Radical irradiation of extracranial oligometastases

Predicting long‑term survival following involved site radiotherapy for oligometastases

The majority of cancer-associated mortalities are due to distant metastases, and systemic therapy alone is generally not curative. Patients with oligometastases are amenable to involved site radiotherapy with the possibility of long-term disease-free survival; however, prognostic factors remain poorly defined. The present retrospective, single institution study consisted of consecutive adult patients with oligometastases from solid tumor malignancy referred to a single high volume radiation oncologist between January 2014 and December 2021. Oligometastases were defined as ≤5 extracranial or intracranial metastatic lesions where all sites of active disease are treatable, including patients requiring treatment of the primary tumor and/or regional lymph nodes. The study population consisted of 130 patients with 207 treated distant metastases. Radical radiotherapy was administered to all areas of known residual disease and included stereotactic radiotherapy (median dose, 27 Gy in 3 fractions) or intensity modulated radiotherapy (median dose, 50 Gy in 15 fractions). At a median follow-up of 28.8 months, the median overall survival was 37.9 months with a 4-year overall survival of 41.1%. The median progression-free survival was 12.3 months and the 4-year progression-free survival was 22.6%. On multivariate an1alysis, the strongest predictors of overall survival were age, ECOG performance status, primary prostate, breast or kidney tumor and pre-radiation serum albumin (P≤0.01 for all). Overall, the present study demonstrated that long-term overall survival was possible after radical treatment for oligometastases and identified potential prognostic factors.

Unravelling oligometastatic disease from the perspective of radiation and medical oncology. Part II: prostate cancer and colorectal cancer

Oligometastatic disease (OMD) defines a status of cancer that is intermediate between localized and widely spread metastatic disease, and can be treated with curative intent. While imaging diagnostic tools have considerably improved in recent years, unidentified micrometastases can still escape from current detection techniques allowing disease to progress. The variety of OMD scenarios are mainly defined by the number of metastases, the biological and molecular tumour profiles, and the timing of the development of metastases. Increasing knowledge has contributed to the earlier and improved detection of OMD, underlining the importance of an early disease control. Based on increasing detection rates of OMD in the current real clinical practice and the lack of standardized evidence-based guidelines to treat this cancer status, a board of experts from the Spanish Societies of Radiation Oncology (SEOR) and Medical Oncology (SEOM) organized a series of sessions to update the current state-of-the-art on OMD from a multidisciplinary perspective, and to discuss how results from clinical studies may translate into promising treatment options. This experts' review series summarizes what is known and what it is pending clarification in the context of OMD in the scenarios of Non-Small Cell Lung Cancer and Breast Cancer (Part I), and Prostate Cancer and Colorectal Cancer (Part II), aiming to offer specialists a pragmatic framework that might contribute to the improved management of patients.

Unravelling oligometastatic disease from the perspective of radiation and medical oncology. Part I: non-small cell lung cancer and breast cancer

Oligometastatic disease (OMD) defines a cancer status that is intermediate between localized and widely spread metastatic disease, and can be treated with curative intent. While diagnostic imaging tools have considerably improved in recent years, unidentified micrometastases can still evade current detection techniques, allowing the disease to progress. The various OMD scenarios are mainly defined by the number of metastases, the biological and molecular tumour profiles, and the timing of the development of metastases. Increasing knowledge has contributed to the earlier and improved detection of OMD, underlining the importance of early disease control. In view of increasing OMD detection rates in current real-world clinical practice and the lack of standardized evidence-based guidelines to treat this cancer status, a board of experts from the Spanish Societies of Radiation Oncology (SEOR) and Medical Oncology (SEOM) organized a series of sessions to update the current state-of-the-art on OMD from a multidisciplinary perspective, and to discuss how results from clinical studies might translate into promising treatment options. This expert review series summarizes what is known and what it is pending clarification in the context of OMD in the scenarios of non-small cell lung cancer and breast cancer (Part I), and prostate cancer and colorectal cancer (Part II), aiming to offer specialists a pragmatic framework to help improve patient management.

Effectiveness of lenvatinib plus immune checkpoint inhibitors in primary advanced hepatocellular carcinoma beyond oligometastasis

BACKGROUND

Targeted therapy combined with immune checkpoint inhibitors is considered a promising treatment for primary advanced hepatocellular carcinoma (HCC). Nevertheless, the difference between synchronous and asynchronous treatment of lenvatinib with programmed death receptor-1 (PD-1) inhibitor in advanced HCC is still unclear. The aim of this investigation is to evaluate the effectiveness of synchronous and asynchronous of lenvatinib and PD-1 inhibitor on the advanced HCC beyond oligometastasis.

METHODS

In this study, 213 patients from four institutions in China were involved. Patients were split into two collections: (1) lenvatinib plus PD-1 inhibitor were used synchronously (synchronous treatment group); (2) patients in asynchronous treatment group received PD-1 inhibitor after 3 months of lenvatinib treatment prior to tumour progression. To analyse progression-free survival (PFS), overall survival (OS), efficacy and safety of patients in both groups, we employed propensity score matching (PSM).

RESULTS

The 6-, 12- and 24-month OS rates were 100%, 93.4% and 58.1% in the synchronous treatment group and 100%, 71.5% and 25.3% in the asynchronous treatment group, respectively. In contrast to the asynchronous treatment group, the group treated synchronously exhibited a substantially enhanced OS (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.30-0.66; p < .001). The 6-, 12- and 18-month PFS rates were 82.6%, 42.6% and 10.8% in the synchronous treatment group and 63.3%, 14.2% and 0% in the asynchronous treatment group, respectively. A significant difference was observed in the PFS rate (HR, 0.46; 95% CI, 0.33-0.63; p < .001) between the two collections.

CONCLUSIONS

Patients with advanced HCC beyond oligometastasis, simultaneous administration of lenvatinib and PD-1 inhibitor led to significant improvements in survival.

The "new" oligometastatic disease state and associated therapies in non-small cell lung cancer: A narrative review

Patients with non-small cell lung cancer (NSCLC) at stage IV have typically been considered incurable. Nonetheless, there is growing evidence that certain patient groups with fewer metastases, or so-called oligometastatic disease, which may have a more indolent biological nature than widespread metastatic diseases, may survive longer if definitive local treatment is administered to all metastatic sites. According to several retrospective investigations, this subgroup had a better prognosis than other stage IV patients, and the eighth edition of TNM staging was revised to reflect these findings. As a result of rapidly emerging systemic therapies, such as immune checkpoint inhibitors and a growing number of targeted therapies, more patients with this uncommon clinical opportunity have been identified and have received greater clinical attention. Currently, there is no established protocol for the management of oligometastatic disease, and the majority of therapeutic decisions are made through multidisciplinary discussion. In addition to systemic treatment, the two primary local therapeutic options for oligometastatic diseases are surgery and radiotherapy. A few phase 2 trials suggest that aggressive local ablative therapy may significantly improve the prognosis of patients with oligometastatic NSCLC. This review summarizes the most recent data on the management of oligometastatic NSCLC, with a focus on the prognostic significance of local ablative therapy in these patients.

Management of Oligometastatic Breast Cancer: An Expert Committee's Opinion

Patients with oligometastatic breast cancer (BC) are candidates of choice for metastasis-directed therapy (MDT). This paper summarizes the opinions of an expert committee about the management of oligometastatic BC. The experts could complete the questionnaire from 13 September 2021, to 10 October 2021, followed by a discussion. The experts were physicians working in the Province of Quebec (Canada) and specialized in BC care, including surgical oncologists, medical oncologists, and radiation oncologists. The experts provided their opinions about the context of the disease and therapeutic approach, local and systemic therapies, and the prognosis of oligometastatic BC. In addition to the expert panel's opinions about the management of oligometastatic disease per se, the experts stated that a prospective data registry should be implemented to collect data about oligometastatic BC to improve knowledge about oligometastatic BC and implement data-driven MDT. These data could also allow for the design of treatment algorithms. In conclusion, this paper presents the expert panel's opinions about the management of oligometastatic BC and highlights the needs to be met to improve the care of this condition.

Case Report: Extensive Tumor Profiling in Primary Neuroendocrine Breast Cancer Cases as a Role Model for Personalized Treatment in Rare and Aggressive Cancer Types

Neuroendocrine breast cancer (NEBC) is a rare entity accounting for <0.1% of all breast carcinomas and <0.1% of all neuroendocrine carcinomas. In most cases treatment strategies in NEBC are empirical in absence of prospective trial data on NEBC cohorts. Herein, we present two case reports diagnosed with anaplastic and small cell NEBC. After initial therapies failed, comprehensive tumor profiling was applied, leading to individualized treatment options for both patients. In both patients, targetable alterations of the PI3K/AKT/mTOR pathway were found, including a PIK3CA mutation itself and an STK11 mutation that negatively regulates the mTOR complex. The epicrisis of the two patients exemplifies how to manage rare and difficult to treat cancers and how new diagnostic tools contribute to medical management.

Comparing Outcomes of Oligometastases Treated with Hypofractionated Image-Guided Radiotherapy (HIGRT) with a Simultaneous Integrated Boost (SIB) Technique versus Metastasis Alone: A Multi-Institutional Analysis

Simple Summary

Hypofractionated image-guided radiotherapy (HIGRT) is a common method in which high doses of radiation are delivered to treat oligometastatic disease. We have previously reported on the clinical outcomes of treating oligometastases with radiation using an elective simultaneous integrated boost technique (SIB), delivering higher doses to known metastases and reduced doses to adjacent bone or nodal basins. Here we compare outcomes of oligometastases receiving radiation targeting metastases alone (MA) versus those treated via an SIB. Both SIB and MA irradiation of oligometastases achieved high rates of tumor metastases control and similar pain control. Further investigation of this technique with prospective trials is warranted.

Abstract

Purpose: We previously reported on the clinical outcomes of treating oligometastases with radiation using an elective simultaneous integrated boost technique (SIB), delivering higher doses to known metastases and reduced doses to adjacent bone or nodal basins. Here we compare outcomes of oligometastases receiving radiation targeting metastases alone (MA) versus those treated via an SIB. Methods: Oligometastatic patients with ≤5 active metastases treated with either SIB or MA radiation at two institutions from 2013 to 2019 were analyzed retrospectively for treatment-related toxicity, pain control, and recurrence patterns. Tumor metastasis control (TMC) was defined as an absence of progression in the high dose planning target volume (PTV). Marginal recurrence (MR) was defined as recurrence outside the elective PTV but within the adjacent bone or nodal basin. Distant recurrence (DR) was defined as any recurrence that is not within the PTV or surrounding bone or nodal basin. The outcome rates were estimated using the Kaplan–Meier method and compared between the two techniques using the log-rank test. Results: 101 patients were treated via an SIB to 90 sites (58% nodal and 42% osseous) and via MA radiation to 46 sites (22% nodal and 78% osseous). The median follow-up among surviving patients was 24.6 months (range 1.4–71.0). Of the patients treated to MA, the doses ranged from 18 Gy in one fraction (22%) to 50 Gy in 10 fractions (50%). Most patients treated with an SIB received 50 Gy to the treated metastases and 30 Gy to the elective PTV in 10 fractions (88%). No acute grade ≥3 toxicities occurred in either cohort. Late grade ≥3 toxicity occurred in 3 SIB patients (vocal cord paralysis and two vertebral body compression), all related to the high dose PTV and not the elective volume. There was similar crude pain relief between cohorts. The MR-free survival rate at 2 years was 87% (95% CI: 70%, 95%) in the MA group and 98% (95% CI: 87%, 99%) in the SIB group (p = 0.07). The crude TMC was 89% (41/46) in the MA group and 94% (85/90) in the SIB group. There were no significant differences in DR-free survival (65% (95% CI: 55–74%; p = 0.24)), disease-free survival (60% (95% CI: 40–75%; p = 0.40)), or overall survival (88% (95% CI: 73–95%; p = 0.26)), between the MA and SIB cohorts. Conclusion: Both SIB and MA irradiation of oligometastases achieved high rates of TMC and similar pain control, with a trend towards improved MR-free survival for oligometastases treated with an SIB. Further investigation of this technique with prospective trials is warranted.

[Role of stereotactic radiotherapy in the treatment of oligometastatic colorectal cancer]

Stereotactic radiotherapy is used for patients with oligometastases from colorectal cancer. It results in good local tumour control, especially for hepatic and pulmonary metastases, subject to a sufficiently high biologically effective dose, and is well-tolerated. It can be associated with other local treatments such as surgery or radiofrequency as part of combined treatments, in order to increase patient survival.

Evaluation of Safety of Stereotactic Body Radiotherapy for the Treatment of Patients With Multiple Metastases: Findings From the NRG-BR001 Phase 1 Trial

IMPORTANCE

Stereotactic body radiotherapy (SBRT) for oligometastases is hypothesized to improve survival and is increasingly used. Little evidence supports its safe use to treat patients with multiple metastases.

OBJECTIVE

To establish safety of SBRT dose schedules in patients with 3 to 4 metastases or 2 metastases in close proximity to each other.

DESIGN, SETTING, AND PARTICIPANTS

This phase 1 trial opened on August 4, 2014, and closed to accrual on March 20, 2018. Metastases to 7 anatomic locations were included: bone/osseous (BO), spinal/paraspinal (SP), peripheral lung (PL), central lung (CL), abdominal-pelvic (AP), mediastinal/cervical lymph node (MC), and liver (L). Six patients could be enrolled per anatomic site. The setting was a consortium of North American academic and community practice cancer centers participating in NRG Oncology trials. Patients with breast, prostate, or non-small cell lung cancer with 3 to 4 metastases or 2 metastases in close proximity (≤5 cm) amenable to SBRT were eligible for this phase 1 study. Statistical analyses were performed from December 31, 2017, to September 19, 2019.

INTERVENTIONS

The starting dose was 50 Gy in 5 fractions (CL, MC), 45 Gy in 3 fractions (PL, AP, L), and 30 Gy in 3 fractions (BO, SP).

MAIN OUTCOMES AND MEASURES

The primary end point was dose-limiting toxicity (DLT) defined by the Common Terminology Criteria for Adverse Events, version 4.0, as specific adverse events (AEs) of grades 3 to 5 (definite or probable per the protocol DLT definition) related to SBRT within 180 days of treatment. Dose levels were considered safe if DLTs were observed in no more than 1 of 6 patients per location; otherwise, the dose at that location would be de-escalated.

RESULTS

A total of 42 patients enrolled, 39 were eligible, and 35 (mean [SD] age, 63.1 [14.2] years; 20 men [57.1%]; 30 White patients [85.7%]) were evaluable for DLT. Twelve patients (34.3%) had breast cancer, 10 (28.6%) had non-small cell lung cancer, and 13 (37.1%) had prostate cancer; there was a median of 3 metastases treated per patient. Median survival was not reached. No protocol-defined DLTs were observed. When examining all AEs, 8 instances of grade 3 AEs, most likely related to protocol therapy, occurred approximately 125 to 556 days from SBRT initiation in 7 patients.

CONCLUSIONS AND RELEVANCE

This phase 1 trial demonstrated the safety of SBRT for patients with 3 to 4 metastases or 2 metastases in close proximity. There were no treatment-related deaths. Late grade 3 AEs demonstrate the need for extended follow-up in long-surviving patients with oligometastatic disease. Treatment with SBRT for multiple metastases has been expanded into multiple ongoing randomized phase 2/3 National Cancer Institute-sponsored trials (NRG-BR002, NRG-LU002).

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02206334.

Role of modern radiotherapy in managing patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Several treatment options are available for managing HCC patients, classified roughly as local, local-regional, and systemic therapies. The high post-monotherapy recurrence rate of HCC urges the need for the use of combined modalities to increase tumor control and patient survival. Different international guidelines offer treatment recommendations based on different points of view and classification systems. Radiotherapy (RT) is a well-known local-regional treatment modality for managing many types of cancers, including HCC. However, only some of these treatment guidelines include RT, and the role of combined modalities is rarely mentioned. Hence, the present study reviewed clinical evidence for the use of different combined modalities in managing HCC, focusing on modern RT's role. Modern RT has an increased utility in managing HCC patients, mainly due to two driving forces. First, technological advancement (e.g., stereotactic body radiotherapy and advanced proton-beam therapy) enables precise delivery of radiation to increase tumor control and reduce side effects in the surrounding normal tissue. Second, the boom in developing target therapies and checkpoint-blockade immunotherapy prolongs overall survival in HCC patients, re-emphasizing the importance of local tumor control. Remarkably, RT combines with systemic therapies to generate the systemic therapy augmented by radiotherapy effect, a benefit now being actively investigated.

Stereotactic body radiotherapy for kidney cancer: a 10-year experience from a single institute

The purpose of this retrospective study was to investigate survival outcomes and irradiated tumor control (local control [LC]) and locoregional control (LRC) after stereotactic body radiotherapy (SBRT) for T1 or recurrent T1 (rT1) kidney cancer. Twenty-nine nonconsecutive patients with 30 tumors were included. SBRT doses of 70 Gy, 60 Gy or 50 Gy in 10 fractions were prescribed with a linear accelerator using daily image guidance. The Kaplan-Meier method was used to estimate time-to-event outcomes, and the log-rank test was used to compare survival curves between groups divided by each possible factor. The median follow-up periods for all patients and survivors were 57 months and 69.6 months, respectively. The five-year LC rate, LRC rate, progression-free survival (PFS) rate, disease-specific survival (DSS) rate and overall survival (OS) rate were 94%, 88%, 50%, 96% and 68%, respectively. No significant factor was related to OS and PFS. Three of 24 non-hemodialysis (HD) patients had new-onset-HD because of the progression of underlying kidney disease. Grade 3 or higher toxicities from SBRT did not occur. In conclusion, SBRT for kidney cancer provided a high rate of LC, LRC and DSS with minimal toxicities, but patient selection and indication for SBRT should be done carefully considering the relatively low OS rate.

Metastases-directed Radiotherapy in Addition to Standard Systemic Therapy in Patients with Oligometastatic Breast Cancer: Study protocol for a randomized controlled multi-national and multi-center clinical trial (OLIGOMA)

BACKGROUND

Several recent randomized therapeutic exploratory trials demonstrated improvement of progression-free survival and in some even overall survival using stereotactic body radiotherapy in patients with oligometastatic disease. However, only very few patients enrolled in these trials had breast cancer, and results from confirmatory trials are lacking.

METHODS/DESIGN

The OLIGOMA-trial is a randomized controlled multi-national multi-center therapeutic confirmatory trial studying the role of local ablative radiotherapy as an additive treatment in patients with oligometastatic breast cancer receiving standard systemic therapy. Patients will be randomized 1:1 to standard systemic therapy according to national guidelines with or without radiotherapy to all metastatic sites. Randomization will be stratified according to type and line of systemic therapy, which has to be determined by a multidisciplinary tumor board before enrollment. Patients with up to five metastatic lesions are eligible, including patients with up to three brain metastases (only in case of extracranial disease) and with locoregional recurrence (only in case of additional metastatic lesions). In the standard arm, palliative radiotherapy to symptomatic metastases is permitted if at least one lesion remains untreated. The co-primary endpoints are progression-free survival and quality of life. The primary hypothesis is that progression-free survival in the experimental arm will be superior to the standard arm while simultaneously demonstrating non-inferiority of quality of life at 12 weeks after randomization. Secondary endpoints are feasibility, overall survival, toxicity, quality of life and patient satisfaction. A translational sub-study with collection of ctDNA will be conducted.

DISCUSSION

The OLIGOMA-trial will provide high level evidence on the use of and benefit from local ablative radiotherapy for patients with oligometastatic breast cancer.

TRIAL REGISTRATION

The OLIGOMA-trial is registered at clinicialtrials.gov under the identification NCT04495309. The related information was first posted on July 31st 2020.

Stereotactic robotic body radiotherapy for patients with oligorecurrent pulmonary metastases

BACKGROUND

Our aim is to report treatment efficacy and toxicity of patients treated by robotic (Cyberknife®) stereotactic body radiotherapy (SBRT) for oligorecurrent lung metastases (ORLM). Additionally we wanted to evaluate influence of tumor, patient and treatment related parameters on local control (LC), lung and distant progression free- (lung PFS/Di-PFS) and overall survival (OS).

METHODS

Consecutive patients with up to 5 ORLM (confirmed by FDG PET/CT) were included in this study. Intended dose was 60Gy in 3 fractions (prescribed to the 80% isodose volume). Patients were followed at regular intervals and tumor control and toxicity was prospectively scored. Tumor, patient and treatment data were analysed using competing risk- and Cox regression.

RESULTS

Between May 2010 and March 2016, 104 patients with 132 lesions were irradiated from primary lung carcinoma (47%), gastro-intestinal (34%) and mixed primary histologies (19%). The mean tumor volume was 7.9 cc. After a median follow up of 22 months, the 1, 2 and 3 year LC rate (per lesion) was 89.3, 80.0 and 77.8% respectively. The corresponding (per patient) 1, 2 and 3 years lung PFS were 66.3, 50.0, 42.6%, Di-PFS were 80.5, 64.4, 60.6% and OS rates were 92.2, 80.9 and 72.0% respectively. On univariable analysis, gastro-intestinal (GI) as primary tumor site showed a significant superior local control versus the other primary tumor sites. For OS, significant variables were primary histology and primary tumor site with a superior OS for patients with metastases of primary GI origin. LC was significantly affected by the tumor volume, physical and biologically effective dose coverage. Significant variables in multivariable analysis were BED prescription dose for LC and GI as primary site for OS. The vast majority of patients developed no toxicity or grade 1 acute and late toxicity. Acute and late grade 3 radiation pneumonitis (RP) was observed in 1 and 2 patients respectively. One patient with a centrally located lesion developed grade 4 RP and died due to possible RT-induced pulmonary hemorrhage.

CONCLUSIONS

SBRT is a highly effective local therapy for oligorecurrent lung metastases and could achieve long term survival in patients with favourable prognostic features.

Hypofractionated Image-Guided Radiation Therapy With Simultaneous-Integrated Boost Technique for Limited Metastases: A Multi-Institutional Analysis

Purpose: To perform a multi-institutional analysis following treatment of limited osseous and/or nodal metastases in patients using a novel hypofractionated image-guided radiotherapy with simultaneous-integrated boost (HIGRT-SIB) technique.

Methods: Consecutive patients treated with HIGRT-SIB for ≤5 active metastases at Duke University Medical Center or Durham Veterans' Affairs Medical Center between 2013 and 2018 were analyzed to determine toxicities and recurrence patterns following treatment. Most patients received 50 Gy to the PTV_boost and 30 Gy to the PTV_elect simultaneously in 10 fractions. High-dose treatment volume recurrence (HDTVR) and low-dose treatment volume recurrence (LDTVR) were defined as recurrences within PTV_boost and PTV_elect, respectively. Marginal recurrence (MR) was defined as recurrence outside PTV_elect, but within the adjacent bone or nodal chain. Distant recurrence (DR) was defined as recurrences not meeting HDTVR, LDTVR, or MR criteria. Freedom from pain recurrence (FFPR) was calculated in patients with painful osseous metastases prior to HIGRT-SIB. Outcome rates were estimated at 12 months using the Kaplan-Meier method.

Results: Forty-two patients met inclusion criteria with 59 sites treated with HIGRT-SIB (53% nodal and 47% osseous). Median time from diagnosis to first metastasis was 31 months and the median age at HIGRT-SIB was 69 years. The most common primary tumors were prostate (36%), gastrointestinal (24%), and lung (24%). Median follow-up was 11 months. One acute grade ≥3 toxicity (febrile neutropenia) occurred after docetaxel administration immediately following HIGRT-SIB. Four patients developed late grade ≥3 toxicities: two ipsilateral vocal cord paralyzes and two vertebral compression fractures. The overall pain response rate was 94% and the estimated FFPR at 12 months was 72%. The estimated 12 month rate of HDTVR, LDTVR, MR, and DR was 3.6, 6.2, 7.6, and 55.8%, respectively. DR preceded MR, HDTVR, or LDTVR in each instance. The estimated 12 month probability of in-field and marginal control was 90.0%.

Conclusion: Targeting areas at high-risk for occult disease with a lower radiation dose, while simultaneously boosting gross disease with HIGRT in patients with limited osseous and/or nodal metastases, has a high rate of treated metastasis control, a low rate of MR, acceptable toxicity, and high rate of pain palliation. Further investigation with prospective trials is warranted.

Managing Patients With Oligometastatic Non-Small-Cell Lung Cancer

Metastatic lung cancer has long been considered incurable, with the goal of treatment being palliation. However, a clinically meaningful number of these patients with limited metastases (approximately 25%) are living long term after definitive treatment to all sites of active disease. These patients with so-called oligometastatic disease likely represent a distinct clinical group who may possess a more indolent biology compared with their more widely metastatic counterparts. Hellman and Weichselbaum proposed the existence of the oligometastatic state, on the basis of the spectrum theory of cancer spread. The literature suggests that an oligometastatic state exists in patients with non-small-cell lung cancer (NSCLC). This observation in the setting of rapidly evolving systemic therapies, including immune checkpoint inhibitors and an increasing number of targeted therapies, represents a unique clinical opportunity. Metastasis-directed therapies to address sites of disease include surgery (metastasectomy) and/or radiation therapy. Available evidence suggests that treating patients with limited or oligometastases may improve outcomes in a meaningful way; however, the majority of the randomized data includes patients with intracranial metastatic disease, and there are limited robust, randomized data available in the setting of NSCLC with only extracranial sites of metastatic disease. Ongoing randomized trials, including NRG-LU002 and the UK Conventional Care Versus Radioablation (Stereotactic Body Radiotherapy) for Extracranial Oligometastases trial, are aimed at evaluating this question further. One of the current limitations of aggressive treatment of oligometastatic NSCLC is the inability to accurately identify these patients before therapy, yet molecular markers, including microRNA profiles, are being investigated as a promising way to identify these patients.

Hypofractionated Stereotactic Radiotherapy for Non-breast or Prostate Cancer Oligometastases: A Tail of Survival Beyond 10 Years

Purpose and Objective(s): We sought to analyze the long-term follow-up of patients treated with hypofractionated, stereotactic radiotherapy (HSRT) for oligometastases from malignancies other than breast or prostate cancer. Materials and Methods: From 2001 to 2006, 82 cancer patients with 1-5 radiographically apparent metastatic lesions (in 1-3 organs) from primary sites other than breast or prostate cancer, were enrolled on a prospective study of HSRT. Freedom from widespread metastasis (FFWM) was defined from date of enrollment until death, an event (i.e., widespread distant metastasis not amenable to local therapy), or last radiographic study. Local recurrence was scored as an event if pathologically confirmed or if a treated lesion increased by ≥20% using RECIST criteria. Prognostic variables were assessed using Cox regression analysis. Results: The mean age was 61 ± 11 years, with a male to female ratio of 46:36. The most common metastatic sites were liver (50%), lung (48%), thoracic lymph nodes (18%), and bone (5%). Sixty-one patients (74%) had 1 involved organ and 18 (22%) had 1 lesion treated. The preferred dose-fractionation scheduled was 50 Gy in 10 fractions (52 patients). The median follow-up was 1.7 years. Eleven patients lived >5 years, and 6 lived >10 years. The 5-year OS, PFS, FFWM, and LC rates were 13.4, 7.3, 18.3, and 63.4%, and the 10-years OS, PFS, FFWM, and patient LC rates were 7.3, 6.1, 13.4, and 62.2%, respectively. A greater net gross tumor volume (GTV) was significantly adverse for OS (p < 0.01) and LC (p < 0.01). For FFWM, net GTV was not a significant factor (p = 0.14). Four patients remain alive at >13 years from enrollment and treatment, without evidence of active disease. Conclusion: A small subset of select non-breast, non-prostate cancer patients with limited metastasis treated with HSRT are long-term survivors. Net GTV is a significant factor for tumor control and survival. Further research is needed to help better select patients most likely to benefit from local therapy for metastatic disease.

Stereotactic Radiotherapy for Oligometastasis

Oligometastatic disease is defined as “a condition with a few metastases arising from tumors that have not acquired a potential for widespread metastases.” Its behavior suggests a transitional malignant state somewhere between localized and metastatic cancer. Treatment of oligometastatic disease is expected to achieve long-term local control and to improve survival. Historically, patients with oligometastases have often undergone surgical resection since it was anecdotally believed that surgical resection could result in progression-free or overall survival benefits. To date, no prospective randomized trials have demonstrated surgery-related survival benefits. Short courses of highly focused, extremely high-dose radiotherapies (e.g., stereotactic radiosurgery and stereotactic ablative body radiotherapy (SABR)) have frequently been used as alternatives to surgery for treatment of oligometastasis. A randomized study has demonstrated the overall survival benefits of stereotactic radiosurgery for solitary brain metastasis. Following the success of stereotactic radiosurgery, SABR has been widely accepted for treating extracranial metastases, considering its efficacy and minimum invasiveness. In this review, we discuss the history of and rationale for the local treatment of oligometastases and probe into the implementation of SABR for oligometastatic disease.

Oligometastatic breast cancer treated with hypofractionated stereotactic radiotherapy: Some patients survive longer than a decade

BACKGROUND

The clinical state of oligometastases describes metastases limited in number and extent, amenable to metastasis-directed therapy. We sought to analyze long-term outcomes and characterize potential prognostic factors, in women with breast cancer (BC) oligometastases treated with hypofractionated stereotactic radiation (HSRT) therapy on a prospective phase II protocol.

METHODS

Forty-eight women with 1-5 extracranial BC oligometastases received HSRT to all radiographically apparent sites of disease. Various dose-fractionation schedules were used. Most (n = 27) received 10 daily fractions, typically ≥50 Gy (n = 17).

RESULTS

BC patients with bone-only oligometastases (BO, n = 12) vs. all other patients (non-BO; n = 36) were significantly younger, more likely to present with oligometastases at the time of primary BC diagnosis (i.e., synchronous), and significantly more likely to have had hormone receptor-positive disease. The 5-year and 10-year overall survival (OS) rates after HSRT were 83% and 75%, respectively, for BO patients vs. 31% and 17%, respectively, for non-BO patients (p = 0.002). BO patients experienced a significantly (p = 0.018) greater freedom from widespread metastases (FFWM). Among non-BO patients, net oligometastatic GTV >25 cc (reflecting disease burden) was a significant factor for freedom from local recurrence (p = 0.047) and FFWM (p = 0.028). The number of oligometastatic lesions (p = 0.007) and organs (p = 0.001) involved were also significant factors for FFWM in non-BO patients.

CONCLUSIONS

Some patients with BC oligometastases treated with HSRT can survive >10 years. Tumor burden (volume and number of lesions) appears to impact risk of recurrence. Further research is needed to help better identify BC patients most likely to benefit from metastasis-directed radiotherapy.

Survival, local control, and health-related quality of life in patients with oligometastatic and polymetastatic spinal tumors: A multicenter, international study

BACKGROUND

The treatment of oligometastatic (≤5 metastases) spinal disease has trended toward ablative therapies, yet to the authors' knowledge little is known regarding the prognosis of patients presenting with oligometastatic spinal disease and the value of this approach. The objective of the current study was to compare the survival and clinical outcomes of patients with cancer with oligometastatic spinal disease with those of patients with polymetastatic (>5 metastases) disease.

METHODS

The current study was an international, multicenter, prospective study. Patients who were admitted to a participating spine center with a diagnosis of spinal metastases and who underwent surgical intervention and/or radiotherapy between August 2013 and May 2017 were included. Data collected included demographics, overall survival, local control, and treatment information including surgical, radiotherapy, and systemic therapy details. Health-related quality of life (HRQOL) measures included the EuroQOL 5 dimensions 3-level questionnaire (EQ-5D-3L), the 36-Item Short Form Health Survey (SF-36v2), and the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ).

RESULTS

Of the 393 patients included in the current study, 215 presented with oligometastatic disease and 178 presented with polymetastatic disease. A significant survival advantage of 90.1% versus 77.3% at 3 months and 77.0% versus 65.1% at 6 months from the time of treatment was found for patients presenting with oligometastatic disease compared with those with polymetastatic disease. It is important to note that both groups experienced significant improvements in multiple HRQOL measures at 6 months after treatment, with no differences in these outcome measures noted between the 2 groups.

CONCLUSIONS

The treatment of oligometastatic disease appears to offer a significant survival advantage compared with polymetastatic disease, regardless of treatment choice. HRQOL measures were found to improve in both groups, demonstrating a palliative benefit for all treated patients.

Implication of Biomarker Mutations for Predicting Survival in Patients With Metastatic Lung Cancer to the Spine

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

We performed a retrospective study of patients treated at our institution over the last 7 years to ascertain whether gene expression signatures in patients with advanced metastatic disease are associated with survival, when the disease has progressed to the spine.

SUMMARY OF BACKGROUND DATA

Spinal metastases are a major cause of morbidity in patients with cancer. Molecular profiling strategies to characterize lung cancer have identified several genetic biomarkers that may lead to more effective prognostication.

METHODS

We queried our institutional database for patients with metastatic lung cancer who underwent treatment for spinal metastases between 2011 and 2017. Genetic mutations in ALK, MET, ROS1, EGFR, and KRAS were chosen a priori for study based on availability by standard SNaPshot Lung Tumor Genotyping Analysis. Survival time was the duration between treatment for spinal metastases and death. Kaplan-Meier methods and the log-rank test were applied to characterize survival data.

RESULTS

Twenty-six patients met criteria for inclusion. Median survival after surgery was 0.67 years. Median overall survival (OS) after diagnosis was 2.7 years. The presence of molecular abnormalities in patients with spinal metastases was significantly associated with increased OS (HR 0.38, 95% CI 0.12-1.22, P = 0.03).

CONCLUSION

Molecular phenotyping may provide prognostic insight in patients undergoing surgery for spinal metastases. This is the first study to demonstrate an association between genetic mutational data and OS in this patient population. It also represents the largest published series of such patients (n = 26) for which genetic mutational data are reported. Future models estimating survival for patients with spinal metastases may be enhanced by incorporation of molecular criteria.

LEVEL OF EVIDENCE

4.

Curative-intent radiotherapy in patients with oligometastatic lesions from colorectal cancer: A single-center study

The purpose of the present study was to investigate the efficacy and safety of radiotherapy for patients with oligometastases from colorectal cancer (CRC).This was a retrospective cross-sectional study. Patients with liver and/or lung oligometastatic lesions from CRC treated with curative-intent radiotherapy in West China Hospital, Sichuan University, between 2009 and 2013 were included. Radiotherapy modality included 3-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and stereotactic body radiation therapy (SBRT); simultaneous chemotherapies along with radiotherapy of metastasis were allowed. Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method. Local control (LC) rates, toxicities, and factors of prognostic significance were also assessed.A total of 40 CRC patients with 57 liver and/or lung oligometastatic lesions were included. Most of the patients (95%) had received at least 1 line of previous systemic chemotherapy. Among them, 19 patients with 26 lesions received 3D-CRT with a median dose of 51.5 Gy in 16.1 fractions, 7 patients with 11 lesions received IMRT with a median dose of 49.3 Gy in 10.4 fractions, and 14 patients with 20 lesions received SBRT with a median dose of 56.4 Gy in 6.7 fractions, respectively. The median follow-up time was 34 months (range, 9-86 months). Median OS and PFS for patients were 30.0 months [95% confidence interval (95% CI), 21.3-38.7] and 11.0 months (95% CI, 9-13), respectively. One, 3, and 5 years' LC rates for metastasis were 63.2%, 24.6%, and 16.9%, respectively. In subgroup analysis, patients with metachronous metastases had longer OS (median, 41.0 months; 95% CI, 33.3-48.7) than patients with synchronous lesions (median, 17.0 months; 95% CI, 7.4-26.6, P = .001). All patients tolerated the radiation treatment well, and there was no treatment-related death. Multivariate analysis showed that number of metastasis lesions and simultaneous liver and lung metastases were potential survival predictors.The study demonstrated that curative radiotherapy might be a tolerable and potential alternative for the treatment of patients with liver and/or lung oligometastases from CRC, and patients with metachronous lesions might have better survival than those with synchronous lesions when treated with curative-intent radiotherapy.

Multisite stereotactic body radiotherapy for metastatic non-small-cell lung cancer: Delaying the need to start or change systemic therapy?

OBJECTIVES

The purpose of this study was to review the clinical outcomes following the use of stereotactic body radiotherapy (SBRT) in patients with metastatic non-small-cell lung cancer (NSCLC) from a large academic institution.

MATERIALS AND METHODS

Metastatic NSCLC patients treated with extracranial SBRT were identified from an institutional database. Treatment indications were: (1) oligometastases, (2) oligoprogression, and (3) local control of dominant tumors. Endpoints included overall survival (OS), progression-free survival (PFS), time to starting/changing systemic therapy (SCST), and local failure (LF). Univariate and multivariable analyses were performed to look for predictive factors.

RESULTS

108 patients with 165 tumors were treated. SBRT was delivered for oligometastases in 66 patents, for oligoprogression in 20 patients, and for local control in 22 patients. Median OS and PFS for all patients were 27.3 months and 4.4 months, respectively, with treatment indication being the only predictive factor on multivariable analysis (patients with oligometastases having the highest median OS and PFS of 39.3 months and 7.6 months respectively). Cumulative incidence of SCST was only 21.5% at 1 year after SBRT, with larger tumor size and positivity for EGFR/ALK mutation being predictive of higher rates of SCST on multivariable analysis. LF was 15.6% at 1 year, with larger tumor size and exposure to previous systemic therapy being predictive of higher rates of LF on multivariable analysis.

CONCLUSION

Patients treated with SBRT for oligometastases have better OS and PFS than those treated for oligoprogression or for local control of dominant tumors. Use of SBRT may delay the need for SCST. Larger tumors and previous exposure to systemic therapy were predictive of higher rates of LF.

Stereotactic ablative body radiotherapy in patients with prostate cancer

Prostate is the most common non-cutaneous cancer diagnosed among men in North America. Fortunately most prostate cancers are screen detected and non-metastatic on diagnosis. Treatment options for men with localized prostate cancer include surgery ± postoperative radiation or radiation ± androgen deprivation therapy (ADT). Brachytherapy ± external beam radiation treatment (EBRT) appears to have superior long-term disease control over EBRT alone likely because of higher biologic effective dose delivered. Stereotactic ablative body radiation (SABR) is a novel, non-invasive, high-precision EBRT technique that allows safe delivery of biologic doses similar to brachytherapy with similar or lower side effects [measured using toxicity or quality of life (QOL) scales]. Efficacy for SABR appears to be similar to brachytherapy including positive biopsy rates 2-3 years post treatment, biochemical failure (BF) rates out to 10-year and incidence of metastases. SABR dose escalation reduces biopsy positivity and prostate-specific antigen (PSA) nadirs but increases genitourinary (GU) and gastrointestinal (GI) toxicity-no effect on BF has been realized yet. The overall treatment time (OTT) varies in many protocols. Phase 2 randomized data shows that QOL is better in the acute setting with a weekly course of treatment compared to an every other day treatment regimen with no difference in late setting. Follow-up data are immature and likely underpowered to determine efficacy differences. SABR is cheaper and uses less resource than any other radiation technique. Given the healthcare resource challenges (including financial resources), SABR would be a welcomed addition if studies show non-inferiority to other radiation techniques. For patients with de novo or metastatic disease on relapse, there is much enthusiasm regarding the use of SABR in the setting of oligometastatic prostate cancer. SABR appears to be feasible to deliver, well tolerated and may delay the next line of therapy. However, until adequately powered randomized studies confirm a benefit, such an approach cannot be considered standard of care treatment at this time. Enrollment of eligible prostate cancer patients onto SABR clinical trials should be encouraged.

Treatment of Liver Metastases Using an Internal Target Volume Method for Stereotactic Body Radiotherapy

The prognosis of patients with metastatic cancers has improved in the past decades due to effective chemotherapy and oligometastatic surgery. For inoperable patients, local ablation therapies, such as stereotactic body radiotherapy (SBRT), can provide effective local tumor control with minimal toxicity. Because of its high precision and accuracy, SBRT delivers a higher radiation dose per fraction, is more effective, and targets smaller irradiation volumes than does conventional radiotherapy. In addition, steep dose gradients from target lesions to surrounding normal tissues are achieved using SBRT; thus, SBRT provides more effective tumor control and exhibits fewer side effects than conventional radiotherapy. The use of SBRT is prevalent for treating intracranial lesions (known as stereotactic radiosurgery); however, it is now also used for treating spinal and adrenal metastases. Because of advancements in image-guided assistance and respiratory motion management, several studies have investigated the use of SBRT for treating lung or liver tumors, which move as a patient breathes. The results of these studies have suggested that SBRT favorably controls tumors in the case of moving lesions. Four-dimensional computed tomography (4D-CT) with an abdominal compressor (AC) is clinically convenient for effective respiratory motion management. Because this method is noninvasive and allows free breathing, its use reduces complications. Furthermore, patients consider this method convenient. Moreover, it is considered more efficient than other methods of respiratory motion management by physicians and therapists. The use of 4D-CT with an AC for treating pulmonary lesions has also been widely investigated, and the technique is gaining acceptance for treating hepatic lesions. However, the protocols for using 4D-CT with an AC for treating hepatic lesions are different from those used for treating pulmonary lesions. In this article, we describe a new protocol for SBRT with 4D-CT and an AC for treating liver metastases.

Classification for long-term survival in oligometastatic patients treated with ablative radiotherapy: A multi-institutional pooled analysis

Background

Radiotherapy is increasingly used to treat oligometastatic patients. We sought to identify prognostic criteria in oligometastatic patients undergoing definitive hypofractionated image-guided radiotherapy (HIGRT).

Methods

Exclusively extracranial oligometastatic patients treated with HIGRT were pooled. Characteristics including age, sex, primary tumor type, interval to metastatic diagnosis, number of treated metastases and organs, metastatic site, prior systemic therapy for primary tumor treatment, prior definitive metastasis-directed therapy, and systemic therapy for metastasis associated with overall survival (OS), progression-free survival (PFS), and treated metastasis control (TMC) were assessed by the Cox proportional hazards method. Recursive partitioning analysis (RPA) identified prognostic risk strata for OS and PFS based on pretreatment factors.

Results

361 patients were included. Primary tumors included non-small cell lung (17%), colorectal (19%), and breast cancer (16%). Three-year OS was 56%, PFS was 24%, and TMC was 72%. On multivariate analysis, primary tumor, interval to metastases, treated metastases number, and mediastinal/hilar lymph node, liver, or adrenal metastases were associated with OS. Primary tumor site, involved organ number, liver metastasis, and prior primary disease chemotherapy were associated with PFS.

OS RPA identified five classes: class 1: all breast, kidney, or prostate cancer patients (BKP) (3-year OS 75%, 95% CI 66–85%); class 2: patients without BKP with disease-free interval of 75+ months (3-year OS 85%, 95% CI 67–100%); class 3: patients without BKP, shorter disease-free interval, ≤ two metastases, and age < 62 (3-year OS 55%, 95% CI 48–64%); class 4: patients without BKP, shorter disease-free interval, ≥ three metastases, and age < 62 (3-year OS 38%, 95% CI 24–60%); class 5: all others (3-year OS 13%, 95% CI 5–35%). Higher biologically effective dose (BED) (p < 0.01) was associated with OS.

Conclusions

We identified clinical factors defining oligometastatic patients with favorable outcomes, who we hypothesize are most likely to benefit from metastasis-directed therapy.

Volumetric modulated arc therapy for thoracic node metastases: a safe and effective treatment for a neglected disease

Purpose

To evaluate the outcome of Stereotactic Body Radiation Therapy (SBRT) with Volumetric Modulated Arc Therapy (VMAT) for thoracic node metastases.

Results

18 out of 29 patients presented with isolated thoracic node metastases with no other sites of disease. Median prescribed dose was 45Gy (range 30–60Gy).

Acute toxicity was recorded as G0 in 28 patients, while one patient was scored as G1. Late toxicity was G0 in 26 patients, one patient was scored G1, one as G2, and one as G4 presented acute myocardial infarction.

During follow up, the best local response was complete remission in 14 patients and partial remission in 11 patients. With a median follow up of 12 months (range 2–35) 9 patients died from disease progression, 10 were still alive with distant metastases, 5 had a locally controlled disease and 5 patients were disease free.

The median OS estimated was 18 months (76%, 49% at one, two years). The median PFS was 9 months (28%, 17% at one, two years).

Materials and Methods

Twenty-nine patients with 32 thoracic nodes metastases were treated with SBRT in our institution. Toxicities and response were assessed. Overall Survival (OS) and Progression Free Survival (PFS) were evaluated.

Conclusions

SBRT is an efficient treatment for thoracic node metastases.

Stereotactic Body Radiotherapy for Lung Metastases from Colorectal Cancer: Prognostic Factors for Disease Control and Survival

OBJECTIVES

To evaluate disease control and survival after stereotactic body radiotherapy (SBRT) for lung metastases from colorectal cancer and to identify prognostic factors after treatment.

METHODS

Patients with metastatic colorectal cancer to the lungs treated with SBRT from 2002 to 2013 were identified from a prospectively maintained database. Patients may have received prior systemic therapy, radiotherapy to nonthoracic sites and/or resection of thoracic and/or nonthoracic metastases. Endpoints were timed from end of SBRT and included overall survival (OS), progression-free survival, distant metastases-free survival, and local failure-free survival. Univariate and multivariate analysis using Cox proportional hazard modeling was used to identify prognostic factors.

RESULTS

Sixty-five patients were identified. Before SBRT, 69.2% and 33.8% of patients received systemic therapy and lung-directed local therapy, respectively, for metastatic disease. At the time of SBRT, 64.6% had lung-only involvement. Median survivals were: OS of 20.3 months (95% confidence intervals [CI], 15.9-27.0 mo), progression-free survival of 5.7 months (95% CI, 3.2-7.0 mo), distant metastases-free survival of 5.8 months (95% CI, 3.2-7.6 mo), and local failure-free survival of 15.4 months (95% CI, 8.5-21.1 mo). Nearly all (98%) patients developed distant progression. Extra lung and liver involvement at the time of initial metastases (hazard ratios [HR] 2.10) and extra lung involvement at SBRT (HR 2.67) were the only independent predictors of OS. Net gross target volume of >14.1 mL (HR 2.49) was the only independent predictor of local failure-free survival.

CONCLUSIONS

Reasonable survival and local control can be achieved with SBRT. We identified several prognostic factors testable in future prospective trials that may help improve patient selection.

Stereotactic Body Radiotherapy for Oligometastasis: Opportunities for Biology to Guide Clinical Management

Oligometastasis refers to a state of limited metastatic disease burden, in which surgical or ablative treatment to all known visible metastases holds promise to extend survival or even effect cure. Stereotactic body radiotherapy is a form of radiation treatment capable of delivering a high biologically effective dose of radiation in a highly conformal manner, with a favorable toxicity profile. Enthusiasm for oligometastasis ablation, however, should be counterbalanced against the limited supporting evidence. It remains unknown to what extent (if any) ablation influences survival or quality of life. Rising clinical equipoise necessitates the completion of randomized controlled trials to assess this, several of which are underway. However, a lack of clear identification criteria or biomarkers to define the oligometastatic state hampers optimal patient selection.This narrative review explores the evolutionary origins of oligometastasis, the steps of the metastatic process at which oligometastases may arise, and the biomolecular mediators of this state. It discusses clinical outcomes with treatment of oligometastases, ongoing trials, and areas of basic and translational research that may lead to novel biomarkers. These efforts should provide a clearer, biomolecular definition of oligometastatic disease and aid in the accurate selection of patients for ablative therapies.

ACR Appropriateness Criteria® Management of Recurrent Endometrial Cancer

OBJECTIVES

In women with endometrial carcinoma (EC), tumor recurrences tend to occur in the 2- to 3-year period following surgical staging. Management of disease recurrence in EC poses significant challenges. These patients represent a heterogenous group where histologic subtypes, previous adjuvant management, interval since completion of adjuvant therapy, and size and site(s) of disease recurrence all have important implications on salvage therapies and prognosis. No randomized controlled trials have been published to determine optimal management in this group of patients. An expert panel was convened to reach consensus on the most appropriate management options in this group of patients.

METHODS

The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

RESULTS

Five clinical variants were developed to address common scenarios in the management of women with recurrent EC. Group members reached consensus on the appropriateness of specific evaluation and treatment approaches with numerical ratings.

CONCLUSIONS

In combining available medical literature and expert opinions, this manuscript may serve as an aid for other practitioners in the appropriate management of women with recurrent EC.

Stereotactic Robotic Body Radiotherapy for Patients With Unresectable Hepatic Oligorecurrence

BACKGROUND

The purpose of this study was to analyze local control (LC), liver progression-free survival (PFS), and distant PFS (DFS), overall survival (OS), and toxicity in a cohort of patients treated with stereotactic body radiotherapy (SBRT) with fiducial tracking for oligorecurrent liver lesions; and to evaluate the potential influence of lesion size, systemic treatment, physical and biologically effective dose (BED), treatment calculation algorithms and other parameters on the obtained results.

PATIENTS AND METHODS

Unoperable patients with sufficient liver function had [18F]-fluorodeoxyglucose-positron emission tomography-computed tomography and liver magnetic resonance imaging to confirm the oligorecurrent nature of the disease and to further delineate the gross tumor volume (GTV). An intended dose of 45 Gy in 3 fractions was prescribed on the 80% isodose and adapted if risk-related. Treatment was executed with the CyberKnife system (Accuray Inc) platform using fiducials tracking. Initial plans were recalculated using the Monte Carlo algorithm. Patient and treatment data were processed using the Kaplan-Meier method and log rank test for survival analysis.

RESULTS

Between 2010 and 2015, 42 patients (55 lesions) were irradiated. The mean GTV and planning target volume (PTV) were 30.5 cc and 96.8 cc, respectively. Treatments were delivered 3 times per week in a median of 3 fractions to a PTV median dose of 54.6 Gy. The mean GTV and PTV D98% were 51.6 Gy and 51.2 Gy, respectively. Heterogeneity corrections did not influence dose parameters. After a median follow-up of 18.9 months, the 1- and 2-year LC/liver PFS/DFS/OS were 81.3%/55%/62.4%/86.9%, and 76.3%/42.3%/52%/78.3%, respectively. Performance status and histology had a significant effect on LC, whereas age (older than 65 years) marginally influenced liver PFS. Clinical target volume physical dose V45 Gy > 95%, generalized equivalent uniform dose (a = -30) > 45 Gy and a BED (α/β = 10) V105 Gy > 96% showed statistically significant effect on the LC. Acute Grade 3 gastrointestinal (GI) and late Grade 2 GI and fatigue toxicity were found in 5% and 11% patients, respectively.

CONCLUSION

Favorable survival and toxicity results support the potential paradigm shift in which the use of SBRT in oligorecurrent liver disease could benefit patients with unresectable or resectable liver metastases.

Multicenter Evaluation of the Tolerability of Combined Treatment With PD-1 and CTLA-4 Immune Checkpoint Inhibitors and Palliative Radiation Therapy

PURPOSE

To analyze immune-related adverse events (ir-AEs) in patients treated with radiation and immune checkpoint blockade.

METHODS AND MATERIALS

We retrospectively reviewed records from patients with metastatic non-small cell lung cancer, melanoma, or renal cell cancer who received at least 1 cycle of a CTLA-4 or PD-1 inhibitor and radiation. Immune-related adverse events, defined using Common Terminology Criteria for Adverse Events version 4.0, were tabulated in relation to treatment variables, and associations with sequencing and timing were assessed.

RESULTS

We identified 133 patients, of whom 28 received a CTLA-4 inhibitor alone, 88 received a PD-1 inhibitor alone, and 17 received both classes of inhibitors either sequentially (n=13) or concurrently (n=4). Fifty-six patients received radiation within 14 days of an immune checkpoint inhibitor. Forty-six patients experienced at least 1 ir-AE (34.6%). Patients receiving both CTLA-4 and PD-1 inhibitors experienced more any-grade ir-AEs as compared with either individually (71% vs 29%, P=.0008). Any-grade ir-AEs occurred in 39% of patients in whom radiation was administered within 14 days of immunotherapy, compared with 23% of other patients (P=.06) and more often in patients who received higher equivalent dose in 2-Gy fractions (EQD2) EQD2 (P=.01). However, most toxicities were mild. There were no associations between site irradiated and specific ir-AEs.

CONCLUSIONS

Our data suggest the combination of focal palliative radiation and CTLA-4 and/or PD-1 inhibitors is well tolerated, with manageable ir-AEs that did not seem to be associated with the particular site irradiated. Although conclusions are limited by the heterogeneity of patients and treatments, and future confirmatory studies are needed, this information can help guide clinical practice for patients receiving immune checkpoint therapy who require palliative radiation therapy.

Use of Systemic Therapy Concurrent With Cranial Radiotherapy for Cerebral Metastases of Solid Tumors

The incidence of brain metastases of solid tumors is increasing. Local treatment of brain metastases is generally straightforward: cranial radiotherapy (e.g., whole-brain radiotherapy or stereotactic radiosurgery) or resection when feasible. However, treatment becomes more complex when brain metastases occur while other metastases, outside of the central nervous system, are being controlled with systemic therapy (chemotherapeutics, molecular targeted agents, or monoclonal antibodies). It is known that some anticancer agents can increase the risk for neurotoxicity when used concurrently with radiotherapy. Increased neurotoxicity decreases quality of life, which is undesirable in this predominantly palliative patient group. Therefore, it is of utmost importance to identify the compounds that should be temporarily discontinued when cranial radiotherapy is needed.This review summarizes the (neuro)toxicity data for combining systemic therapy (chemotherapeutics, molecular targeted agents, or monoclonal antibodies) with concurrent radiotherapy of brain metastases. Because only a limited amount of high-level data has been published, a risk assessment of each agent was done, taking into account the characteristics of each compound (e.g., lipophilicity) and the microenvironment of brain metastasis. The available trials suggest that only gemcitabine, erlotinib, and vemurafenib induce significant neurotoxicity when used concurrently with cranial radiotherapy. We conclude that for most systemic therapies, the currently available literature does not show an increase in neurotoxicity when these therapies are used concurrently with cranial radiotherapy. However, further studies are needed to confirm safety because there is no high-level evidence to permit definitive conclusions. The Oncologist 2017;22:222-235Implications for Practice: The treatment of symptomatic brain metastases diagnosed while patients are receiving systemic therapy continues to pose a dilemma to clinicians. Will concurrent treatment with cranial radiotherapy and systemic therapy (chemotherapeutics, molecular targeted agents, and monoclonal antibodies), used to control intra- and extracranial tumor load, increase the risk for neurotoxicity? This review addresses this clinically relevant question and evaluates the toxicity of combining systemic therapies with cranial radiotherapy, based on currently available literature, in order to determine the need to and interval to interrupt systemic treatment.

Stereotactic radiation therapy for oligometastases or oligorecurrence within mediastinal lymph nodes

Aims

This study evaluated the safety and efficacy of stereotactic radiation therapy (SRT) for the treatment of patients with oligometastases or oligorecurrence within mediastinal lymph nodes (MLNs) originating from different tumors.

Methods

Between October 2006 and May 2015, patients with MLN oligometastases or oligorecurrence were enrolled and treated with SRT at our hospital. The primary endpoint was MLN local control (LC). Secondary endpoints were time to symptom alleviation, overall survival (OS) after SRT, and toxicity using the Common Terminology Criteria for Adverse Events (CTCAE v4.0).

Results

Eighty-five patients with 98 MLN oligometastases or oligorecurrences were treated with SRT. For the entire cohort, the 1-year and 5-year actuarial LC rates were 97% and 77%, respectively. Of 53 symptomatic patients, symptom alleviation was observed in 47 (89%) after a median of 5 days (range, 3-30 days). The median OS was 27.2 months for all patients. For patients with non-small cell lung cancer, univariate and multivariate analyses revealed that a shorter interval between diagnosis of primary tumors and SRT and larger MLN SRT volume were associated with worse OS. CTCAE v4.0 ≥ Grade 3 toxicities occurred in six patients (7%), with Grade 5 in three patients (all with RT history to MLN station 7).

Conclusions

SRT is a safe and efficacious treatment modality for patients with oligometastases or oligorecurrence to MLNs originating from different tumors, except for patients who received radiotherapy to MLN station 7. Further investigation is warranted to identify the patients who benefit most from this treatment modality.

Stereotactic body radiotherapy for oligoprogressive cancer

Stereotactic body radiotherapy (SBRT) is a focused tumour treatment that produces high local control rates with low toxicity. Its use in metastatic cancer is evolving rapidly, with purported benefits in the oligometastatic setting and for better palliation of symptomatic disease. Another potential indication for SBRT is in the setting of oligoprogression, where there is progression of a solitary or a few tumours while all other tumours are responding or stable on a systemic therapy strategy. SBRT to the progressing "rogue" tumours may delay the need to start or change systemic therapy. This may have clinical benefits including improved progression-free/overall survival and quality of life for patients. This review will summarize the limited published data. More prospective clinical trials are urgently needed to better identify and quantify the potential clinical benefits.

The use of spine stereotactic radiosurgery for oligometastatic disease

OBJECTIVE

The authors investigated the outcomes following spine stereotactic radiosurgery (SSRS) for patients with oligometastatic disease of the spine.

METHODS

The study was a secondary analysis of 38 of 209 patients enrolled in 2 separate institutional Phase I/II prospective protocols and treated with SSRS between 2002 and 2011. Of these 38 patients, 33 (87%) were treated for a solitary spine metastasis, with no other history of metastatic disease. SSRS was prescribed to 24 Gy in 1 fraction (8%), 18 Gy in 1 fraction (18%), 16 Gy in 1 fraction (11%), 27 Gy in 3 fractions (53%), 30 Gy in 5 fractions (8%), or 20 Gy in 5 fractions (3%). Seventeen patients (45%) received prior conventional external beam radiation therapy.

RESULTS

The median overall survival (OS) was 75.7 months, and the 2- and 5-year OS rates were 84% and 60%, respectively. In multivariate analysis, patients who had prior spine surgery and a better Karnofsky Performance Scale score had an improved OS (HR 0.16, 95% CI 0.05–0.52, p < 0.01, and HR 0.33, 95% CI 0.13%–0.84%, p = 0.02, respectively), and those who had undergone prior radiation therapy had a worse OS (HR 3.6, 95% CI 1.2%–10%, p = 0.02). The 1-, 2-, and 5-year local progression-free survival rates were 85%, 82%, and 78%, respectively. The median time to systemic therapy modification was 41 months. Two patients (5%) experienced late Grade 3–4 toxicity.

CONCLUSIONS

Patients with oligometastatic disease of the spine treated with SSRS can experience long-term survival and a long time before needing a modification in systemic therapy. In addition, SSRS leads to excellent local control and minimal late toxicity.

Integration of Stereotactic Body Radiation Therapy With Tyrosine Kinase Inhibitors in Stage IV Oncogene-Driven Lung Cancer

: Genotype-based selection of patients for targeted therapies has had a substantial impact on the treatment of non-small cell lung cancers (NSCLCs). Tyrosine kinase inhibitors (TKIs) directed at cancers driven by oncogenes, such as epidermal growth factor receptor mutations or anaplastic lymphoma kinase rearrangements, often achieve dramatic responses and result in prolonged survival compared with chemotherapy. However, TKI resistance invariably develops. Disease progression can be limited to only one or a few sites and might not be symptomatic, raising the important question of whether this type of oligoprogression warrants a change in systemic therapy or consideration of local treatment. Recent clinical observations suggest a growing role for stereotactic body radiation therapy (SBRT) in the treatment of oligoprogressive and perhaps even oligopersistent disease (primary and/or metastases) in oncogene-driven NSCLC. SBRT might allow patients to continue with existing TKI treatments longer and delay the need to switch to other systemic options. We review the current data with regard to the use of SBRT for metastatic NSCLC and particularly oncogene-driven disease. Although there is great promise in the marriage of targeted therapies with SBRT, prospective data are urgently needed. In the meantime, such strategies are being used in carefully selected patients, with risk-adapted SBRT dose-fractionation regimens used to optimize the therapeutic index.

IMPLICATIONS FOR PRACTICE

Stereotactic body radiation therapy (SBRT) or SBRT-like treatments are increasingly being used for oligoprogression in patients with oncogene-driven non-small cell lung cancer. This approach allows patients to extend the duration of tyrosine kinase inhibitor therapy and has the potential to prolong survival times. Careful patient selection and risk-adapted radiation dosing is of critical importance to minimize toxicity and preserve patient quality of life.

Rationale of technical requirements for NRG-BR001: The first NCI-sponsored trial of SBRT for the treatment of multiple metastases

INTRODUCTION

In 2014, the NRG Oncology Group initiated the first National Cancer Institute-sponsored, phase 1 clinical trial of stereotactic body radiation therapy (SBRT) for the treatment of multiple metastases in multiple organ sites (BR001; NCT02206334). The primary endpoint is to test the safety of SBRT for the treatment of 2 to 4 multiple lesions in several anatomic sites in a multi-institutional setting. Because of the technical challenges inherent to treating multiple lesions as their spatial separation decreases, we present the technical requirements for NRG-BR001 and the rationale for their selection.

METHODS AND MATERIALS

Patients with controlled primary tumors of breast, non-small cell lung, or prostate are eligible if they have 2 to 4 metastases distributed among 7 extracranial anatomic locations throughout the body. Prescription and organ-at-risk doses were determined by expert consensus. Credentialing requirements include (1) irradiation of the Imaging and Radiation Oncology Core phantom with SBRT, (2) submitting image guided radiation therapy case studies, and (3) planning the benchmark. Guidelines for navigating challenging planning cases including assessing composite dose are discussed.

RESULTS

Dosimetric planning to multiple lesions receiving differing doses (45-50 Gy) and fractionation (3-5) while irradiating the same organs at risk is discussed, particularly for metastases in close proximity (≤5 cm). The benchmark case was selected to demonstrate the planning tradeoffs required to satisfy protocol requirements for 2 nearby lesions. Examples of passing benchmark plans exhibited a large variability in plan conformity.

DISCUSSION

NRG-BR001 was developed using expert consensus on multiple issues from the dose fractionation regimen to the minimum image guided radiation therapy guidelines. Credentialing was tied to the task rather than the anatomic site to reduce its burden. Every effort was made to include a variety of delivery methods to reflect current SBRT technology. Although some simplifications were adopted, the successful completion of this trial will inform future designs of both national and institutional trials and would allow immediate clinical adoption of SBRT trials for oligometastases.

Clinical and molecular markers of long-term survival after oligometastasis-directed stereotactic body radiotherapy (SBRT)

BACKGROUND

The selection of patients for oligometastasis-directed ablative therapy remains a challenge. The authors report on clinical and molecular predictors of survival from a stereotactic body radiotherapy (SBRT) dose-escalation trial for oligometastases.

METHODS

Patients who had from 1 to 5 metastases, a life expectancy of >3 months, and a Karnofsky performance status of >60 received escalating SBRT doses to all known cancer sites. Time to progression, progression-free survival, and overall survival (OS) were calculated at the completion of SBRT, and clinical predictors of OS were modeled. Primary tumor microRNA expression was analyzed to identify molecular predictors of OS.

RESULTS

Sixty-one evaluable patients were enrolled from 2004 to 2009. The median follow-up was 2.3 years for all patients (range, 0.2-9.3 years) and 6.8 years for survivors (range, 2.0-9.3 years). The median, 2-year, and 5-year estimated OS were 2.4 years, 57%, and 32%, respectively. The rate of progression after SBRT was associated with an increased risk of death (hazard ratio [HR], 1.44; 95% confidence interval [CI], 1.24-1.82). The time from initial cancer diagnosis to metastasis (HR, 0.98; 95% CI, 0.98-0.99), the time from metastasis to SBRT (HR, 0.98; 95% CI, 0.98-0.99), and breast cancer histology (HR, 0.12; 95% CI, 0.07-0.37) were significant predictors of OS. In an exploratory analysis, a candidate classifier using expression levels of 3 microRNAs (miR-23b, miR-449a, and miR-449b) predicted survival among 17 patients who had primary tumor microRNA expression data available.

CONCLUSIONS

A subset of oligometastatic patients achieves long-term survival after metastasis-directed SBRT. Clinical features and primary tumor microRNA expression profiling, if validated in an independent dataset, may help select oligometastatic patients most likely to benefit from metastasis-directed therapy. Cancer 2016;122:2242-50. © 2016 American Cancer Society.