Radiotherapy to the surviving kidney after unilateral nephrectomy in bilateral Wilms' tumour

Bilateral renal cancer in children: a difficult, challenging and changing management problem

Bilateral disease occurs in 6% of patients with Wilms' tumour. Bilateral renal involvement is present in 25%-50% of children with B-cell non-Hodgkin's lymphoma. Paediatric oncologists therefore encounter bilateral renal disease relatively frequently. A patient with bilateral Wilms' tumour is presented, in whom at least 16 synchronous tumours in the kidneys were treated successfully by primary chemotherapy and 'nephron-sparing' surgery, without renal radiotherapy. We believe the successful treatment without radiotherapy will allow greater potential for normal growth in the future. The case history of a patient with renal failure due to the infiltration of both kidneys by lymphoma and who was treated successfully by chemotherapy, is also presented. One kidney has completely returned to normal function and growth; the other has completely failed and almost disappeared, demonstrating complete reversibility of the damage up to some critical point, beyond which, failure and atrophy result. These two case histories demonstrate extreme examples of clinical dilemmas involving bilateral renal tumours and allow discussion of modern management aimed at preserving renal function.

Local control in synchronous bilateral Wilms tumor

PURPOSE

To evaluate the role of radiation therapy (RT), chemotherapy (CT), and surgery in the local control of synchronous bilateral Wilms Tumor (WT).

METHODS AND MATERIALS

Between 1962 to 1993, 45 children were treated for bilateral WT; 38 patients with synchronous tumors were reviewed. Initial surgery depended on the era of treatment and included unilateral nephrectomy (N)/partial nephrectomy (PN) and contralateral PN in 6, unilateral N/PN alone in 7, and biopsy only in 25. Chemotherapy (CT) consisted of vincristine, actinomycin-D, and adriamycin in 32 and vincristine/ actinomycin-D in 6. Radiation therapy (RT) was given to 32 patients. Treatment included both kidneys in 20, unilateral kidney plus contralateral renal bed in 9, unilateral kidney in 2, and unilateral renal bed in 1. Follow-up was 16 months to 25 years (median: 6.3 years).

RESULTS

Local control (LC) has been maintained in 66 out of 76 sites (87%). For Stage I-II disease with initial N/PN, LC was 10 out of 12 with RT and 11 out of 11 without RT; for Stage III with initial N/PN, LC was 8 out of 9 with RT and 1 out of 1 without RT. Initial CT and RT was followed by delayed N/PN for 20 sites; LC was 15 out of 17 in post induction Stage I-II and 1 out of 3 in postinduction Stage III. In 23 sites undergoing biopsy and chemotherapy, LC was 19 out of 20 with RT and 1 out of 3 without RT. Seven of 23 sites had a complete response (CR) after induction CT, and LC was maintained in four out of four with RT and one out of three without RT. Univariate Cox Regression analysis demonstrated that sites receiving two drugs had a statistically significant increase in loco-regional relapse when compared to sites receiving three drugs (p = 0.004). Major morbidities related to multimodality therapy have included renal failure in one patient and small bowel obstruction requiring lysis of adhesions in two patients.

CONCLUSIONS

Local control does not seem to be compromised by renal conservation therapy. Local control is excellent in sites treated with radiation therapy in combination with three drug chemotherapy.

Case report: renal morbidity and compensatory renal responses associated with flank radiotherapy in two children

Unilateral kidney irradiation, above renal tolerance, is occasionally necessary in the treatment of flank tumours in childhood. Renal atrophy follows. There is often a gradual increase in the function of the contralateral kidney to compensate for the radiation injury. The development of this compensatory response appears to be influenced by both age and any dose of radiation received. We report the cases of two children who received high dose unilateral kidney radiotherapy as part of the multimodality treatment of a flank tumour and consider the influences on compensatory hypertrophy of the contralateral kidney.