Increased survival of children with solid tumours: how did we get there and how to keep the success going?

Survival after childhood cancer has dramatically increased in the last 3 to 4 decades. Among extracranial tumours, Wilms tumours and other less common kidney tumours have the best results, but treatment of neuroblastoma, often disseminated at diagnosis, is still extremely challenging. How did survival of solid tumours in childhood increase from around 30% in the 1970s to 70–90% today? This is the result of a multidisciplinary effort and access to improved diagnostic techniques and treatment modalities. This article focuses on the role of imaging in this positive evolution and particularly, how imaging will contribute to keep the survival curves improving. Radiologists and other imaging experts retain a key position before diagnosis and during and after treatment. Investigations before diagnosis are key to further investigations and referral with no delay. The first investigations will most often involve radiologists through radiography or ultrasonography, according to tumour site. The description of these first observations and particularly the conclusion and its wording are crucial to the subsequent events leading to diagnosis. In imaging at diagnosis, the aim is to obtain a precise description of the primary tumour and its local spread as soon as possible. The choice of technique depends on local conditions but may include ultrasonography, computed tomography (CT)/magnetic resonance imaging (MRI) scanning, scintigraphies (bone, meta-iodobenzylguanidine (MIBG), octreotide), or fluorodeoxyglucose (FDG)-positron emission tomography (PET), combined with low dose CT or MRI scanning. CT scan and chest radiography are recommended for investigating the presence of lung metastases. There is no infiltrate too small to be a metastasis. Overall there is no specific imaging criterion. The pathologists hold this diagnostic key. Tumour response is evaluated during and after preoperative chemotherapy using techniques and measurements comparable with those used at diagnosis. Following evaluation of tumour response, additional investigations may be needed to define the resectability of the tumour, combining different imaging techniques, e.g. CT scanning and/or MRI angiographies, ultrasound with Doppler. After tumour resection and particularly in the case of non-radical resection, imaging of the tumour residue is required as baseline for further surveillance and eventually planning of irradiation fields. How do we secure further improvement in treatment results for childhood cancer? Multidisciplinary teams, optimal logistics and continuous education are the best tools with focus on reduction in delay to diagnosis and improvement in the multidisciplinary forum allowing optimal therapeutic decisions.