Radiation as a therapy uses either external beam radiation or radiosynoviorthesis (radiosynovectomy), which administers ionizing radiation to a targeted location to kill abnormal cells. External beam radiation uses a guided machine that produces a high dose of radiation and aims it at the tumor location. Radiosynoviorthesis involves a local injection of radioactive material (Yttrium-90, Y-90) to kill tumor cells within that location (1). Both of these radiation techniques can be given alone or in combination with another treatment, such as surgery. However, the effectiveness of either external beam radiation and radiosynoviorthesis remains unclear. Recent studies have shown that the use of radiosynoviorthesis does not impact recurrence rates in patients with diffuse TGCT of the knee (2). The associated risks with the radioactive isotope limits the use of the radiosynovectomy and this is now considered an investigational strategy that is not recommended (3). A consensus paper for the best practices for TGCT was developed by a community of 50 global experts and describes that the radiosynovectomy has not been shown to be effective in the treatment of TGCT and does not compensate for the inability to remove all the disease during surgery (4). Additionally, no expert within that community uses external beam radiation and the use of the modality is controversial among providers.
Other studies have found no difference in TGCT patients pain, overall physical and mental health, or treatment satisfaction 7 years post-treatment with radiation (2). This means that radiation does not seem to benefit patients following treatment. However, due to the limited number of studies and the poor quality of the data, it is hard to determine if radiation impacts the outcome for TGCT patients long-term.
There are many complications associated with the use of radiation therapy. One of the most concerning complications is the increased risk for radiation-induced sarcoma. This means that radiation treatment on these tumors can lead to the tumors becoming cancerous (5). Additional complications include joint stiffness, joint damage, joint bleeding, and fibrosis. Due to the concerns of the uncertainty in the effectiveness of this treatment and the complications associated, it is generally recommended to avoid the use of radiation in TGCT patients when other options are available (6). However, it can vary based on disease severity, recurrence, available therapies, geographical location, and patient characteristics.
Consult with your healthcare team about the risks and benefits of all options.
Consult with your healthcare team about the risks and benefits of all options.
References
1. Özcan Z. Radiosynovectomy in Hemophilic Synovitis. Malecular Imaging Radionucl Ther. 2014. doi:10.4274/mirt.49369 2. Gortzak Y, Vitenberg M, Frenkel Rutenberg T, et al. Inconclusive benefit of adjuvant 90 Yttrium hydroxyapatite to radiosynovectomy for diffuse-type tenosynovial giant-cell tumour of the knee. Bone Jt J. 2018;100-B(7):984-988. doi:10.1302/0301-620X.100B7.BJJ-2017-0867.R3 3. Heiden, Gibbons, Hassan, Kroeber, Gelderblom, van Rijswijk, Nout, Bradley, Athanasou, Dijksta, Hogendoorn, van de Sande. A multidisciplinary approach to giant cell tumors of tendon sheath and synovium--a critical appraisal of literature and treatment proposal. J Surg Onco. 107(4):433-45. doi: 10.1002/jso.23220 4. Stacchiotti S, Durr R, Schaefer I-M, Stern S, Van De Sande M, Bauer S, et al. Best clinical management of tenosynovial giant cell tumour (TGCT): a consensus paper from the community of experts. Cancer Treatment Review. 2022 5. Mollon B, Lee A, Busse JW, et al. The effect of surgical synovectomy and radiotherapy on the rate of recurrence of pigmented villonodular synovitis of the knee: An individual patient meta-analysis. Bone Jt J. 2015. doi:10.1302/0301-620X.97B4.34907 6. Bernthal NM, Ishmael CR, Burke ZDC. Management of Pigmented Villonodular Synovitis (PVNS): an Orthopedic Surgeon’s Perspective. Curr Oncol Rep. 2020. doi:10.1007/s11912-020-00926-7
