Preservation of adrenal function after successful stereotactic body radiation therapy of metastatic renal cell carcinoma involving the remaining contralateral adrenal gland

Adrenal Metastasectomy in the Era of Immuno- and Targeted Therapy

Adrenal metastasectomy has an increasing role in multimodality oncologic care for diverse primary cancer types. In this review, we discuss the epidemiology, evaluation, and contemporary best practices in the management of adrenal metastases from various primaries. Initial evaluation of suspected adrenal metastases should include diagnostic imaging to assess the extent of tumor involvement and determine surgical resectability, as well as biochemical evaluation for hormone secretion. Biopsy has a minimal role and should only be performed in tumors that are established to be non-hormone secreting and when the biopsy results would change clinical management. Adrenal metastasectomy is associated with survival benefit in selected patients. We suggest that adrenal metastasectomy has the greatest benefit in four clinical scenarios: (1) disease limited to the adrenal gland in which adrenalectomy renders the patient disease-free; (2) isolated progression in the adrenal gland in the setting of otherwise controlled metastatic extra-adrenal disease; (3) need for palliation of symptoms related to adrenal metastases; or (4) in the context of tissue-based clinical trials. Both minimally invasive and open adrenalectomy techniques are safe and appear to have equivalent oncologic outcomes. Minimally invasive approaches are favored when technically feasible while maintaining oncologic principles. A multidisciplinary evaluation including clinicians with expertise in the primary cancer type is essential to the successful management of adrenal metastases.

Two-institution results of Stereotactic Body Radiation Therapy (SBRT) for treating adrenal gland metastases from liver cancer

OBJECTIVE

Stereotactic Body Radiation Therapy (SBRT) has been found beneficial for adrenal gland metastases (AGMs) with a high local control rate and low toxicity. The role of SBRT for AGMs in patients with liver cancer has not been well-discussed before. We, therefore, report our two-institution experience to further elaborate on the feasibility and effectiveness of SBRT in the treatment of AGMs from liver cancer.

METHODS

A total of 23 liver cancer patients (19 males, 4 females) with 24 AGMs treated by SBRT from July 2006 to April 2021 were retrospectively included in this study. Toxicity was assessed based on clinical adverse events using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The effectiveness was assessed based on local control (LC), progression-free survival (PFS), and overall survival (OS), which were calculated using the Kaplan-Meier method. Univariate analyses were compared by log-rank test. The relevant covariates were evaluated using Cox proportional hazards models.

RESULTS

The median dose was 40 Gy in 5 fractions, with the corresponding median biological effective dose (BED10, α/β = 10 Gy) of 72 Gy. The median overall follow-up time was 15.4 months (range: 4.2-70.6 months). The complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) rates were 25.0%, 20.8%, 33.3%, and 20.8%, respectively. All 6 patients with AGMs accompanying symptoms had varying degrees of alleviation after SBRT. The 0.5-, 1-year and 2-year LC rates were 87.5%, 77.8%, and 77.8%, respectively. The 0.5-, 1-year and 2-year OS rates were 95.5%, 66.8%, and 41.1%, respectively. The treatments were all tolerated with only one patient reporting a grade-3 hepatic injury. The univariate analysis concluded that only gross tumor volume (GTV) < 34.5 ml (p = 0.039) was associated with a favorable LC rate. After multivariate analysis, favorable predictors correlated with OS were GTV < 34.5 ml (p = 0.043), systemic therapy (p = 0.017), and without additional organ metastasis after SBRT (p = 0.009).

CONCLUSION

Our results suggest that SBRT is a safe and effective technique to treat AGM from liver cancer, especially for small GTV (< 34.5ml). Moreover, the small metastatic lesion volume, fewer metastatic lesions, and intervention of systemic therapy are more likely to improve OS.

Single-institutional outcome-analysis of low-dose stereotactic body radiation therapy (SBRT) of adrenal gland metastases

BACKGROUND

Adrenal gland metastases are a common diagnostic finding in various tumor diseases. Due to the increased use of imaging methods, they are diagnosed more frequently, especially in asymptomatic patients. SBRT has emerged as a new, alternative treatment option in the field of radiation oncology. In the past, it was often used for treating inoperable lung, liver, prostate, and brain tumors. Meanwhile, it is also an established keystone in the treatment of oligometastatic diseases. This retrospective study aims to evaluate the effect of low-dose SBRT in patients with adrenal metastases.

METHODS

We analyzed a group of 31 patients with 34 adrenal gland lesions treated with low-dose SBRT between July 2006 and July 2019. Treatment-planning was performed through contrast-enhanced CT, followed by image-guided stereotactic radiotherapy using cone-beam CT. The applied cumulative median dose was 35 Gy; the median single dose was 7 Gy. We focused on local control (LC), progression-free survival (PFS), overall survival (OS), as well as acute and late toxicity.

RESULTS

Seven adrenal gland metastases (20.6%) experienced local failure, 80.6% of the patients faced a distant progression. Fourteen patients were still alive. Median follow-up for all patients was 9.8 months and for patients alive 14.4 months. No treatment-related side-effects >grade 2 occurred. Of all, 48.4% suffered from acute gastrointestinal disorders; 32.3% reported acute fatigue, throbbing pain in the renal area, and mild adrenal insufficiency. Altogether, 19.4% of the patients faced late-toxicities, which were as follows: Grade 1: 12.9% gastrointestinal disorders, 3.2% fatigue, Grade 2: 9.7% fatigue, 6.5% headache, 3.2% loss of weight. The 1-year OS and probability of LF were 64 and 25.9%, respectively.

CONCLUSION

Low-dose SBRT has proven as an effective and safe method with promising outcomes for treating adrenal metastases. There appeared no high-grade toxicities >grade 2, and 79.4% of treated metastases were progression-free. Thus, SBRT should be considered as a therapy option for adrenal metastases as an individual therapeutic concept in the interdisciplinary discussion as an alternative to surgical or systemic treatment.

Stereotactic body radiation therapy for adrenal gland metastases: Outcomes and toxicity

Purpose

This study aimed to report on our institutional experience in the use of stereotactic body radiation therapy (SBRT) for the treatment of adrenal gland metastases. Specifically, we examined the outcomes and toxicity from this treatment modality on adjacent organs at risk.

Methods and Materials

Data were retrieved from patients with adrenal metastases who were treated with SBRT between 2008 and 2017. Patients with primary adrenal malignancies were excluded. Toxicities were graded in accordance with the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.03. Time-to-event rates were calculated from the date of SBRT delivery.

Results

In total, 35 patients with adrenal metastases were identified. Four patients were treated for bilateral disease. The median dose was 40 Gy (range, 20-54 Gy) in 5 fractions (range, 1-6 fractions). The median follow-up time was 37 months (range, 14-451 months) from disease diagnosis and 7 months (range, 1-54 months) from the SBRT start date. With death treated as a competing risk event, the cumulative incidence of local failure was 7.6% at 1 year after SBRT and 19.2% at 3 years. The median overall survival (OS) time was 19 months (95% confidence interval, 8-54 months) and tumor size correlated with survival (P = .0006). Patients with metastases <2.9 cm had a median OS of 54 months compared with 11 months for those with adrenal metastases ≥2.9 cm (P = .01). Incidence of grade 2 toxicity was 17% with no case of grade ≥3 toxicity. SBRT did not impact renal function with a mean estimated decline in glomerular filtration rate of only 2.6 ± 8 mL/min/1.73 m² compared with baseline. Combined kidneys V5 and combined renal cortex V17.5 did not correlate with a change in estimated glomerular filtration rate (P = .7 and P = .9, respectively).

Conclusions

SBRT offers excellent local control for the treatment of adrenal gland metastases with very low toxicity rates and no significant short-term impact on renal function.