conventional fractionation RT (CFRT), hypofractionation RT (HFRT), stereotactic body RT (SBRT), adaptive RT, and re-irradiation are often used to treat head and neck (HN) cancers. Combining and/or comparing these strategies requires calculating biological effective dose (BED). The purpose of this study is to develop a practical process to estimate organ-specific radiobiologic model parameters that may be used for BED calculations in individualized RT planning for HN cancers.Approach.Clinical dose constraint data for CFRT, HFRT and SBRT for 5 organs at risk (OARs) namely spinal cord, brainstem, brachial plexus, optic pathway, and esophagus obtained from literature were analyzed. These clinical data correspond to a particular endpoint. The linear-quadratic (LQ) and linear-quadratic-linear (LQ-L) models were used to fit these clinical data and extract relevant model parameters (alpha/beta ratio, gamma/alpha,dTand BED) from the iso-effective curve. The dose constraints in terms of equivalent physical dose in 2 Gy-fraction (EQD2) were calculated using the obtained parameters.Main results.The LQ-L and LQ models fitted clinical data well from the CFRT to SBRT with the LQ-L representing a better fit for most of the OARs. The alpha/beta values for LQ-L (LQ) were found to be 2.72 (2.11) Gy, 0.55 (0.30) Gy, 2.82 (2.90) Gy, 6.57 (3.86) Gy, 5.38 (4.71) Gy, and the dose constraint EQD2 were 55.91 (54.90) Gy, 57.35 (56.79) Gy, 57.54 (56.35) Gy, 60.13 (59.72) Gy and 65.66 (64.50) Gy for spinal cord, optic pathway, brainstem, brachial plexus, and esophagus, respectively. Additional two LQ-L parametersdTwere 5.24 Gy, 5.09 Gy, 7.00 Gy, 5.23 Gy, and 6.16 Gy, and gamma/alpha were 7.91, 34.02, 8.67, 5.62 and 4.95.Significance.A practical process was developed to extract organ-specific radiobiological model parameters from clinical data. The obtained parameters can be used for biologically based radiation planning such as calculating dose constraints of different fractionation regimens.

Prediction Factors of Radiation Esophagitis in Breast Cancer Patients Undergoing Supraclavicular Radiotherapy

Purpose

The aim of this study was to investigate demographic and dosimetric parameters which may link with esophagitis in patients with breast cancer receiving three-dimensional conformal radiotherapy to the supraclavicular fossa.

Materials and Methods

We examined 27 breast cancer patients with supraclavicular metastases. All patients were treated with radiotherapy (RT) with a prescribed dose of 40.5 Gy in 15 fractions for 3 weeks. Esophagitis was recorded weekly and esophagus toxicity was evaluated and graded according to the tadiation therapy oncology group. The following factors were examined regarding their correlation with grade 1 or worse esophagitis by univariate and multivariate analyses: age, chemotherapy, smoking history, maximum dose (Dmax), mean dose (Dmean), esophagus volume receiving 10 Gy (V10), esophagus volume receiving 20 Gy (V20), and length of esophagus in the treatment field.

Results

Of 27, 11 (40.7%) patients developed no esophageal irritation throughout therapy. Approximately half of the patients 13/27 (48.1%) had maximum grade 1 esophagitis. 2/27 (7.4%) patients had grade 2 esophagitis. The incidence of grade 3 esophagitis was (3.7%). Dmean, Dmax, V10, and V20 were 10.48 ± 5.10 Gy, 38.18 ± 5.12Gy, 29.83 ± 15.16, and 19.32 ± 10.01, respectively. Our results showed that Dmean, V10, and V20 were the significant factors for the development of esophagitis, whereas esophagitis was not significantly associated with the chemotherapy regimen, age, and smoking status.

Conclusions

We found that Dmean, V10, and V20 correlated significantly with acute esophagitis. However, the chemotherapy regimen, age, and smoking status did not affect esophagitis development.

Contralateral esophageal sparing technique in definitive radiotherapy for non-small cell lung cancer: dosimetric parameters and normal tissue complication probability modeling

Background

The purpose of this study was to assess the benefit of the contralateral esophageal sparing technique (CEST) in definitive radiotherapy of non-small cell lung cancer (NSCLC).

Materials and methods

We retrospectively reviewed radiation plans for 13 patients who underwent definitive chemoradiation for locally advanced NSCLC. Alternative plans were prepared with the use of CEST, with an additional margin of 5 mm from planning treatment volume (PTV). Normal tissue complication probability (NTCP) analyses for the esophagus and tumor control probability (TCP) for the PTV were performed for original and CEST plans using the equivalent uniform dose (EUD)-based mathematical model.

Results

In all cases, the CEST plan allowed for the reduction of esophageal dose, with a mean of 3.8 Gy (range, 0.7 to 8.7 Gy). The mean reductions of V40 and V60 to the esophagus were 6.4 Gy (range, 2.1 to 17.2 Gy) and 1.9 Gy (range, 3.4 to 10.0 Gy), respectively. There was no substantial decrease in the maximal dose to the esophagus. Reduction of NTCP was achieved for all patients (range, 5-73%), and TCP was not affected (-1.8 to +6.7%).

Conclusions

The application of CEST in definitive radiotherapy of locally advanced NSCLC allows for reducing selected dosimetric parameters to the esophagus without compromising TCP.

Rational Design of Nanomaterials for Various Radiation-Induced Diseases Prevention and Treatment

Radiation treatments often unfavorably damage neighboring healthy organs and cause a series of radiation sequelae, such as radiation-induced hematopoietic system diseases, radiation-induced gastrointestinal diseases, radiation-induced lung diseases, and radiation-induced skin diseases. Recently, emerging nanomaterials have exhibited good superiority for these radiation-induced disease treatments. Given this background, the rational design principle of nanomaterials, which helps to optimize the therapeutic efficiency, has been an increasing need. Consequently, it is of great significance to perform a systematic summarization of the advances in this field, which can trigger the development of new high-performance nanoradioprotectors with drug efficiency maximization. Herein, this review highlights the advances and perspectives in the rational design of nanomaterials for preventing and treating various common radiation-induced diseases. Furthermore, the sources, clinical symptoms, and pathogenesis/injury mechanisms of these radiation-induced diseases will also be introduced. Furthermore, current challenges and directions for future efforts in this field are also discussed.

Sparing Organs at Risk with Simultaneous Integrated Boost Volumetric Modulated Arc Therapy for Locally Advanced Non-Small Cell Lung Cancer: An Automatic Treatment Planning Study

Background

The technique of simultaneous integrated boost volumetric modulated arc therapy (SIB-VMAT) has been widely used in locally advanced non-small cell lung cancer; however, its dosimetric advantages are seldom reported. This study aimed to quantify dosimetric advantages of SIB-VMAT.

Methods

Forty patients with stage III non-small cell lung cancer in our hospital were retrospectively included. SIB-VMAT and conventional VMAT (C-VMAT) plans were generated for every patient using the automatic treatment planning system. A reduced dose was delivered to PTV in SIB-VAMT plans compared to C-VMAT plans (50.4Gy vs 60Gy). The prescribed dose was 50.4 Gy in 28 fractions to PTV and 59.92 Gy in 28 fractions to PGTV in SIB-VMAT plans, while 60 Gy in 30 fractions to PTV in C-VMAT plans. Dose-volume metrics of PTV, total lung, heart, esophagus and spinal cord were recorded. The quality score was used to evaluate organs at risk (OAR) protection for two type prescription plans.

Results

Conformal coverage of the targets (PGTV/PTV) by 95% of the prescription dose was well achieved in radiation plans. SIB-VMAT plans achieved significantly higher quality score than C-VMAT plans (Mean: 68.15±13.32 vs 49.15±13.35, P<0.001). More plans scored above sixty in SIB-VMAT group compared to C-VMAT group (72.5% vs 20%, P<0.001). Notable reductions in mean dose, V₃₀, V₄₀ and V₅₀ of total lung were observed in SIB-VMAT plans compared to C-VMAT plans, with median decreased proportions of 6.5%, 8.7%, 19.6% and 32.1%, respectively. Statistically significant decrease in heart V₃₀ and V₄₀ was also achieved in SIB-VMAT plans, with median decreased proportions of 26.1% and 38.8%. SIB-VMAT plans achieved significant reductions in the maximum doses to both esophagus and spinal cord. Patients with CTV/(GTV+GTVnd) ≥8.6 showed more notable decrease in total lung V₅₀ (median, 33.6% vs 28.8%, P=0.001) in SIB-VMAT plans compared to those with the ratio being less than 8.6.

Conclusion

SIB-VMAT technique could lead to a substantial sparing of normal organs, including lung, heart, esophagus and cord, mainly through reducing high and inter-median dose exposure. Patients with CTV/(GTV+GTVnd) ≥8.6 might benefit more from SIB-VMAT.

Dose-volume effects of breast cancer radiation therapy on the risk of second oesophageal cancer

PURPOSE

To investigate the relationship between oesophagus dose-volume distribution and long-term risk of oesophageal cancer after radiation therapy for breast cancer.

MATERIALS AND METHODS

In a case-control study nested within a cohort of 289,748 ≥5-year survivors of female breast cancer treated in 1943-2003 in five countries, doses to the second primary cancer (D_SPC) and individual dose-volume histograms (DVH) to the entire oesophagus were reconstructed for 252 oesophageal cancer cases and 488 matched controls (median follow-up time: 13, range: 5-37 years). Using conditional logistic regression, we estimated excess odds ratios (EOR) of oesophageal cancer associated with DVH metrics. We also investigated whether DVH metrics confounded or modified D_SPC-related -risk estimates.

RESULTS

Among the DVH metrics evaluated, median dose (D_median) to the entire oesophagus had the best statistical performance for estimating risk of all histological types combined (EOR/Gy = 0.071, 95% confidence interval [CI]: 0.018 to 0.206). For squamous cell carcinoma, the most common subtype, the EOR/Gy for D_median increased by 31% (95% CI: 3% to 205%) for each increment of 10% of V30 (p = 0.02). Adjusting for DVH metrics did not materially change the EOR/Gy for D_SPC, but there was a borderline significant positive interaction between D_SPC and V30 (p = 0.07).

CONCLUSION

This first study investigating the relationship between oesophagus dose-volume distribution and oesophageal cancer risk showed an increased risk per Gy for D_median with larger volumes irradiated at high doses. While current techniques allows better oesophagus sparing, constraints applied to D_median and V30 could potentially further reduce the risk of oesophageal cancer.

Exploring the Relationship of Radiation Dose Exposed to the Length of Esophagus and Weight Loss in Patients with Lung Cancer

PURPOSE

We investigate whether esophageal dose-length parameters (L_dose) can robustly predict significant weight loss-≥5% weight loss during radiation therapy (RT) compared with the weight before RT-in patients with lung cancer treated with definitive intent.

METHODS AND MATERIALS

Patients with lung cancer treated with conventionally fractionated RT between 2010 and 2018 were retrospectively identified. L_Fdose and L_Pdose, the length of full- and partial-circumferential esophagus receiving greater than a threshold dose in Gy, respectively, were created. Multivariate logistic regression examined the associations between individual L_dose and weight loss after adjusting for clinical parameters and correcting for multiple comparisons. Ridge logistic regression examined the relative importance of L_dose compared with dose-volume (V_dose), mean dose (D_mean), and clinical parameters in determining weight loss. Univariate logistic regression examined the unadjusted probability of weight loss for important L_dose parameters.

RESULTS

Among the 214 patients identified, median age was 66.9 years (range, 31.5-88.9 years), 50.5% (n = 108) were male, 68.2% (n = 146) had stage III lung cancer, median RT dose was 63 Gy (range, 60-66 Gy), and 88.3% (n = 189) received concurrent chemotherapy. Esophagus lengths receiving high full-circumferential (L_F50-L_F60) and high partial-circumferential doses (L_P60) were associated with significant weight loss (P ≤ .05). L_F65 and L_P65 reached near significance (P = .06 and .053, respectively). L_F65 > L_F60 > L_P65 were the most important dose parameters in determining weight loss compared with other L_dose, V_dose, and D_mean parameters.

CONCLUSIONS

Esophageal L_dose parameters are an efficient way of interpreting complex dose parameters in relation to weight loss toxicity among patients with lung cancer receiving definitive RT.

A new formalism of Dose Surface Histograms for robust modeling of skin toxicity in radiation therapy

PURPOSE

To present a new formalism for a robust computation of Dose-Surface Histograms (DSHs) to be exploited in the analysis of surface effects in radiation induced toxicity phenomena.

METHODS

A new formal recipe for the DSH extraction is described. It is based on the computation of the Dose-Volume Histogram (DVH) on a 3D structure in the limit of vanishing thickness to approach the two-dimensional organ manifold. The theory is customized for the application to skin description.

RESULTS

The derived formalism resulted in a redefinition of the generalized equivalent uniform dose (gEUD) and, accordingly, in an extension of the scope of the classical Lyman-Kutcher-Burman (LKB) Normal Tissue Complication Probability (NTCP) to a DSH-based toxicity modeling.

CONCLUSIONS

Our approach properly fits the intrinsic 3D nature of the DSH computation issue, and guarantees the rotational invariance and the robustness of the results. The proposed formalism can be easily implemented in treatment planning systems for dose optimization and potentially paves the way to a consistent analysis of radiation-induced morbidity endpoints related to surface effects in hollow organs.

A model combining age, equivalent uniform dose and IL-8 may predict radiation esophagitis in patients with non-small cell lung cancer

BACKGROUND AND PURPOSE

To study whether cytokine markers may improve predictive accuracy of radiation esophagitis (RE) in non-small cell lung cancer (NSCLC) patients.

MATERIALS AND METHODS

A total of 129 patients with stage I-III NSCLC treated with radiotherapy (RT) from prospective studies were included. Thirty inflammatory cytokines were measured in platelet-poor plasma samples. Logistic regression was performed to evaluate the risk factors of RE. Stepwise Akaike information criterion (AIC) and likelihood ratio test were used to assess model predictions.

RESULTS

Forty-nine of 129 patients (38.0%) developed grade ≥2 RE. Univariate analysis showed that age, stage, concurrent chemotherapy, and eight dosimetric parameters were significantly associated with grade ≥2 RE (p < 0.05). IL-4, IL-5, IL-8, IL-13, IL-15, IL-1α, TGFα and eotaxin were also associated with grade ≥2 RE (p < 0.1). Age, esophagus generalized equivalent uniform dose (EUD), and baseline IL-8 were independently associated grade ≥2 RE. The combination of these three factors had significantly higher predictive power than any single factor alone. Addition of IL-8 to toxicity model significantly improves RE predictive accuracy (p = 0.019).

CONCLUSIONS

Combining baseline level of IL-8, age and esophagus EUD may predict RE more accurately. Refinement of this model with larger sample sizes and validation from multicenter database are warranted.

The dosimetric effects of limited elective nodal irradiation in volumetric modulated arc therapy treatment planning for locally advanced non-small cell lung cancer

Objective

Contemporary radiotherapy guidelines for locally advanced non-small cell lung carcinoma (LA-NSCLC) recommend omitting elective nodal irradiation, despite the fact that evidence supporting this came primarily from older reports assessing comprehensive nodal coverage using 3D conformal techniques. Herein, we evaluated the dosimetric implications of the addition of limited elective nodal irradiation (LENI) to standard involved field irradiation (IFI) using volumetric modulated arc therapy (VMAT) planning.

Method

Target volumes and organs-at-risk (OARs) were delineated on CT simulation images of 20 patients with LA-NSCLC. Two VMAT plans (IFI and LENI) were generated for each patient. Involved sites were treated to 60 Gy in 30 fractions for both IFI and LENI plans. Adjacent uninvolved nodal regions, considered high risk based on the primary tumor site and extent of nodal involvement, were treated to 51 Gy in 30 fractions in LENI plans using a simultaneous integrated boost approach.

Results

All planning objectives for PTVs and OARs were achieved for both IFI and LENI plans. LENI resulted in significantly higher esophagus D_mean (15.3 vs. 22.5 Gy, p < 0.01), spinal cord D_max (34.9 vs. 42.4 Gy, p = 0.02) and lung D_mean (13.5 vs. 15.9 Gy, p = 0.02), V₂₀ (23.0 vs. 27.9%, p = 0.03), and V₅ (52.6 vs. 59.4%, p = 0.02). No differences were observed in heart parameters. On average, only 32.2% of the high-risk nodal volume received an incidental dose of 51 Gy when untargeted in IFI plans.

Conclusion

The addition of LENI to VMAT plans for LA-NSCLC is feasible, with only modestly increased doses to OARs and marginal expected increase in associated toxicity.

Dosimetric predictors for acute esophagitis during radiation therapy for lung cancer: Results of a large statewide observational study

PURPOSE

The purpose of this study is to identify dosimetric variables that best predict for acute esophagitis in patients treated for locally advanced non-small cell lung cancer in a prospectively accrued statewide consortium.

METHODS AND MATERIALS

Patients receiving definitive radiation therapy for stage II-III non-small cell lung cancer within the Michigan Radiation Oncology Quality Consortium were included in the analysis. Dose-volume histogram data were analyzed to determine absolute volumes (cc) receiving doses from 10 to 60 Gy (V10, V20, V30, V40, V50, and V60), as well as maximum dose to 2 cc (D2cc), mean dose (MD), and generalized equivalent uniform dose (gEUD). Logistic regression models were used to characterize the risk of toxicity as a function of dose and other covariates. The ability of each variable to predict esophagitis, individually or in a multivariate model, was quantified by receiver operating characteristic analysis.

RESULTS

There were 533 patients who met study criteria and were included; 437 (81.9%) developed any grade of esophagitis. Significant variables on univariate analysis for grade ≥2 esophagitis were concurrent chemotherapy, V20, V30, V40, V50, V60, MD, D2cc, and gEUD. For grade ≥3 esophagitis, the predictive variables were: V30, V40, V50, V60, MD, D2cc, and gEUD. In multivariable modeling, gEUD was the most significant predictor of both grade ≥2 and grade ≥3 esophagitis. When gEUD was excluded from the model, D2cc was selected as the most predictive variable for grade ≥3 esophagitis. For an estimated risk of grade ≥3 esophagitis of 5%, the threshold values for gEUD and D2cc were 59.3 Gy and 68 Gy, respectively.

CONCLUSIONS

In this study, we report the novel finding that gEUD and D2cc, rather than MD, were the most predictive dose metrics for severe esophagitis. To limit the estimated risk of grade ≥3 esophagitis to <5%, thresholds of 59.3 Gy and 68 Gy were identified for gEUD and D2cc, respectively.

Digestive toxicities after palliative three-dimensional conformal radiation therapy (3D-CRT) for cervico-thoracic spinal metastases

OBJECTIVE

The palliative treatment for cervico-thoracic spinal metastases is based on a three-dimensional conformal radiation therapy (3D-CRT). Digestive toxicities are common and cause a clinical impact frequently underestimated in patients. We performed a retrospective study of digestive side effects occurring after palliative 3D-CRT for cervico-thoracic spinal metastases.

PATIENTS AND METHODS

All patients receiving palliative 3D-CRT at Jean Bernard Center from January 2013 to December 2014 for spinal metastases between the 5th cervical vertebra (C5) and the 12th thoracic vertebra (T12) were eligible. Three-dimensional conformal RT was delivered by a linear accelerator (CLINAC, Varian). Premedication to prevent digestive toxicities was not used. Adverse events ("esophagitis" and "nausea and/or vomiting") were evaluated according to the NCI-CTCae (version 4).

RESULTS

From January 2013 to December 2014, 128 patients met the study criteria. The median age was 68.6 years [31.8; 88.6]. Most patients (84.4%) received 30 Gy in 10 fractions. The median overall time of treatment was 13 days [3-33]. Forty patients (31.3%) suffered from grade ≥ 2 of "esophagitis" (35 grade 2 (27.4%) and 5 grade 3 (3.9%)). Eight patients (6.3%) suffered from grade ≥ 2 of "nausea and/or vomiting" (6 grade 2 (4.7%), 1 grade 3 (0.8%), and 1 grade 4 (0.8%)).

CONCLUSION

The high incidence of moderate to severe digestive toxicities after palliative 3D-CRT for cervico-thoracic spinal metastases led to consider static or dynamic intensity-modulated radiation therapy (IMRT) to reduce the dose to organ at risk (the esophagus and stomach). Dosimetric studies and implementation in the clinic should be the next steps.

Prediction of Radiation Esophagitis in Non-Small Cell Lung Cancer Using Clinical Factors, Dosimetric Parameters, and Pretreatment Cytokine Levels

Radiation esophagitis (RE) is a common adverse event associated with radiotherapy for non-small cell lung cancer (NSCLC). While plasma cytokine levels have been correlated with other forms of radiation-induced toxicity, their association with RE has been less well studied. We analyzed data from 126 patients treated on 4 prospective clinical trials. Logistic regression models based on combinations of dosimetric factors [maximum dose to 2 cubic cm (D2cc) and generalized equivalent uniform dose (gEUD)], clinical variables, and pretreatment plasma levels of 30 cytokines were developed. Cross-validated estimates of area under the receiver operating characteristic curve (AUC) and log likelihood were used to assess prediction accuracy. Dose-only models predicted grade 3 RE with AUC values of 0.750 (D2cc) and 0.727 (gEUD). Combining clinical factors with D2cc increased the AUC to 0.779. Incorporating pretreatment cytokine measurements, modeled as direct associations with RE and as potential interactions with the dose-esophagitis association, produced AUC values of 0.758 and 0.773, respectively. D2cc and gEUD correlated with grade 3 RE with odds ratios (ORs) of 1.094/Gy and 1.096/Gy, respectively. Female gender was associated with a higher risk of RE, with ORs of 1.09 and 1.112 in the D2cc and gEUD models, respectively. Older age was associated with decreased risk of RE, with ORs of 0.992/year and 0.991/year in the D2cc and gEUD models, respectively. Combining clinical with dosimetric factors but not pretreatment cytokine levels yielded improved prediction of grade 3 RE compared to prediction by dose alone. Such multifactorial modeling may prove useful in directing radiation treatment planning.

Persistence of dysphagia and odynophagia after mediastinal radiation and chemotherapy in patients with lung cancer or lymphoma

Esophageal symptoms are common during radiation and chemotherapy. It is unclear how often these symptoms persist after therapy. We retrospectively reviewed medical records of 320 adults treated for nonmetastatic breast cancer (84), lung cancer (109), or Hodgkin and non-Hodgkin lymphoma (127) who were disease-free at 10-14 months after therapy. Treatment included chemotherapy with or without nonmediastinal radiation therapy (150 patients), chemotherapy plus sequential mediastinal radiation therapy (MRT) (48 patients), chemotherapy plus concurrent MRT (61 patients), or non-MRT only (61 patients). Proton pump inhibitor use was documented. All treatment groups had similar prevalence of the esophageal symptom of heartburn before therapy. Rates were higher during treatment in those who received MRT with or without chemotherapy, but declined by 10-14 months after treatment. However, low baseline rates of dysphagia (4%) and odynophagia (2%) increased significantly after combined chemotherapy and MRT to 72% for dysphagia and 62% for odynophagia (P < 0.01) during treatment and stayed significantly elevated over baseline with 27% of the patients having dysphagia and 11% having odynophagia at 10-14 months after treatment. The use of proton pump inhibitors by patients who had MRT with chemotherapy was significantly increased during and after treatment (P = 0.002). Dysphagia, odynophagia and the use of proton pump inhibitors were significantly more common both during and after treatment than before treatment in patients who received both chemotherapy and mediastinal radiation. Our data highlight the important challenge for clinicians of managing patients with lung cancer and lymphoma who have persistent esophageal problems, particularly dysphagia and odynophagia, at approximately 1 year after treatment.

Lower Incidence of Esophagitis in the Elderly Undergoing Definitive Radiation Therapy for Lung Cancer

INTRODUCTION

Most patients with lung cancer are elderly and poorly represented in randomized clinical trials. They are often undertreated because of concerns about their ability to tolerate aggressive treatment. We tested the hypothesis that elderly patients undergoing definitive lung radiation might tolerate treatment differently than younger patients.

METHODS

A total of 125 patients who underwent definitive lung radiotherapy were identified from a prospective institutional database (University of Michigan cohort). Logistic regression modeling was performed to assess the impact of age on esophagitis grade 2 or higher or grade 2 or higher and pneumonitis grade 3 or higher or grade 2 or higher, with adjustment for esophageal and lung dose, respectively, as well as for chemotherapy utilization, smoking status, and performance status. The analysis was validated in a large cohort of 691 patients from the Michigan Radiation Oncology Quality Consortium registry, an independent statewide prospective database.

RESULTS

In the University of Michigan cohort, multivariable regression models revealed a significant inverse correlation between age and rate of esophagitis for both toxicity levels, (adjusted OR = 0.93 for both models and 95% confidence intervals of 0.88-0.98 and 0.87-0.99), with areas under the curve of 0.747 and 0.721, respectively, demonstrating good fit. This same association was noted in the Michigan Radiation Oncology Quality Consortium cohort. There was no significant association between age and pneumonitis.

CONCLUSIONS

There is a lower incidence of esophagitis with increasing age even after adjustment for use of chemotherapy. This is a novel finding in thoracic oncology. No age dependence was noted for pulmonary toxicity. The elderly are able to tolerate definitive thoracic radiation well and should be offered this option when clinically warranted.

Lycopene in the Prevention of Radiation-Induced Esophagitis

We aimed to research whether lycopene (L) could prevent radiation-induced acute esophageal toxicity in Wistar albino rats. 60 rats were placed in five groups as follows: control, L, radiotherapy (RT), L before RT (L + RT), and L before and after RT (L + RT + L). 6 mg/kg bw/day L was administered 7 days in the L group, 7 days before RT in the L + RT group, and 7 days before and after in the L + RT + L group. 35 Gy thoracic RT was performed. Serum L levels were measured, and the esophagi were evaluated histopathologically for intraepithelial degenerative changes-necrosis, vacuole formation, inflammation, regeneration-mitosis, and subepithelial bulla formation. L levels were significantly higher in the L receiving groups. All histopathologic results were significantly worse in the RT group than in the none-RT groups. The L + RT and the L + RT + L groups had better results than the RT group. Grade 2-3 degenerative changes-necrosis and vacuole formation were significantly lesser in the L + RT and the L + RT + L groups than those in the RT group. There was a trend toward decreased subepithelial bulla formation and inflammation in the L + RT and the L + RT + L groups compared to the RT group. Regeneration-mitosis was insignificantly lesser in the L + RT and significantly fewer in the L + RT + L groups than that in the RT group.

Independent test of a model to predict severe acute esophagitis

PURPOSE

Treatment planning factors are known to affect the risk of severe acute esophagitis during thoracic radiation therapy. We tested a previously published model to predict the risk of severe acute esophagitis on an independent data set.

METHODS AND MATERIALS

The data set consists of data from patients who had recoverable treatment plans and received definitive radiation therapy for non-small cell carcinoma of the lung at a single institution between November 2004 and January 2010. Complete esophagus dose-volume and available clinical information was extracted using our in-house software. The previously published model was a logistic function with a combination of mean esophageal dose and use of concurrent chemotherapy. In addition to testing the previous model, we used a novel, machine learning-based method to build a maximally predictive model.

RESULTS

Ninety-four patients (81.7%) developed Common Terminology Criteria for Adverse Events, Version 4, Grade 2 or more severe esophagitis (Grade 2: n = 79 and Grade 3: n = 15). Univariate analysis revealed that the most statistically significant dose-volume parameters included percentage of esophagus volume receiving ≥40 to 60 Gy, minimum dose to the highest 20% of esophagus volume (D20) to D35, and mean dose. Other significant predictors included concurrent chemotherapy and patient age. The previously published model predicted risk effectively with a Spearman's rank correlation coefficient (r_s) of 0.43 (P < .001) with good calibration (Hosmer-Lemeshow goodness of fit: P = .537). A new model that was built from the current data set found the same variables, yielding an r_s of 0.43 (P < .001) with a logistic function of 0.0853 × mean esophageal dose [Gy] + 1.49 × concurrent chemotherapy [1/0] - 1.75 and Hosmer-Lemeshow P = .659. A novel preconditioned least absolute shrinkage and selection operator method yielded an average r_s of 0.38 on 100 bootstrapped data sets.

CONCLUSIONS

The previously published model was validated on an independent data set and determined to be nearly as predictive as the best possible two-parameter logistic model even though it overpredicted risk systematically. A novel, machine learning-based model using a bootstrapping approach showed reasonable predictive power.

Predictors for severe acute esophagitis in lung cancer patients treated with chemoradiotherapy: a systematic review

PURPOSE

To identify the risk factors for severe acute esophagitis (AE) in lung cancer patients undergoing chemoradiotherapy (CRT).

METHODS

Articles from PubMed, EMBASE, and the Cochrane Library were searched in August 2015. Articles reporting studies of the predictors for severe AE in lung cancer patients after CRT were included. Study quality was assessed using a modified quality assessment tool that was designed previously for an observational study. The effects of studies were combined with the study quality score using a best-evidence synthesis model. Severe AE incidence was also performed using the Metafor package of R-2.11.1.

RESULTS

A total of nine observational studies involving 1641 patients were included. The estimated incidence of severe AE was 14%. According to the best-evidence synthesis criteria, there were two strong-evidence risk factors for severe AE, which were the use of concurrent chemotherapy (CCT) and dose volume histogram (DVH). We also identified four limited-evidence risk factors.

CONCLUSIONS

More attention should be paid to the levels of patients' esophagus function. Although there is no conclusive evidence for severe AE in lung cancer patients after CRT, the above-mentioned factors provide evidence to guide clinicians as to which patients will have severe AE and to choose an optimal prophylactic strategy.

Oesophagus side effects related to the treatment of oesophageal cancer or radiotherapy of other thoracic malignancies

The oesophagus as a serial organ located in the central chest is frequent subject to "incidental" dose application in radiotherapy for several thoracic malignancies including oesophageal cancer itself. Especially due to the radiosensitive mucosa severe radiotherapy induced sequelae can occur, acute oesophagitis and strictures as late toxicity being the most frequent side-effects. In this review we focus on oesophageal side effects derived from treatment of gastrointestinal cancer and secondly provide an overview on oesophageal toxicity from conventional and stereotactic fractionated radiotherapy to the thoracic area in general. Available data on pathogenesis, frequency, onset, and severity of oesophageal side effects are summarized. Whereas for conventional radiotherapy the associations of applied doses to certain volumes of the oesophagus are well described, the tolerance dose to the mediastinal structures for hypofractionated therapy is unknown. The review provides available attempts to predict the risk of oesophageal side effects from dosimetric parameters of SBRT.

The clinical characteristics and manifestations of cytomegalovirus esophagitis

Esophagitis is the second most common gastrointestinal manifestation of cytomegalovirus (CMV) infection after colitis. CMV esophagitis has been reported in patients who have undergone transplantation, are on long-term renal dialysis, or who have the human immunodeficiency virus infection. This study aimed to investigate the clinical characteristics and manifestations of CMV esophagitis in patients who underwent diagnostic endoscopy. A total of 16 patients with histologically proven CMV infection were identified from 1539 patients with esophageal ulcers and analyzed retrospectively (January 2006 to December 2013). Patients' personal data (age, smoking, and alcohol consumption), underlying systemic diseases (diabetes mellitus, end-stage renal disease, and chronic obstructive pulmonary disease), malignancy, indication for esophagogastroduodenoscopy, endoscopic characteristics, and diagnostic methods (pathological or serological findings) were collected for further analysis. Among the patients with CMV esophagitis, the mean age was 59.94 years (range, 23-84 years). The male : female ratio was 1.67:1. Odynophagia and epigastralgia were common symptoms. Of the 16 patients, 3 (18.75%) were infected with the human immunodeficiency virus and 9 (56.25%) had an underlying malignancy, including lung cancer (6 patients), esophageal cancer (2 patients), gastric cancer (1 patient), ampulla of Vater cancer (1 patient), and lymphoma (1 patient). Six of the 9 patients (66.7%) with malignancy had been administered concurrent chemoradiotherapy (CCRT). In this study, patients with malignancy who had been administered CCRT were at increased risk for CMV esophagitis, which had not been reported before in the literature. CMV esophagitis should be considered as a potential treatment-related complication of CCRT.

Role of liver in modulating the release of inflammatory cytokines involved in lung and multiple organ dysfunction in severe acute pancreatitis

The objective of this study was to understand the role of liver in modulating remote organ dysfunction during severe acute pancreatitis (SAP). We used sodium taurocholate and endotoxin to induce SAP in the rats and confirmed the development of this condition by measuring serum and ascite levels of the biomarkers of liver and lung damage. Our results showed that expression of tumor necrosis factor (TNF)-α was up-regulated sequentially, first in the gut, then in the liver, and finally in lung. Moreover, the SAP-induced increase in the expressions of TNF-α and IL-6 occurring in gut, liver, and lung was directly related to the increase in time. However, in liver and lung, the transcriptional activity of NF-κB and expression of TNF-α at 4 and 8 h were not increased. The distribution sequence of the pro-inflammatory cytokines to various organs was determined by their detection in the blood from portal vein and inferior vena cava. Although liver received TNF-α during 0.5-8 h of the SAP induction, the release of this cytokine into vena cava was not increased in this period of time. In conclusion, our results suggest that the aggravation of SAP leading to development of MODS exhibited the gut-liver-lung cytokine axis. Furthermore, this study indicates that liver performs both protective and stimulatory activities in the modulation of pro-inflammatory cytokine generation and their distribution to remote organs, such as lungs.

Multivariable normal-tissue complication modeling of acute esophageal toxicity in advanced stage non-small cell lung cancer patients treated with intensity-modulated (chemo-)radiotherapy

BACKGROUND AND PURPOSE

The majority of normal-tissue complication probability (NTCP) models for acute esophageal toxicity (AET) in advanced stage non-small cell lung cancer (AS-NSCLC) patients treated with (chemo-)radiotherapy are based on three-dimensional conformal radiotherapy (3D-CRT). Due to distinct dosimetric characteristics of intensity-modulated radiation therapy (IMRT), 3D-CRT based models need revision. We established a multivariable NTCP model for AET in 149 AS-NSCLC patients undergoing IMRT.

MATERIALS AND METHODS

An established model selection procedure was used to develop an NTCP model for Grade ⩾2 AET (53 patients) including clinical and esophageal dose-volume histogram parameters.

RESULTS

The NTCP model predicted an increased risk of Grade ⩾2 AET in case of: concurrent chemoradiotherapy (CCR) [adjusted odds ratio (OR) 14.08, 95% confidence interval (CI) 4.70-42.19; p<0.001], increasing mean esophageal dose [Dmean; OR 1.12 per Gy increase, 95% CI 1.06-1.19; p<0.001], female patients (OR 3.33, 95% CI 1.36-8.17; p=0.008), and ⩾cT3 (OR 2.7, 95% CI 1.12-6.50; p=0.026). The AUC was 0.82 and the model showed good calibration.

CONCLUSIONS

A multivariable NTCP model including CCR, Dmean, clinical tumor stage and gender predicts Grade ⩾2 AET after IMRT for AS-NSCLC. Prior to clinical introduction, the model needs validation in an independent patient cohort.

Normal tissue complication models for clinically relevant acute esophagitis (≥ grade 2) in patients treated with dose differentiated accelerated radiotherapy (DART-bid)

Background

One of the primary dose-limiting toxicities during thoracic irradiation is acute esophagitis (AE). The aim of this study is to investigate dosimetric and clinical predictors for AE grade ≥ 2 in patients treated with accelerated radiotherapy for locally advanced non-small cell lung cancer (NSCLC).

Patients and methods

66 NSCLC patients were included in the present analysis: 4 stage II, 44 stage IIIA and 18 stage IIIB. All patients received induction chemotherapy followed by dose differentiated accelerated radiotherapy (DART-bid). Depending on size (mean of three perpendicular diameters) tumors were binned in four dose groups: <2.5 cm 73.8 Gy, 2.5–4.5 cm 79.2 Gy, 4.5–6 cm 84.6 Gy, >6 cm 90 Gy. Patients were treated in 3D target splitting technique. In order to estimate the normal tissue complication probability (NTCP), two Lyman models and the cutoff-logistic regression model were fitted to the data with AE ≥ grade 2 as statistical endpoint. Inter-model comparison was performed with the corrected Akaike information criterion (AIC_c), which calculates the model’s quality of fit (likelihood value) in relation to its complexity (i.e. number of variables in the model) corrected by the number of patients in the dataset. Toxicity was documented prospectively according to RTOG.

Results

The median follow up was 686 days (range 84–2921 days), 23/66 patients (35 %) experienced AE ≥ grade 2. The actuarial local control rates were 72.6 % and 59.4 % at 2 and 3 years, regional control was 91 % at both time points. The Lyman-MED model (D50 = 32.8 Gy, m = 0.48) and the cutoff dose model (D_c = 38 Gy) provide the most efficient fit to the current dataset. On multivariate analysis V38 (volume of the esophagus that receives 38 Gy or above, 95 %-CI 28.2–57.3) was the most significant predictor of AE ≥ grade 2 (HR = 1.05, CI 1.01–1.09, p = 0.007).

Conclusion

Following high-dose accelerated radiotherapy the rate of AE ≥ grade 2 is slightly lower than reported for concomitant radio-chemotherapy with the additional benefit of markedly increased loco-regional tumor control. In the current patient cohort the most significant predictor of AE was found to be V38. A second clinically useful parameter in treatment planning may be MED (mean esophageal dose).

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-015-0429-1) contains supplementary material, which is available to authorized users.

Incidence and predictors of severe acute esophagitis and subsequent esophageal stricture in patients treated with accelerated hyperfractionated chemoradiation for limited-stage small cell lung cancer

PURPOSE

Clinical and dosimetric predictors of severe (grade 3 or greater) acute esophageal toxicity and subsequent esophageal dilation were explored in patients with limited-stage small cell lung cancer treated with accelerated hyperfractionated chemoradiation.

METHODS AND MATERIALS

A total of 130 patients were identified who were treated to 45 Gy in 1.5-Gy twice-daily fractions with concurrent platinum-based chemotherapy between 2000 and 2009. Data on clinical, disease-related, and treatment-related variables were collected. Patients with percutaneous endoscopic gastrostomy tube insertion or intravenous hydration because of poor oral intake were designated as having acute grade 3 esophagitis. Univariate and multivariate analyses that associated treatment characteristics with esophagitis were assessed via logistic regression, and optimal cut points were identified with recursive partitioning analysis.

RESULTS

Twenty-five patients developed severe acute esophagitis, at a rate of 26% (18/69) in patients treated with earlier 3-dimensional conformal radiation therapy techniques and 11.5% (7/61) in patients treated with intensity modulated radiation therapy techniques and omission of elective nodal irradiation. The incidence of esophageal stricture was 6% overall (8 of 128 eligible) but 26% (6/23) among those who experienced prior grade 3 acute esophagitis and 2% (2/105) among those with acute esophagitis less than or equal to grade 2. Significant multivariate predictors of acute esophagitis were mean dose and volume of esophagus receiving at least 5% to 35% of the prescribed dose (V5 to V40). Patients with V5 ≥ 74% had a 44.4% risk of severe acute esophagitis (12/27) versus 12.6% (13/103) among those with V5 < 74%. V45 was the only dosimetric predictor for esophageal stricture, with 13.7% of patients in whom V45 was ≥37.5% requiring subsequent dilation.

CONCLUSIONS

Modern radiation techniques are associated with a lower frequency of severe acute esophagitis than previous paradigms. The proportion of esophagus receiving low- to moderate-range doses (mean, V5 through V40) predicts acute esophagitis, whereas the proportion of esophagus that receives high doses (V45) predicts the development of esophageal stricture that requires dilation. Patients who develop grade 3 acute esophagitis are at significant risk for subsequent esophageal stricture, whereas those with acute esophagitis of grade 2 or less display minimal risk.

Treatment-related acute esophagitis for patients with locoregionally advanced non-small cell lung cancer treated with involved-field radiotherapy and concurrent chemotherapy

PURPOSE

To explore the incidence and risk factors for treatment-related acute esophagitis associated with involved-field radiation therapy (RT) delivered concurrently with chemotherapy for patients with locoregionally advanced non-small cell lung cancer.

MATERIALS AND METHODS

Forty-nine consecutive patients diagnosed with locoregionally advanced non-small cell lung cancer were treated using involved-field RT. Radiotherapy target volumes included the primary lung tumor and involved mediastinal lymphadenopathy as defined on imaging studies including computed tomography of the chest and fluorodeoxyglucose-positron emission tomography/computed tomography. The patients were treated to a median total dose of 63 Gy (range, 55.8 to 74 Gy) using daily fractions of 1.8 or 2.0 Gy. No elective radiotherapy of mediastinal lymph nodes was used. Concurrent platinum-based chemotherapy was delivered to all patients. Treatment-related toxicity was evaluated during the course of RT and subsequent follow-up visits.

RESULTS

Thirty-one (63%) patients were female and 18 (37%) were male. Median age at the time of diagnosis was 68 years (range, 36 to 83 y). Thirty-one patients (63%) developed treatment-related acute esophagitis: 24 patients (49%) grade 2 and 7 (14%) patients grade 3 esophagitis, with the peak occurring during the seventh week of radiotherapy. No grade ≥ 4 esophagitis was seen in this cohort. Eighteen patients (37%) did not develop radiation-induced esophagitis associated with their course of chemoradiotherapy. In the univariate analysis, age at the time of diagnosis, radiation dose per fraction, and total volume of the esophagus were significantly associated with the risk of acute esophagitis. Increasing age reduced the risk of acute esophagitis (odds ratio [OR] for 10-y increase = 0.40) as did increasing total esophagus volume (OR for 10-U increase = 0.27). Dose per fraction of 1.8 Gy was associated with lower risk of acute esophagitis when compared with dose per fraction of 2 Gy (OR = 0.19). Marginal associations were observed for all of the volume variables. Higher volume variable values had a nonsignificant association with an increase in risk of acute esophagitis. However, only the total volume of the esophagus (P = 0.0032) and larger dose per fraction (2 vs. 1.8 Gy) (P = 0.011) remained significantly associated with higher risk of developing grade ≥ 2 acute esophagitis in the multivariate analysis.

CONCLUSIONS

Higher risk of grade ≥ 2 treatment-related esophagitis was associated with lower total esophageal volume and higher radiotherapy dose per fraction and should be taken into consideration during patient treatment planning. Inclusion of total esophageal volume and dose per fraction into future clinical protocols may further help our understanding of treatment-related esophagitis and enable the development of novel preventative approaches.

Dosimetric and clinical predictors of acute esophagitis in lung cancer patients in Turkey treated with radiotherapy

BACKGROUND

The purpose of this study was to determine the clinical and dosimetric factors associated with acute esophagitis (AE) in lung cancer patients treated with conformal radiotherapy (RT) in Turkey.

MATERIALS AND METHODS

In this retrospective review 104 lung cancer patients were examined. Esophagitis grades were verified weekly during treatment, and at 1 week, and 1 and 2 months afterwards. The clinical parameters included patient age, gender, tumor pathology, number of chemotherapy treatments before RT, concurrent chemotherapy, radiation dose, tumor response to RT, tumor localization, interruption of RT, weight loss, tumor and nodal stage and tumor volume. The following dosimetric parameters were analyzed for correlation of AE: The maximum (Dmax) and mean (Dmean) doses delivered to the esophagus, the percentage of esophagus volume receiving ≥10 Gy (V10), ≥20 Gy (V20), ≥30 Gy (V30), ≥35 Gy (V35), ≥40 Gy (V40), ≥45 Gy (V45), ≥50 Gy (V50) and ≥60 Gy (V60).

RESULTS

Fifty-five patients (52.9%) developed AE. Maximum grades of AE were recorded: Grade 1 in 51 patients (49%), and Grade 2 in 4 patients (3.8%). Clinical factors had no statistically significant influence on the incidence of AE. In terms of dosimetric findings, correlation analyses demonstrated a significant association between AE and Dmax (>5117 cGy), Dmean (>1487 cGy) and V10-60 (percentage of volume receiving >10 to 60 Gy). The most significant relationship between RT and esophagitis were in Dmax (>5117 cGy) (p=0.002) and percentage of esophageal volume receiving >30 Gy (V30>31%) (p=0.008) in the logistic regression analysis.

CONCLUSIONS

The maximum dose esophagus greater than 5117 cGy and approximately one third (31%) of the esophageal volume receiving >30 Gy was the most statistically significant predictive factor associated with esophagitis due to RT.

Prognostic parameters for acute esophagus toxicity in intensity modulated radiotherapy and concurrent chemotherapy for locally advanced non-small cell lung cancer

BACKGROUND AND PURPOSE

The aim of this study was to correlate clinical and dosimetric variables with acute esophageal toxicity (AET) following Intensity Modulated Radiotherapy (IMRT) with concurrent chemotherapy for locally advanced non-small cell lung cancer (NSCLC). In addition, timeline of AET was reported.

MATERIAL AND METHODS

153 patients with locally advanced NSCLC treated with 66 Gy/2.75 Gy/24 fractions of radiotherapy and concurrent daily low dose cisplatin were selected. Medical records and treatments of these patients were retrospectively reviewed. Maximum AET grade ≥2 and maximum grade 3 were the endpoints of this study. Dates for onset, maximum and recovery (to baseline) of AET were reported. Univariate and multivariate analysis were applied to correlate clinical, tumor, dosimetric and chemotherapy dose variables to AET grade ≥2 and grade 3.

RESULTS

AET grade 2 occurred in 37% and grade 3 in 20% of the patients. The median onset of AET was around day 15 for all grades. The median onset of the maximum grade was day 30 for both grades 2 and 3. The median duration was 43 days for grade 1, 50 days for grade 2 and >80 days for grade 3. Of the grade 3 AET patients, 48% recovered within 3 months. Esophagus V50, ethnic background, and the number of cisplatin administrations were significantly correlated with grade 3 AET.

CONCLUSIONS

For NSCLC patients treated with concurrent chemotherapy and IMRT A higher number of cisplatin administrations, non-Caucasian background and higher V50oes were associated with grade 3 AET. The median onset of AET grade 3 is 15 days after the start of treatment, maximized at day 30, with a median duration of >80 days.

Gastrointestinal radiation injury: Symptoms, risk factors and mechanisms

Ionising radiation therapy is a common treatment modality for different types of cancer and its use is expected to increase with advances in screening and early detection of cancer. Radiation injury to the gastrointestinal tract is important factor working against better utility of this important therapeutic modality. Cancer survivors can suffer a wide variety of acute and chronic symptoms following radiotherapy, which significantly reduces their quality of life as well as adding an extra burden to the cost of health care. The accurate diagnosis and treatment of intestinal radiation injury often represents a clinical challenge to practicing physicians in both gastroenterology and oncology. Despite the growing recognition of the problem and some advances in understanding the cellular and molecular mechanisms of radiation injury, relatively little is known about the pathophysiology of gastrointestinal radiation injury or any possible susceptibility factors that could aggravate its severity. The aims of this review are to examine the various clinical manifestations of post-radiation gastrointestinal symptoms, to discuss possible patient and treatment factors implicated in normal gastrointestinal tissue radiosensitivity and to outline different mechanisms of intestinal tissue injury.

Esophagitis, treatment-related toxicity in non-small cell lung cancer

OBJECTIVES

Radiation esophagitis represents a significant complication experienced by non-small cell cancer (NSCLC) patients receiving thoracic irradiation. The objective of the current review was to assess the clinical and dosimetrical parameters that may predict radiation esophagitis.

METHODS

Studies were identified by searching PubMed electronic databases. Both prospective and retrospective studies were included. Information regarding clinical and dosimetrical parameters predicting for radiation-induced esophagitis was extracted and analyzed.

RESULTS

The esophageal clinical and dosimetric parameters that best predict acute esophagitis remain unclear. In many reports, Vx (the volume of esophagus receiving x Gy) stands out, with values of x ranging from 20-70 Gy. Other studies conclude that the maximal dose received by any point of the esophagus is the best predictor of esophagitis. Another metric implicated with esophageal toxicity in some reports is the proportion of the esophageal circumference or surface area that receives high doses of radiation.

CONCLUSIONS

Technological advancements in patient immobilization, setup verification, and radiotherapy delivery are increasingly being employed to limit the toxicity of thoracic irradiation. Future efforts are required to determine how these complex techniques should best be implemented to minimize the risks of acute and long-term esophageal injury.

[Esophageal toxicity of radiation therapy: clinical risk factors and management]

Acute radiation-induced esophagitis includes all clinical symptoms (odynophagia, dysphagia) occurring within 90 days after thoracic irradiation start. Its severity can be graded using RTOG and CTCAE scales. The clinical risk factors are: age, female gender, initial performance status, pre-therapeutic body mass index, pre-therapeutic dysphagia, tumoral and nodal stage, delivered dose, accelerated hyperfractionned radiotherapy, concomitant association of chemotherapy to radiotherapy and response to the treatment. The dosimetric parameters predictive of esophagitis are: mean dose, V(20Gy), V(30Gy), V(40Gy), V(45Gy) and V(50Gy). Amifostine is the only drug to have a proven radioprotective efficacy (evidence level C, ESMO recommendation grade III). The medical management of esophagitis associates a diet excluding irritant food, medication against gastroesophageal reflux, analgesic treatment according to the WHO scale and management of dehydration and denutrition by enteral feeding.

Correlation of dosimetric parameters obtained with the analytical anisotropic algorithm and toxicity of chest chemoradiation in lung carcinoma

The purpose of this study was to analyze and revisit toxicity related to chest chemoradiotherapy and to correlate these side effects with dosimetric parameters obtained using analytical anisotropic algorithm (AAA) in locally unresectable advanced lung cancer. We retrospectively analyzed data from 47 lung cancer patients between 2005 and 2008. All received conformal 3D radiotherapy using high-energy linear accelerator plus concomitant chemotherapy. All treatment planning data were transferred into Eclipse 8.05 (Varian Medical Systems, Palo Alto, CA) and dosimetric calculations were performed using AAA. Thirty-three patients (70.2%) developed acute pneumopathy after radiotherapy (grades 1 and 2). One patient (2.1%) presented with grade 3 pneumopathy. Thirty-one (66%) presented with grades 1-2 lung fibrosis, and 1 patient presented with grade 3 lung fibrosis. Thirty-four patients (72.3%) developed grade 1-2 acute oesophagic toxicity. Four patients (8.5%) presented with grades 3 and 4 dysphagia, necessitating prolonged parenteral nutrition. Median prescribed dose was 64 Gy (range 50-74) with conventional fractionation (2 Gy per fraction). Dose-volume constraints were respected with a median V20 of 23.5% (maximum 34%) and a median V30 of 17% (maximum 25%). The median dose delivered to healthy contralateral lung was 13.1 Gy (maximum 18.1 Gy). At univariate analysis, larger planning target volume and V20 were significantly associated with the probability of grade ≥2 radiation-induced pneumopathy (p = 0.022 and p = 0.017, respectively). No relation between oesophagic toxicity and clinical/dosimetric parameters could be established. Using AAA, the present results confirm the predictive value of the V20 for lung toxicity as already demonstrated with the conventional pencil beam convolution approach.

Modeling the risk of radiation-induced acute esophagitis for combined Washington University and RTOG trial 93-11 lung cancer patients

PURPOSE

To construct a maximally predictive model of the risk of severe acute esophagitis (AE) for patients who receive definitive radiation therapy (RT) for non-small-cell lung cancer.

METHODS AND MATERIALS

The dataset includes Washington University and RTOG 93-11 clinical trial data (events/patients: 120/374, WUSTL = 101/237, RTOG9311 = 19/137). Statistical model building was performed based on dosimetric and clinical parameters (patient age, sex, weight loss, pretreatment chemotherapy, concurrent chemotherapy, fraction size). A wide range of dose-volume parameters were extracted from dearchived treatment plans, including Dx, Vx, MOHx (mean of hottest x% volume), MOCx (mean of coldest x% volume), and gEUD (generalized equivalent uniform dose) values.

RESULTS

The most significant single parameters for predicting acute esophagitis (RTOG Grade 2 or greater) were MOH85, mean esophagus dose (MED), and V30. A superior-inferior weighted dose-center position was derived but not found to be significant. Fraction size was found to be significant on univariate logistic analysis (Spearman R = 0.421, p < 0.00001) but not multivariate logistic modeling. Cross-validation model building was used to determine that an optimal model size needed only two parameters (MOH85 and concurrent chemotherapy, robustly selected on bootstrap model-rebuilding). Mean esophagus dose (MED) is preferred instead of MOH85, as it gives nearly the same statistical performance and is easier to compute. AE risk is given as a logistic function of (0.0688 MED+1.50 ConChemo-3.13), where MED is in Gy and ConChemo is either 1 (yes) if concurrent chemotherapy was given, or 0 (no). This model correlates to the observed risk of AE with a Spearman coefficient of 0.629 (p < 0.000001).

CONCLUSIONS

Multivariate statistical model building with cross-validation suggests that a two-variable logistic model based on mean dose and the use of concurrent chemotherapy robustly predicts acute esophagitis risk in combined-data WUSTL and RTOG 93-11 trial datasets.

Association of TGF-β1 and XPD polymorphisms with severe acute radiation-induced esophageal toxicity in locally advanced lung cancer patients treated with radiotherapy

PURPOSE

Radiation-induced esophageal toxicity (RIET) is a dose-limiting toxicity in lung cancer patients receiving radiotherapy. Accumulating evidence indicates that DNA repair and the cytokine pathways play essential roles in radiation-induced diseases. Genetic polymorphisms of genes in these pathways may affect gene function and/or gene expression and lead to different treatment-related esophageal toxicity.

MATERIALS AND METHODS

This study investigated the association of 21 polymorphisms in 14 genes, with the occurrence of ≥ grade 2 acute RIET. Genotypes were analyzed among 213 stage III lung cancer patients receiving radiotherapy.

RESULTS

We used Cox proportional hazard model to examine the effects of genotypes on ≥ grade 2 acute RIET risk and Kaplan-Meier estimator to compare effects of different genotypes on such risk. Multivariate analysis showed that CT or TT genotype of TGF-β1-509C/T polymorphism was associated with a significantly higher RIET risk (adjusted hazard ratio [HR]=2.47; 95% confidence interval (CI)=1.17-5.24; P=0.018, or HR=3.86; 95% CI=1.50-9.92; P=0.005), respectively, compared with the CC genotype. Moreover, Lys/Gln+Gln/Gln genotypes of XPD Lys751Gln polymorphism were also associated with a significantly decreased RIET risk (adjusted HR=0.55; 95% CI=0.32-0.96; P=0.030).

CONCLUSIONS

This report, for the first time, examined the influence of inherited variation in the DNA repair and the cytokine pathways on RIET.

Analysis of acute radiation-induced esophagitis in non-small-cell lung cancer patients using the Lyman NTCP model

PURPOSE

To analyze acute esophagitis (AE) in a Chinese population receiving 3D conformal radiotherapy (3DCRT) for non-small cell lung cancer (NSCLC), combined or not with chemotherapy (CT), using the Lyman-Kutcher-Burman (LKB) normal tissue complication probability (NTCP) model.

MATERIALS AND METHODS

157 Chinese patients (pts) presented with NSCLC received 3DCRT: alone (34 pts) or combined with sequential CT (59 pts) (group 1) or with concomitant CT (64 pts) (group 2). Parameters (TD(50), n, and m) of the LKB NTCP model predicting for>grade 2 AE (RTOG grading) were identified using maximum likelihood analysis. Univariate and multivariate analyses using a binary regression logistic model were performed to identify patient, tumor and dosimetric predictors of AE.

RESULTS

Grade 2 or 3 AE occurred in 24% and 52% of pts in group 1 and 2, respectively (p<0.001). For the 93 group 1 pts, the fitted LKB model parameters were: m=0.15, n=0.29 and TD(50)=46 Gy. For the 64 group 2 pts, the parameters were: m=0.42, n=0.09 and TD(50)=36 Gy. In multivariate analysis, the only significant predictors of AE were: NTCP (p<0.001) and V(50), as continuous variable (RR=1.03, p=0.03) or being more than a threshold value of 11% (RR=3.6, p=0.009).

CONCLUSIONS

A LKB NTCP model has been established to predict AE in a Chinese population, receiving thoracic RT, alone or combined with CT. The parameters of the models appear slightly different than the previous one described in Western countries, with a lower volume effect for Chinese patients.

Consideration of dose limits for organs at risk of thoracic radiotherapy: atlas for lung, proximal bronchial tree, esophagus, spinal cord, ribs, and brachial plexus

PURPOSE

To review the dose limits and standardize the three-dimenional (3D) radiographic definition for the organs at risk (OARs) for thoracic radiotherapy (RT), including the lung, proximal bronchial tree, esophagus, spinal cord, ribs, and brachial plexus.

METHODS AND MATERIALS

The present study was performed by representatives from the Radiation Therapy Oncology Group, European Organization for Research and Treatment of Cancer, and Soutwestern Oncology Group lung cancer committees. The dosimetric constraints of major multicenter trials of 3D-conformal RT and stereotactic body RT were reviewed and the challenges of 3D delineation of these OARs described. Using knowledge of the human anatomy and 3D radiographic correlation, draft atlases were generated by a radiation oncologist, medical physicist, dosimetrist, and radiologist from the United States and reviewed by a radiation oncologist and medical physicist from Europe. The atlases were then critically reviewed, discussed, and edited by another 10 radiation oncologists.

RESULTS

Three-dimensional descriptions of the lung, proximal bronchial tree, esophagus, spinal cord, ribs, and brachial plexus are presented. Two computed tomography atlases were developed: one for the middle and lower thoracic OARs (except for the heart) and one focusing on the brachial plexus for a patient positioned supine with their arms up for thoracic RT. The dosimetric limits of the key OARs are discussed.

CONCLUSIONS

We believe these atlases will allow us to define OARs with less variation and generate dosimetric data in a more consistent manner. This could help us study the effect of radiation on these OARs and guide high-quality clinical trials and individualized practice in 3D-conformal RT and stereotactic body RT.

Clinical and dosimetric risk factors of acute esophagitis in patients treated with 3-dimensional conformal radiotherapy for non-small-cell lung cancer

PURPOSE

To analyze the clinical and dosimetric risk factors of acute esophagitis (AE) in non-small-cell lung cancer (NSCLC) patients treated with 3-dimensional conformal radiotherapy (3D-CRT).

METHODS AND MATERIALS

One hundred two NSCLC patients treated with 3D-CRT were retrospectively analyzed. Forty of these 102 patients analyzed were treated with concurrent chemotherapy (CCT). The median biologic effective dose of radiotherapy was 72.0 Gy. AE was scored according to the Radiation Therapy Oncology Group criteria. The clinical and dosimetric factors associated with grade 2 or worse AE were analyzed using univariate and multivariate binary logistic analysis.

RESULTS

There were no grade 4 or 5 AE observed in the 102 patients analyzed. Thirty-four of 102 patients (33.3%) developed grade 2 or 3 AE. Univariate analysis showed that clinical factors, such as lymph nodes stage (N 0/1 vs. N 2/3), pretreatment weight loss > or =5%, CCT, and the use of late-course hyperfractionated radiotherapy were significantly associated with grade 2 and 3 AE. Dose volume parameters of esophagus including mean esophageal dose, maximal esophageal dose, rV15, rV20, rV25, rV30, rV35, rV40, rV45, rV50, rV55, rV60 were also associated with AE. On multivariate forward step-wise logistic analysis, CCT, lymph nodes stage, and rV55 emerged as the statistically most significant factors of AE with OR parameters of 8.911, 4.832, and 1.083, respectively.

CONCLUSION

CCT, lymphatic status, and rV55 were strong predictors of grade 2 or worse AE in NSCLC treated with 3D-CRT.

Radiation dose-volume effects in the esophagus

Publications relating esophageal radiation toxicity to clinical variables and to quantitative dose and dose-volume measures derived from three-dimensional conformal radiotherapy for non-small-cell lung cancer are reviewed. A variety of clinical and dosimetric parameters have been associated with acute and late toxicity. Suggestions for future studies are presented.

Exposure to both radiation and chemotherapy increases the risk of Barrett's and multilayered epithelium

The relationship between radiation and/or chemotherapy and the development of Barrett's and/or multilayered epithelium has not been investigated before. We ascertained a group of patients exposed to radiation and/or chemotherapy and an unexposed group to compare the prevalence rates of Barrett's epithelium and multilayered epithelium at the time of endoscopy in these two groups. Barrett's epithelium was found in ten of the 19 (53%) exposed patients, compared to eight of 38 (21%) unexposed subjects (P = 0.02). Six of 19 (32%) exposed patients had multilayered epithelium, compared to four of 38 (11%) unexposed subjects (P = 0.06). Twelve of the 19 exposed patients (63%) had either Barrett's or multilayered epithelium, in contrast to ten of 38 (26%) unexposed subjects (P = 0.01). Those with exposure to both chemotherapy and radiation had a significant increase in the risk for Barrett's and/or multilayered epithelium (P = 0.003). This study suggests a relationship between exposure to a combination of radiation and chemotherapy and the development of Barrett's and/or multilayered epithelium.

Systematic review of dose-volume parameters in the prediction of esophagitis in thoracic radiotherapy

PURPOSE

With dose escalation and increasing use of concurrent chemoradiotherapy, radiation esophagitis (RE) remains a common treatment-limiting acute side effect in the treatment of thoracic malignancies. The advent of 3DCT planning has enabled investigators to study esophageal dose-volume histogram (DVH) parameters as predictors of RE. The purpose of this study was to assess published dosimetric parameters and toxicity data systematically in order to define reproducible predictors of RE, both for potential clinical use, and to provide recommendations for future research in the field.

MATERIALS AND METHODS

We performed a systematic literature review of published studies addressing RE in the treatment of lung cancer and thymoma. Our search strategy included a variety of electronic medical databases, textbooks and bibliographies. Both prospective and retrospective clinical studies were included. Information relating to the relationship among measured dosimetric parameters, patient demographics, tumor characteristics, chemotherapy and RE was extracted and analyzed.

RESULTS

Eighteen published studies were suitable for analysis. Eleven of these assessed acute RE, while the remainder assessed both acute and chronic RE together. Heterogeneity of esophageal contouring practices, individual differences in information reporting and variability of RE outcome definitions were assessed. Well-described clinical and logistic modeling directly related V(35Gy), V(60Gy) and SA(55Gy) to clinically significant RE.

CONCLUSIONS

Several reproducible dosimetric parameters exist in the literature, and these may be potentially relevant in the prediction of RE in the radiotherapy of thoracic malignancies. Further clarification of the predictive relationship between such standardized dosimetric parameters and observed RE outcomes is essential to develop efficient radiation treatment planning in locally advanced NSCLC in the modern concurrent chemotherapy and image-guided IMRT era.

Prevention of acute radiation-induced esophagitis with glutamine in non-small cell lung cancer patients treated with radiotherapy: evaluation of clinical and dosimetric parameters

BACKGROUND

The purpose of this study was to evaluate the efficacy of oral glutamine in the prevention of acute radiation-induced esophagitis (ARIE) and weight loss in lung carcinoma patients, and to determine the clinical/dosimetric predictors of ARIE.

PATIENTS AND METHODS

Data from 41 patients with stage III lung carcinoma treated with thoracic irradiation were retrospectively analyzed. Twenty-two patients (53.6%) received prophylactic powdered glutamine in doses of 10g/8h. Prescribed radiation dose to planning target volume was 60Gy, in 30 fractions, 5 days/week. The primary endpoint included the ARIE incidence and its correlation with clinical/dosimetric factors relative to treatment with glutamine.

RESULTS

Glutamine was well tolerated. Grade 2 or 3 ARIE occurred in 20 (48.8%) of 41 patients: seven in the glutamine-supplemented group, and 13 in the glutamine-free group (p=0.002). All seven patients with grade 3 esophagitis were in the glutamine-free group (36.8% vs. 0%). Glutamine supplementation appeared to significantly delay ARIE onset for six days (22 days vs. 16 days; p=0.002). Glutamine-supplemented patients demonstrated a lower incidence of grade 2 or 3 ARIE (27.2%), and gained weight during radiotherapy (p=0.04). V55 was the only dosimetric parameter that correlated with the severity of ARIE in glutamine-free patients: a V55 of <35% had a 31% risk of ARIE grade 2 or 3, and the risk increased to 76% with a V55 of >or=35% (p=0.01).

CONCLUSION

This schedule and dosage of glutamine may be beneficial in the prevention of ARIE and weight loss in lung cancer patients undergoing thoracic irradiation.

A state-of-the-art review of esophageal trauma: where do we stand?

The esophagus provides a diagnostic and therapeutic pathway not only for gastroenterologists but for surgeons, radiologists, cardiologists, and other specialists. Unfortunately, this procedural traffic occasionally leads to iatrogenic injury. As well, though reasonably well protected anatomically, frank esophageal injuries due to non-iatrogenic causes are not uncommon. We present a review of the literature on this subject covering anatomy, etiology, diagnostics, therapeutics, and management generally.