Response to chemotherapy estimates by FDG PET is an important prognostic factor in patients with Ewing sarcoma.

BACKGROUND: Response to chemotherapy is a prognostic factor in patients with Ewing sarcoma (ES); the role of FDG PET to predict response in these patients has not been thoroughly investigated. We evaluated the diagnostic accuracy and the potential of FDG PET to predict response to chemotherapy (CHT). MATERIALS AND METHODS: We analyzed data of 50 patients with ES (median age 12.6 years). All patients were treated with neoadjuvant CHT, and underwent surgery for local control. All patients had (18)F-FDG PET/CT at diagnosis and after induction CHT, prior to local control. We compared response assessed by histopathology with FDG PET using standard uptake values (SUVs). RESULTS: Median SUV at diagnosis (SUV I) was 5 (range 1.2-17), and median SUV after neoadjuvant chemotherapy (SUV II) was 1.8 (range 0-8.4). Median SUV II/I ratio was 0.3 (range 0-1). SUV at diagnosis was significantly lower in patients with good histological response than in patients with poor histological response (median 3.8 vs. 7.2, p 0.02). We found a significant correlation between SUV II and outcome; the positive predictive value of an SUV II ≤ 2.5 for favorable response was 84.21 %, and the median SUV II was significantly higher in patients with disease progression (2.3 vs. 1.6, p = 0.04). In multivariate analysis, necrosis and SUV II were significant predictors of outcome. CONCLUSIONS: (18)F-FDG PET demonstrates high diagnostic accuracy for response to initial chemotherapy in patients with ES and it correlates with outcome. The role of FDG PET in predicting response and outcome should be further investigated.

[Application of Ethyol during chemotherapy in patients with impaired kidney function. Description of three cases]. / Zastosowanie ethyolu u pacjentów z uposledzona funkcja nerek poddawanych chemioterapii. Opis 3 przypadków.

Nephrotoxicity is observed in 30% of patient's treated with chemotherapy schedules based on cisplatin analogues. Ethyol (amiphostin) was used as a protectant of kidney in 3 paediatric patients with neoplastic disease. Two patients suffered from Wilms tumour. One of them, a 5 month old boy presented with agenesis of the right kidney and stage II tumour in the left kidney. Bilateral Wilms tumour was recognised in a 6 year old girl. In both cases glomerular filtration was diminished. The third patient was a girl aged 5 who had isolated relapse of neuroblastoma in the central nervous system. Primary treatment caused nephrotoxic complications such as Fanconi syndrome and diminished glomerular filtration (66 ml/min). In these 3 cases Ethyol was used every lime before analogues of cisplatin were given. Tolerance and the effect of this protectant were good.

[Triton's tumor in children: a report of two cases]. / Guz Tritona wieku rozwojowego--opis dwóch przypadków.

Triton's tumor is a rare neoplasm, consisting of both neurogenic and rhabdomyoblastic components. Triton's tumor does not respond well to chemo- or radiotherapy, resulting in its poor therapy effects. This paper reports on two cases of this malignancy diagnosed in our department. The first one was treated with CWS chemotherapy followed by radical tumor resection, which resulted in 4.5 year complete remission. The other patient was treated with chemotherapy according to CWS protocol, achieving partial regression of the tumor. We suggest that this response may be connected with the sensitivity of the RMS embryonal component of the tumor to chemotherapy. This partial remission may create a possibility of radical tumor resection.