Post-radiosynovectomy imaging utilizing Erbium-169 citrate.

Currently, there is no imaging procedure for radionuclide therapy utilizing Erbium-169 (Er-169). We have recently published the first post-radiosynovectomy imaging of Er-169 citrate in a case report (Farahati et al., 2017). In this study, we performed in-vitro and in-vivo studies to evaluate the feasibility to assess the distribution of Er-169 citrate after radiosynovectomy in fourteen patients with seventeen affected joints treated for refractory chronic synovitis. Post-radiosynovectomy imaging revealed the feasibility of post-radiosynovectomy detection and distribution utilizing Er-169 citrate in all cases. However, additional in-vitro studies including in-vitro imaging, gamma spectrometry and analysis of half-life indicated that emitted gamma-rays of the Ytterbium-169 in the radiopharmaceutical together with bremsstrahlung induced by Er-169 are the imaging source of emitted counts. Post-radiosynovectomy imaging utilizing Er-169 citrate is feasible and should be implemented in the guidelines for theranostics for quality control, patient safety and therapy monitoring.

Post-radiosynovectomy imaging of Er-169 using scintigraphy and autoradiography.

Currently, there is no protocol for the detection of intra-articular distribution of Er-169 citrate after radiosynovectomy. We propose post-therapeutic imaging using scintigraphy and cobalt-57 pen-marker autoradiography. This technique evaluates the efficacy of the radiosynovectomy and patient safety and could be utilized for dosimetric protocol.

Stabilization of the femoral head with a gliding screw in slipped capital femoral epiphysis.

OBJECTIVE: In situ fixation of the proximal femoral epiphysis to prevent further dislocation while maintaining the potential for longitudinal growth by insertion of a central gliding screw. Prevention of secondary coxarthrosis. INDICATIONS: Incipient and imminent slipped capital femoral epiphysis in children with a displacement angle of < 30 degrees in the axial view (ET' < 30 degrees ) and prophylactic treatment of the contralateral side. CONTRAINDICATIONS: Allergies to implant materials. SURGICAL TECHNIQUE: A Kirschner wire is inserted through a lateral proximal approach in the femur into the center of the displaced epiphysis at a right angle to its base. Overdrilling of the wire, thread tapping in the cancellous bone, insertion of the cannulated gliding screw with washer. The screw threads lie only in the epiphysis. The unthreaded part of the screw bridges the growth plate. The screw is allowed to protrude by about 2.5 cm to prevent an epiphyseodesis effect. POSTOPERATIVE MANAGEMENT: Partial weight bearing of the affected extremity up to 10 kg body weight for 6 weeks. Thrombosis prophylaxis during convalescence only for adolescents with signs of puberty (menarche/pubarche). Restriction on sports activities for 3 months. Follow-ups: clinical and radiologic examinations at 3 months postoperatively, then clinical examination every 6 months and radiologic assessment annually (possibly earlier, if there is a growth spurt). The gliding screw is removed when growth is completed. RESULTS: 63 hips (34 prophylactically and 29 therapeutically) were stabilized with the gliding screw. Clinically, the prophylactically stabilized hips showed excellent outcomes; of the therapeutically stabilized hips, the results were 19 excellent, seven good, two satisfactory, and one poor. Differences in leg length were seen in five cases, whereby the average value was 0.3 cm (0-1 cm). Chondrolysis or femoral head necrosis was not observed. Screw revision was necessary in 22 cases because contact between the screw head and the cortex would have prevented continued longitudinal growth (unintentional epiphyseodesis).