SAINT: Single frActIoN eighT Gray Palliative Radiotherapy With Modulated Intensity for Pain Reduction: a Single Arm Cohort Analysis

Palliative antalgic oncological treatments concern a chronically-evolving disease patient with pain control problems, and are a complex problem from different points of view: logistic, clinical and scientific research. An increasing number of patients are afflicted due to the increased incidence of cancer in all its phases and the potential chronicity of the disease linked to new therapies.

The use of palliative anti-radiation radiotherapy treatments involves up to 40% of patients in a Radiotherapy Center. Radiotherapy was used in the palliative treatment of symptomatic bone metastases to improve quality of life (QoL) of these patients. This is the easiest way to respond to problems of home care or long-term care (eg: Hospice). This need is particularly accentuated for patients with a more severe situation. To reduce the overall duration of the treatment, it is necessary to manage hypofractionated regulators (ie with dose fractionation which daily dispense a dose higher than 2Gy). In fact, hypofractionated regimes concern the gold standard for these clinical presentations.

With the same pain control, multiple fractionation boards report better symptom control over time and are therefore very often preferred for patients with a prognosis> 6 months. On the other hand, the treatment regimen with 8 Gy in single therapy session is suggested as preferable for patients with a worse prognosis (ie less than 6 months of life expectancy). Evidence from literature suggests that palliative radiation therapy is effective in controlling pain even in the last weeks of the patient's life and therefore useful to improve the conditions of patients with a more severe prognosis.

The identification of patients with the worst prognosis to which single-agent radiotherapy is reserved is another crucial aspect. Unfortunately, although clinically validated in scientific trials, the routine use of prognostic scores is rarely used in everyday clinical practice to characterize life expectancy and define the most appropriate treatment regimen. This aspect limits the effective personalization of palliative treatments of this type.

Furthermore, the indications available in the literature do not specify a univocally shared standard of technical approach to radiant treatment. The Consensus Conference whose data have been reported by Chow et al. considers as potentially applicable both non-conformed techniques (e.g .: single back beam) and the most modern conformational techniques. The less conformed techniques have the defect of distributing in a more variable way the dose inside the target to irradiate and to save less well the organs at risk (OAR) with consequent increase of the risk of toxicity that could reduce the beneficial to the patient given by the reduction of pain from metastases.