SBRT to adrenal metastases provides high local control with minimal toxicity

Total dose, fraction dose and respiratory motion management impact adrenal SBRT outcome

Purpose/Objectives

Stereotactic body radiotherapy (SBRT) is an effective treatment for oligometastatic disease in multiple sites. However, the optimal radiation dose for long-term local control of adrenal metastases has yet to be determined. The aim of this study is to evaluate outcomes of adrenal SBRT and to evaluate factors that correlate with local control.

Materials/Methods

After IRB approval, a retrospective data review of patients treated with SBRT for adrenal metastases at a medical center in Israel between 2015 and 2021 was conducted. A biological effective dose was calculated using an alpha beta ratio of 10. Kaplan Meier and Cox regression were calculated using SPSS software to describe the hazard ratio for local control and survival.

Results

83 cases of adrenal SBRT were identified. The average age was 67 (range 42-92 years old). Non-small cell lung cancer was the primary site in 44 % of patients. A total of 70 % of the patients had oligometastatic disease (less than five lesions), and the rest were polymetastatic, responding to systemic therapy with oligo progression in the adrenal. The average gross tumor volume (GTV) was 42 ml. Respiratory control was applied in 88 % of cases; 49.3 % used 4-D/ITV, and 38.5 % used breath-hold or continuous positive airway pressure (CPAP) with free breathing. On multivariable analysis, Dose above 75 Gy (biological effective Dose) (HR = 0.41, p = 0.031), Dose above 8 Gy per fraction (HR = 0.53p = 0.038), and breath-holds or CPAP (HR = 0.65, p = 0.047) were significant for local control. From multivariable analysis, we computed a predicted nomogram curve using seven clinical parameters to evaluate local control odds.

Conclusion

In this single institution series reported to date, we found unilateral adrenal SBRT safe, yet bilateral treatment harbors a risk of adrenal insufficiency. Biological effective Dose > 75 Gy (BED), motion management with breath-hold or CPAP, and Dose per fraction > 8 Gy were the enhanced local controls. We propose a nomogram to help in decision-making regarding total Dose and Dose per fraction when treating adrenal SBRT.

Multi-institutional experience of MR-guided stereotactic body radiation therapy for adrenal gland metastases

Purpose

While dose escalation is associated with improved local control (LC) for adrenal gland metastases (AGMs), the proximity of gastrointestinal (GI) organs-at-risk (OARs) limits the dose that can be safely prescribed via CT-based stereotactic body radiation therapy (SBRT). The advantages of magnetic resonance-guided SBRT (MRgSBRT), including tumor tracking and online plan adaptation, facilitate safe dose escalation.

Methods

This is a multi-institutional review of 57 consecutive patients who received MRgSBRT on a 0.35-T MR linac to 61 AGMs from 2019 to 2021. The Kaplan-Meier method was used to estimate overall survival (OS), progression-free survival (PFS), and LC, and the Cox proportional hazards model was utilized for univariate analysis (UVA).

Results

Median follow up from MRgSBRT was 16.4 months (range [R]: 1.1-39 months). Median age was 67 years (R: 28-84 years). Primary histologies included non-small cell lung cancer (N = 38), renal cell carcinoma (N = 6), and melanoma (N = 5), amongst others. The median maximum diameter was 2.7 cm (R: 0.6-7.6 cm), and most AGMs were left-sided (N = 32). The median dose was 50 Gy (R: 30-60 Gy) in 5-10 fractions with a median BED10 of 100 Gy (R: 48-132 Gy). 45 cases (74 %) required adaptation for at least 1 fraction (median: 4 fractions, R: 0-10). Left-sided AGMs required adaptation in at least 1 fraction more frequently than right-sided AGMs (88 % vs 59 %, p = 0.018). There were 3 cases of reirradiation, including 60 Gy in 10 fractions (N = 1) and 40 Gy in 5 fractions (N = 2). One-year LC, PFS, and OS were 92 %, 52 %, and 78 %, respectively. On UVA, melanoma histology predicted for inferior 1-year LC (80 % vs 93 %, p = 0.012). There were no instances of grade 3+ toxicity.

Conclusions

We demonstrate that MRgSBRT achieves favorable early LC and no grade 3 + toxicity despite prescribing a median BED10 of 100 Gy to targets near GI OARs.

Lower fluorodeoxyglucose positron emission tomography maximum standardized uptake value may show a better response to stereotactic body radiotherapy of adrenals in oligometastatic disease

Introduction

Stereotactic body radiotherapy (SBRT) is well established for oligometastatic disease, and it is increasingly used to treat adrenal metastases.

Material and methods

In this retrospective study we performed an analysis of 75 metastatic adrenal lesions in 64 patients with oligometastatic disease. According to the fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) maximum standardized uptake value (SUVmax) of adrenal metastases, patients were categorized into three groups: low, intermediate, and high SUVmax.

Results

For all clinicopathological characteristics we found significant relationships for levels of SUVmax and objective response rate (Kendall Tau-c = 0.290; p = 0.017). Patients who responded to SBRT had a significantly lower SUVmax value than those who did not respond (7.6 ±2.4 vs. 9.7 ±3.8; p = 0.015). At the appropriate SUVmax cut-off values, the biomarker distinguished between patients with and without a response significantly and moderately (area under the curve = 0.670, 95% confidence intervals: 0.540-0.790; p = 0.015).

Conclusions

Lower SUVmax is associated with a better response to SBRT in patients whose disease progressed mainly in the adrenal glands.

Risk factors of local control in adrenal metastases treated by stereotactic body radiation therapy - a systematic review and meta-analysis

Purpose

This study is aimed to explore risk factors affect the therapy outcomes of adrenal metastases (AM) for stereotactic body radiation therapy (SBRT) and guide clinical dose selection.

Methods and materials

PubMed, Embase and Web of Science were searched in September 22, 2022 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). Subgroup analysis and meta-regression were used to search for sources of heterogeneity and identify risky outcomes factors. Publication bias test and sensitivity analysis were also conducted.

Results

Thirty-three studies with full text from 2009 to 2022 about AM with SBRT on 1483 patients were included. Pooled 1- and 2-year local control (LC) and overall survival(OS) were 81.7% (95% confidence interval [CI], 75.6%-86.5%), 62.8% (95% CI, 53.8%-71.8%), 67.4% (95%CI, 61.8%-73.1%) and 46.5% (95%CI, 40.4%-52.6%), respectively. Biological effective dose (BED, α/β=10Gy) and dose per fraction affected 1-year LC (Qm=23.89, 15.10; P<0.0001, 0.0001). In the range of 60-80Gy (BED10), the group of dose per fraction ≥ 9Gy achieved the excellent 1-year LC (< 9Gy: ≥ 9Gy =78%, 91%; χ2 = 10.16, P = 0.001). Tracking technology significantly affected 1- and 2-year OS (Qm = 5.73, 8.75; P = 0.017, 0.003) and high tracking adoption group showed excellent 1- and 2- year OS (78.7% [95%CI, 68.6%- 88.9%]; and 62.9% [95%CI, 53.1%-72.7%]).

Conclusion

Increasing the dose per fraction appropriately may help control locally AM lesious. Tracking technology might contribute to improve survival of advanced patients with AM. But these results need prospective studies to verify them.

Tumor volume changes during stereotactic ablative radiotherapy for adrenal gland metastases under MRI guidance

PURPOSE

Gross tumor volume (GTV) changes during stereotactic ablative radiotherapy (SABR) for adrenal tumors are not well characterized. We studied treatment-induced GTV changes during, and after, 5-fraction MR-guided SABR on a 0.35 T unit.

METHODS AND MATERIALS

Details of patients treated for adrenal metastases using 5-fraction adaptive MR-SABR were accessed. GTV changes between simulation and first fraction (ΔSF1) and all fractions were recorded. Wilcoxon paired tests were used for intrapatient comparisons. Logistic and linear regression models were used for features associated with dichotomous and continuous variables, respectively.

RESULTS

Once-daily fractions of 8 Gy or 10 Gy were delivered to 70 adrenal metastases. Median simulation-F1 interval was 13 days; F1-F5 interval was 13 days. Median baseline GTVs at simulation and F1 were 26.6 and 27.2 cc, respectively (p < 0.001). Mean ΔSF1 was + 9.1% (2.9 cc) relative to simulation; 47% of GTVs decreased in volume at F5 versus F1. GTV variations of ≥ 20% occurred in 59% treatments at some point between simulation to end SABR, and these did not correlate with baseline tumor characteristics. At a median follow-up of 20.3 months, a radiological complete response (CR) was seen in 23% of 64 evaluable patients. CR was associated with baseline GTV (p = 0.03) and ΔF1F5 (p = 0.03). Local relapses were seen in 6%.

CONCLUSION

Frequent changes in adrenal GTVs during 5-fraction SABR delivery support the use of on-couch adaptive replanning. The likelihood of a radiological CR correlates with the baseline GTV and intra-treatment GTV decline.

Prostate-specific membrane antigen-based imaging for stereotactic irradiation of low-volume progressive prostate cancer: a single-center experience

Introduction

Prostate-specific membrane antigen (PSMA) is a transmembrane protein that may be expressed on the surface of prostate cancer (PC) cells. It enables a more sensitive and specific diagnosis PC, compared to conventional anatomical imaging.

Aim

The integration of PSMA-based imaging in the personalized radiotherapy of PC patients and the evaluation of its impact on target volume definition if stereotactic body radiotherapy (SBRT) is planned for locally recurrent or oligometastatic disease.

Patients and methods

The data from 363 examinations were analyzed retrospectively. Inclusion criteria were histologically verified PC and clinical data suggesting local recurrence or distant metastasis. Whole-body 99mTc-PSMA-I&S single-photon emission computed tomography (SPECT)/CT or 18F-JK-PSMA-7 positron emission tomography/computer tomography (PET/CT) was carried out, and the evaluation of the scans and biological tumor volume contouring was performed at the Department of Nuclear Medicine. The target volume delineation on topometric CT (TCT) scan was performed at the Department of Oncotherapy. The comparison of the two volumes was performed by image fusion and registration.

Results

From 363 PSMA isotope-based examinations, 84 lesions of 64 patients were treated with SBRT. In 50 patients, 70 lesions were examined for intermodality comparison. The target volume defined by the PSMA density was significantly smaller than the tumor size defined by the TCT scan: GTVCT (gross tumor volume on the TCT), 27.58 ± 46.07 cm3; BTVPSMA (biological target volume on the PSMA-based examination), 16.14 ± 29.87 cm3. During geometrical analyses, the Dice similarity coefficient (DSC) was 0.56 ± 0.20 (0.07-0.85). Prostate-specific antigen (PSA) control was performed to evaluate the response: mean pre-radiotherapy (pre-RT) PSA was 16.98 ng/ml ( ± SD: 33.81), and post-RT PSA at 3 months after SBRT was 11.19 ng/ml ( ± SD: 32.85). Three-month post-therapy PSMA-based imaging was performed in 14 cases, in which we observed a decrease or cessation of isotope uptake. Conventional imaging control was performed in 42 cases (65.6% of all cases): 22 (52.4%) complete remissions, 14 (33.3%) partial remissions, four (9.5%) stable diseases, and two (4.8%) progressive diseases were described.

Conclusion

PSMA-based imaging is a promising diagnostic method for specifying the stage and detecting the low-volume progression. Our results suggest that PSMA-based hybrid imaging can influence treatment decisions and target volume delineation for SBRT.

Radiation of bilateral adrenal metastases is associated with a high risk of primary adrenal insufficiency

BACKGROUND

Adrenal metastasis is the most common adrenal malignancy and can be bilateral in up to 43% of patients. Radiotherapy (RT) is one option available to treat adrenal metastases. The risk of primary adrenal insufficiency (PAI) after adrenal RT is unclear.

OBJECTIVE

Determine the incidence and the timeline of PAI in patients undergoing adrenal RT.

DESIGN, SETTING AND PARTICIPANTS

Single-centre longitudinal retrospective cohort study of adult patients with adrenal metastases treated with RT between 2010 and 2021.

RESULTS

Of 56 patients with adrenal metastases treated with adrenal RT, eight (14.3%) patients developed PAI at a median of 6.1 months (interquartile range [IQR]: 3.9-13.8) after RT All patients developing PAI had either unilateral RT in the setting of contralateral adrenalectomy or bilateral adrenal RT. Patients who developed PAI received a median RT dose of 50 Gy (IQR: 44-50 Gy), administered in a median of five fractions (IQR: 5-6). Treated metastases decreased in size and/or metabolic activity on positron emission tomography in seven patients (87.5%). Patients were initiated on hydrocortisone (median daily dose of 20 mg, IQR: 18-40) and fludrocortisone (median daily dose of 0.05 mg, IQR: 0.05-0.05 mg). At the end of the study period, five patients died, all due to extra-adrenal malignancy, at a median time of 19.7 months (IQR: 16-21.1 months) since RT and median time of 7.7 months (IQR: 2.9-12.5 months) since the diagnosis of PAI.

CONCLUSION

Patients receiving unilateral adrenal RT with two intact adrenal glands have a low risk of PAI. Patients receiving bilateral adrenal RT have a high risk of PAI and require close monitoring.

Radiation Therapy in the Management of Adrenal Metastases

Adrenal glands represent a common site of metastases from several primary tumors, including lung cancer, breast cancer and melanoma. Surgical resection is considered the standard of care, but surgery is not always feasible given the challenges related to anatomical site and/or due to patient and/or disease characteristics. Stereotactic body radiation therapy (SBRT) represents a promising treatment for oligometastases, though the literature on its role for adrenal metastases is still heterogeneous. Herein are summarized the most relevant published studies on the efficacy and safety of SBRT for adrenal gland metastases. The preliminary data suggests that SBRT yields high local control rates and symptom relief with a mild pattern of toxicity. Advanced radiotherapy techniques including IMRT and VMAT, a BED10 > 72 Gy and the use of 4DCT for motion control should be considered for a high quality ablative treatment of adrenal gland metastases.

The efficacy and outcomes of stereotactic body radiotherapy in adrenal gland metastases

Aim

This retrospective study presents our single-institutional experience with stereotactic body radiotherapy for adrenal gland metastases.

Materials and Methods

We evaluated patients with adrenal metastases treated by stereotactic body radiotherapy (SBRT) from 2014 to 2020. We performed an analysis of 35 patients. The median age of the patients was 62.2. Dosimetric parameters and treatment outcomes were evaluated.

Results

The primary diagnosis of the majority of patients was non-small cell lung cancer (94.3%). Treatment was performed in a median of 3 fractions, and the median prescribed dose was 24 Gy (range 22,5-27). The median follow-up was 17 months. Treatment response according to Response Evaluation Criteria in Solid Tumours was categorized as complete response in 11 patients, partial response in nine patients, stable disease in 7, and progressive disease in eight patients. Twenty seven patients had oligometastatic disease and treatment response. Patients with oligometastatic disease had a significantly higher rate of complete response and partial response to treatment than patients with common disease (P = 0,011). The 6-month and 1-year local control rates were 68.4% and 43%, respectively. In general, SBRT was well tolerated and no acute toxicities were observed.

Conclusion

Our retrospective study shows that SBRT can be applied safely in adrenal metastases with good results especially in patients with oligometastatic disease.

Robotic stereotactic body radiotherapy for the management of adrenal gland metastases: a bi-institutional analysis

PURPOSE

Adrenal gland metastases (AGMs) are a common manifestation of metastatic tumor spread, especially in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). In patients with a limited systemic tumor burden, effective treatments for AGMs are needed. Due to varying fractionation schemes and limited reports, short-course treatment results for stereotactic body radiotherapy (SBRT) for AGMs are lacking. This work analyzes the outcomes of short-course SBRT for AGMs.

METHODS

Patients who underwent robotic SBRT for AGMs with one to five fractions were eligible for analysis.

RESULTS

In total, data from 55 patients with 72 AGMs from two institutions were analyzed. Most AGMs originated from renal cell carcinoma (38%) and NSCLC (35%). The median follow-up was 16.4 months. The median prescription dose and isodose line were 24 Gy and 70%, respectively. Most patients (85%) received SBRT with just one fraction. The median biologically effective dose assuming an α/β ratio of 10 (BED₁₀) was 80.4 Gy. The local control and progression-free survival after 1 and 2 years were 92.9%, 67.8%, and 46.2%, as well as 24.3%, respectively. Thirteen patients (24%) suffered from grade 1 or 2 toxicities. The BED₁₀ showed a significant impact on LC (p < 0.01). Treatments with a BED₁₀ equal to or above the median were associated with a better LC (p < 0.01).

CONCLUSION

Robotic SBRT is an efficient and safe treatment modality for AGM. Treatment-associated side effects are sporadic and manageable. Results suggest short-course SBRT to be a preferable and time-saving treatment option for the management of AGMs if an adequate BED₁₀ can be safely applied.

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.

Effect of stomach size on organs at risk in pancreatic stereotactic body radiotherapy

BACKGROUND

In clinical practice, the organs at risk (OARs) should be carefully determined when performing pancreatic stereotactic body radiotherapy (SBRT). We conducted a simulation study to examine the effect of the stomach size on the radiation dose to the OARs when performing pancreatic SBRT.

METHODS

Twenty-five cases were included in this study. Pancreatic head and body tumors were 2-cm-sized pseudotumors, which were included as gross target volume (GTV) contours. The stomach, pancreas, small intestine, liver, kidneys, and spinal cord were considered as the OARs. The prescription dose for planning target volume (PTV) was 40 Gy/5fx, and the dose limit for the OARs was determined. The dose to X% of the OAR volume at X values of 0.1, 5.0, and 10.0 cc (DX) and the percentage of the OAR volume that received more than X Gy were recorded.

RESULTS

In terms of the radiation dose to the pancreatic body tumors, the stomach size was positively correlated with a dose of D10cc [correlation coefficient (r) = 0.5516) to the stomach. The r value between the radiation dose to the pancreatic head tumor and the stomach size was 0.3499. The stomach size and radiation dose to the head and body of the pancreas were positively correlated (pancreatic head D10cc: r = 0.3979, pancreatic body D10cc: r = 0.3209). The larger the stomach, the larger the radiation dose to the healthy portion of the pancreas outside the PTV.

CONCLUSIONS

When performing pancreatic SBRT, the dose to the OARs depends on the stomach size. Reducing the dose to the stomach and pancreas can be achieved by shrinking the stomach.

Long-term control of melanoma adrenal metastasis treated with radiotherapy

Melanoma remains a large global burden with a significant proportion of patients succumbing to metastatic disease. The adrenal gland is a common area for metastasis with surgical treatment as the main modality. Radiotherapy is less utilised in this setting with uncertainty over deliverability and efficacy. Here, we present the details and outcomes of 20 patients treated with radiotherapy, with or without systemic therapy, for melanoma adrenal metastasis in a single institute. Twenty patients were identified from radiation treatment and medical records from between 2015 and 2019 at our institution. Three patients had bilateral radiotherapy treatments and therefore 23 adrenal lesions were analysed. Demographics, indications for treatment, radiotherapy methodology and outcomes were recorded. Outcomes were based on serial 18F FDG PET/computerized tomography scans reporting using the PERCIST criteria. The most common indication for radiotherapy was oligo-progressive disease (70%) followed by symptom palliation. Eight (35%) of the treatments were delivered by stereotactic ablative body radiotherapy. Twelve (60%) patients had concurrent immunotherapy. Twenty of twenty-three (87%) adrenal lesions had an initial response to treatment with 12 (60%) maintaining local control until death or end of follow-up. Median adrenal-specific progression-free survival was 13 months. Four patients (17%) required salvage adrenalectomy. Symptom palliation was achieved in the majority of patients for which it was indicated and there were no grade three toxicities. The median time from radiotherapy to change of immunotherapy treatment was 4 months. Radiotherapy for melanoma adrenal metastasis is effective and deliverable. With the majority of patients achieving a palliative and clinically relevant durable response, adrenalectomy can be reserved as a salvage option.

Stereotactic Body Radiotherapy of adrenal metastases - A dose-finding study

Optimal doses for the treatment of adrenal metastases with stereotactic radiotherapy (SBRT) are unknown. We aimed to identify dose-volume cut-points associated with decreased local recurrence rates (LRR). A multicenter database of patients with adrenal metastases of any histology treated with SBRT (biologically effective dose, BED10 ≥ 50Gy, ≤ 12 fractions) was analyzed. Details on dose-volume parameters were required (planning target volume: PTV-D98%, PTV-D50%, PTV-D2%; gross tumor volume: GTV-D50%, GTV-mean). Cut-points for LRR were optimized using the R maxstat package. 196 patients with 218 lesions were included, the largest histopathological subgroup was adenocarcinoma (n = 101). Cut-point optimization resulted in significant cut-points for PTV-D50% (BED10: 73.2Gy; p = 0.003), GTV-D50% (BED10: 74.2Gy; p = 0.006), GTV-mean (BED10: 73.0Gy; p = 0.007), and PTV-D2% (BED10: 78.0Gy; p = 0.02) but not for the PTV-D98% (p = 0.06). Differences in LRR were clinically relevant (LRR ≥ doubled for cut-points that were not achieved). Further dose-escalation was not associated with further improved LRR. PTV-D50%, GTV-D50%, and GTV-mean cut-points were also associated with significantly improved LRR in the adenocarcinoma subgroup. Separate dose optimizations indicated a lower cut-point for the PTV-D50% (BED10: 69.1Gy) in adenocarcinoma lesions, other values were similar (< 2% difference). Associations of cut-points with overall survival (OS) and progression-free survival were not significant but durable freedom from local recurrence was associated with OS in a landmark model (p < 0.001). To achieve a significant improvement of LRR for adrenal SBRT, a moderate escalation of PTV-D50% BED10 > 73.2Gy (adenocarcinoma: 69.1Gy) should be considered. This article is protected by copyright. All rights reserved.

Management of an Unusual Metastasis of Cervical Cancer in the Adrenal Bed With Stereotactic Ablative Body Radiation Therapy

Uterine cervical carcinoma is an important type of cancer among Ecuadorian women, especially in adult women. Survival rates have improved with the development of radiotherapy, surgical techniques, and chemotherapy. However, recurrence and/or metastasis are not unusual phenomena. Frequent sites of metastasis are the lungs, regional lymph nodes, and bones. Atypical locations can also occur on solid organs, such as adrenal glands. Treatment for the rare complication that is adrenal metastasis is individualized, it can include surgical resection, chemotherapy, local ablation, or different types of radiotherapy.

We aimed to report a case of an Ecuadorian woman from Quito city with a diagnosis of cervical carcinoma diagnosed in 2009, treated surgically and with adjuvant chemotherapy. Her progression was monitored with medical controls with no recurrence until 2018, when she relapsed with a metastatic invasion of the pelvic ganglia and the surroundings of the abdominal aorta, with a histopathologic diagnosis of adenocarcinoma. She was then treated with chemotherapy and radiotherapy until June 2019. In 2020, she went through a splenectomy and left adrenalectomy to treat vascular thrombosis. In 2021, 37 x 15 mm mass was discovered in the surgical bed of the previously removed adrenal gland. It was treated as an oligometastatic carcinoma with stereotactic body radiotherapy (SBRT) by a linear accelerator.

Stereotactic body radiation therapy for adrenal gland metastases: outcome and predictive factors from a multicenter analysis

Adrenal metastases occur in 15-35% of oncological patients. Surgery is the first treatment option. Stereotactic body radiotherapy (SBRT) has been largely explored in oligometastatic patients unfit for surgery, representing an effective and non-invasive local treatment. The results of a multi-institutional experience of SBRT on adrenal metastases in the oligorecurrent or oligoprogressive setting are herein reported. We collected data of adrenal gland metastases treated with SBRT in three Italian centers from 2010 to 2020. End-points of the present study were: Overall survival (OS), Local control of treated metastases (LC), Progression free survival (PFS), and toxicity. 149 adrenal gland metastases were treated with SBRT in 142 patients. The most common primary tumor was lung cancer (58.4%), followed by kidney cancer (9.4%). Median lesion's volume was 28.5 cm³ (2.5-323.4). The median SBRT dose was 40 Gy (10-60). Median follow-up was 14.4 months. One- and two-year OS were 72.3% and 53.5%. At univariate analysis performance status correlated with survival (HR 1.57, p = 0.006). One- and two-year LC were 85.4% and 79.2%, with lung primary tumor (HR 0.33, p = 0.021) and BED10 (HR 0.97, p = 0.036) significant independent factors. One- and two-year PFS were 37.7% and 24.8%. Median time to polymetastatic disease was 11.3 months. Grade 1 and 2 toxicity occurred in 21 (14.7%) and 3 (2.1%) patients. The results from this large multi-center study confirm the efficacy and safety of SBRT in the management of adrenal gland metastases, as a valid alternative to other more invasive local approaches.

Stereotactic body radiation therapy (SBRT) of adrenal gland metastases in oligometastatic and oligoprogressive disease

BACKGROUND

Stereotactic body radiation therapy (SBRT) as a form of noninvasive treatment that is becoming increasingly used to manage cancers with adrenal gland metastases. There is a paucity of data on safety and efficacy of this modality. The aim of the study was to evaluate the safety and efficacy of adrenal gland SBRT in oligometastatic and oligoprogressive disease.

MATERIALS AND METHODS

In this retrospective study, we performed a single-institution analysis of 26 adrenal lesions from 23 patients with oligometastatic or oligoprogressive disease treated from 2013 to 2019 with the goal of achieving durable local control. Palliative cases were excluded. Radiation dosimetry data was collected. Kaplan Meier product estimator and Cox proportional hazards regression analysis were used for statistical analysis.

RESULTS

The median dose was 36 Gy in 3 fractions (range: 24-50 Gy and 3-6 fractions) with a median biologically effective dose (BED10) of 72 (range: 40-100). 1-year local control rate was 80% and median local control was not achieved due to a low number of failures. 1- and 2-year overall survival rates were 66% and 32%. Toxicity was mild with only one case of grade 2 nausea and no grade 3-5 toxicity. Higher neutrophil to lymphocyte ratio was associated with worse overall survival and a trend toward worse progression-free survival. In addition, worse performance status and lower BED10 were associated with worse survival. No such association could be shown for primary tumor location, histology, size or stage.

CONCLUSION

Adrenal SBRT for oligometastatic or oligoprogressive disease is a safe and effective form of treatment.

Stereotactic or conformal radiotherapy for adrenal metastases: Patient characteristics and outcomes in a multicenter analysis

To report outcome (freedom from local progression [FFLP], overall survival [OS] and toxicity) after stereotactic, palliative or highly conformal fractionated (>12) radiotherapy (SBRT, Pall-RT, 3DCRT/IMRT) for adrenal metastases in a retrospective multicenter cohort within the framework of the German Society for Radiation Oncology (DEGRO). Adrenal metastases treated with SBRT (≤12 fractions, biologically effective dose [BED10] ≥ 50 Gy), 3DCRT/IMRT (>12 fractions, BED10 ≥ 50 Gy) or Pall-RT (BED10 < 50 Gy) were eligible for this analysis. In addition to unadjusted FFLP (Kaplan-Meier/log-rank), we calculated the competing-risk-adjusted local recurrence rate (CRA-LRR). Three hundred twenty-six patients with 366 metastases were included by 21 centers (median follow-up: 11.7 months). Treatment was SBRT, 3DCRT/IMRT and Pall-RT in 260, 27 and 79 cases, respectively. Most frequent primary tumors were non-small-cell lung cancer (NSCLC; 52.5%), SCLC (16.3%) and melanoma (6.7%). Unadjusted FFLP was higher after SBRT vs Pall-RT (P = .026) while numerical differences in CRA-LRR between groups did not reach statistical significance (1-year CRA-LRR: 13.8%, 17.4% and 27.7%). OS was longer after SBRT vs other groups (P < .05) and increased in patients with locally controlled metastases in a landmark analysis (P < .0001). Toxicity was mostly mild; notably, four cases of adrenal insufficiency occurred, two of which were likely caused by immunotherapy or tumor progression. Radiotherapy for adrenal metastases was associated with a mild toxicity profile in all groups and a favorable 1-year CRA-LRR after SBRT or 3DCRT/IMRT. One-year FFLP was associated with longer OS. Dose-response analyses for the dataset are underway.

THE NOVEL USE OF STEREOTACTIC RADIOTHERAPY FOR REMNANT ADRENAL TISSUE IN NELSON SYNDROME

Objective

Recurrent Cushing disease (CD) is a rare complication that occurs in patients who have undergone bilateral adrenalectomy (BLA). We report a case of recurrent CD in a patient with Nelson syndrome and adrenalectomy due to remnant adrenal tissue, and a novel treatment strategy using stereotactic body radiation therapy (SBRT) to the adrenal glands.

Methods

We report a case of recurrent CD in a woman with Nelson syndrome and adrenalectomy and describe her clinical course and management. We also include a literature review of CD management and adrenal radiation.

Results

The patient had persistent pituitary CD despite pituitary surgery and radiosurgery and underwent BLA. She developed recurrent CD due to a remnant adrenal gland post adrenalectomy. She then underwent SBRT to both adrenal beds to treat the remnant adrenal tissue. Her serum cortisol dropped rapidly after adrenal radiation and she experienced minimal side effects. She has been in remission for over 2 years.

Conclusion

This is the first reported case of recurrent CD in a patient post adrenalectomy that was successfully treated with SBRT to the remnant adrenal tissue.

Adrenal SBRT: a multi-institutional review of treatment outcomes and toxicity

The adrenal glands are a common site of metastatic disease. Definitive treatment for oligometastatic disease using ablative radiotherapy is becoming common in modern radiation oncology practice. However, most data on the treatment of adrenal metastases are limited to single institution reports. Furthermore, delivering ablative radiotherapy doses to intra-abdominal lesions can be challenging due to the proximity of the gastrointestinal tract. We report the outcomes of a multi-institutional cohort of patients treated with definitive radiotherapy for adrenal metastases, primarily using 10 fraction regimens. Retrospective review of institutional databases revealed 29 lesions in 27 patients were treated from 2005 to 2018 at two institutions. Outcome data, including local control, disease-free, and overall survival were abstracted from the medical record system. Toxicity was graded using CTCAE v5.0. Detailed radiotherapy data was abstracted from the treatment planning systems. The median dose was 50 Gy in 10 fractions. Actuarial 1 and 2 year local control was 86% and 76% respectively. The median overall and disease-free survival were 22.8 and 5.6 months respectively. There were no associations identified between local failure and GTV and PTV physical or biologic effective dose. Two patients developed late Grade 3 gastrointestinal toxicity. High dose radiotherapy to adrenal metastases is a feasible treatment with excellent local control and a reasonable safety profile. For lesions in close proximity to gastrointestinal structures, moderately hypofractionated 10 fraction regimens may be a reasonable compromise between local control and toxicity.

Stereotactic body radiotherapy for adrenal oligometastasis in lung cancer patients

OBJECTIVE

To report our experience on stereotactic body radiotherapy (SBRT) in adrenal metastases from lung cancer.

METHODS

37 oligometastatic lung cancer patients with 38 adrenal metastases submitted to SBRT were retrospectively analyzed. SBRT was delivered by volumetric modulated arc therapy (VMAT) or helical tomotherapy (HT). Primary study end point was local recurrence-free survival (LR-FS) and secondary end points were distant-progression free survival (d-PFS) and overall survival (OS).

RESULTS

Median age was 67 years and primary tumor was non-small-cell lung cancer in 27 (73%) and small-cell lung cancer in 10 (27%) patients. Adrenal metastases were in the left side in 66% cases. Median prescribed dose was 30 Gy in 5 fractions for a median biologically equivalent dose (α/β ratio 10  Gy, BED10) of 48 Gy. Most patients (62%) were submitted to SBRT alone, while the others (38%) received chemo-, immune- or target- therapies. Median follow-up was 10.5 months, median OS 16 months and median d-PFS 3 months. 27 (70%) patients obtained a local control with a median LR-FS of 32 months. LR-FS was significantly related to BED10 with a better LC with BED10 ≥72 Gy, 1- and 2 year LR-FS rates were 54.1±11.6% and 45±12.7% vs 100 and 100% for BED ≤59.5 Gy and BED ≥72 Gy, respectively (p = 0.05). There was no severe toxicity.

CONCLUSION

SBRT was effective and safe in lung cancer adrenal metastases. A dose-response relationship was found between BED10 >72 Gy and better local control. No significant toxicity was registered thanks to the respect of dose constraints and suspension of chemo- and target-therapies.

ADVANCES IN KNOWLEDGE

SBRT with a BED10 >72 Gy is an effective treatment for adrenal oligometastatic lung cancer patients.

GOECP/SEOR clinical recommendations for lung cancer radiotherapy during the COVID-19 pandemic

The coronavirus disease 2019 crisis has had a major and highly complex impact on the clinical practice of radiation oncology worldwide. Spain is one of the countries hardest hit by the virus, with devastating consequences. There is an urgent need to share experiences and offer guidance on decision-making with regard to the indications and standards for radiation therapy in the treatment of lung cancer. In the present article, the Oncological Group for the Study of Lung Cancer of the Spanish Society of Radiation Oncology reviews the literature and establishes a series of consensus-based recommendations for the treatment of patients with lung cancer in different clinical scenarios during the present pandemic.

The Effect of Concurrent Stereotactic Body Radiation and Anti-PD-1 Therapy for Recurrent Metastatic Sarcoma

Patients diagnosed with metastatic sarcoma have limited options for achieving both local and distant tumor control. While SBRT can achieve local control, distant response rates remain low. There is limited evidence demonstrating the safety and efficacy for combining SBRT with concurrent PD-1 checkpoint blockade in metastatic sarcoma. In this prospective case-series, we examined five patients with metastatic sarcoma on pembrolizumab treated concurrently with SBRT from July 1, 2016-October 30, 2018. Acute and chronic toxicity were recorded using Common Terminology Criteria for Adverse Events (CTCAE, version 5.0). SBRT-treated tumor control was assessed using Response Evaluation Criteria in Solid Tumors (RECIST version 1.1). With median follow-up of 14.9 months, three patients with undifferentiated pleomorphic sarcoma, one with intimal, and one with chondroblastic osteosarcoma received SBRT with concurrent pembrolizumab to 10 sites of metastatic disease. No grade 5 toxicities were observed. There was a single incidence of transient grade 4 lymphopenia which resolved without intervention. Grade 3 toxicities included anemia, thrombocytopenia, lymphopenia and colitis. One tumor demonstrated local progression after SBRT, and all others remained stable or with response. In conclusion, combining SBRT with PD-1 inhibition appeared to be safe in this patient population. Expected high rates of treated-tumor local control after SBRT were observed. Two of five patients demonstrated either enhanced local tumor regression, or possible abscopal effect.

Safety and Efficacy of Stereotactic Body Radiation Therapy for Locoregional Recurrences After Prior Chemoradiation for Advanced Esophageal Carcinoma

Purpose: This study aimed to investigate the feasibility of stereotactic body radiation therapy (SBRT) as salvage therapy for locally recurrent esophageal cancer. We hypothesized that SBRT would provide durable treated tumor control with minimal associated toxicity in patients with progressive disease after definitive radiation, chemotherapy, and surgical resection. Methods: This single-institution retrospective study assessed outcomes in patients who received SBRT for locoregional failure of esophageal cancer after initial curative-intent treatment. Only patients who had received neoadjuvant chemoradiation (≥41.4 Gy) for esophageal cancer were selected. Subsequent surgical resection was optional but institutional follow-up by an oncologist was required. The primary endpoints of this study were gastrointestinal and constitutional toxicity, scored with the Common Terminology Criteria for Adverse Events v5.0. A secondary outcome, treated-tumor control, was assessed with RECIST v1.1. Results: Nine patients (11 locoregional recurrences) treated with SBRT were reviewed, with a median follow-up time of 10.5 months. Most patients initially presented with T3 (88.9%), N1 (55.6%), moderately differentiated (66.7%) adenocarcinoma (88.9%), and had received a median 50.4 Gy delivered over 28 fractions with concurrent carboplatin/paclitaxel chemotherapy followed by surgical resection. Median time to recurrence was 16.3 months. Median total dose delivered by SBRT was 27.5 Gy (delivered in five fractions). Two patients experienced acute grade 1 fatigue and vomiting. No patient experienced grade 3 or higher toxicity. One patient experienced failure in the SBRT treatment field at 5.8 months after treatment and six patients developed distant failure. The median progression-free survival time for SBRT-treated tumors was 5.0 months, and median overall survival time was 12.9 months. Conclusions: This single-institution study demonstrated the feasibility of SBRT for locoregional recurrence of esophageal cancer with minimal treatment-related toxicity and high rates of treated tumor control. Prospective studies identifying ideal salvage SBRT candidates for locoregional failure as well as validating its safety are needed.

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.

Clinical efficacy of Stereotactic Body Radiation Therapy (SBRT) for adrenal gland metastases: A multi-center retrospective study from China

To evaluate the efficacy and safety of CyberKnife Stereotactic Body Radiation Therapy (SBRT) in the treatment of adrenal gland metastases (AGM), we designed a large-scale multicenter retrospective study to report the safety and efficacy of SBRT for inoperable AGM. In this study, 75 (61 males, 14 females) patients with 84 AGM and Karnofsky performance score ≥70 were treated by SBRT from October 2006 to January 2017. Of these, the purpose of treatment were controlling all known metastatic sites for 21 patients while 54 for palliation of bulky adrenal metastases. The efficacy and safety of SBRT were evaluated during follow-up. Potential factors predictive of local control (LC) and overall survival (OS) were identified by univariate and multivariate analysis. Median follow-up time was 12.7 months (range 1.8–96.4). The complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) rates were 23.8%, 23.8%, 31.0% and 21.4%, respectively. The 0.5, 1, and 2-year LC rates were 93.6%, 83.8%, and 62.1%, respectively; OS rates on the same follow-up intervals were 93.7%, 62.5%, and 49.6%, respectively, and the corresponding PFS rates were 48.5%, 33.9%, and 16.0%, respectively. The treatment was well tolerated with 2 patients reporting grade-3 diarrhea and fatigue, respectively. Multivariate analysis showed that simultaneous treatment of SBRT for other metastatic lesions, the number of AGM, initiation of systemic therapy, and the maximum diameter of AGM were predictive of LC rates. Moreover, patients with AGM < 5 cm had a superior OS compared with those with AGM ≥ 5 cm (28.0 months vs. 17.6 months, P = 0.032). SBRT is an effective therapeutic option for treatment of AGM with high LC rates with minimal toxicity.

Novel Dose Escalation Approaches for Stereotactic Body Radiotherapy to Adrenal Oligometastases: A Single-Institution Experience

OBJECTIVES

The role of local disease control in the oligometastatic setting is evolving. Stereotactic body radiation therapy (SBRT) is a noninvasive treatment option for oligometastases; however, using ablative radiation doses for adrenal metastases raises concern given the proximity to radiosensitive organs. Novel treatment techniques may allow for selective dose escalation to improve local control (LC) while minimizing dose to nearby critical structures.

MATERIALS AND METHODS

We retrospectively reviewed patients with adrenal oligometastases treated with SBRT from 2013 to 2018. LC, disease-free survival, and overall survival were estimated using Kaplan-Meier methods. Predictors of outcomes were evaluated by log-rank and Cox proportional hazard analyses.

RESULTS

We identified 45 adrenal oligometastases in 41 patients treated with SBRT. The median age at treatment was 67 years (range, 40 to 80). The most common primary histologies were non-small cell lung cancer (51%), renal cell carcinoma (24%), and small cell lung cancer (10%). The median prescription dose was 50 Gy (range, 25 to 60 Gy), with 30 (67%) lesions receiving ≥50 Gy and 14 (31%) receiving 60 Gy. In total, 26 (58%) lesions received a simultaneous-integrated boost. Of the 42 treatment simulations, 26 (62%) were supine, 5 (12%) prone, and 11 (26%) in the left lateral decubitus position. At a median follow-up of 10.5 months, there were 3 local failures with a 12-month LC rate of 96%.

CONCLUSIONS

Adrenal SBRT for oligometastatic disease is a feasible, noninvasive option with excellent LC and minimal toxicity. Lesions in close proximity to radiosensitive organs may benefit from dynamic patient positioning and selective simultaneous-integrated boost techniques to allow for dose escalation, while also limiting toxicity risks.

Metastatic Small-Cell Lung Cancer Presenting as Primary Adrenal Insufficiency

A 40-year-old male smoker with HIV was admitted for cough, hypotension, and abdominal pain for 5 days. Chest radiography showed a right lower lobe consolidation. CT of the chest, abdomen, and pelvis revealed paratracheal adenopathy, a 5.8 × 4.5 cm mass invading the right bronchus intermedius, and dense bilateral adrenal masses, measuring 5.4 × 4.0 cm on the right and 4.8 × 2.0 cm on the left. Laboratory studies showed white blood cell count of 18.5 K/mm³, sodium of 131 mmol/L, creatinine of 1.6 mg/dL, and CD4 count of 567 cells/mm³. The random morning cortisol level was 7.0 μg/dL, the ACTH stimulation test yielded inappropriate response, and a random serum ACTH was elevated at 83.4 pg/mL. MRI brain revealed no pituitary adenoma confirming primary adrenal insufficiency. The adrenal CT washout study was consistent with solid mass content, concerning for metastasis. Bronchoscopy with endobronchial mass and paratracheal lymph node biopsy confirmed small-cell lung cancer (SCLC). Intravenous steroids, 100 mg hydrocortisone every 8 hours, improved his hypotension and abdominal pain. PET scan revealed metabolically active right paratracheal mass, right hilar mass, and bilateral adrenal masses. Treatment included palliative chemotherapy consisting of carboplatin/etoposide/atezolizumab and chest radiation. We present this novel case to demonstrate SCLC's ability to cause primary adrenal insufficiency, as well as evaluate clinical response to chemotherapeutics.

The Prognostic Role of Pretreatment Neutrophil to Lymphocyte Ratio (NLR) in Malignant Adrenal Lesions Treated With Stereotactic Body Radiation Therapy (SBRT)

OBJECTIVE

The objective of this study was to evaluate a single institution's experience with stereotactic body radiotherapy (SBRT) in treating malignant adrenal lesions, as well as the prognostic value of systemic inflammation biomarkers.

MATERIALS AND METHODS

From November 2007 to February 2018, 27 patients with malignant adrenal lesions received 31 SBRT treatments. Outcomes, measured from the date of SBRT, included overall survival (OS), local control (LC), and freedom from progression. Cox proportional hazard model was utilized to identify potential prognostic factors. Tumor response was assessed with PET Response Evaluation Criteria In Solid Tumors (PERCIST)/Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Acute toxicity was evaluated with the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.03 criteria.

RESULTS

Median follow-up for all patients was 8 months. The complete response, partial response, stable disease, and progressive disease rates were 59%, 9%, 32%, and 0%, respectively. One-year LC, OS, and freedom from progression were 77.7%, 38.0%, and 10.0%, respectively. There was a trend toward significance upon multivariate analysis for pretreatment neutrophil to lymphocyte ratio >4.1 to predict inferior OS (adjusted hazard ratio=3.29, P=0.09, 1-year OS: 11% vs. 80%). There were 3 cases (10%) complicated by grade 2 acute toxicity, including nausea and fatigue. There was 1 grade 5 toxicity, as 1 case was complicated by a fatal gastric ulcer occurring 3 months after SBRT to the left adrenal gland (112.5 BED10).

CONCLUSIONS

These results support the limited existing literature, demonstrating that SBRT provides adequate LC for adrenal lesions with minimal toxicity. Pretreatment neutrophil to lymphocyte ratio may serve as a prognostic factor in these patients.

Stereotactic body radiotherapy (SBRT) for adrenal metastases of oligometastatic or oligoprogressive tumor patients

INTRODUCTION

Local ablative treatment strategies are frequently offered to patients diagnosed with oligometastatic disease. Stereotactic body radiotherapy (SBRT), as ablative treatment option, is well established for lung and liver metastases, whereas for isolated adrenal gland metastases the level of evidence is scarce.

MATERIAL AND METHODS

This single-institution analysis of oligometastatic or oligoprogressive disease was limited to patients who received SBRT to adrenal metastasis between 2012 and 2019. Patient, tumor, treatment characteristics, and dosimetric parameters were analyzed for evaluation of their effect on survival outcomes.

RESULTS

During the period of review 28 patients received ablative SBRT to their adrenal gland metastases. Most common primary tumors were non-small cell lung cancers (46%) with most patients diagnosed with a single adrenal gland metastasis (61%), which occurred after a median time of 14 months. SBRT was delivered to a median biological effective dose at α/β of 10 (BED₁₀) of 75 Gy (range: 58-151 Gy). Median gross tumor volume (GTV) and median planning target volume (PTV) were 42 and 111 mL, respectively. The homogeneity and conformity indices were 1.17 (range: 1.04-1.64) and 0.5 (range: 0.4.0.99), respectively, with the conformity index being affected by dose restrictions to organs at risk (OARs) in 50% of the patients. Overall response rate based on RECIST criteria was 86% (CR = 29%, PR = 57%) with 2-year local control (LC) of 84.8%, 2-year progression-free survival (PFS) of 26.3%, and 1-and 2-year overall survival (OS) of 46.6 and 32.0%, respectively. During follow up, only two local recurrences occurred. A trend for superior LC was seen if BED₁₀ was ≥75Gy (p = 0.101) or if the PTV was < 100 ml (p = 0.072). SBRT was tolerated well with only mild toxicity.

CONCLUSION

SBRT for adrenal metastases resulted in promising LC with low toxicity. Treatment response appeared to be superior, if SBRT was applied with higher BED. As the close proximity of OARs often limits the application of sufficiently high doses, further dose escalations strategies and techniques should be investigated in future.

Stereotactic Body Radiation Therapy of Adrenal Metastases: A Pooled Meta-Analysis and Systematic Review of 39 Studies with 1006 Patients

PURPOSE

To perform a systematic review and pooled meta-analysis of adrenal metastasis stereotactic body radiation therapy (SBRT) outcomes, treatment characteristics, and toxicity to define the efficacy and propose guidelines for intervention.

METHODS AND MATERIALS

We performed a comprehensive literature search of the Embase and PubMed databases of studies reporting outcome or toxicity data for photon-based SBRT of adrenal metastases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We then conducted a meta-analysis to estimate pooled overall response, local control (LC), and overall survival and analyzed these outcomes in the context of dosimetric parameters and toxicity using metaregression.

RESULTS

Thirty-nine studies published between 2009 and 2019 reporting outcomes on 1006 patients were included. The median follow-up was 12 months, and the median biological equivalent dose (BED10, alpha/beta = 10) was 67 Gy. The pooled overall response was 54.6% (95% confidence interval [CI], 46.5%-62.5%). The pooled 1- and 2-year rates of LC were 82% (95% CI, 74%-88%) and 63% (95% CI, 50%-74%), respectively, and the pooled 1- and 2-year overall survival rates were 66% (95% CI, 57%-74%) and 42% (95% CI, 31%-53%), respectively. There was a strong positive association between SBRT dose and 1- and 2-year LC (P < .0001, P = .0002) and an association with 2-year OS (P = .03). Based on a metaregression of dose and LC, BED10 of 60 Gy, 80 Gy, and 100 Gy predicted 1-year LC of 70.5%, 84.8%, and 92.9% and 2-year LC of 47.8%, 70.1%, and 85.6%, respectively. The overall rate of grade 3 or higher toxicity was 1.8%.

CONCLUSIONS

SBRT of adrenal metastases provides good 1-year LC with an excellent safety profile, and dose escalation may be associated with improved LC. Prospective studies are needed to validate these findings and determine whether there are subsets of patients for whom adrenal metastasis-directed SBRT may confer a survival advantage.

Management of oligometastatic non-small cell lung cancer patients: Current controversies and future directions

Oligometastatic non-small cell lung cancer (NSCLC) describes an intermediate stage of NSCLC between localized and widely-disseminated disease. This stage of NSCLC is characterized by a limited number of metastases and a more indolent tumor biology. Currently, the management of oligometastatic NSCLC involves radical treatment (radiotherapy or surgery) that targets the metastatic lesions and the primary tumor to achieve disease control. This approach offers the potential to achieve prolonged survival in patients who, in the past, would have only received palliative measures. The optimal therapeutic strategies for the different scenarios of oligometastatic disease (intracranial vs extracranial disease, synchronous vs metachronous) remain undefined. Given the lack of head-to-head studies comparing radiotherapy to surgery in these patients, the decision to apply surgery or radiotherapy (with or without systemic treatment) must be based on prognostic factors that allow us to classify patients. This classification will allow us to select the most appropriate therapeutic strategy on an individualized basis. In the future, the molecular or microRNA profiles will likely improve the treatment selection process. The objective of the present article is to review the most relevant scientific evidence on the management of patients with oligometastatic NSCLC, focusing on the role of radiotherapy and surgery. We also discuss areas of controversy and future directions.

Real-Time Tumor-Tracking Radiotherapy and General Stereotactic Body Radiotherapy for Adrenal Metastasis in Patients With Oligometastasis

Background:

Precise local radiotherapy for adrenal metastasis can prolong the useful life of patients with oligometastasis. The aim of this retrospective, 2-center study was to establish the safety and effectiveness of real-time tumor-tracking radiotherapy and general stereotactic body radiotherapy in treating patients with adrenal metastatic tumors.

Materials and Methods:

Thirteen lesions in 12 patients were treated with real-time tumor-tracking radiotherapy (48 Gy in 8 fractions over 2 weeks) and 8 lesions in 8 patients were treated with general stereotactic body radiotherapy (40-50 Gy in 5-8 fractions over 2 weeks or 60-70 Gy in 10 fractions over 2 weeks). Overall survival rates, local control rates, and adverse effects were analyzed.

Results:

The actuarial overall survival rates for all patients at 1 and 2 years were 78.5% and 45.8%, respectively, with a median follow-up of 17.5 months, and the actuarial local control rates for all tumors at 1 and 2 years were 91.7% and 53.0%, respectively, with a median follow-up of 9 months. A complete local tumor response was obtained in 3 tumors treated by real-time tumor-tracking radiotherapy (lung adenocarcinomas with diameters of 35, 40, and 60 mm). There was a statistically significant difference in the local control between the groups treated by real-time tumor-tracking radiotherapy (100% at 1 year) and general stereotactic body radiotherapy (50% at 1 year; P < .001). No late adverse reactions at Grade 2 or higher were reported for either treatment group.

Conclusions:

This study showed that although both treatments are safe and effective, the real-time tumor-tracking radiotherapy is more effective than general stereotactic body radiotherapy in local control for adrenal metastasis.

Short-term outcomes and clinical efficacy of stereotactic body radiation therapy (SBRT) in treatment of adrenal gland metastases from lung cancer

Background

To assess the efficacy and safety of stereotactic body radiation therapy (SBRT) in the management of adrenal gland metastases (AGMs) from lung cancer. Moreover, it is the first two-institutional experience and the largest-to-date study to report the safety and efficacy of SBRT for inoperable AGM from lung cancer.

Methods

In this retrospective study, 30 patients (27 males, 3 females) with 32 AGMs were treated by SBRT from October 2006 to June 2016. Of these, 11 patients were treated with the intent of controlling all known metastatic sites and 19 for palliation of bulky AGMs. Follow-up was performed every 3 months for evaluations of efficacy and safety. Factors predictive of overall survival (OS) and local control (LC) were identified with univariate and then multivariate analysis.

Results

Median follow-up time was 10.7 months (2.9–96.4 months). The complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) rates were 23.3%, 33.3%, 33.3% and 16.7% respectively. The 6-month, 1, and 2-year LC rates were 96.9%, 96.9%, and 72.7% respectively. Additionally, the 6-month, 1, and 2-year OS rates were 85.6%, 58.1%, and 54.0% respectively while 6-month, 1, and 2-year progression free survival (PFS) rates were 39.5%, 24.6%, and 8.2%, respectively. All the patients with cancer-induced pain (8 with abdominal pain and 6 with lumbar back pain) had significant alleviations after SBRT. The treatment was well tolerated with only 1 patient reporting grade-3 diarrhoea. No predictors of OS and LC were found after multivariate analysis, while it was demonstrated that biologic equivalent dose (BED₁₀, α/β = 10) ≥85.5Gy (P = 0.007) and gross tumor volume < 30 ml (P = 0.003) correlated with LC only after univariate analysis.

Conclusion

SBRT is a safe and effective treatment modality in the management of AGMs from lung cancer with high LC rates and acceptable toxicity.