Stereotactic body radiotherapy (SBRT) can delay polymetastatic conversion in patients affected by liver oligometastases

Stereotactic radiotherapy for managing ovarian cancer oligoprogression under poly (ADP-ribose) polymerase inhibitors (PARPi)

OBJECTIVE

Poly (ADP-ribose) polymerase inhibitors (PARPi) have become a new standard of care for the maintenance treatment of advanced epithelial ovarian cancer. This study aims to evaluate the efficacy and safety of combining stereotactic body radiotherapy with PARPi continuation as a strategy to treat ovarian cancer oligoprogression on PARPi.

METHODS

This is a multicenter retrospective study including ovarian cancer patients treated with stereotactic body radiotherapy and PARPi continuation for oligoprogression under PARPi maintenance therapy between June 2012 and May 2023 in three Italian centers. PARPi treatment was continued until further disease progression or unacceptable toxicity. The primary endpoint was the next-line systemic therapy-free interval. The Kaplan-Meier method was used to assess local control, progression-free survival, and overall survival. Univariate and multivariate Cox regression analyses were performed to evaluate potential clinical outcomes predictors.

RESULTS

46 patients were included, with a total of 89 lesions treated over 63 radiotherapy treatments. Lymph nodes were the most frequently treated lesions (80, 89.9%), followed by visceral lesions (8, 9%) and one case with a bone lesion (1.1%). Median follow-up was 25.9 months (range 2.8-122). The median next-line systemic therapy-free interval was 12.4 months (95% CI 8.3 to 19.5). A number of prior chemotherapy lines greater than five was significantly associated with a reduced next-line systemic therapy-free interval (HR 3.21, 95% CI 1.11 to 9.32, p=0.032). At the time of analysis, 32 (69.6%) patients started a new systemic therapy regimen, while 14 (30.4%) remained on the PARPi regimen. The 2-year progression-free survival, local failure-free survival, and overall survival rates were 10.7%, 78.1%, and 76.5%, respectively. Four patients (8.7%) experienced acute toxicity with G1 gastrointestinal events.

CONCLUSION

Stereotactic body radiotherapy combined with PARPi continuation may be an effective and safe strategy for managing ovarian cancer patients with oligoprogression on PARPi maintenance therapy. Prospective research is warranted to shed more light on this approach.

Stereotactic radiotherapy for liver oligometastases: a pooled analysis following the estro/eortc consensus recommendations

A large pooled analysis of liver oligometastases, classified accordingly to the ESTRO/EORTC recommendations, treated by stereotactic radiotherapy (SBRT) and Radiosurgery (SRS) was carried out. The clinical and dosimetric data of patients who underwent SBRT/SRS for liver metastases were analysed in terms of efficacy and toxicity profile. In particular, the Local Control (LC), the Distant Metastases Free Survival (DMFS), the Disease-Free Survival (DFS), the Overall Survival (OS), and the Next Systemic Therapy Free Survival (NEST-FS) rates were analysed. 113 patients (M/F: 49/64), accounting for a total of 150 hepatic lesions (March 2006-February 2023) in two Italian radiotherapy Institutions were evaluated. Median age was 67 years old (36-92) and 48 (42.5%) patients had at least one comorbidity. The majority of the lesions were induced (30.7%) or repeated oligoprogressive (12.7%) metastases. 98 lesions were treated with more than one daily fraction (mainly 50 Gy in 5 fractions), while 52 were radiosurgery treatments (mainly 32 Gy). The treatment response at 3-4 months was evaluable in 147 lesions: complete response was 32.0%, partial response 17.0%, and stable disease 32.0%. Actuarial LC, DMFS, DFS, OS, and NEST-FS at 1 year were 75.8%, 37.7%, 34.9%, 78.7%, and 59.4% respectively; while actuarial LC, DMFS, DFS, OS, and NEST-FS at 2 years were 52.1%, 24.9%, 21.9%, 51.3%, and 36.8%, respectively. The achievement of complete response, synchronous oligometastases, and no treatment interruptions correlated with a more favorable outcomes. As per the toxicity profile, we registered only two acute and one late toxicity cases higher than grade 2. Stereotactic treatment for liver metastases seems to be a safe and promising option in terms of local control. The best results in term of outcomes have been obtained in patients with complete response, synchronous oligometastases, favorable histology, and no treatment interruptions.

SBRT in Lymph-Nodal Oligometastases from Prostate Cancer: Different Outcomes between Pelvic and Para-Aortic Disease

Background: Lymph-nodal prostate cancer oligometastases are differently treated according to their site: pelvic are locoregional lymph nodes; instead, para-aortic lymph nodes are considered as distant metastases. The aim of the study was a comparison between para-aortic and pelvic oligometastases treated with stereotactic body radiation therapy (SBRT). Methods: This is a retrospective analysis. De novo metastatic or extra-nodal disease were excluded. Univariate and multivariate analyses were performed; the pattern of recurrence was also evaluated. A propensity score matching (PSM) was applied to create comparable cohorts. The primary end-point was the progression-free survival (PFS). The secondary end-points were biochemical relapse-free survival (BRFS), ADT-free survival (ADTFS), polymetastases-free survival (PMFS), local progression-free survival (LPFS), and pattern of relapse. Results: In total, 240 lymph-nodal oligometastases in 164 patients (127 pelvic and 37 para-aortic) were treated. The median PFS was 20 and 11 months in pelvic and para-aortic patients, respectively (p = 0.042). The difference was not confirmed in the multivariate analysis (p = 0.06). The median BRFS was 16 and 9 months, respectively, in the pelvic and para-aortic group (p = 0.07). No statistically significant differences for ADTFS or PMFS were detected. The cumulative 5-year LPFS was 90.5%. In PSM, no statistically significant differences for all the study end-points were detected. Conclusions: Patients affected by para-aortic disease might have a PFS comparable to pelvic disease; local control is high in both cohorts. Our results also support the use of SBRT for para-aortic metastases.

High dose proton and photon-based radiation therapy for 213 liver lesions: a multi-institutional dosimetric comparison with a clinical perspective

BACKGROUND

Stereotactic radiotherapy (SRT) and Proton therapy (PT) are both options in the management of liver lesions. Limited clinical-dosimetric comparison are available. Moreover, dose-constraint routinely used in liver PT and SRT considers only the liver spared, while optimization strategies to limit the liver damaged are poorly reported.

METHODS

Primary endpoint was to assess and compare liver sparing of four contemporary RT techniques. Secondary endpoints were freedom from local recurrence (FFLR), overall survival (OS), acute and late toxicity. We hypothesize that Focal Liver Reaction (FLR) is determined by a similar biologic dose. FLR was delineated on follow-up MRI. Mean C.I. was computed for all the schedules used. A so-called Fall-off Volume (FOV) was defined as the area of healthy liver (liver-PTV) receiving more than the isotoxic dose. Fall-off Volume Ratio (FOVR) was defined as ratio between FOV and PTV.

RESULTS

213 lesions were identified. Mean best fitting isodose (isotoxic doses) for FLR were 18Gy, 21.5 Gy and 28.5 Gy for 3, 5 and 15 fractions. Among photons, an advantage in terms of healthy liver sparing was found for Vmat FFF with 5mm jaws (p = 0.013) and Cyberknife (p = 0.03). FOV and FOVR resulted lower for PT (p < 0.001). Three years FFLR resulted 83%. Classic Radiation induced liver disease (RILD, any grade) affected 2 patients.

CONCLUSIONS

Cyberknife and V-MAT FFF with 5mm jaws spare more liver than V-MAT FF with 10 mm jaws. PT spare more liver compared to photons. FOV and FOVR allows a quantitative analysis of healthy tissue sparing performance showing also the quality of plan in terms of dose fall-off.

Stereotactic Body Radiotherapy for Spine Oligometastases: A Multicentre Retrospective Study From the Italian Association of Radiotherapy and Clinical Oncology (AIRO)

AIM

To evaluate the efficacy of stereotactic body radiotherapy (SBRT) for spine oligometastases.

MATERIALS AND METHODS

This was a multicentre retrospective study of a series of patients who received SBRT for spine oligometastases. The efficacy of SBRT was evaluated in terms of local control as the primary endpoint. Survival outcomes were also analysed to identify predictive factors for clinical outcomes. Toxicity was assessed according to CTCAE v4.0.

RESULTS

Between March 2018 and July 2022, 183 lesions in 177 patients were analysed. In most patients, SBRT was delivered to a single spine metastasis (82%) for a median total dose of 21 Gy (14-35 Gy) in three fractions (one to five fractions) and a median BED10 = 119 Gy (57.7-152 Gy). Local control rates were 90.3% at 1 year, 84.3% at 2 years and 84.3% at 3 years. Distant progression-free survival rates were 33.1%, 18.5% and 12.4% at 1, 2 and 3 years, with prostate histology (P = 0.023), oligorecurrent disease (P = 0.04) and BED10 > 100 Gy (P = 0.04) found to be predictive on univariate analysis. A further oligometastatic progression was observed in 33 patients (18.6%) treated with a second course of SBRT, reporting at univariate analysis improved overall survival rates (P = 0.01). Polymetastases-free survival rates were 57.8%, 43.4% and 32.4%; concurrent therapy was related to improved outcomes at multivariate analysis (P = 0.009). Overall survival rates were 91.8%, 79.6% and 65.9%, with prostate histology and non-cervical metastases related to better overall survival at multivariate analysis. Pain-flare after SBRT was recorded in 3.3%; five patients underwent surgical decompression after SBRT; there were no grade ≥3 adverse events.

CONCLUSIONS

In our experience of only oligometastatic patients, spine SBRT gave excellent results in terms of safety and efficacy. Prostate histology and oligorecurrent disease were predictive factors for improved clinical outcomes; also, patients who experienced a further oligoprogression after SBRT maintained a survival advantage compared with polymetastatic progression. No severe adverse events were reported.

Dosimetric comparison in sparing normal tissue dosage by using auto-SBRT planning in oligo liver tumors

Purpose

The study aimed to compare the dosimetric distribution of VMAT plans by increasing the number of half arcs in liver SBRT and investigate the effect by using automatic plan software in plan optimization.

Method

Thirty-one patients with oligo liver tumors were randomly selected. VMAT treatment plans with different numbers of coplanar half arcs were generated.

Result

Adding arcs significantly increased the PTV, D2%, D50%, and CI, but sacrificed the plan homogeneity. It also decreased the maximum dose of normal tissues such as the stomach, duodenum, and spinal cord and reduced Dmean, D500cc, and D700cc for the liver. Nevertheless, the diminishing effect gradually decayed into three arcs. Meanwhile, the addition of arcs substantially extended the beam-on time.

Conclusion

In the context of SBRT for oligo liver tumors, increasing the number of coplanar half arcs will improve PTV conformity and offer better protection for OARs, albeit at the expense of increased treatment duration. Considering the trade-off between plan quality and treatment efficiency, a three-arc plan may be more suitable for clinical implementation.

Efficacy and Safety of Stereotactic Body Radiation Therapy in Oligometastatic Uterine Cancer (MITO-RT2/RAD): A Large, Real-World Study in Collaboration With Italian Association of Radiation Oncology, Multicenter Italian Trials in Ovarian Cancer, and Mario Negri Gynecologic Oncology Group Groups

PURPOSE

This retrospective, multicenter study analyzes the efficacy and safety of stereotactic body radiation therapy in a large cohort of patients with oligometastatic/persistent/recurrent uterine cancer.

METHODS AND MATERIALS

Clinical and radiation therapy data from several radiation therapy centers treating patients by stereotactic body radiation therapy between March 2006 and October 2021 were collected. Objective response rate was defined as complete and partial response, and clinical benefit included objective response rate plus stable disease. Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer and Common Terminology Criteria for Adverse Events scales were used to grade toxicities. Primary endpoints were the rate of complete response to stereotactic body radiation therapy, and the 2-year actuarial local control rate "per-lesion" basis. Secondary endpoints were progression-free survival and overall survival, as well as toxicity.

RESULTS

In the study, 157 patients with oligometastatic/persistent/recurrent uterine cancer bearing 272 lesions treated by stereotactic body radiation therapy at 14 centers were analyzed. Lymph node metastases (137, 50.4%) were prevalent, followed by parenchyma lesions (135, 49.6%). Median total dose was 35 Gy (10-75.2), in 5 fractions (range, 1-10). Complete and partial responses were 174 (64.0%), and 54 (19.9%), respectively. Stable disease was registered in 29 (10.6%), and 15 (5.5%) lesions progressed. Type of lesion (lymph node), volume (≤13.7 cc) and total dose (BED10 >59.5 Gy) were significantly associated with a higher probability of achieving complete response. Patients achieving complete response (CR) "per-lesion" basis experienced a 2-year actuarial local control rate of 92.4% versus 33.5% in lesions not achieving complete response (NCR; P < .001). Moreover, the 2-year actuarial progression-free survival rate in patients with CR was 45.4%, and patients with NCR had a 2-year rate of 17.6% (P < .001). Finally, patients who had a CR had a 2-year overall survival rate of 82.7%, compared with 56.5% for NCR patients (P <.001). Severe acute toxicity was around 2%, including one toxic death due to gastric perforation, and severe late toxicity around 4%.

CONCLUSIONS

The efficacy of stereotactic body radiation therapy in this setting was confirmed. The low toxicity profile and the high local control rate in complete responder patients encourage the wider use of this approach.

Lenvatinib with or without stereotactic body radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis: a retrospective study

BACKGROUND AND OBJECTIVES

Patients with hepatocellular carcinoma (HCC) involving portal vein tumor thrombosis (PVTT) are presently lacking effective treatment options. We aimed to compare the efficacy and safety of lenvatinib with or without SBRT for HCC with PVTT.

MATERIALS AND METHODS

This retrospective analysis included 37 patients treated with lenvatinib in combination with SBRT and 77 patients treated with lenvatinib alone from August 2018 to August 2021. Overall survival (OS), progression-free survival (PFS), intrahepatic PFS (IHPFS) and objective remission rate (ORR) were compared between the two groups, while adverse events (AEs) was analyzed between the two groups to assess safety profiles.

RESULTS

Median OS, PFS and IHPFS were significantly prolonged in the combination treatment group compared with the single treatment group (median OS, 19.3 vs. 11.2 months, p < 0.001; median PFS: 10.3 vs. 5.3 months, p < 0.001; median IHPFS, 10.7 vs. 5.3 months, p < 0.001). Moreover, a higher ORR (56.8% vs. 20.8%, P < 0.001) were observed in the lenvatinib combined with SBRT group. In subgroup analyses of Vp1-2 and Vp3-4 group, median OS, PFS and IHPFS were also significantly longer in the lenvatinib combined with SBRT group than those in the lenvatinib alone group. AEs in the combined therapy group were mostly manageable and the incidence was not statistically significant compared to the monotherapy group.

CONCLUSION

Lenvatinib plus SBRT had a significantly better survival benefit than lenvatinib monotherapy in the treatment of HCC patients with PVTT and was well tolerated.

A predictive model of polymetastatic disease from a multicenter large retrospectIve database on colorectal lung metastases treated with stereotactic ablative radiotherapy: The RED LaIT-SABR study

Aim

Stereotactic ablative radiotherapy (SABR) showed increasing survival in oligometastatic patients. Few studies actually depicted oligometastatic disease (OMD) evolution and which patient will remain disease-free and which will rapidly develop a polymetastatic disease (PMD) after SABR. Therefore, apart from the number of active metastases, there are no clues on which proven factor should be considered for prescribing local treatment in OMD. The study aims to identify predictive factors of polymetastatic evolution in lung oligometastatic colorectal cancer patients.

Methods

This international Ethical Committee approved trial (Prot. Negrar 2019-ZT) involved 23 Centers and 450 lung oligometastatic patients. Primary end-point was time to the polymetastatic conversion (tPMC). Additionally, oligometastases number and cumulative gross tumor volume (cumGTV) were used as combined predictive factors of tPMC. Oligometastases number was stratified as 1, 2-3, and 4-5; cumGTV was dichotomized to the value of 10 cc.

Results

The median tPMC in the overall population was 26 months. Population was classified in the following tPMC risk classes: low-risk (1-3 oligometastases and cumGTV ≤ 10 cc) with median tPMC of 35.1 months; intermediate-risk (1-3 oligometastases and cumGTV > 10 cc), with median tPMC of 13.9 months, and high-risk (4-5 oligometastases, any cumGTV) with median tPMC of 9.4 months (p = 0.000).

Conclusion

The present study identified predictive factors of polymetastatic evolution after SABR in lung oligometastatic colorectal cancer. The results demonstrated that the sole metastases number is not sufficient to define the OMD since patients defined oligometastatic from a numerical point of view might rapidly progress to PMD when the cumulative tumor volume is high. A tailored approach in SABR prescription should be pursued considering the expected disease evolution after SABR, with the aim to avoid unnecessary treatment and toxicity in those at high risk of polymetastatic spread, and maximize local treatment in those with a favorable disease evolution.

Imaging Features in the Liver after Stereotactic Body Radiation Therapy

Historically, radiation therapy was not considered in treatment of liver tumors owing to the risk of radiation-induced liver disease. However, development of highly conformed radiation treatments such as stereotactic body radiation therapy (SBRT) has increased use of radiation therapy in the liver. SBRT is indicated in treatment of primary and metastatic liver tumors with outcomes comparable to those of other local therapies, especially in treatment of hepatocellular carcinoma. After SBRT, imaging features of the tumor and surrounding background hepatic parenchyma demonstrate a predictable pattern immediately after treatment and during follow-up. The goals of SBRT are to deliver a lethal radiation dose to the targeted liver tumor and to minimize radiation dose to normal liver parenchyma and other adjacent organs. Evaluation of tumor response after SBRT centers on changes in size and enhancement; however, these changes are often delayed secondary to the underlying physiologic effects of radiation. Knowledge of the underlying pathophysiologic mechanisms of SBRT should allow better understanding of the typical imaging features in detection of tumor response and avoid misinterpretation from common pitfalls and atypical imaging findings. Imaging features of radiation-induced change in the surrounding liver parenchyma are characterized by a focal liver reaction that can potentially be mistaken for no response or recurrence of tumor. Knowledge of the pattern and chronology of this phenomenon may allay any uncertainty in assessment of tumor response. Other pitfalls related to fiducial marker placement or combination therapies are important to recognize. The authors review the basic principles of SBRT and illustrate post-SBRT imaging features of treated liver tumors and adjacent liver parenchyma with a focus on avoiding pitfalls in imaging evaluation of response. Online supplemental material is available for this article. ^©RSNA, 2022.

The evolving role of radiation therapy as treatment for liver metastases

Liver metastases occur commonly in many solid malignancies. With advances in systemic therapies and increased life expectancy, the role of using local therapies in oligo-metastases is rapidly increasing. Stereotactic body radiotherapy (SBRT) is an emerging precision therapy that is being used more frequently in the treatment for unresectable liver metastases. This review focuses on the role of SBRT for liver metastases, principles of treatment, clinical outcomes, toxicity, and optimal patient selection.

Stereotactic body radiotherapy (SBRT) and concomitant systemic therapy in oligoprogressive breast cancer patients

Breast cancer is a heterogenous disease with a deep tailoring level. Evidence is accumulating on the role of stereotactic body radiotherapy (SBRT) in the management of oligometastatic disease, however this is limited in breast cancer. The aim of the present study is to show the effectiveness of SBRT in delaying the switch to a subsequent systemic treatment in oligoprogressive breast cancer patients. Retrospective analysis from two Institutions. Primary endpoint: time to next systemic treatment (NEST). Secondary endpoints: freedom from local progression (FLP), time to the polymetastatic conversion (tPMC) and overall survival (OS). One-hundred fifty-three (153) metastases in 79 oligoprogressive breast cancer patients were treated with SBRT. Median follow-up 24 months. Median NEST 8 months. Predictive factor of NEST at the multivariate analysis (MVA) was the number of treated oligometastases (HR 1.765, 95%CI 1.322-2.355; p = < 0.01). Systemic treatment after SBRT was changed in 29 patients for polymetastatic progression and in 10 patients for oligometastatic progression < 6 months after SBRT. The 2-year FLP in the overall population was 86.7%. A biological effective dose (BED) > 70Gy₁₀ was associated with improved FLP (90% versus 74.2%). The median tPMC was 10 months. At the MVA the only factors significantly associated with tPMC were the number of oligometastases (HR 1.172, 95%CI 1.000-1.368; p = 0.03), and the local control of the treated metastases (HR 2.726, CI95% 1.108-6.706; p = 0.02). SBRT can delay the switch to a subsequent systemic treatment, however patient selection is necessary. Several predictive factors for treatment tailoring have been identified.

Clinical Values and Markers of Radiation-Induced Liver Disease for Hepatocellular Carcinoma With Portal Vein Tumor Thrombus Treated With Stereotactic Body Radiotherapy

Background

Information about radiation-induced liver disease (RILD) in hepatocellular carcinoma (HCC) patients preexisting hepatitis B cirrhosis with portal vein tumor thrombus (PVTT) extended to the main portal vein treated with stereotactic body radiotherapy (SBRT) is still inadequate and the predictive markers for RILD have not been cleared in these patients. The aim of the study is to identify factors that can be used to predict RILD and to evaluate the influence of RILD in these patients.

Methods

In our study, 59 patients were analyzed and evaluated from December 2015 to June 2019, according to the entry criteria. After treatment, 59 patients were followed up within the first month and then every 3 months. Hematology test, tumor markers, three-phasic CT scan of the lungs, and CT or MRI scan of the liver were performed at each follow up.

Results

Median overall survival time was 10.7 months (range, 5.8 to 14.9). RILD appeared in 17 of the 59 patients (28.8%) at the 3rd month after SBRT. In the univariate analysis, not only the CP score class (A or B) but also each different pretreatment CP score (p < 0.05) was a significant predictive factor of RILD. More RILD cases were detected with the increase of CP score. The recovery rate decreased as the baseline CP score increased (p < 0.05). It was found that the overall survival time was affected by only baseline CP score and RILD (p < 0.05).

Conclusions

The development of RILD has a dependency on the CP score in these patients. CP scores before treatment and RILD are significantly associated with overall survival. SBRT is an effective and safe method for patients with CP ≤ B7. For patients with CP-B8, liver function should be monitored more frequently. It is not safe enough for the SBRT treatment in CP-B9 patients.

A multicenter LArge retrospectIve daTabase on the personalization of Stereotactic ABlative Radiotherapy use in lung metastases from colon-rectal cancer: the LaIT-SABR study

INTRODUCTION

stereotactic ablative radiotherapy (SABR) has been shown to increase survival in oligometastatic disease, but local control of colorectal metastases remains poor. We aimed to identify potential predictive factors of SBRT response through a multicenter large retrospective database and to investigate the progression to the polymetastatic disease (PMD).

MATERIAL AND METHODS

the study involved 23 centers, and was approved by the Ethical Committee (Prot. Negrar 2019-ZT). 1033 lung metastases were reported. Clinical and biological parameters were evaluated as predictive for local progression-free survival (FLP). Secondary end-point was the time to the polymetastatic conversion (tPMC).

RESULTS

Two-year FLP was 75.4%. Two-year FLP for lesions treated with a BED <100 Gy, 100-124 Gy, and ≥125 Gy was 76.1%, 70.6%, and 94% (p=0.000). Two-year FLP for lesion measuring ≤10 mm, 10-20 mm, and >20 mm was 79.7%, 77.1%, and 66.6% (p=0.027). At the multivariate analysis a BED ≥125 Gy significantly reduced the risk of local progression (HR 0.24, 95%CI 0.11-0.51; p=0.000). Median tPMC was 26.8 months. Lesions treated with BED ≥125 Gy reported a significantly longer tPMC as compared to lower BED. The median tPMC for patients treated to 1, 2-3 or 4-5 simultaneous oligometastases was 28.5, 25.4, and 9.8 months (p=0.035).

CONCLUSION

The present is the largest series of lung colorectal metastases treated with SABR. The results support the use of SBRT in lung oligometastatic colorectal cancer patients as it might delay the transition to PMD or offer relatively long disease-free period in selected cases. Predictive factors were identified for treatment personalization.

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.

The use of SBRT in the management of oligometastatic gynecological cancer: report of promising results in terms of tolerability and clinical outcomes

BACKGROUND

The use of stereotactic radiotherapy (SBRT) for oligometastases is supported by several literature studies, but in the setting of gynecological malignancies, this scenario remains quite unexplored. This study reports a preliminary assessment of clinical outcomes in a cohort of 40 patients with oligometastatic gynecological neoplasms.

METHODS

Radiotherapy was delivered in 3-10 fractions with VMAT-IGRT technique. Toxicity was retrospectively collected according to CTCAE v4.0. Data were retrospectively collected and analyzed. Univariate and multivariate analyses were performed for assessing any potential predictive factor for clinical outcomes.

RESULTS

A total of 63 oligometastases were treated from December 2014 to February 2021. Median age was 63 years (range 30-89). Most frequent primary tumors were ovarian cancer in 42.5% and endometrium cancer in 42.5%. With a median follow-up of 27 months (range 6-69), no local failures were observed, our progression-free survival rates were 43.6% and 23% at one and 2 years, respectively, while 1 and 2-year overall survival rates were both 70%. No acute or late G ≥ 2 adverse events were observed.

CONCLUSIONS

In our experience, SBRT for oligometastatic gynecological malignancies resulted in promising results in terms of clinical outcomes, with excellent local control and no evidence of severe toxicity, highlighting the effectiveness of this therapeutic option. Prospective studies to further explore this approach in this setting are advocated.

Late metastatic presentation is associated with improved survival and delayed wide-spread progression after ablative stereotactic body radiotherapy for oligometastasis

Background

Stereotactic body radiotherapy (SBRT) is increasingly used to treat oligometastatic disease (OMD), but the effect of metastasis timing on patient outcomes remains uncertain.

Methods

An international database of patients with OMD treated with SBRT was assembled with rigorous quality assurance. Early versus late metastases were defined as those diagnosed ≤24 versus >24 months from the primary tumor. Overall survival (OS), progression‐free survival (PFS), and incidences of wide‐spread progression (WSP) were estimated using multivariable Cox proportional hazard models stratified by primary tumor types.

Results

The database consists of 1033 patients with median follow‐up of 24.1 months (0.3–104.7). Late metastatic presentation (N = 427) was associated with improved OS compared to early metastasis (median survival 53.6 vs. 33.0 months, hazard ratio [HR] 0.59, 95% confidence interval [CI]: 0.47–0.72, p < 0.0001). Patients with non‐small cell lung cancer (NSCLC, N = 255, HR 0.49, 95% CI: 0.33–0.74, p = 0.0005) and colorectal cancer (N = 235, HR 0.50, 95% CI: 0.30–0.84, p = 0.008) had better OS if presenting with late metastasis. Late metastasis correlated with longer PFS (median 17.1 vs. 9.0 months, HR 0.71, 95% CI: 0.61–0.83, p < 0.0001) and lower 2‐year incidence of WSP (26.1% vs. 43.6%, HR 0.60, 95% CI: 0.49–0.74, p < 0.0001). Fewer WSP were observed in patients with NSCLC (HR 0.52, 95% CI: 0.33–0.83, p = 0.006) and kidney cancer (N = 63, HR 0.37, 95% CI: 0.14–0.97, p = 0.044) with late metastases. Across cancer types, greater SBRT target size was a significant predictor for worse OS.

Conclusion

Late metastatic presentation is associated with improved survival and delayed progression in patients with OMD treated with SBRT.

Radiotherapeutic treatment options for oligotopic malignant liver lesions

Background

Several radiotherapeutic approaches for patients with oligotopic malignant liver lesions unfit for surgical resection exist. The most advanced competitive techniques are high-dose-rate (HDR) brachytherapy, Cyberknife, volume-modulated-arc therapy (VMAT) and Tomotherapy. We evaluated the optimal technique by a planning study for a single ablative dose with different lesion sizes.

Methods

We compared dose distributions of HDR-brachytherapy with stereotactic ablative radiotherapy using the Cyberknife, VMAT or Tomotherapy. Tumor-control-probabilities (TCP), normal-tissue-complication-probabilities (NTCP) were determined in a theoretical framework applying a single dose of 20 Gy (demanding 95% coverage) for intrahepatic lesions of 1–5 cm in size. We evaluated therapeutic ratios by TCP (mean dose in the lesion) relative to high-dose (conformality) or low-dose liver exposition in dependency on the lesion size for each technique. In addition, we considered treatment times and accuracy (clinical target volume vs planning target volume).

Results

HDR-brachtherapy has the highest therapeutic ratios with respect to high-dose as well as low-dose liver exposition even for extended lesions, and the Cyberknife being suited second best. However, for lesions ≥ 3 cm diameter the therapeutic ratios of all ablative techniques are increasingly converging, and better tolerance and shorter treatment times of noninvasive external techniques become more important. On the other hand, mean tumor doses of HDR-brachytherapy of near 60 Gy are unattainable by the other techniques gaining only 22–34 Gy, and the conformality of HDR-brachytherapy is still rather good for lesions ≥ 3 cm diameter.

Conclusions

HDR-brachytherapy is by far the most effective technique to treat intrahepatic lesions by a single fraction, but sparing of the surroundings declines with increasing lesion size and approaches the benchmarks of external beam radiosurgery techniques. External beam radiotherapy has the advantage to use suitable fractionation schedules.

Combination of Brachytherapy with Iodine-125 Seeds and Systemic Chemotherapy versus Systemic Chemotherapy Alone for Synchronous Extracranial Oligometastatic Non-Small Cell Lung Cancer

Background

A proportion of patients with synchronous oligometastatic non-small cell lung cancer (NSCLC) have poor survival, and currently no standard treatment is available, which poses a great challenge to physicians. This study aimed to assess and compare the efficacy and safety of the combination of brachytherapy with iodine-125 seeds and systemic chemotherapy versus systemic chemotherapy alone for synchronous extracranial oligometastatic NSCLC.

Materials and Methods

After a systematic retrospective review of the case database between 1st Mar 2014 and 30th Mar 2018, data were obtained on 69 NSCLC patients with extracranial oligometastatic NSCLC. Among them, 32 patients received brachytherapy with iodine-125 seeds combined with systemic chemotherapy (group A), and the remaining 37 patients received chemotherapy alone (group B). The primary endpoint was overall survival (OS), and the secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and complications.

Results

The demographic and clinical characteristics were not significantly different between the groups (all p>0.05). The overall 3-month ORR was significantly higher in group A (65.6% vs 37.8%, p=0.030) than in group B. With a median follow-up time of 23 months, the PFS and OS were 11.6 (95% CI: 7.0–16.2) months vs 6.3 (95% CI: 3.4–9.2) months (p=0.036) and 17.6 (95% CI: 13.9–21.3) months vs 11.2 (95% CI: 7.7–14.7) months (p=0.042) in groups A and B, respectively. Furthermore, in Cox regression analysis, local brachytherapy was an independent prognostic factor for both PFS (HR=0.416, 95% CI: 0.246–0.702, p=0.001) and OS (HR=0.375, 95% CI: 0.216–0.653, p=0.001). Severe complications were not observed in either of the groups.

Conclusion

The combination of brachytherapy with iodine-125 seeds and systemic chemotherapy is superior to chemotherapy alone for synchronous extracranial oligometastatic NSCLC.

Stereotactic Body Radiation Therapy in Oligometastatic Uterine Cancer: Clinical Outcomes and Toxicity

We report on clinical outcomes in patients with oligometastatic uterine cancer treated with stereotactic body radiation therapy (SBRT). Twenty-seven patients with 61 lesions were treated with SBRT. Median follow-up was 16.9 months. Local control was achieved in 49/61 (80.3%) lesions. One-year local-progression-free survival and overall survival were 75.9% and 65.4%. Lesions with favorable response were smaller than lesions with unfavorable response (p = .007). Liver lesions were less likely to achieve favorable response (p = .0128). There were no grade 3 or 4 events. Treatment with SBRT can provide excellent local control in oligometastatic uterine cancer with minimal toxicity.