Metastasis to the adrenal glands: An update

Table 3 Stereotactic body radiation therapy and radiation therapy series for adrenal metastases

Ref.	Study design/population	n (patients/lesions)	Dose/fractions	Key outcomes	Toxicity
Chen et al[36]	Systematic review + pooled meta-analysis (photon SBRT)	39 studies; 1006 patients	Median follow-up 12 months; median BED10 67 gray	Pooled overall response 54.6%; pooled LC 1-year 82%, 2-year 63%; pooled OS 1-year 66%, 2-year 42%; dose-LC association	Grade ≥ 3 toxicity 1.8%
Yuste et al[37]	Multi-institution (11 French centers), retrospective; oligometastatic SBRT	110/121	Median prescription 40 gray; mean BED10 74.2 gray; median planning target volume 70 cm3	LC 1-year 85.9%, 2-year 72.5%; median OS 31.6 months, median PFS 8.5 months	No grade 3-4 toxicity; LC improved with peri-SBRT systemic treatment and BED10 ≥ 50 gray
Franzese et al[38]	Multicenter (3 Italian centers), retrospective; oligorecurrent/oligoprogressive	142/149	Median SBRT dose 40 gray (10-60); median lesion volume 28.5 cm3; follow-up 14.4 months	OS 1-year 72.3%, 2-year 53.5%; LC 1-year 85.4%, 2-year 79.2%; PFS 1-year 37.7%, 2-year 24.8%	Grade 1 14.7%, grade 2 2.1%; BED10 and lung primary associated with LC
Franzese et al[39]	Prospective phase II trial; endocrine function focus	36/(treated lesions not specified)	45 gray/3 consecutive fractions; median follow-up 9.5 months	LC 1-year 94.7%, 2-year 88.4%; PFS median 14.7 months (1-year 50.5%, 2-year 29.8%); OS 1-year 62.9%, 2-year 44.1%	No grade ≥3 toxicity; mild side effects 22.2%; endocrine/electrolytes largely preserved
Holy et al[40]	Single-institution; non-small-cell lung carcinoma adrenal metastasis (isolated vs multi-metastasis)	18/(lesions not specified)	5 × 4 gray to 5 × 8 gray (varied intent/size); median max dose 132% (center)	Median PFS: 4.2 months (all) vs 12 months (isolated 13/18); LC 77% (10/13) for isolated group; median OS: 21 months (all) vs 23 months (isolated 13/18)	Grade 1 nausea 6/18; Multiple gastric ulcers at 2 weeks 1/18; Gastric and duodenal ulcers at 4 weeks 1/18
Zhao et al[41]	Two-institution retrospective; lung cancer adrenal metastasis	30/32	Median 44.4 gray (35-50) in median 5 fractions (3-8); corresponding BED10 85.5 gray	Response: Complete response 23.3%, partial response 33.3%, stable disease 33.3%, progressive disease 16.7%; LC 6-month/1-year/2-year 96.9%/96.9%/72.7%; OS 6-month/1-year/2-year 85.6%/58.1%/54.0%; PFS 6-month/1-year/2-year 39.5%/24.6%/8.2%	1 grade 3 diarrhea; pain improvement reported; BED10 ≥ 85.5 gray + gross tumor volume < 30 mL correlated with LC (univariate)
Torok et al[42]	Single-institution retrospective; mixed primaries	7/9	Single fraction median 16 gray (10-22) to 80% isodose; or 3 fractions median 27 gray (24-36)	Imaging response (8 Lesions): 1 complete response, 2 partial response, 5 stable; 1-year LC 63%; median time to local failure 12 months; median OS 8 months from SBRT	No acute or late toxicity. Concluded SBRT safely deliverable (single or hypofractionated)
Scouarnec et al[43]	Single-institution retrospective; multiple primaries	31/33	30-55 gray in 3-9 fractions; median BED10 112.5 gray	Competing-risk LC 1-year 96.5%, 2-year 92.6%; median OS 33.5 months; median PFS 7.4 months; responses: Complete response 32.3%, partial response 32.3%, stable disease 25.8%	Grade 1-2 toxicity 42.4%; no acute ≥ 3 or late toxicity
Plichta et al[44]	Single-institution retrospective; oligometastatic (≤ 5 sites)	10/(lesions not specified)	30-48 gray in 3-5 fractions; median follow-up 6 months	Median OS 9.9 months; median PFS 3.4 months; 1 Local progression at 18.8 months; 7 developed new distant metastasis	Acute: Nausea (grade 1-2) 4, fatigue (grade 1) 3, diarrhea (grade 1) 1; GI bleed at 3 months (noted as late event)
Buergy et al[45]	Retrospective; hypo-/conventional image-guided radiotherapy (includes SBRT intent language)	18/22	Median 35 gray (20-60) in median 7 fractions (4-25)	Median OS 11.9 months; 5 local failures (22.7%); OS differed by state: Oligometastatic 33 months, oligoprogressive 6.5 months, palliative/polymetastatic 1.6 months	No grade ≥ 3 toxicity; symptom improvement in all treated for symptomatic lesions

BED10: Biological equivalent dose calculated with an α/β ratio of 10; LC: Local control; OS: Overall survival; PFS: Progression-free survival; SBRT: Stereotactic body radiotherapy; GI: Gastrointestinal.