KEY POINTS
- This secondary ancillary analysis included 181 patients from the randomized phase III STRASS trial who underwent ipsilateral nephrectomy: 91 received surgery alone and 90 received preoperative radiotherapy followed by surgery.
- Preoperative radiotherapy delivered 50.4 Gy in 28 fractions, predominantly with intensity-modulated radiotherapy; the median mean dose to the contralateral kidney was 5.9 Gy.
- Creatinine-clearance trajectories from 60 days after surgery were comparable between groups, with no significant treatment-by-time interaction (p = 0.483).
- By 60 days, RIFLE-defined renal events occurred in 64.4% after preoperative radiotherapy and 77.1% after surgery alone; treatment was not significantly associated with risk after adjustment (relative risk 0.85, 95% confidence interval 0.71–1.02).
- Contralateral-kidney V5, V10 and mean kidney dose were not significantly associated with RIFLE events. During follow-up extending to 80 months, renal complications remained no more frequent with preoperative radiotherapy.
CLINICAL TAKEAWAY
Preoperative radiotherapy using modern planning and strict contralateral-kidney constraints did not appear to add measurable renal toxicity after nephrectomy for retroperitoneal sarcoma. The findings are reassuring when radiotherapy is otherwise considered appropriate, but they do not overturn the negative primary STRASS efficacy result or justify routine preoperative treatment.
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