Postoperative phase
The panel suggests postoperative abdominal radiation therapy within 14 days of surgery for patients with WT who require adjuvant radiation therapy. (Weak recommendation; Quality of evidence: Very Low)
Panel deliberation. Postoperatively, patients who need radiation therapy, especially those with high-risk WT, should be referred to a radiation oncologist within 1 week of surgery to receive abdominal radiation within 14 days. A radiation oncologist should be part of the multi-disciplinary team discussion of all patients at diagnosis, so referral and need for radiation therapy can be anticipated. Delayed radiation therapy of the abdominal primary tumor in non-metastatic patients is associated with suboptimal local control.64-66 In contrast, for patients with metastatic disease, radiation of the abdominal primary within 14 days post nephrectomy is of no clear significance. Therefore, in these patients, abdominal irradiation can be performed at the same time as lung irradiation (when indicated). Suboptimal nutritional status of patients should be considered when combining whole-lung radiation therapy with flank versus whole-abdomen radiation therapy.
The panel suggests that resection of residual pulmonary oligometastasis after completion of chemotherapy (when feasible) be considered in a setting of local protocols that allow the omission of whole-lung irradiation in patients with favorable histology, stage IV WT with pulmonary metastasis. (Weak recommendation; Quality of evidence: Very Low)
Panel deliberation. The decision to omit whole-lung irradiation is based on tumor biology, histological risk group of the abdominal primary, and chemosensitivity; and can be applied in the context of local treatment protocols. Lung irradiation can be avoided for patients with non-anaplastic histology who are complete responders (i.e., those who have no residual pulmonary metastases on a chest CT after chemotherapy). In patients with residual post-chemotherapy oligometastasis that are amenable to resection, radiation therapy can be omitted if there was no residual viable tumor in the surgically cleared nodules.60-62,67,68 Resection of residual nodules may be helpful when institutional protocols/guidelines allow the omission of whole-lung radiotherapy in patients with non-anaplastic histology and no viable tumor in respected lesions.