A Multi-Institutional Analysis of Radiation Dosimetric Predictors of Toxicity After Trimodality Therapy for Esophageal Cancer

Minimizing Long-Term Toxicities for Patients with Primary Mediastinal B-Cell Lymphoma Undergoing Modern Radiotherapy: Results from a Monocentric Biophysical Risk Evaluation

Introduction: Primary mediastinal B-cell lymphoma (PMBCL) is a rare form of aggressive B-cell lymphoma with a predominant onset in young patients. The minimization of potential (late) side effects is of cardinal interest for these patients. An anticipation of the individual risk profile is desirable to counsel the patient on the putative impact of radiotherapy (RT). Methods: RT plans for a cohort of 25 patients with PMBCL were prospectively designed. One plan with two parallel- opposing fields (APPA) and another with volume-modulated arc therapy (VMAT) technique with 40 Gy in 2 Gy fractions each. Normal The normal tissue complication probability (NTCP) was calculated using the Lyman--Kutcher--Burman model for heart, lung and oesophageal toxicity. Results: APPA planning resulted in lower median doses (Dmedian) for the heart and lungs, whereas all other dose metrics for heart, lungs and esophagus were lower in VMAT planning. A significant difference in the mean NTCPs when comparing the APPA to VMAT plans was seen for increased cardiac mortality, pneumonitis and esophagitis. PTV size correlated with increased cardiac mortality and esophagitis in both plan variations and with pneumonitis for VMAT plans. Dmean, Dmedian, and V20Gy correlated with the risk for pneumonitis, and Dmean, Dmedian, and V1% with the risk for esophagitis in both variants. Conclusions: We showed decreased risk of different NTCPs for VMAT and APPA planning for thoracic toxicities. The use of an IMRT technique like VMAT showed advantages for several DVH metrics in organs at risk and should therefore be recommended for radiation treatment of PMBCL.

Outcomes from a single institution cohort of 248 patients with stage I-III esophageal cancer treated with radiotherapy: Comparison of younger and older populations

Outcomes for patients receiving radiotherapy (RT) for non-metastatic esophageal cancer at a single institution were assessed, as well as the impact of factors including age and intensity modulated RT (IMRT) planning on patient outcomes. A retrospective cohort of patients treated with RT for stage I-III esophageal cancer between 2010 and 2018 was identified. Among 248 identified patients, 28 % identified as older (≥75 years of age). Other than histology, there were no other statistically significant differences in patient and tumour characteristics between the younger and older populations. Treatments varied between the two age groups, with significantly less older patients completing trimodality treatments (17 % vs 58 %). Median overall survival (M-OS) and progression-free survival (M-PFS) were 20 months and 12 months for all patients and 40 months and 26 months for trimodality patients, respectively. In the older patients, the M-OS improved from 13 months for all to 34 months for trimodality patients; and M-PFS from 10 months to 16 months. On multivariate analysis, the use of trimodality therapy showed improved OS (HR 0.26, p < 0.001). In the non-surgical older patient group, significantly better survival was seen in patients who had a heart V30Gy under 46 %. There was no significant difference in M-OS in patients planned with IMRT compared with 3D-conformal RT. Clinical outcomes in the treatment of esophageal cancer vary significantly by treatment approach, with the most favourable results in those receiving trimodality therapy. Among older patients deemed fit after assessment by the multidisciplinary team for trimodality treatments, the M-OS is comparable to the younger patient group.

A Prospective Pilot Study of Pencil Beam Scanning Proton Radiation Therapy as a Component of Trimodality Therapy for Esophageal Cancer

Purpose

To evaluate the safety and efficacy of pencil beam scanning (PBS) proton radiation therapy (RT) in trimodality therapy for esophageal cancer.

Methods and Materials

This prospective pilot study was planned to accrue 30 patients with locally advanced esophageal or gastroesophageal junction carcinoma medically suitable for chemoradiation therapy (CRT) followed by esophagectomy. PBS proton RT consisted of 25 fractions, 50 Gy to tumor + 1 cm and 45 Gy to a 3.5 cm mucosal expansion and regional lymph nodes. Chemotherapy included weekly carboplatin (area under the curve, 2 mg/mL/min) and paclitaxel (50 mg/m2). At 4 to 8 weeks after CRT, patients underwent restaging and potential esophagectomy. The primary endpoint was acute grade 3+ adverse events (AEs) attributed to CRT. Overall survival and progression-free survival were assessed using the Kaplan-Meier methodology; local-regional recurrence and distant metastases rates were assessed using the cumulative incidence methodology. The Functional Assessment of Cancer Therapy-Esophagus assessed quality of life.

Results

Thirty eligible patients were enrolled from June 2015 to April 2017. Median age was 68 years. Histology was adenocarcinoma in 87%, and location was distal esophagus/gastroesophageal junction in 90%. Stage was T3 to T4 in 87% and N1 to N3 in 80%. All patients completed the planned RT dose. Acute grade 3+ AEs occurred in 30%, most commonly leukopenia and neutropenia. Acute grade 3+ nonhematologic AEs occurred in 3%. Esophagectomy was performed in 90% of patients (R0 in 93%). Pathologic complete response rate was 40%. Major postoperative complications (Clavien-Dindo score, ≥3) occurred in 34%. Postoperative mortality at 30 days was 3.7%. Median follow-up was 5.2 years. Five-year outcome estimates were overall survival at 46%, progression-free survival at 39%, local-regional recurrence at 17%, and distant metastases at 40%. Functional Assessment of Cancer Therapy-Esophagus scores (medians) at baseline, at the end of CRT, before esophagectomy, at 12 months, and at 24 months were 145, 136 (p = .0002 vs baseline), 144, 146 and 157, respectively.

Conclusions

PBS proton RT is feasible and safe as a component of trimodality therapy for esophageal cancer.

A nomogram based on pretreatment radiomics and dosiomics features for predicting overall survival associated with esophageal squamous cell cancer

OBJECTIVES

To propose a nomogram-based survival prediction model for esophageal squamous cell carcinoma (ESCC) treated with definitive chemoradiotherapy using pretreatment computed tomography (CT), positron emission tomography (PET) radiomics and dosiomics features, and common clinical factors.

METHODS

Radiomics and dosiomics features were extracted from CT and PET images and dose distribution from 2 institutions. The least absolute shrinkage and selection operator (LASSO) with logistic regression was used to select radiomics and dosiomics features by calculating the radiomics and dosiomics scores (Rad-score and Dos-score), respectively, in the training model. The model was trained in 81 patients and validated in 35 patients at Center 1 using 10-fold cross validation. The model was externally tested in 26 patients at Center 2. The predictive clinical factors, Rad-score, and Dos-score were identified to develop a nomogram model.

RESULTS

Using LASSO Cox regression, 13, 11, and 19 CT, PET-based radiomics, and dosiomics features, respectively, were selected. The clinical factors T-stage, N-stage, and clinical stage were selected as significant prognostic factors by univariate Cox regression. In the external validation cohort, the C-index of the combined model of CT-based radiomics, PET-based radiomics, and dosiomics features with clinical factors were 0.74, 0.82, and 0.92, respectively. Significant differences in overall survival (OS) in the combined model of CT-based radiomics, PET-based radiomics, and dosiomics features with clinical factors were observed between the high- and low-risk groups (P = 0.019, 0.038, and 0.014, respectively).

CONCLUSION

The dosiomics features have a better predicter for OS than CT- and PET-based radiomics features in ESCC treated with radiotherapy.

CLINICAL RELEVANCE STATEMENT

The current study predicted the overall survival for esophageal squamous cell carcinoma patients treated with definitive chemoradiotherapy. The dosiomics features have a better predicter for overall survival than CT- and PET-based radiomics features.

External validation of a lung cancer-based prediction model for two-year mortality in esophageal cancer patient cohorts

PURPOSE/OBJECTIVE

Chemo-radiotherapy can improve the oncological outcome of esophageal cancer (EC) patients, but may cause long term radiation-induced toxicity, including an increased risk of non-cancer related death. For lung cancer patients, a model to predict 2-year total mortality using mean heart dose (MHD) and gross tumor volume (GTV) has previously been developed and validated. This project aimed to externally validate this model in EC patients.

METHODS

Five EC patient cohorts from 3 different Dutch centres were used for model validation. External validity of the model was assessed separately in definitive (n = 170) and neo-adjuvant (n = 568) chemoradiotherapy (dCRT and nCRT) patients. External validity was assessed in terms of calibration by calibration plots, calibration-in-the-large (CITL) and calibration slope (CS), and discrimination by assessment of the c-statistic. If suboptimal model performance was observed, the model was further updated accordingly.

RESULTS

For the dCRT patients, good calibration was found after adjustment of the intercept (CITL 0.00; CS 1.08). The c-statistic of the adjusted model was 0.67 (95%CI: 0.58 to 0.75). For nCRT patients the model needed adjustment of both the slope and the intercept because of initial miscalibration in the validation population (CITL 0.00; CS 1.72). After recalibration, the model showed perfect calibration (i.e., CITL 0, CS 1), as is common after recalibration. The c-statistic of the recalibrated model equaled 0.62 (95%CI: 0.57 to 0.67).

CONCLUSION

The existing model for 2-year mortality prediction in lung cancer patients, based on the predictive factors MHD and GTV, showed good performance in EC patients after updating the intercept and/or slope of the original model.

Incident Atrial Fibrillation and Survival Outcomes in Esophageal Cancer following Radiotherapy

PURPOSE

Radiation therapy (RT) associates with long-term cardiotoxicity. In preclinical models, RT exposure induces early cardiotoxic arrhythmias including atrial fibrillation (AF). Yet, whether this occurs in patients is unknown.

METHODS AND MATERIALS

Leveraging a large cohort of consecutive patients with esophageal cancer treated with thoracic RT from 2007 to 2019, we assessed incidence and outcomes of incident AF. Secondary outcomes included major adverse cardiovascular events (MACE), defined as AF, heart failure, ventricular arrhythmias, and sudden death, by cardiac RT dose. We also assessed the relationship between AF development and progression-free and overall survival. Observed incident AF rates were compared with Framingham predicted rates, and absolute excess risks were estimated. Multivariate regression was used to define the relationship between clinical and RT measures, and outcomes. Differences in outcomes, by AF status, were also evaluated via 30-day landmark analysis. Furthermore, we assessed the effect of cardiac substructure RT dose (eg, left atrium, LA) on the risk of post RT-related outcomes.

RESULTS

Overall, from 238 RT treated patients with esophageal cancer, 21.4% developed incident AF, and 33% developed MACE with the majority (84%) of events occurring ≤2 years of RT initiation (median time to AF, 4.1 months). Cumulative incidence of AF and MACE at 1 year was 19.5%, and 25.7%, respectively; translating into an observed incident AF rate of 824 per 10,000 person-years, compared with the Framingham predicted rate of 92 (relative risk, 8.96; P < .001, absolute excess risk 732). Increasing LA dose strongly associated with incident AF (P = .001); and those with AF saw worse disease progression (hazard ratio, 1.54; P = .03). In multivariate models, outside of traditional cancer-related factors, increasing RT dose to the LA remained associated with worse overall survival.

CONCLUSIONS

Among patients with esophageal cancer, radiation therapy increases AF risk, and associates with worse long-term outcomes.

Comparison of esketamine versus dexmedetomidine for attenuation of cardiovascular stress response to double-lumen tracheal tube intubation: a randomized controlled trial

Introduction

The insertion of a double-lumen tracheal tube may cause a transient but more intense sympathetic response. We examined the effects of esketamine vs. dexmedetomidine as an adjuvant to anesthesia induction to blunt double lumen tracheal (DLT) intubation induced cardiovascular stress response.

Methods

In a randomized, double-blind trial, 78 adult patients scheduled for elective thoracotomy under general anesthesia requiring DLT intubation were enrolled. The patients were randomly divided into three groups: each group received one of the following drugs prior to induction of anesthesia: dexmedetomidine 0.8 µg/kg (Group A), esketamine 0.5 mg/kg (Group B), or normal saline (group C). The primary outcome was the incidence of a DLT intubation-related cardiovascular stress response, defined as an increase in mean arterial pressure or heart rate of >30% above the baseline values. The secondary outcomes were changes in hemodynamic and cardiac function.

Results

The incidence of the response to cardiovascular stress was 23.1%, 30.8%, and 65.4% in groups A, B, and C, respectively. There was a significant decrease in intubation response in groups A and B in comparison with group C (P < 0.01); however, there was no significant difference between group A and group B (P > 0.05). Following the drug infusion and the induction of anesthesia, there was a significant decrease in HR and cardiac output in group A compared with group B. In contrast, no significant differences were observed in the left ventricular ejection fraction or in stroke volume between the three groups during induction of anesthesia.

Discussion

Esketamine 0.5 mg/kg and dexmedetomidine 0.8 µg/kg attenuate cardiovascular stress responses related to DLT intubation. As adjuvants to etomidate induction, they do not impair cardiac function (ChiCTR1900028030).

Development and validation of a nomogram to predict cardiac death after radiotherapy for esophageal cancer

Background

Patients frequently die from cardiac causes after radiotherapy for esophageal cancer. Early detection of cardiac death risk in these patients is crucial to improve clinical decision-making and prognosis. Thus, we modeled the risk of cardiac death after irradiation for esophageal cancer.

Methods

A retrospective analysis of 37,599 esophageal cancer cases treated with radiotherapy in the SEER database between 2000 and 2018 was performed. The selected cases were randomly assigned to the model development group (n = 26,320) and model validation group (n = 11,279) at a ratio of 7:3. We identified the risk factors most commonly associated with cardiac death by least absolute shrinkage and selection operator regression analysis (LASSO). The endpoints for model development and validation were 5- and 10-year survival rates. The net clinical benefit of the models was evaluated by decision curve analysis (DCA) and concordance index (C-index). The performance of the models was further assessed by creating a receiver operating characteristic curve (ROC) and calculating the area under the curve (AUC). Kaplan-Meier (K-M) survival analysis was performed on the probability of death. Patients were classified according to death probability thresholds. Five- and ten-year survival rates for the two groups were shown using K-M curves.

Results

The major risk factors for cardiac death were age, surgery, year of diagnosis, sequence of surgery and radiotherapy, chemotherapy and a number of tumors, which were used to create the nomogram. The C-indexes of the nomograms were 0.708 and 0.679 for the development and validation groups, respectively. DCA showed the good net clinical benefit of nomograms in predicting 5- and 10-year risk of cardiac death. The model exhibited moderate predictive power for 5- and 10-year cardiac mortality (AUC: 0.833 and 0.854, respectively), and for the development and validation cohorts (AUC: 0.76 and 0.813, respectively).

Conclusions

Our nomogram may assist clinicians in making clinical decisions about patients undergoing radiotherapy for esophageal cancer based on early detection of cardiac death risk.

Risk stratification of postoperative cardiopulmonary toxicity after trimodality therapy for esophageal cancer

Purpose/objective

Postoperative toxicity for esophageal cancer impacts patient quality of life and potentially overall survival (OS). We studied whether patient and toxicity parameters post-chemoradiation therapy predict for post-surgical cardiopulmonary total toxicity burden (CPTTB) and whether CPTTB was associated with short and long-term outcomes.

Materials/methods

Patients had biopsy-proven esophageal cancer treated with neoadjuvant chemoradiation and esophagectomy. CPTTB was derived from total perioperative toxicity burden (Lin et al. JCO 2020). To develop a CPTTB risk score predictive for major CPTTB, recursive partitioning analysis was used.

Results

From 3 institutions, 571 patients were included. Patients were treated with 3D (37%), IMRT (44%), and proton therapy (19%). 61 patients had major CPTTB (score ≥ 70). Increasing CPTTB was predictive of decreased OS (p<0.001), lengthier post-esophagectomy length of stay (LOS, p<0.001), and death or readmission within 60 days of surgery (DR60, p<0.001). Major CPTTB was also predictive of decreased OS (hazard ratio = 1.70, 95% confidence interval: 1.17-2.47, p=0.005). The RPA-based risk score included: age ≥ 65, grade ≥ 2 nausea or esophagitis attributed to chemoradiation, and grade ≥ 3 hematologic toxicity attributed to chemoradiation. Patients treated with 3D radiotherapy had inferior OS (p=0.010) and increased major CPTTB (18.5% vs. 6.1%, p<0.001).

Conclusion

CPTTB predicts for OS, LOS, and DR60. Patients with 3D radiotherapy or age ≥ 65 years and chemoradiation toxicity are at highest risk for major CPTTB, predicting for higher short and long-term morbidity and mortality. Strategies to optimize medical management and reduce toxicity from chemoradiation should be strongly considered.

Cardiotoxicity of Anti-Cancer Radiation Therapy: a Focus on Heart Failure

PURPOSE OF REVIEW

As the percentage of patients achieving long-term survival following treatment of their cancer grows, it is increasingly important to understand the long-term toxicities of cancer-directed treatment. In this review, we highlight the recent findings regarding radiation-induced cardiotoxicity across multiple disease sites, with a particular focus on heart failure.

RECENT FINDINGS

Despite its relative lack of study historically, radiation-induced heart failure has now recently been implicated in several studies of breast cancer, lung cancer, esophageal cancer, and lymphoma as a non-trivial potential consequence of thoracic radiotherapy. Data regarding specific cardiac dosimetric endpoints relevant to cardiotoxicity continue to accumulate. Radiation-induced heart failure is a rare but significant toxicity of thoracic radiotherapy, that is likely underreported. Important areas for future focus include understanding the interplay between thoracic radiotherapy and concurrent cardiotoxic systemic therapy as well as development of potential mitigation strategies and novel therapeutics.

CArdiac and REspiratory adaptive Computed Tomography (CARE-CT): a proof-of-concept digital phantom study

Current respiratory 4DCT imaging for high-dose rate thoracic radiotherapy treatments are negatively affected by the complex interaction of cardiac and respiratory motion. We propose an imaging method to reduce artifacts caused by thoracic motion, CArdiac and REspiratory adaptive CT (CARE-CT), that monitors respiratory motion and ECG signals in real-time, triggering CT acquisition during combined cardiac and respiratory bins. Using a digital phantom, conventional 4DCT and CARE-CT acquisitions for nineteen patient-measured physiological traces were simulated. Ten respiratory bins were acquired for conventional 4DCT scans and ten respiratory bins during cardiac diastole were acquired for CARE-CT scans. Image artifacts were quantified for 10 common thoracic organs at risk (OAR) substructures using the differential normalized cross correlation between axial slices (ΔNCC), mean squared error (MSE) and sensitivity. For all images, on average, CARE-CT improved the ΔNCC for 18/19 and the MSE and sensitivity for all patient traces. The ΔNCC was reduced for all cardiac OARs (mean reduction 21%). The MSE was reduced for all OARs (mean reduction 36%). In the digital phantom study, the average scan time was increased from 1.8 ± 0.4 min to 7.5 ± 2.2 min with a reduction in average beam on time from 98 ± 28 s to 45 s using CARE-CT compared to conventional 4DCT. The proof-of-concept study indicates the potential for CARE-CT to image the thorax in real-time during the cardiac and respiratory cycle simultaneously, to reduce image artifacts for common thoracic OARs.

Efficacy and Safety of Simultaneous Integrated Boost Intensity-Modulation Radiation Therapy Combined with Systematic and Standardized Management for Esophageal Cancer

Objective

To analyze and compare the efficacy and safety of simultaneous integrated boost intensity-modulation radiation therapy (SIB-IMRT) combined with systematic and standardized management for esophageal cancer.

Methods

From January 2012 to January 2019, 200 patients with esophageal cancer who received radical chemoradiotherapy in our hospital were treated with lymphatic drainage area radiation prevention combined with systematic and standardized management. According to difference in radiotherapy methods, the patients were divided into local lesion 92 patients treated with simultaneous integrated boost intensity-modulation radiation therapy (SIB-IMRT) combined with systematic standardized management (SIB-IMRT group), and late course boost intensity-modulation radiation therapy (LCB-IMRT) combined with systematic standardized management 108 patients (LCB-IMRT group). The short-term eficacy of the two groups were compared. The dose volume parameters of the organ in danger are evaluated based on the dose volume histogram. The related adverse reactions during chemoradiotherapy were compared between two groups. The local control rate and survival rate were compared between the two groups.

Results

The recent total effective rates of rats in the SIB-IMRT group and LCB-IMRT group were 95.65% and 90.74%, respectively, and there was no significant difference between the two groups (p > 0.05). The mean doses to left and right lung, heart and spinal cord in the SIB-IMRT group were significantly lower than that in the LCB-IMRT group (p < 0.05). There was no significant difference in the incidence of adverse reactions such as radiation esophagitis, radiation pneumonitis, radiation tracheitis, gastrointestinal reaction and bone marrow suppression between the SIB-IMRT group and LCB-IMRT groups (p > 0.05). The one-year and three-year overall survival rates in the SIB-IMRT group and LCB-IMRT groups were 82.61%, 42.39% and 77.78%, 34.26%, respectively, and the median survival times were 38 and 29 months, respectively. The local control rates in the SIB-IMRT group and LCB-IMRT group in one and three years were 84.78%, 56.52% and 75.93%, 41.67%, respectively. The 3-year local control rate in the SIB-IMRT group was higher than that in the LCB-IMRT group (p < 0.05), but there was no significant difference in the 1-and 3-year overall survival rates between the two groups (p > 0.05).

Conclusion

SIB-IMRT combined with systematic and standardized management in the treatment of esophageal cancer can reduce the amount of some organs at risk and improve the local control rate of the lesion.

Treatment planning comparison in the PROTECT-trial randomising proton versus photon beam therapy in oesophageal cancer: results from eight european centres

PURPOSE

To compare dose distributions and robustness in treatment plans from eight European centres in preparation for the European randomized phase-III PROTECT-trial investigating the effect of proton therapy (PT) versus photon therapy (XT) for oesophageal cancer.

MATERIALS AND METHODS

All centres optimized one PT and one XT nominal plan using delineated 4DCT scans for four patients receiving 50.4Gy(RBE) in 28 fractions. Target volume receiving 95% of prescribed dose (V95%_iCTVtotal) should be >99%. Robustness towards setup, range, and respiration was evaluated. The plans were recalculated on a surveillance 4DCT (sCT) acquired at fraction ten and robustness evaluation was performed to evaluate the effect of respiration and inter-fractional anatomical changes.

RESULTS

All PT and XT plans complied with V95%_iCTVtotal>99% for the nominal plan and V95%_iCTVtotal>97% for all respiratory and robustness scenarios. Lung and heart dose varied considerably between centres for both modalities. The difference in mean lung dose and mean heart dose between each pair of XT and PT plans was in median [range] 4.8Gy [1.1;7.6] and 8.4Gy [1.9;24.5], respectively. Patients B and C showed large inter-fractional anatomical changes on sCT. For patient B, the minimum V95%_iCTVtotal in the worst-case robustness scenario was 45% and 94% for XT and PT, respectively. For patient C, the minimum V95%_iCTVtotal was 57% and 72% for XT and PT, respectively. Patient A and D showed minor inter-fractional changes and the minimum V95%_iCTVtotal was >85%.

CONCLUSION

Large variability in dose to the lungs and heart was observed for both modalities. Inter-fractional anatomical changes led to larger target dose deterioration for XT than PT plans.

All for one, though not one for all: team players in normal tissue radiobiology

PURPOSE

As part of the special issue on 'Women in Science', this review offers a perspective on past and ongoing work in the field of normal (non-cancer) tissue radiation biology, highlighting the work of many of the leading contributors to this field of research. We discuss some of the hypotheses that have guided investigations, with a focus on some of the critical organs considered dose-limiting with respect to radiation therapy, and speculate on where the field needs to go in the future.

CONCLUSIONS

The scope of work that makes up normal tissue radiation biology has and continues to play a pivotal role in the radiation sciences, ensuring the most effective application of radiation in imaging and therapy, as well as contributing to radiation protection efforts. However, despite the proven historical value of preclinical findings, recent decades have seen clinical practice move ahead with altered fractionation scheduling based on empirical observations, with little to no (or even negative) supporting scientific data. Given our current appreciation of the complexity of normal tissue radiation responses and their temporal variability, with tissue- and/or organ-specific mechanisms that include intra-, inter- and extracellular messaging, as well as contributions from systemic compartments, such as the immune system, the need to maintain a positive therapeutic ratio has never been more urgent. Importantly, mitigation and treatment strategies, whether for the clinic, emergency use following accidental or deliberate releases, or reducing occupational risk, will likely require multi-targeted approaches that involve both local and systemic intervention. From our personal perspective as five 'Women in Science', we would like to acknowledge and applaud the role that many female scientists have played in this field. We stand on the shoulders of those who have gone before, some of whom are fellow contributors to this special issue.