The primary aim of this monocentric randomised controlled study is to evaluate the impact of using GAS to maintain the functional abilities of children and adolescents undergoing TCSE. The secondary aims include evaluating parents' and adolescents' perceived changes in the subject's functional abilities from the moment of stem cell transplantation unit (SCTU) admission to subsequent follow-ups. Another secondary aim is to evaluate the achievement of functional goals as defined by GAS in the experimental group (EG). Other aims include investigating the feasibility of the exercise program and the rehabilitation counselling indications in both groups, as well as the effectiveness of the two interventions and GAS use in the EG.

HSCT is a potentially curative option for many diseases, including haematological malignancies and refractory solid tumours in children and adolescents. Its use in this age group has increased over the last three decades, as have survival rates decades. However, HSCT can cause a significant number of clinical complications and side effects in both the short and long term. Short-term effects include mucositis, fever, nausea and vomiting, while long-term effects include organ toxicity and fatigue. Allogeneic HSCT recipients can indeed develop graft-versus-host disease, which can lead to extensive multiorgan failure, systemic toxicity and mortality. Previous treatments, the severity of the conditioning regimen, the length of isolation and hospitalisation can all severely impair physical, cognitive and psychosocial functions, resulting in a reduction in quality of life (QoL). Recent studies have shown that exercise and rehabilitation are promising tools for decreasing the side effects of HSCT and improving QoL in the paediatric population undergoing HSCT). A systematic meta-analysis review reported that physical exercise is safe, feasible, and effective in preventing the decline in quality of life and physical performance in paediatric patients undergoing HSCT.

It is widely recognized that rehabilitation treatment in developmental age should consider the multiplicity of altered motor, perceptive, cognitive, affective, communicative and relational functions, their mutual interactions, as well as variables such as age and the role of the family, while respecting the individuality of each child. Health care professionals should treat patients with dignity, sensitivity, kindness, and respect for their individual needs and preferences for medical, clinical and rehabilitative care. These principles characterize the Family Centered Care (FCC), an approach based on the active involvement of the patients and their families in the care process. Other studies showed that uptake of an FCC approach in paediatric settings can positively impact children's HRQL. The FCC approach has been recognized as a model of best practice in pediatric rehabilitation, where it can be integrated in the rehabilitation programme by identifying clinically relevant and functional goals for the patients and their caregivers. Moreover, the approach can increase patient's compliance. Goal Attainment Scaling (GAS) has revealed itself as being a powerful tool to establish personalized goals and to objectively quantify the benefits of rehabilitation treatment. The GAS value lies in the possibility of identifying specific concrete objectives for each patient. The tool, which is used in different fields, is widely applied in pediatric rehabilitation. To date, the effects of active involvement of children, adolescents and their families in the definition of functional goals during hospitalization for HSCT have not yet been studied. The use of GAS to identify and achieve personalized, concrete and functional short-term goals during hospitalization could help patients to maintain a more active lifestyle. Consequently, it will reduce sedentary behaviors which are very frequent in this population. The increase in activity levels could significantly contribute to the maintenance of functional abilities that are often reduced during the treatment phase.

Inclusion Criteria:

• age between 6 months - 17 years and 11 months
• diagnosis of oncological or hematological disease undergoing HSCT
• No specific rehabilitation treatment ongoing at the moment of recruitment
• Written informed consent from patient or parents/legal representative, and age-appropriate assent.

Exclusion Criteria:

• Patients that are not able and willing to comply with study visits and procedures.