From January 2003 a long term follow-up project started for adult patients treated in our Centre for cancer in pediatric age, to evaluate late effects of therapy. For all patients a personalized follow-up was scheduled (time, function-tests, etc).

We analyzed 24 cases of bone tumors: 14 osteosarcoma (OS) and 10 Ewing’s sarcoma (ES). Median age at diagnosis was 13 years (range 11–18) for OS patients, 11.6 years (range 6–18) for ES; 50% males in both groups. All patients were treated according current CNR/ISG-protocols: all OS cases underwent surgery; in 5/10 ES patients local treatment was surgery, in 5/10 radiotherapy; 7/24 received hematopoietic stem cells transplantation (HSCT).

Median age at evaluation is respectively 26.5 years (range 18.7–34) and 23.5 (range 21.6–32); median follow-up is 13 years (range 6–22) and 13.7 (range 6.7–22.3).

Cardiovascular function is normal in all OS cases; 3/10 ES patients developed asymptomatic ejection fraction reduction, currently not treated.

One OS patient underwent bilateral thoracotomy and HSCT for multiple metastases at diagnosis and had a mild lung function alteration. One OS patient developed mild chronic kidney disease, one ES nephrolithiasis. Liver function is normal in all cases.

Height velocity and final height are normal in 10/14 OS and 9/10 ES patients; in remaining 5/24 no growth hormone secretion deficit was found.

One OS patient developed primitive hypothyroidism and one OS benign thyroid nodule with partial thyroidectomy; one patient multifocal papillary thyroid carcinoma with total thyroidectomy at 11 years from diagnosis of ES.

Spermatogenesis deficit is a common find (5/7 OS and 5/5 ES male patients); one female treated with HSCT and radiotherapy for ES pelvic relapse has primitive hypogonadism. No other hypothalamo-hypophyseal-adrenocortical system hormones deficit was found.

We reported no significant neuropsychological alterations nor employment problems: 20/24 patients have a job, 4/24 are students. Three OS females have children.

PET/CT is successfully used in metabolic characterization of lung nodules in adult patients. An SUV max of 2.5 is generally accepted to distinguish benign from malignant lesions; for small solitary lung nodules some authors recommend visual evaluation rather than only SUV, suggesting that classical SUV criterion of 2.5 is inappropriate.

In pediatric patients interpretation of nodular opacity is still a clinical problem: specificity of CT in a pulmonary nodule, especially when small, is still limited.

Aim of this prospective study was to evaluate PET/ CT for non invasive characterization of pulmonary nodules in pediatric bone sarcomas.

Materials and methods: 56 whole-body PET-CT exams were performed in 19 patients with OS (14 female, 5 male) and 9 with ES (4 female and 5 male); median age at the first PET/CT exam was 14 years 8 months. PET/ CT results have been correlated with conventional imaging (CI), hystologic findings and clinical follow-up.

Results: PET/CT correctly identified pulmonary metastases, according with CI, in 33/56 exams (59%), PET/ CT revealed correctly “understaging” in 15 exams (27%) (10 in ES, 5 in OS) and incorrect “understaging” in 8 (14%) exams (4 in OS, 4 in ES). There were no false positive in either groups.

Conclusion: Correct diagnosis of a pulmonary opacity is fundamental for prognosis and choice of treatment in patients with doubtful lung lesions. Our preliminary results suggest the feasibility of a correct characterization by PET/CT in paediatric bone sarcoma patients. In particular PET/CT seems accurate and sensitive for lung nodules higher than 5 mm: an SUV max (and SUV ratio) higher than 1 seems to be significant when size is higher than 5 mm, while no significant SUV max (and SUV ratio) differences were found for smaller lesions.

Prospective studies are needed to clarify benefit of PET/CT in management of these patients.