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.

1. Tsukamoto S., Kido A., Tanaka Y. et al. Current overview of treatment for metastatic bone disease. Curr Oncol 2021;28(5):3347–72. DOI: 10.3390/curroncol28050290

2. Ong W.L., Wong S., Soliman H. et al. Radiation myelopathy following stereotactic body radiation therapy for spine metastases. J Neuroоncol 2022;159(1):23–31. DOI: 10.1007/s11060-022-04037-0

3. Dheerendra P., Schiff D. Malignant spinal-cord compression. Lancet Oncol 2005;6(1):15–24. DOI: 10.1016/S1470-2045(04)01709-7

4. Feng W., Hao Z., Li Y. et al. Epidemiological characteristics of 1196 patients with spinal metastases: a retrospective study. Orthop Surg 2019;11(6):1048–53. DOI: 10.1111/os.12552

5. Shibata H., Kato S., Sekine I. et al. Diagnosis and treatment of bone metastasis: comprehensive guideline of the Japanese Society of Medical Oncology, Japanese Orthopedic Association, Japanese Urological Association, and Japanese Society for Radiation Oncology. ESMO Open 2016;1(2):e000037. DOI: 10.1136/esmoopen-2016-000037

6. Hoskin P.J., Grover A., Bhana R. Metastatic spinal cord compression: radiotherapy outcome and dose fractionation. Radiother Oncol 2003;68(2):175–80. DOI: 10.1016/s0167-8140(03)00191-9

7. Chow E., Zeng L., Salvo N. et al. Update on the systematic review of palliative radiotherapy trials for bone metastases. Clin Oncol (R Coll Radiol) 2012;24(2):112–24. DOI: 10.1016/j.clon.2011.11.004

8. Maranzano E., Latini P. Effectiveness of radiation therapy without surgery in metastatic spinal cord compression: final results from a prospective trial. Int J Radiat Oncol Biol Phys 1995;32(4):959–67. DOI: 10.1016/0360-3016(95)00572-g

9. Alcorn S., Cortés Á.A., Bradfield L. et al. External beam radiation therapy for palliation of symptomatic bone metastases: an ASTRO clinical practice guideline. Pract Radiat Oncol 2024;14(5):377–97. DOI: 10.1016/j.prro.2024.04.018

10. Rades D., Stalpers L.J., Veninga T. et al. Evaluation of five radiation schedules and prognostic factors for metastatic spinal cord compression. J Clin Oncol 2005;23(15):3366–75. DOI: 10.1200/JCO.2005.04.754

11. Katagiri H., Takahashi M., Inagaki J. et al. Clinical results of nonsurgical treatment for spinal metastases. Int J Radiat Oncol Biol Phys 1998;42(5):1127–32. DOI: 10.1016/s0360-3016(98)00288-0

12. Martin A., Gaya A. Stereotactic body radiotherapy: a review. Clin Oncol 2010;22(3):157–72. DOI: 10.1016/j.clon.2009.12.003

13. Anderson A.B., Wedin R., Fabbri N. et al. External validation of PATHFx version 3.0 in patients treated surgically and nonsurgically for symptomatic skeletal metastases. Clin Orthop Relat Res 2020;478(4):808–18. DOI: 10.1097/corr.0000000000001081

14. Laufer I., Rubin D.G., Lis E. et al. The NOMS framework: approach to the treatment of spinal metastatic tumors. Oncologist 2013;18(6):744–51. DOI: 10.1634/theoncologist.2012-0293

15. Lutz S., Berk L., Chang E. et al. Palliative radiotherapy for bone metastases: an ASTRO evidence-based guideline. Int J Radiat Oncol Biol Phys 2011;79(4):965–76. DOI: 10.1016/j.ijrobp.2010.11.026

16. Lutz S., Balboni T., Jones J. et al. Palliative radiation therapy for bone metastases: Update of an ASTRO Evidence-Based Guideline. Pract Radiat Oncol 2017;7(1):4–12. DOI: 10.1016/j.prro.2016.08.001

17. Husain Z.A., Sahgal A., De S.A. et al. Stereotactic body radiotherapy for de novo spinal metastases: systematic review. J Neurosurg Sp 2017;27(3):295–302. DOI: 10.3171/2017.1.SPINE16684

18. Myrehaug S., Sahgal A., Hayashi M. et al. Reirradiation spine stereotactic body radiation therapy for spinal metastases: systematic review. J Neurosurg Spine 2017;27(4):428–35. DOI: 10.3171/2017.2.SPINE16976

19. Lubgan D., Ziegaus A., Semrau S. et al. Effective local control of vertebral metastases by simultaneous integrated boost radiotherapy. Strahlenther Onkol 2015;191(3):264–71. DOI: 10.1007/s00066-014-0780-4

20. Potkrajcic V., Mueller A.C., Frey B. et al. Dose-escalated radiotherapy with simultaneous integrated boost for bone metastases in selected patients with assumed favourable prognosis. Radiol Oncol 2022;56(4):515–24. DOI: 10.2478/raon-2022-0053

21. Lee Y.K., Bedford J.L., McNair H.A et al. Comparison of deliverable IMRT and VMAT for spine metastases using a simultaneous integrated boost. Br J Radiol 2013;86(1022):20120466. DOI: 10.1259/bjr.20120466

22. Guckenberger M., Mantel F., Sweeney R.A. et al. Long-term results of dose-intensified fractionated Stereotactic Body Radiation Therapy (SBRT) for painful spinal metastases. Int J Radiat Oncol Biol Phys 2021;110(2):348–57. DOI: 10.1016/j.ijrobp.2020.12.045