Intraoperative radiation therapy for brain metastasis in a pregnant patient: a case report.

We present the rare case of a 42-year-old woman with oligometastatic lung adenocarcinoma in her first trimester of pregnancy who was treated for brain metastases with metastasectomy and intraoperative radiation therapy (IORT) using the INTRABEAM® system (Zeiss AG, Jena, Germany). This case underscores the potential of IORT in optimizing cancer treatment while safeguarding fetal health in pregnant patients.

Alliance for clinical trials in Oncology (Alliance) trial A022101/NRG-GI009: a pragmatic randomized phase III trial evaluating total ablative therapy for patients with limited metastatic colorectal cancer: evaluating radiation, ablation, and surgery (ERASur).

BACKGROUND: For patients with liver-confined metastatic colorectal cancer (mCRC), local therapy of isolated metastases has been associated with long-term progression-free and overall survival (OS). However, for patients with more advanced mCRC, including those with extrahepatic disease, the efficacy of local therapy is less clear although increasingly being used in clinical practice. Prospective studies to clarify the role of metastatic-directed therapies in patients with mCRC are needed. METHODS: The Evaluating Radiation, Ablation, and Surgery (ERASur) A022101/NRG-GI009 trial is a randomized, National Cancer Institute-sponsored phase III study evaluating if the addition of metastatic-directed therapy to standard of care systemic therapy improves OS in patients with newly diagnosed limited mCRC. Eligible patients require a pathologic diagnosis of CRC, have BRAF wild-type and microsatellite stable disease, and have 4 or fewer sites of metastatic disease identified on baseline imaging. Liver-only metastatic disease is not permitted. All metastatic lesions must be amenable to total ablative therapy (TAT), which includes surgical resection, microwave ablation, and/or stereotactic ablative body radiotherapy (SABR) with SABR required for at least one lesion. Patients without overt disease progression after 16-26 weeks of first-line systemic therapy will be randomized 1:1 to continuation of systemic therapy with or without TAT. The trial activated through the Cancer Trials Support Unit on January 10, 2023. The primary endpoint is OS. Secondary endpoints include event-free survival, adverse events profile, and time to local recurrence with exploratory biomarker analyses. This study requires a total of 346 evaluable patients to provide 80% power with a one-sided alpha of 0.05 to detect an improvement in OS from a median of 26 months in the control arm to 37 months in the experimental arm with a hazard ratio of 0.7. The trial uses a group sequential design with two interim analyses for futility. DISCUSSION: The ERASur trial employs a pragmatic interventional design to test the efficacy and safety of adding multimodality TAT to standard of care systemic therapy in patients with limited mCRC. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05673148, registered December 21, 2022.

Locoregional Therapies for Primary and Metastatic Breast Cancer: AJR Expert Panel Narrative Review.

Minimally invasive locoregional therapies have a growing role in the multidisciplinary treatment of primary and metastatic breast cancer. Factors contributing to the expanding role of ablation for primary breast cancer include earlier diagnosis, when tumors are small, and increased longevity of patients whose condition precludes surgery. Cryoablation has emerged as the leading ablative modality for primary breast cancer owing to its wide availability, the lack of need for sedation, and the ability to monitor the ablation zone. Emerging evidence suggests that in patients with oligometastatic breast cancer, use of locoregional therapies to eradicate all disease sites may confer a survival advantage. Evidence also suggests that transarterial therapies-including chemoembolization, chemoperfusion, and radioembolization-may be helpful to some patients with advanced liver metastases from breast cancer, such as those with hepatic oligoprogression or those who cannot tolerate systemic therapy. However, the optimal modalities for treatment of oligometastatic and advanced metastatic disease remain unknown. Finally, locoregional therapies may produce tumor antigens that in combination with immunotherapy drive anti-tumor immunity. Although key trials are ongoing, additional prospective studies are needed to establish the inclusion of interventional oncology in societal breast cancer guidelines to support further clinical adoption and improved patient outcomes.

Management of Oligometastatic and Locally Recurrent Urothelial Carcinoma.

PURPOSE OF REVIEW: To summarize and evaluate the literature on treatment approaches for oligometastatic and locally recurrent urothelial cancer. RECENT FINDINGS: There is no clear definition for oligometastatic urothelial cancers due to limited data. Studies focusing on oligometastatic and locally recurrent urothelial cancer have been primarily retrospective. Treatment options include local therapy with surgery or radiation, and generalized systemic therapy such as chemotherapy or immunotherapy. Oligometastatic and locally recurrent urothelial cancers remain challenging to manage, and treatment requires an interdisciplinary approach. Systemic therapy is nearly always a component of current care in the form of chemotherapy, but the role of immunotherapy has not been explored. Consideration of surgical and radiation options may improve outcomes, and no studies have compared directly between the two localized treatment options. The development of new prognostic and predictive biomarkers may also enhance the treatment landscape in the future.

Measured Steps: Navigating the Path of Oligoprogressive Lung Cancer with Targeted and Immunotherapies.

PURPOSE OF REVIEW: This review discusses the definitions, treatment modalities, management, future directions, and ongoing clinical trials of oligoprogressive disease in oncogene-driven and non-oncogene-driven NSCLC. RECENT FINDINGS: During the last decades, diagnostic and treatment modalities for oligometastatic NSCLC have advanced significantly, leading to improved survival. Additionally, our understanding of the tumor biology of oligoprogressive disease has expanded. However, despite the efforts of organizations, such as EORTC, ESTRO, and ASTRO proposing definitions for oligometastatic and oligoprogressive disease, heterogeneity in definitions persists in (ongoing) trials. Recognizing the significance of subclassification within oligoprogressive disease in NSCLC and the varying risks associated with subsequent metastatic spread, there is a call for tailored management strategies. A consensus on standardized criteria for the definition of oligoprogressive disease is urgently needed and will not only facilitate meaningful comparisons between studies but also pave the way for the development of personalized treatment plans that take into account the heterogeneous nature of oligoprogressive disease.

Magnetic resonance-guided stereotactic body radiation therapy (MRgSBRT) for oligometastatic patients: a single-center experience.

PURPOSE: Stereotactic body radiotherapy is increasingly used for the treatment of oligometastatic disease. Magnetic resonance-guided stereotactic radiotherapy (MRgSBRT) offers the opportunity to perform dose escalation protocols while reducing the unnecessary irradiation of the surrounding organs at risk. The aim of this retrospective, monoinstitutional study is to evaluate the feasibility and clinical benefit (CB) of MRgSBRT in the setting of oligometastatic patients. MATERIALS AND METHODS: Data from oligometastatic patients treated with MRgSBRT were collected. The primary objectives were to define the 12-month progression-free survival (PFS) and local progression-free survival (LPFS) and 24-month overall survival (OS) rate. The objective response rate (ORR) included complete response (CR) and partial response (PR). CB was defined as the achievement of ORR and stable disease (SD). Toxicities were also assessed according to the CTCAE version 5.0 scale. RESULTS: From February 2017 to March 2021, 59 consecutive patients with a total of 80 lesions were treated by MRgSBRT on a 0.35 T hybrid unit. CR and PR as well as SD were observed in 30 (37.5%), 7 (8.75%), and 17 (21.25%) lesions, respectively. Furthermore, CB was evaluated at a rate of 67.5% with an ORR of 46.25%. Median follow-up time was 14 months (range: 3-46 months). The 12-month LPFS and PFS rates were 70% and 23%, while 24-month OS rate was 93%. No acute toxicity was reported, whereas late pulmonary fibrosis G1 was observed in 9 patients (15.25%). CONCLUSION: MRgSBRT was well tolerated by patients with reported low toxicity levels and a satisfying CB.

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.

Clinical significance of the neutrophil-to-lymphocyte ratio in oligometastatic breast cancer.

PURPOSE: This study investigated the clinical impact of pretreatment neutrophil-to-lymphocyte ratio (NLR) on survival in patients with oligometastatic breast cancer. PATIENTS AND METHODS: We collected data from 397 patients who underwent primary breast surgery from 2004 to 2015 and developed recurrence during the follow-up. We reviewed the images and clinical information and defined OMD according to the European Society for Medical Oncology advanced breast cancer guidelines. The NLR was calculated using pretreatment data of primary breast cancer. The cutoff value of the NLR was determined by receiver operating characteristic curve with Youden Index. RESULTS: Among 397 patients, 131 had OMD at recurrence. The low-NLR group included patients of significantly older age at primary cancer than those in the high-NLR group. A low NLR indicated a better overall survival (p = 0.023) after adjusting for relevant factors, including estrogen receptor status, surgical resection of metastatic disease, metastatic organ number, disease-free interval, and liver metastasis than did the high-NLR group. We developed prognostic models for OMD using six independent prognostic factors, including the NLR. The number of factors was associated with overall survival; patients with all six favorable factors showed a good overall survival of 90.9% at 8 years and those with four or more factors showed 70.4%. CONCLUSIONS: The NLR was an independent prognostic factor for overall survival in OMD. The number of favorable prognostic factors was associated with overall survival. A prognostic model, including the NLR, will help identify patients with a favorable prognosis.

Stereotactic body radiotherapy for pulmonary oligometastases: a monoinstitutional analysis of clinical outcomes and potential prognostic factors.

PURPOSE: We report the retrospective data of a cohort of patients who received stereotactic body radiotherapy for pulmonary oligometastases, aiming to assess the clinical factors potentially affecting clinical outcomes. METHODS: The present series reports the outcomes of a cohort of 71 patients with pulmonary oligometastases with no extrapulmonary disease. All patients were treated with stereotactic body radiotherapy (SBRT) performed with volumetric modulated arc therapy-image guided radiotherapy (VMAT-IGRT) to up to five secondary lesions. Survival estimates were performed using the Kaplan-Meier method. RESULTS: A total of 98 lesions in 71 patients were treated from February 2014 to August 2020. The most frequent histologies were colorectal in 37.7%, lung cancer in 44.8%, head and neck cancer in 8.1%, and other in 9.4%. Median age was 71 years (range 32-93 years). Concurrent systemic therapy was administered in 32.3%. SBRT was delivered to a median total dose of 60 Gy (range 55-70 Gy) in 3-10 fractions for a median BED10 = 105 Gy (range 96-180 Gy). Median follow-up was 29.5 months (range 6-81), with no acute or late G > 2 adverse event. Our LC rates at 2 and 4 years were 92.4 and 89.8%, respectively. DPFS rates at 2 and 4 years were 45.3 and 27.2%, respectively. A second SBRT course was proposed in 21 patients (29.5%) who developed an oligoprogression, resulting in median time to second progression of 9 months (range 2-44) and 2­year PFS2 rate of 42.4%. At univariate analysis, patients with sequential oligometastases reported better OS rates (p = 0.002), which was also confirmed at multivariate analysis, where distant progression was also related to worse OS (p = 0.022). Higher local control rates relate to better PFS (p = 0.04). The 2­ and 4­year OS rates were 61 and 39.7% CONCLUSION: SBRT is feasible for pulmonary oligometastases with favorable outcomes and toxicity. At multivariate analysis, patients with sequential oligometastatic progression maintain a survival advantage. Also, local control was found to be related to improved PFS rates.

Endoscopic nodal staging in oligometastatic non-small cell lung cancer (NSCLC) being treated with stereotactic ablative radiotherapy (ENDO-SABR).

BACKGROUND: Research in treatment of non-small cell lung cancer (NSCLC) has shown promising results with stereotactic ablative radiotherapy (SABR) of oligometastatic disease, wherein distant disease may be limited to one or a few distant organs by host factors. Traditionally, PET/CT has been used in detecting metastatic disease and avoiding futile surgical intervention, however, sensitivity and specificity is limited to only 81 and 79%, respectively. Mediastinal staging still identifies occult nodal disease in up to 20% of NSCLC patients initially thought to be operative candidates. Endobronchial ultrasound and transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive tool for the staging and diagnosis of thoracic malignancy. When EBUS is combined with endoscopic ultrasound using the same bronchoscope (EUS-B), the diagnostic sensitivity and negative predictive value increase to 84 and 97%, respectively. Endoscopic staging in patients with advanced disease has never been studied, but may inform treatment if a curative SABR approach is being taken. METHODS: This is a multi-centre, prospective, cohort study with two-stage design. In the first stage, 10 patients with oligometastatic NSCLC (lung tumour ± hilar/mediastinal lymphadenopathy) with up to 5 synchronous metastases will be enrolled An additional 19 patients will be enrolled in the second stage if rate of treatment change is greater than 10% in the first stage. Patients will be subject to EBUS or combined modality EBUS/EUS-B to assess bilateral lymph node stations using a N3 to N2 to N1 progression. Primary endpoint is defined as the rate of change to treatment plan including change from SABR to conventional dose radiation, change in mediastinal radiation field, and change from curative to palliative intent treatment. DISCUSSION: If a curative approach with SABR for oligometastatic disease is being explored, invasive mediastinal staging may guide treatment and prognosis. This study will provide insight into the use of endoscopic mediastinal staging in determining changes in treatment plan of NSCLC. Results will inform the design of future phase II trials. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT04852588. Date of registration: April 19, 2021. PROTOCOL VERSION: 1.1 on December 9, 2021.

Optimal Treatment for Patients with Oligometastatic Prostate Cancer.

Oligometastatic prostate cancer (PCa) can be defined as cancer with a limited number of metastases, typically fewer than 5 lesions, and involves lesions contained within the axial versus the appendicular skeleton. Patients can present with de novo oligometastatic, oligorecurrent, or oligoprogressive PCa. Oligometastatic PCa patients demonstrate considerable improvements in survival outcomes, with a better prognosis than patients with extensive metastatic disease. However, the management of patients that present with nonsymptomatic oligometastatic PCa remains difficult. In the oligometastatic setting, the benefit of local therapies such as prostatectomy and radiotherapy on survival outcomes is an intriguing topic; however, their impact on oncological outcomes is still unknown.

Proposing synchronous oligometastatic non-small-cell lung cancer based on progression after first-line systemic therapy.

Despite the importance of accurate disease definitions for effective management and treatment decisions, there is currently no consensus on what constitutes oligometastatic non-small-cell lung cancer (NSCLC). Predominant patterns of initial progressive disease (PD) after first-line systemic therapy have been shown to be a substantial basis for local ablative therapy (LAT) for all disease sites in patients with oligometastatic NSCLC, suggesting that these patterns could be helpful in defining synchronous oligometastatic NSCLC. Therefore, this retrospective study aimed to propose a threshold number of metastases for synchronous oligometastatic NSCLC, based on the pattern of initial PD after first-line systemic therapy. The cut-off threshold number of metastases compatible with synchronous oligometastatic NSCLC was determined using receiver operating characteristic (ROC) curve analyses of PD at the initially involved sites alone. ROC analysis of 175 patients revealed that the presence of 1-3 metastases before first-line treatment (sensitivity, 85.9%; specificity, 97.3%; area under the curve, 0.91) was compatible with oligometastatic NSCLC, therefore we divided patients into oligometastatic NSCLC and non-oligometastatic NSCLC groups. Multivariate logistic regression analyses revealed oligometastatic NSCLC to be the only independent predictor of PD at initially involved sites alone (odds ratio 165.7; P < .001). The median survival times in patients with oligometastatic or non-oligometastatic NSCLC were 23.0 and 10.9 mo (hazard ratio, 0.51; P = .002), respectively. Based on these findings, we propose synchronous oligometastatic NSCLC as 1-3 metastases in accordance with patterns of initial progression. The result of our study might be contributory to provide a common definition of synchronous oligometastatic NSCLC.

Phase II study of multidisciplinary therapy combined with pembrolizumab for patients with synchronous oligometastatic non-small cell lung cancer TRAP OLIGO study (WJOG11118L).

BACKGROUND: Synchronous oligometastatic non-small cell lung cancer (NSCLC) is generally characterised by the limited number of metastases at the time of diagnosis. Several clinical trials have shown that local ablative therapy (LAT) at all sites of the disease might be beneficial for patients with oligometastatic NSCLC. In recent years, the combination of programmed cell death 1 (PD-1) inhibitors or programmed cell death ligand 1 with cytotoxic chemotherapy has become a new standard treatment for patients with metastatic NSCLC. Furthermore, multisite LAT would inherently reduce the overall tumour burden, and this could promote T cell reinvigoration to enhance the efficacy of PD-1 inhibitors. Few studies have evaluated the efficacy of the combination of PD-1 inhibitors with LAT at all sites of disease. The aim of the present multicentre single-arm phase II study is to evaluate the efficacy of LAT at all sites of disease following standard platinum doublet chemotherapy with pembrolizumab in patients with oligometastatic NSCLC. METHODS: Thirty patients with synchronous oligometastatic NSCLC will be enrolled in the trial. All patients will receive 2-4 cycles of a systemic treatment including pembrolizumab and chemotherapy as induction therapy. Patients who will receive LAT will be determined by a multidisciplinary tumour board, including medical oncologists, radiation oncologists, and thoracic surgeons. LAT will be administered at all sites of disease within 21-56 days of the last dose of induction therapy and will be followed by maintenance therapy within 42 days of the last day of LAT. The primary endpoint is the progression-free survival (PFS) rate of 24 months from the date of initiation of LAT. The secondary endpoints are toxicity, response to induction therapy, PFS, overall survival, and the frequency of LAT. DISCUSSION: This study will provide novel data on the efficacy and safety profile of the combination of LAT and chemotherapy plus immune-checkpoint inhibitors in patients with synchronous oligometastatic NSCLC. If the primary endpoint of this study is met, extensive phase III studies further assessing this strategy will be recommended. TRIAL REGISTRATION: jRCT identifier: jRCTs041200046 (date of initial registration: 28 October 2020).

Oligometastatic prostate cancer treatment.

Oligometastatic prostate cancer is an intermediate state between localized disease and widespread metastasis. Its biological and clinical peculiarities are still to be elucidated. New imaging techniques contribute to the detection of patients with oligometastatic disease. PET/CT scanning with prostate-specific membrane antigen can improve the selection of men with true early, low-volume oligometastatic disease, who are candidates for metastasis-directed therapy. Clinical studies demonstrated that androgen deprivation therapy can be delayed in oligometastatic patients with a low tumor burden, although no survival benefit has been demonstrated at present. This article presents available evidence on the treatment strategies for oligometastatic prostate cancer.

Defining the role of high-dose radiation in oligometastatic & oligorecurrent cervical cancer.

Around 5-8 per cent of women diagnosed with cervical cancer present with metastatic disease at presentation and 16-25 per cent of patients fail at either within irradiated fields or at distant sites post-curative therapy in advanced cervical cancers. Conventionally, chemotherapy with palliative intent constituted the mainstay of treatment with modest survival outcomes and radiation therapy was reserved for symptomatic benefit only. While targeted therapies and immunotherapy have been added in therapeutic armamentarium, the impact on the outcomes is modest. In limited metastatic disease, radiation therapy to metastatic sites from different primary cancers has shown survival benefits; however, the data are scarce in cervical cancer. With a better understanding of the molecular biology of the metastases and recurrence pattern, emphasis is laid upon total eradication of the disease rather than offering relief from symptoms. This article summarizes the role of radiation therapy in limited metastatic disease and recurrent cervical cancer.

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 Body Radiation Therapy (SBRT) in Pelvic Lymph Node Oligometastases.

The role of stereotactic body radiation therapy (SBRT) in achieving durable local control and palliation of pain in pelvic lymph node oligometastatic disease is not well-studied. We performed a retrospective analysis of 30 patients with 43 pelvic lymph node oligometastases from various primary cancers all but one with non-prostate primaries treated at our institution with SBRT. The median follow-up time was 21 months. The median SBRT dose was 24 Gy in four fractions. The one-, two-, and five-year local control was 74%, 71%, and 70% and one-, two-, and five-year overall survival was 70%, 47%, and 31%. Toxicities were mild with no grade 3 or higher.

Metastatic castration-sensitive prostate cancer: Abiraterone, docetaxel, or .

For decades, the management of patients with advanced prostate cancer has been hormonal therapy, known as androgen deprivation therapy, which is intended to lower testosterone levels. Further incremental progress in the treatment of men with metastatic hormone-sensitive prostate cancer (mHSPC) has come from the addition of docetaxel or abiraterone acetate to androgen deprivation therapy for more aggressive upfront treatment regimens. Other combinatorial regimens testing the addition of novel therapies currently are in the late stages of development and are expected to further improve the clinical outcomes of these patients. The emergence of new positron emission tomography tracers specifically for prostate cancer, particularly prostate-specific membrane antigen and fluciclovine, has increased the ability to detect metastatic disease earlier in the course of the disease and has helped to describe a new group of patients with mHSPC and oligometastatic disease. For this group of patients with mHSPC, the authors discuss the existing data with metastasis-directed therapy and primary tumor-directed therapy.

Stereotactic body radiotherapy for bone oligometastatic disease in prostate cancer.

PURPOSE: There are sparse data describing outcomes of bone-only oligometastatic prostate cancer in comparison with lymph node disease treated with stereotactic body radiotherapy (SBRT). The primary aim of this study was to report progression-free survival (PFS) data for patients with bone-only disease. Influence of hormone sensitivity and androgen deprivation therapy use was also assessed. METHODS: This is a single-centre retrospective cohort study. Hormone-sensitive and castrate-resistant patients with oligometastatic (≤ 3) bone-only prostate cancer treated with SBRT were included. Data were collected using electronic records. Kaplan-Meier survivor function, log rank test, as well as Cox regression were used to calculate PFS and overall survival. RESULTS: In total, 51 patients with 64 bone metastases treated with SBRT were included. Nine patients were castrate resistant and 42 patient's hormone sensitive at the time of SBRT. Median follow-up was 23 months. Median PFS was 24 months in hormone-sensitive patients and 3 months in castrate-resistant patients. No patients experienced grade 3 or 4 toxicities. There were three in-field recurrences. CONCLUSIONS: In this study, patients with bone oligometastatic disease showed potential benefit from SBRT with a median PFS of 11 months. Hormone-sensitive patients showed the greatest benefit, with results similar to that published for oligometastatic pelvic nodal disease treated with SBRT. Prospective randomised control trials are needed to determine the survival benefit of SBRT in oligometastatic bone-only prostate cancer and to determine prognostic indicators.

Long-term outcomes in radically treated synchronous vs. metachronous oligometastatic non-small-cell lung cancer.

BACKGROUND: Radical treatment for oligometastatic non-small-cell lung cancer (NSCLC) has a curative potential for selected patients. The present retrospective study was designed to examine the relevance of synchronous vs. metachronous manifestations as a potential prognostic factor when ablative treatments are performed in oligometastatic disease. METHODS: Seventy-five patients with radically treated oligometastatic NSCLC were identified, of whom 39 presented with synchronous and 36 with metachronous metastatic manifestations. For patients with synchronous metastases, an additional therapy of the thoracic locoregional disease with a curative intent (either surgery or radiochemotherapy) was required. All patients with metachronous metastases had a documented remission of the primary tumor. Ablative treatment of the complete extent of oligometastatic disease consisted (as a minimum requirement) of either complete surgical resection or definitive ablative stereotactic radiotherapy. A comparative survival analysis of two groups of patients with oligometastatic NSCLC (synchronous vs. metachronous) and a complementary analysis of prognostic factors for the whole group of patients (by means of Cox regression analysis) was performed. Endpoints were median overall and progression-free survival (OS, PFS, respectively). RESULTS: Of the 75 patients, 57 presented with a solitary metastasis, in only 7 patients metastastatic lesions were present in ≥2 organs and 66 patients had a Karnofsky performance score (KPS) of 80 % or 90 %. The median follow-up was 54.0 months (95 % CI 28-81), the median OS 21.8 months (16.1-27.6) and the median PFS 13.7 months (9.7-17.6). In univariable Cox regression analysis, no single clinical factor was significantly associated with OS. For PFS both 'metastatic involvement of ≥2 organs vs. 1 organ' (hazard ratio (HR) 0.43, 0.23-0.83, p = 0.012) and a 'KPS of 90 % vs. 70-80 %' (HR 4.32, 1.73-10.89, p = 0.02) were significant prognostic factors as calculated by multivariable analysis. Comparing the cohorts with synchronous (n = 39) vs. metachronous oligometastases (n = 36), no differences in median OS and PFS were found. Both cohorts were well-balanced except for the KPS, which was significantly superior in patients with synchronous oligometastases. CONCLUSIONS: Radical treatment of oligometastatic NSCLC was associated with acceptable long-term survival rates in patients with good KPS and it was equally effective for synchronous and metachronous manifestations.