Particularly with improving survival times for cancer patients, re-irradiation is an increasingly important consideration. Eight percent to 42% of patients will undergo re-irradiation following palliative bone radiotherapy.13 No prospective clinical studies of re-irradiation outcomes have been published, but perhaps not surprisingly, single-dose palliative radiotherapy appears to require re-irradiation more frequently due to nonresponsive or recurring metastatic bone tumors than does multifraction radiotherapy regimens.13
A systematic review of 10 published studies, found that overall, 20% of clinical trial participants undergo re-irradiation, and that pain alleviation was achieved in only 58% of those patients.13 Forty percent of patients represented in the review did not benefit from re-irradiation.13 Additional studies are clearly needed, but based on the three reviewed studies that included adverse events data, re-irradiation-associated toxicities include mostly mild (grade 1 or 2) nausea, vomiting, and diarrhea and severe fatigue.13
When bone metastases or their recurrence are widespread throughout the skeleton, systematic administration of bone-seeking radionuclides, bisphosphonates, or denosumab are appropriate.13 But for localized, nonresponding or recurrent metastatic bone pain, the authors find a focal approach seems more suitable.13 “Options include more focused radiotherapy, such as stereotactic body radiotherapy (SBRT) for spinal metastases, as well as image-guided therapies,” said the authors.
OTHER EMERGING MODALITIES
Radioresistant tumor recurrence frequently precludes effective re-irradiation, highlighting the need for alternative modalities for bone tumor palliation. Newer treatment modalities that might help patients for whom radiotherapy is no longer viable are entering the clinic.
Two relatively new treatments are microwave tumor ablation and magnetic resonance imaging (MRI)-guided focused ultrasound ablation (MRIgFUS), a form of high-intensity focused ultrasound (HIFU).14 In 2012, the FDA approved MRIgFUS for bone metastasis palliation in patients whose tumors do not respond to or who are not candidates for external-beam radiotherapeutic palliation.14 ONA
Bryant Furlow is a medical journalist based in Albuquerque, New Mexico.
1. Ashford RU, Bejamin L, Pendlebury S, Stalley PD. The modern surgical and non-surgical management of appendicular skeletal metastases. Orthop Trauma. 2012;26(3):184-199.
2. Rades D, Schild SE, Abrahm JL. Treatment of painful bone metastases. Nat Rev Clin Oncol. 2010;7(4):220-229.
3. Lutz S, Berk L, Chang E, et al; American Society for Radiation Oncology (ASTRO). Palliative radiotherapy for bone metastases: an ASTRO evidence-based guideline. Int J Radiat Oncol Biol Phys. 2011;79(4):965-976. http://download.journals.elsevierhealth.com/pdfs/journals/0360-3016/PIIS0360301610035777.pdf. Accessed July 16, 2013.
4. Sturge J, Caley MP, Waxman J. Bone metastases in prostate cancer: emerging therapeutic strategies. Nat Rev Clin Oncol. 2011;8(6):357-368.
5. Christensen MH, Petersen LJ. Radionuclide treatment of painful bone metastases in patients with breast cancer: a systematic review. Cancer Treat Rev. 2012;38(2):164-171.
6. Goyal J, Antonarakis ES. Bone-targeting radiopharmaceuticals for the treatment of prostate cancer with bone metastases. Cancer Lett. 2012;323(2):135-146.
7. Lutz S, Korytko T, Nguyen J, et al. Palliative radiotherapy: when is it worth it and when is it not? Cancer J. 2010;16(5):473-482.
8. Zeng L, Chow E, Bedard G, et al. Quality of life after palliative radiation therapy for patients with painful bone metastases: results of an international study validating the EORTC QLQ-BM22. Int J Radiat Oncol Biol Phys. 2012;84(3):e337-e342. doi:10.1016/j.irobp.2012.05.028.
9. Fairchild A, Barnes E, Ghosh S, et al. International patterns of practice in palliative radiotherapy for painful bone metasatases: evidence-based practice? Int J Radiation Oncology Biol Phys. 2009;75(5):1501-1510.
10. Zeng L, Chow E. The added challenges of bone metastases treatment in elderly patients. Clinical Oncol (R Coll Radiol). 2013;25(5):383-289.
11. Dennis K, Mahhani L, Zeng L, et al. Single fraction conventional external beam radiation therapy for bone metastases: a systematic review of randomised controlled trials [published online ahead of print January 13, 2013]. Radiother Oncol. 2013;106(1):5-14. doi:10.1016/j.radonc.2012.12.009.
12. Chow E, Hoskin P, Mitera G, et al; International Bone Metastases Consensus Working Party. Update on the international consensus on palliative radiotherapy endpoints for future clinical trials in bone metastases. Int J Radiat Oncol Biol Phys. 2012;82(5):1730-1737. Doi:10.1016/j.ijrobp.2011.02.008.
13. Huisman M, van den Bosch MA, Wijlemans JW, et al. Effectiveness of reirradiation for painful bone metastases: a systematic review and meta-analysis. Int J Radiat Oncol Biol Phys. 2012;84(1):8-14. doi:10.1016/j.ijrobp.2011.10.080.
14. Furlow B. MRI-guided focused ultrasound ablation offers new treatment option for bone tumor pain. Chemotherapy Advisor.com Web site. Published November 5, 2012. http://www.chemotherapyadvisor.com/mri-guided-focused-ultrasound-ablation-offers-new-treatment-option-for-bone-tumor-pain/article/267023/. Accessed July 16, 2013.