Changes in computed tomography features following preoperative chemotherapy for nephroblastoma: relation to histopathological classification

Abstract

The objective of this study is to assess computed tomography (CT) changes, both volume estimates and subjective features, following preoperative chemotherapy for nephroblastoma (Wilms' tumour) in patients treated on the United Kingdom Children's Cancer Study Group Wilms' Tumour Study-3 (UKW-3) protocol and to compare CT changes and histopathological classification. Twenty-one nephroblastomas in 15 patients treated on UKW-3 were included. All patients were examined by CT before and after preoperative chemotherapy treatment. CT images were reviewed (estimated volume change and subjectively assessed features). CT changes were compared to histopathological classification. Of the 21 tumours, all five high-risk tumours decreased in volume following chemotherapy (median -79%; range -37 to -91%). The sole low-risk tumour decreased in volume by 98%. Ten intermediate-risk tumours decreased in volume (median -72%; range -6 to -98%) and five intermediate-risk tumours increased (median +110%; range +11 to +164%). None of the five high-risk tumours, compared to 15/16 intermediate or low-risk tumours, became less dense and/or more homogeneous, or virtually disappeared, following chemotherapy. Volume change following chemotherapy did not relate to histopathological risk group. Changes in subjectively assessed qualitative CT features were more strongly related to histopathological risk group.

Variations in apparent diffusion coefficient values following chemotherapy in pediatric neuroblastoma

“…As indicated in previous studies, our findings suggest a correlation between ADC distribution and biological response to chemotherapy (12,13,(17)(18)(19)(20)(21). Previous studies have shown that tumor shrinkage might be a delayed or insensitive marker (in case of partial response) to evaluate chemotherapy response; absence of reduction in tumor size does not necessarily mean no response (13,14,22). Particularly for solid, viable tumors, new methods are needed to histopathologically detect a lack of chemotherapy response in a shrinking tumor or the degree of response in a growing tumor.…”

“…The ADC values of malignant masses are relatively lower than those of benign masses, although overlapping ADC values of malignant and benign lesions have also been reported (1, 6-12). Currently, in children the assessment of solid tumors' response to chemotherapy is based on size reduction; but this method can be unreliable as a marker, as tumors that shrink substantially may still be composed mainly of malignant cells (13,14).…”

“…The ADC values of malignant masses are relatively lower than those of benign masses, although overlapping ADC values of malignant and benign lesions have also been reported (1, 6-12). Currently, in children the assessment of solid tumors' response to chemotherapy is based on size reduction; but this method can be unreliable as a marker, as tumors that shrink substantially may still be composed mainly of malignant cells (13,14).Here, we aimed to evaluate whether ADC values in viable portions of childhood neuroblastomas show any changes depending on tumor cellularity before and after chemotherapy. We hypothesized that an increase in ADC values over the course of chemotherapy could be used as a noninvasive marker of therapy response.…”

“…Currently, in children the assessment of solid tumors' response to chemotherapy is based on size reduction; but this method can be unreliable as a marker, as tumors that shrink substantially may still be composed mainly of malignant cells (13,14).…”

Local behavior and lymph node metastases of Wilms' tumor: accuracy of computed tomography

“…Initially, such methods were utilized to confirm the presence of a mass, suggesting a specific diagnosis, but later they started playing a role in the therapy and surgical plannings, besides the evaluation of the treatment response (2,(5)(6)(7)(8) . Certain imaging findings such as presence of metastases or vascular invasion have contributed to the therapeutic planning.…”