Differences in Normal Tissue Response in the Esophagus Between Proton and Photon Radiation Therapy for Non-Small Cell Lung Cancer Using In Vivo Imaging Biomarkers

Proton versus photon radiation therapy: A clinical review

While proton radiation therapy offers substantially better dose distribution characteristics than photon radiation therapy in certain clinical applications, data demonstrating a quantifiable clinical advantage is still needed for many treatment sites. Unfortunately, the number of patients treated with proton radiation therapy is still comparatively small, in some part due to the lack of evidence of clear benefits over lower-cost photon-based treatments. This review is designed to present the comparative clinical outcomes between proton and photon therapies, and to provide an overview of the current state of knowledge regarding the effectiveness of proton radiation therapy.

Revisiting the dose constraints for head and neck OARs in the current era of IMRT

Head and neck cancer poses a particular challenge in radiation therapy, whilst being an effective treatment modality it requires very high doses of radiation to provide effective therapy. This is further complicated by the fact that the head and neck region contains a large number of radiosensitive tissues, often resulting in patients experiencing debilitating normal tissue complications. In the era of intensity-modulated radiation therapy (IMRT) treatments can be delivered using non-uniform dose distributions selectively aimed at reducing the dose to critical organs-at-risk while still adequately covering the tumor target. Dose-volume constraints for the different risk organs play a vital role in one's ability to devise the best IMRT treatment plan for a head and neck cancer patient. To this end, it is pivotal to have access to the latest and most relevant dose constraints available and as such the goal of this review is to provide a summary of suggested dose-volume constraints for head and neck cancer RT that have been published after the QUANTEC reports were made available in early 2010.

Esophagitis associated with multimodality management of pediatric Ewing sarcoma of thorax

BACKGROUND

Ewing sarcoma of the thoracic spine and chest wall is frequently treated with concurrent chemotherapy and radiation therapy (RT). Treatment-related acute esophagitis can lead to hospitalization and treatment delays. The aim of this study was to analyze the incidence, risk factors, and management of esophagitis in pediatric patients with Ewing sarcoma of the thoracic region.

METHODS

We conducted a single-institution retrospective review of patients treated over a 10-year period. Medical records were reviewed for patient and treatment characteristics associated with Common Terminology Criteria for Adverse Events grade 2 or higher esophagitis. RT plans were also reviewed and various esophageal dose metrics were analyzed.

RESULTS

Twelve of 37 patients (32%) developed acute esophagitis. Neutropenia was associated with an increased risk of esophagitis (60% vs. 14%; P < 0.01). RT significantly contributed to its incidence when maximum esophageal dose was >47 Gy (69% vs. 5%; P < 0.0001) and esophageal D5cm³ was >15 Gy (67% vs. 9%; P < 0.001). All 12 patients with esophagitis were managed with oral opioid analgesics. Nine patients with persistent symptoms received subsequent fluconazole for empiric fungal treatment and each had a decreased need for opioid analgesics within 2-5 days.

CONCLUSION

Approximately one-third of patients with Ewing sarcoma of the thoracic region will develop acute esophagitis. An esophageal D5cm³ dose < 15 Gy and maximal esophageal dose < 47 Gy may keep the rate of acute esophagitis under 5%. However, the association with neutropenia and consistent response to antifungal therapy suggest chemotherapy-associated toxicity and an infectious component as part of the process.