Treatment Paradigm

Question 1

What is the Tx paradigm for WT in the United States?

Answer 1

WT Tx paradigm: initial surgical resection → risk-adapted adj chemo +/– RT

Question 2

What is the major difference b/t the International Society of Pediatric Oncology (SIOP) Tx paradigm (European Cooperative Group) and the National Wilms Tumor Study (NWTS) paradigm (American Cooperative Group)?

Answer 2

SIOP trials incorporate preop therapy (CRT), whereas the NWTS/COG trials do not.

Question 3

Under what circumstance is the SIOP paradigm favored in the United States?

Answer 3

In unresectable or bilat Wilms, preop chemo is used.

Question 4

What are the indications for postop RT in the current COG protocols (AREN0532,533)?

Answer 4

Indications for postop RT depend on histology and stage:

Favorable histology: stages III–IV

Unfavorable histology: stages I–IV

Question 5

What chemotherapeutic agents are typically used in Wilms?

Answer 5

Vincristine, actinomycin D (Adr/VP-16/Cytoxan/carboplatin added in UH)

Question 6

Summarize COG Wilms protocol

Answer 6

Question 7

Summarize Chemotherapy for COG protocol

Answer 7

Question 8

Summarize COG Radiation planning and doses

Answer 8

Question 9

What characteristics define stage III in Wilms tumor and are therefore indications for radiotherapy for patients with favorable histology?

Answer 9

SLURPT-B (mnemonic): Spillage (either before or during surgery), lymph nodes (pathologically + in the abdomen or pelvis), unresectable (patient required neoadjuvant chemotherapy), residual disease (gross or microscopic tumor remains postoperatively or tumor was removed in greater than one piece), peritoneal disease (tumor penetrated peritoneal surface or peritoneal implants), tumor thrombus within renal vein (if removed separately from nephrectomy specimen), biopsy prior to removal.

Question 10

What are the appropriate Wilms tumor radiation doses for flank irradiation, whole abdominal irradiation, whole lung irradiation, bone metastases, liver irradiation, and residual disease?

Answer 10

Flank irradiation: 10.8 Gy (19.8 Gy if age ≥16 years or stage III with diffuse anaplasia)

Whole abdominal irradiation: 10.5 Gy

Whole lung irradiation: 10.5 Gy (age <12 months) or 12 Gy (age ≥12 months)

Bone metastases: 30.6 Gy (or 25.2 Gy if age <16 years)

Liver irradiation: 19.8 Gy to focal metastases

Residual disease: Additional 10.8 Gy boost

Question 11

What are the indications for whole abdominal irradiation?

Answer 11

Cytology-positive ascites, any preoperative tumor rupture, diffuse surgical spillage, and peritoneal seeding are indications for whole abdominal irradiation. The borders for whole abdominal irradiation are: superior, 1 cm above the dome of the diaphragm (must account for respiratory motion); lateral, 1 cm beyond lateral abdominal wall; and inferior, the bottom of the obturator foramina (the femoral heads should be blocked).