Radiotherapy for non-malignant shoulder syndrome: Is there a risk for radiation-induced carcinogenesis?

Risk factors of secondary cancer in laryngeal, oropharyngeal, or hypopharyngeal cancer after definitive therapy

BACKGROUND

Our previous research showed that a high rate of secondary carcinogenesis is observed during follow-up after transoral surgery in patients with early-stage laryngeal, oropharyngeal, and hypopharyngeal cancers. We speculate that the contributing factors are alcohol drinking, smoking, and aging; however, we could not provide clear evidence. In this study, we aimed to identify the risk factors for secondary carcinogenesis in patients with these cancers, particularly factors associated with drinking and/or smoking.

METHODS

The medical records of all-stage laryngeal, oropharyngeal, and hypopharyngeal cancer patients who had undergone definitive treatment were retrospectively analyzed. Assessments included visual and endoscopic observations of the primary site, enhanced cervical CT or US of the primary site and regional lymph nodes, PET-CT, and enhanced whole-body CT. Clinical characteristics were compared in patients with and without secondary carcinogenesis and in patients with hypopharyngeal cancer and patients with other cancers.

RESULTS

Hypopharyngeal cancer was an independent risk factor for secondary cancer. The 5-year incidence rate of secondary cancer was 25.5%, 28.6%, and 41.2% in laryngeal, oropharyngeal, and hypopharyngeal cancers, respectively. Radiotherapy was defined as an independent risk factor in hypopharyngeal cancer patients with secondary cancers. No direct correlation was found between secondary carcinogenesis and alcohol consumption, smoking, or aging.

CONCLUSIONS

Patients with hypopharyngeal cancer require close follow-up as they are at high risk of developing secondary cancer, possibly because out-of-field radiation exposure may induce systemic secondary carcinogenesis in hypopharyngeal cancer patients with genetic abnormality induced by alcohol consumption.

Radiotherapy CT-based contouring atlas for non-malignant skeletal and soft tissue disorders: a practical proposal from Spanish experience

OBJECTIVE

Interest in low-dose radiotherapy (LD-RT) for the symptomatic treatment of nonmalignant conditions, including inflammatory and degenerative disorders of the joints and para-articular soft tissues, has increased substantially in recent years. In the present document, we provide a CT-based contouring atlas to help identify and delineate the most common osteoarticular regions susceptible to LD-RT.

METHODS

The clinical efficacy of LD-RT is supported by a large body of evidence. However, there is no consensus on the parameters for contouring the planning target volume (PTV). Moreover, 3D simulation and planning should be the standard of care even for nonmalignant disorders. For this reason, the present guidelines were prepared to help guide PTV contouring based on CT images, with the same quality criteria for patient immobilization, treatment simulation, planning and delivery as those routinely applied for cancer radiotherapy.

RESULTS

PTV for radiotherapy requires precise identification of the target areas based on CT and other imaging techniques. Using a series of cases treated at our institution, we have defined the PTVs for each location on the simulation CT to establish the relationship between the image and the anatomical structures to be treated. We also specify the immobilization systems used to ensure treatment accuracy and reproducibility.

CONCLUSIONS

This comprehensive atlas based on CT images may be of value to radiation oncologists who wish to use LD-RT for the symptomatic treatment of degenerative or inflammatory osteoarticular diseases.

ADVANCES IN KNOWLEDGE

The recommendations and contouring atlas described in this article provide an eminently practical tool for LD-RT in non-malignant conditions, based on the same quality criteria recommended for all modern radiotherapy treatments in Spain.