Radiotherapy of spinal metastases using simultaneous integrated boost

Introduction. Stereotactic radiation therapy (SRT) is increasingly used for the treatment of bone metastases. In cases where stereotactic radiation therapy is contraindicated, an increase in the radiation dose at the site of the lesion can be achieved using the simultaneous integrated boost (SIB).Aim. The aim of our study is to investigate the role of radiation therapy using the SIB in the treatment of patients with painful spinal metastases.Materials and methods. The study examined the results of radiation therapy in patients with painful spinal metastases who were treated at the National Medical Research Center of Oncology named after N. N . Blokhin in the period from 2022 to 2023. Patients received radiation therapy with a regimen of 25 Gy in 5 fractions, with dose escalation at the site of the lesion to 30–35 Gy using the simultaneous integrated boost (SIB) (n = 65), or with a regimen of 25 Gy in 5 fractions without the use of SIB (n = 70). Primary endpoint was pain response at 12 months after radiotherapy. Secondary outcomes were long-term treatment results, data from control X-ray examinations, local relapses and mortality.Results. 12 months after radiation therapy, the survival rate in the main group was 33.8 %, compared to 41.4 % in the control group (p = 0.855). Pain response was achieved in 86.3 % (n = 19) of the main group patients and 75.8 % (n = 22) of the control group patients (p = 0.483). The frequency of recurrence of pain syndrome was significantly higher in the control group (p = 0.031). Neurological status improvement following radiation therapy was observed in 59 % of the main group and 46 % of the control group patients who had neurological deficits related to vertebral metastases. Early complications of radiotherapy of grades I–II were observed in 26 (40 %) of the main group patients and 23 (32.8 %) of the control group. Grade III toxicity was recorded in only 1 (1.42 %) patient in the control group, in the form of increased pain to 7 points on the visual analog scale. No grade IV–V complications were noted.Conclusions. In radiotherapy of spinal metastases, increasing the radiation dose in the macroscopic lesion area using SIB reduces the risk of pain relapse in the irradiated area. Furthermore, this approach does not increase the risk of radiation complications and may serve as a possible alternative to stereotactic radiation therapy for a specific group of patients.