Evaluation of predictive value of 1H MR spectroscopy for response of neoadjuvant chemotherapy in musculoskeletal tumors.

PURPOSE: Bone and soft tissue tumors are rare. There is a variety of types and each one has its own particular behavior, treatment and patient outcome. The assessment of treatment response following the 3rd cycle of chemotherapy is one of the most important aspects of patient care, as therapeutic options and the timing of surgery may vary depending on the achievement of response. Hence, we focused on the advanced imaging technique, proton magnetic resonance spectroscopy (1H MRS), aiming at improving the diagnostic accuracy and the tumor response to therapy, based on the absolute concentration of choline (Cho) as biomarker of malignancy. METHODS: Twenty patients were studied. All of them had a pathological diagnosis after biopsy. MRI examinations were performed using a 1.5 T MR scanner (Avanto; Siemens, Erlangen, Germany). Single-voxel 1H MR spectroscopy was performed by using a PRESS with TR/TE 1530/100 ms, before chemotherapy and after the 3rd cycle. 1H MRS was processed in LCmodel. RESULTS: Of 20 patients, 7 responded to neoadjuvant chemotherapy and 13 did not. In responders, the mean concentration of tCho before therapy was 4.7±2.5 mmol/kg, which showed statistically significant reduction after therapy. In non-responders, the mean tCho concentration before therapy was 2.9±0.9 mmol/kg which remained the same or increased after the 3rd cycle of neoadjuvant chemotherapy (2.7±2.5 mmol/kg; range from 2.05 to 5.79 with no statistical significance). Compared to reference healthy group, tCho concentrations were increased in all cases. CONCLUSIONS: 1H MRS appears to be valuable technique for evaluation of response to neoadjuvant chemotherapy of patients with musculoskeletal tumors (MSK).

Treatment results of childhood Ewing's sarcoma of the bone in Serbia.

PURPOSE: The purpose of this study was to present treatment results of childhood Ewing's sarcoma (ES) of the bone in Serbia and to analyze prognostic factors. METHODS: We performed a detailed analysis on a series of 107 patients with ES of the bone treated at the Institute for Oncology and Radiology of Serbia between 2000 and 2014, using modern multimodal therapy. RESULTS: Median age at the time of diagnosis was 14 years, with 56.07% of the patients being ≤14 years. There was a male predominance (59.81%). The most common primary sites were pelvis (25.23%), femur (17.76%) and tibia (12.15%). Thirty-four patients (31.78%) had metastatic disease, 17 of which had isolated lung metastases, 9 bone metastases and 8 patients had both. Tumor size ≤ 8 cm had 38.32% and >8 cm had 61.68% patients. Overall, 51.4% patients underwent surgery and radiotherapy as a local treatment modality after neoadjuvant chemotherapy. Radiotherapy alone was performed in 24 patients. The 5-year overall survival (OS) was 43.8%. For patients with localized disease, the 5-year OS was 56.4% and for patients with metastatic disease 17.6%. In patients with initially nonmetastatic disease, age under 14 years, with tumor size <8 cm and a good response to the neoadjuvant chemotherapy, the OS correlated with better outcome. CONCLUSIONS: Modern multidisciplinary approach in treatment of childhood ES of the bone in accordance with the recommended pediatric protocols, gives good treatment results. Therapy should be performed in referral centers.