Imaging methods in the diagnostics of solid tumors in children

Considering the specific anatomy, physiology and pathology of children, diagnostic medical technology, including diagnostic imaging, very often differs considerably in terms of its application to children and adults. In this regard, special heed should be taken of children with oncologic diseases. Major advances in diagnostic imaging methods over the last two decades have revolution ized the diagnostics in oncologic patients, which, owing to its greater speed, precision and reliability, has significantly contributed to a more successful treatment of such patients.

The development of diagnostic imaging, especially ultrasound, CT, MRI, PET/CT, has upgraded the diagnostics of solid tumors in children, which has contributed to a more successful therapy and significantly improved the prognosis of some types of solid tumor processes. Each of these diagnostic modalities has its place in the algorithm of diagnostic imaging methods, specifically in making the diagnosis, in tumor localization, staging evaluation and tumor process characterization. Diagnostic imaging methods are also of exceptional importance in assessing the effects of therapy during and after treatment. In the algorithm of diagnostic imaging methods, ultrasound imaging, owing to its advantages over other methods, is as a rule the first choice when it comes to a suspected solid abdominal tumor in a child patient. It provides us with information on the origin of tumor, its size, structure, relationship with the surrounding soft-tissue structures and the large blood vessels, the tumor vascularization. It also provides us with very important information in terms of differential diagnosis, and gives direction for further diagnostic treatment. Ultrasound is also a very convenient method for monitoring the effects of preoperative chemotherapy, postoperative monitoring, targeted cytopunction and tumor formation biopsy. Next in the algorithm of imaging methods is computerized tomography or magnetic resonance. These methods are used in the definitive staging evaluation and the characterization of a tumor process. Likewise, these diagnostic methods are extremely valuable in the preoperative assessment of the resectability or the operability of a tumor process. In the area of children’s oncology the PET/CT technology is also increasingly widely used. Combined in a single system, PET (Positron Emission Tomography) and CT (Computed Tomography) show the morphological traits and, in addition to it, enable us to evaluate the functioning of organs or tissues at the molecular and cellular levels. Scanning is done after the patient intravenously receives isotopes, mostly as FDG (2-fluoro-2-deoxy-D-glucose), a glucose analog (positive electron emitting isotope).

PET detects any excessive cell metabolism. Malignant carcinoma cells exhibit a high glucose metabolism, whereas normal cells are using glucose at a much lower rate. This procedure in oncology allows early detection of carcinoma, its precise location and staging, a diagnosis of metastases, and the classification of the extent of staging. It is also possible to find if we have a case of malignant or benign tumor, evaluate malignity, analyze the effects of therapy and determine the activity of a malignant process.
Each of the mentioned diagnostic imaging methods has its specific indications, as well as limitations, and should be applied as methods complementing each other. Correct interpretation requires a team approach by a pediatric radiologist, an oncologist and a surgeon.

Read more