Purpose: Radiosynoviorthesis involves injecting a radiocolloid into the synovial joint and can be used in the management of haemophilic synovitis. In adults, 90Y is administered to knee joints and 186Re to elbows and ankles. The purpose of this research project is to assess the biodistribution and the associated absorbed dose to the target (synovium) and non-target tissues (cartilage, bone and epiphyseal plate) for paediatric patients. Methods: 186Re Sulphide was administered to knee, elbow and ankle joints. Twelve joints were treated (nine patients, 14±2 years-old at treatment). The biodistribution was assessed from post-procedural SPECT/CT images co-registered to pre-treatment MRIs. A Monte Carlo model of the joint was developed in Geant4. The activity, volume and tissues utilised in the model were determined from the SPECT/CT and MR images. The dose to target and non-target tissue was assessed for model simulations of 186Re and 90Y. For one patient significant hepatosplenic migration occurred from the treated knee joint. The absorbed dose to the liver and spleen was calculated using a local deposition and organ dosimetry MIRD model. Results: When the model simulated administration of 186Re the dose to the synovium was lower than the current target dose. For simulations using 186Re dose constraints were generally not exceeded. Conversely, for 90Y the target dose to the synovium was generally met, but this was at the expense of exceeding the cartilage dose constraint. The tissue doses depended on the activity concentration in the joint capsule. In the case of significant hepatosplenic migration, the absorbed doses calculated using both methods agreed well. Conclusions: Increasing the activity concentration of 186Re would, in some cases, achieve the target dose without exceeding dose constraints. The use of 90Y requires further consideration given the dose to cartilage. The tissue dose is affected by practical aspects such as aspiration of joint fluid before injection. A target activity concentration is a basis for personalised planning but requires further validation. Whole-body and SPECT/CT imaging are essential to identify any migration and quantify the absorbed dose.
Date of Award | 31 Dec 2022 |
---|
Original language | English |
---|
Awarding Institution | - The University of Manchester
|
---|
Supervisor | Jill Tipping (Supervisor) |
---|
- dosimetry
- paediatric
- haemophilic synovitis
- Radiosynoviorthesis
Dosimetric Review and Assessment of the use of Radiosynoviorthesis in the Paediatric Haemophilic Synovial Joint
Price, L. (Author). 31 Dec 2022
Student thesis: Unknown