Clinical Report: Reduced Fractionation SBRT for Malignant Adrenal and Renal Tumors
Overview
This retrospective multicenter study evaluated stereotactic body radiotherapy (SBRT) as an alternative to surgery for renal cell carcinoma (RCC) and adrenal malignancies (AM). High biological equivalent doses (BED) delivered in reduced fractionation schedules demonstrated promising local control and manageable toxicity in inoperable or surgery-refusing patients.
Background
Renal cell carcinoma incidence has risen to approximately 2%, and adrenal malignancies occur in 15–35% of cases. Surgery remains the standard treatment but is contraindicated in certain patients due to factors like bilateral tumors or chronic renal failure. SBRT has emerged as a non-invasive alternative, overcoming traditional radioresistance of RCC by delivering high BED. Despite its potential, SBRT remains underutilized for adrenal malignancies, which are generally more radiosensitive.
Data Highlights
Parameter
Value/Range
Number of lesions/patients
25 lesions in 23 patients
Median prescribed dose
60 Gy (range 40–64 Gy)
Median number of fractions
5 (range 3–8)
Median lesion volume
14.11 cm³ (range 4.3–111 cm³)
BED10 > 100 Gy
All but 3 patients
Follow-up schedule
6 weeks post-RT, then every 3 months
Adverse events
One duodenal ulcer requiring hospitalization
Key Findings
SBRT was delivered using LINAC, CyberKnife®, and Tomotherapy® with consistent immobilization and planning protocols.
High BED10 (>100 Gy) was achieved in most patients, overcoming RCC radioresistance.
Local control was the primary endpoint, assessed by RECIST 1.1 criteria via CT scans during follow-up.
Toxicity was generally low; only one patient experienced a grade 3 duodenal ulcer managed conservatively.
SBRT was effective in patients with inoperable tumors or those refusing surgery, with ECOG performance status 0–1.
Multidisciplinary team involvement ensured comprehensive patient selection and treatment planning.
Clinical Implications
SBRT with reduced fractionation and high BED offers a viable, non-invasive treatment option for patients with RCC and AM who are not surgical candidates. Careful planning and adherence to organ-at-risk dose constraints can minimize toxicity. Regular imaging follow-up is essential to monitor local control and manage potential adverse events.
Conclusion
Reduced fractionation SBRT provides effective local tumor control with acceptable toxicity in malignant adrenal and renal tumors, representing a promising alternative to surgery in selected patients. Further prospective studies are warranted to confirm these findings.
by Daniel Rivas, Alejandro de la Torre-Luque, Elena Moreno-Olmedo, Paloma Moreno, Vladimir Suárez, Ana Serradilla, Gregorio Arregui, David Álvarez, Morena Sallabanda, Antonio Lazo, María Isabel Núñez, Escarlata López
Experts from Roswell Park Comprehensive Cancer Center will share the findings of a novel approach using radiation therapy to treat lung cancer at the American Society for Radiation Oncology (ASTRO) Annual Meeting Sept. 27-Oct. 1, 2025, in San Francisco.
Recent research at Roswell Park Comprehensive Cancer Center led by Anurag Singh, MD, Director of Radiation Research, has shown that for patients with peripherally located lung cancer, one treatment of stereotactic body radiation therapy (SBRT) is equally effective as longer courses radiation therapy.
