Predictive Factors for Response and Survival in a Cohort of Oligometastatic Patients Treated With Stereotactic Body Radiation Therapy

Treatment of oligometastatic breast cancer: The role of patient selection

Up to 90 % of death from solid tumors are caused by metastases. By 2040, breast cancer (BC) is predicted to increase to over 3 million new cases. Additionally, with the personalization and intensification of BC follow-up, many patients will relapse with oligometastatic disease (OMD). Over the past decades, advances in treatment planning, image guidance, target position reproducibility, and online tracking, along with a compelling radiobiological rationale, have led to the implementation of Stereotactic Body Radiation Therapy (SBRT). This has become a valid ablative treatment option for OMD patients. However, there are still concerns about which patients benefit the most from ablative treatment. In this review, we will analyze the literature regarding SBRT for OMD in BC patients. We aim to present the current data on its effectiveness and define the optimal tailored scenarios for SBRT outcomes.

Predictive value of perilesional edema volume in melanoma brain metastasis response to stereotactic radiosurgery

BACKGROUND AND AIM

Stereotactic radiotherapy (SRT) is an established treatment for melanoma brain metastases (MBM). Recent evidence suggests that perilesional edema volume (PEV) might compromise the delivery and efficacy of radiotherapy to treat BM. This study investigated the association between SRT efficacy and PEV extent in MBM.

MATERIALS AND METHODS

This retrospective study reviewed medical records from January 2020 to September 2023. Patients with up to 5 measurable MBMs, intracranial disease per RANO/iRANO criteria, and on low-dose corticosteroids were included. MRI scans assessed baseline neuroimaging, with PEV analyzed using 3D Slicer. SRT plans were based on MRI-CT fusion, delivering 18-32.5 Gy in 1-5 fractions. Outcomes included intracranial objective response rate (iORR) and survival measures (L-iPFS and OS). Statistical analysis involved decision tree analysis and multivariable logistic regression, adjusting for clinical and treatment variables.

RESULTS

Seventy-two patients with 101 MBM were analyzed, with a mean age of 68.83 years. The iORR was 61.4%, with Complete Response (CR) in 21.8% and Partial Response (PR) in 39.6% of the treated lesions. PEV correlated with KPS, BRAF status, and treatment response. Decision tree analysis identified a PEV cutoff at 0.5 cc, with lower PEVs predicting better responses (AUC = 0.82 sensitivity: 86.7%, specificity:74.4%,). Patients with PEV ≥ 0.5 cc had lower response rates (iORR 44.7% vs. 63.8%, p < 0.001). Median OS was 9.4 months, with L-iPFS of 27 months. PEV significantly impacted survival outcomes.

CONCLUSIONS

A more extensive PEV was associated with a less favorable outcome to SRT in MBM.

Time to Next Treatment Following Sub-Ablative Progression Directed Radiation Therapy for Oligoprogressive Non-Small-Cell Lung Cancer

We aimed to evaluate whether progression-directed radiation therapy (PDRT) can prolong the initiation of a subsequent systemic therapy regimen in a cohort of patients with oligoprogressive NSCLC. A retrospective analysis was conducted on NSCLC patients who underwent PDRT for extracranial oligoprogressive NSCLC, defined as limited (up to five) progressing lesions following initial complete, partial, or stable response to systemic therapy according to REC1ST 1.1 and/or PERCIST 1.0 criteria. Cox proportional hazard regressions were performed to identify factors influencing time to next treatment (TTNT), which was considered the primary endpoint. Forty patients were analyzed. First, second, and ≥3 lines of systemic therapy were administered in 22 (58.2%), 14 (27.2%), and 4 (14.6%) cases, respectively. The median total dose was 36 Gy (range: 12-60) in five fractions (1-10), with a median biological effective dose for tumor control (BED10) of 52 Gy (26.4-151.2). After a median follow-up of 11 months (2-50), PDRT delayed further systemic therapy in 32 (80.0%) treatments. Median TTNT was not reached at 8 months (1-47) with a one-year Kaplan-Meier estimate of 81.4% (95% CI: 75.0% to 87.8%). No >grade 3 adverse event was observed. On multivariate analysis, patients with ≥3 lines of systemic therapy and/or with larger CTV volumes did not benefit from PDRT. Despite the use of sub-ablative doses, our findings show that PDRT represents an effective, safe, and viable option for oligoprogressive NSCLC. Patients irradiated early during their systemic treatment course, with a low volume of disease and nonmetastatic oligoprogression, could derive substantial benefits from PDRT.

Challenges in the Understanding of Oligometastatic Disease in Clinical Practice

Introduction: There is little data describing oligometastatic disease (OMD) and decision-making. We sought to understand the knowledge gaps and challenges in deciphering and delivering treatments.

MATERIALS AND METHODS

 This is a quality improvement (QI) study conducted via an anonymous survey. Three different clinical scenarios of OMD (oligo-recurrence disease, synchronous de-novo OMD, and oligo-progressive disease) were presented to assess participants' comprehension. A qualitative approach was used, involving four open-ended questions. Summary statistics and descriptive analysis were utilized to describe survey answers.

RESULTS

 The survey was answered by 70 clinicians, 56% (n=39) medical oncologists, 24% (n=17) radiation oncologists, 7% (n=5) surgeons, and the remaining 13% (n=9) from anatomical pathology, radiology, and palliative care. The three clinical cases were correctly identified as oligo-recurrence, de-novo, and oligo-progression disease in 63% (n=44), 94% (n=66), and 76% (n=53) of responses, respectively. Additionally, for each case, the majority of respondents indicated that they would offer local treatment (n=59, 84%; n=57, 81%; n=55, 79%, respectively). Seventy-nine percent (n=49) perceived differences between each modality of local therapies. Physicians perceived challenges including the lack of prospective trial data and unclear approach to OMD. An important determinant in deciding whether patients may benefit from treatment was tumor histology.

CONCLUSION

 The term OMD involves certain difficulties in definition and management. Positive and negative trials have further added uncertainty regarding who would best benefit from local treatment. The discordance in outcome expectations from physicians and patients will need to be addressed to ensure that patient's goals of care are met.

Efficacy of stereotactic body radiotherapy and response prediction using artificial intelligence in oligometastatic gynaecologic cancer

PURPOSE

We present a large real-world multicentric dataset of ovarian, uterine and cervical oligometastatic lesions treated with SBRT exploring efficacy and clinical outcomes. In addition, an exploratory machine learning analysis was performed.

METHODS

A pooled analysis of gynecological oligometastases in terms of efficacy and clinical outcomes as well an exploratory machine learning model to predict the CR to SBRT were carried out. The CR rate following radiotherapy (RT) was the study main endpoint. The secondary endpoints included the 2-year actuarial LC, DMFS, PFS, and OS.

RESULTS

501 patients from 21 radiation oncology institutions with 846 gynecological metastases were analyzed, mainly ovarian (53.1%) and uterine metastases(32.1%).Multiple fraction radiotherapy was used in 762 metastases(90.1%).The most frequent schedule was 24 Gy in 3 fractions(13.4%). CR was observed in 538(63.7%) lesions. The Machine learning analysis showed a poor ability to find covariates strong enough to predict CR in the whole series. Analyzing them separately, in uterine cancer, if RT dose≥78.3Gy, the CR probability was 75.4%; if volume was <13.7 cc, the CR probability became 85.1%. In ovarian cancer, if the lesion was a lymph node, the CR probability was 71.4%; if volume was <17 cc, the CR probability rose to 78.4%. No covariate predicted the CR for cervical lesions. The overall 2-year actuarial LC was 79.2%, however it was 91.5% for CR and 52.5% for not CR lesions(p < 0.001). The overall 2-year DMFS, PFS and OS rate were 27.3%, 24.8% and 71.0%, with significant differences between CR and not CR.

CONCLUSIONS

CR was substantially associated to patient outcomes in our series of gynecological cancer oligometastatic lesions. The ability to predict a CR through artificial intelligence could also drive treatment choices in the context of personalized oncology.

Prediction of SBRT response in liver cancer by combining original and delta cone-beam CT radiomics: a pilot study

This study aims to explore the feasibility of utilizing a combination of original and delta cone-beam CT (CBCT) radiomics for predicting treatment response in liver tumors undergoing stereotactic body radiation therapy (SBRT). A total of 49 patients are included in this study, with 36 receiving 5-fraction SBRT, 3 receiving 4-fraction SBRT, and 10 receiving 3-fraction SBRT. The CBCT and planning CT images from liver cancer patients who underwent SBRT are collected to extract overall 547 radiomics features. The CBCT features which are reproducible and interchangeable with pCT are selected for modeling analysis. The delta features between fractions are calculated to depict tumor change. The patients with 4-fraction SBRT are only used for screening robust features. In patients receiving 5-fraction SBRT, the predictive ability of both original and delta CBCT features for two-level treatment response (local efficacy vs. local non-efficacy; complete response (CR) vs. partial response (PR)) is assessed by utilizing multivariable logistic regression with leave-one-out cross-validation. Additionally, univariate analysis is conducted to validate the capability of CBCT features in identifying local efficacy in patients receiving 3-fraction SBRT. In patients receiving 5-fraction SBRT, the combined models incorporating original and delta CBCT radiomics features demonstrate higher area under the curve (AUC) values compared to models using either original or delta features alone for both classification tasks. The AUC values for predicting local efficacy vs. local non-efficacy are 0.58 for original features, 0.82 for delta features, and 0.90 for combined features. For distinguishing PR from CR, the respective AUC values for original, delta and combined features are 0.79, 0.80, and 0.89. In patients receiving 3-fraction SBRT, eight valuable CBCT radiomics features are identified for predicting local efficacy. The combination of original and delta radiomics derived from fractionated CBCT images in liver cancer patients undergoing SBRT shows promise in providing comprehensive information for predicting treatment response.

Machine-learning prediction of treatment response to stereotactic body radiation therapy in oligometastatic gynecological cancer: A multi-institutional study

BACKGROUND AND PURPOSE

We aimed to develop and validate different machine-learning (ML) prediction models for the complete response of oligometastatic gynecological cancer after SBRT.

MATERIAL AND METHODS

One hundred fifty-seven patients with 272 lesions from 14 different institutions and treated with SBRT with radical intent were included. Thirteen datasets including 222 lesions were combined for model training and internal validation purposes, with an 80:20 ratio. The external testing dataset was selected as the fourteenth Institution with 50 lesions. Lesions that achieved complete response (CR) were defined as responders. Prognostic clinical and dosimetric variables were selected using the LASSO algorithm. Six supervised ML models, including logistic regression (LR), classification and regression tree analysis (CART) and support vector machine (SVM) using four different kernels, were trained and tested to predict the complete response of uterine lesions after SBRT. The performance of models was assessed by receiver operating characteristic curves (ROC), area under the curve (AUC) and calibration curves. An explainable approach based on SHapley Additive exPlanations (SHAP) method was deployed to generate individual explanations of the model's decisions.

RESULTS

63.6% of lesions had a complete response and were used as ground truth for the supervised models. LASSO strongly associated complete response with three variables, namely the lesion volume (PTV), the type of lesions (lymph-nodal versus parenchymal), and the biological effective dose (BED10), that were used as input for ML modeling. In the training set, the AUCs for complete response were 0.751 (95% CI: 0.716-0.786), 0.766 (95% CI: 0.729-0.802) and 0.800 (95% CI: 0.742-0.857) for the LR, CART and SVM with a radial basis function kernel, respectively. These models achieve AUC values of 0.727 (95% CI: 0.669-0.795), 0.734 (95% CI: 0.649-0.815) and 0.771 (95% CI: 0.717-0.824) in the external testing set, demonstrating excellent generalizability.

CONCLUSION

ML models enable a reliable prediction of the treatment response of oligometastatic lesions receiving SBRT. This approach may assist radiation oncologists to tailor more individualized treatment plans for oligometastatic patients.

Radiotherapy in the management of lung oligometastases

In recent years, the development of both medical imaging and new systemic agents (targeted therapy and immunotherapy) have revolutionized the field of oncology, leading to a new entity: oligometastatic disease. Adding local treatment of oligometastases to systemic treatment could lead to prolonged survival with no significant impact on quality of life. Given the high prevalence of lung oligometastases and the new systemic agents coming with increased pulmonary toxicity, this article provides a comprehensive review of the current state-of-art for radiotherapy of lung oligometastases. After reviewing pretreatment workup, the authors define several radiotherapy regimen based on the localization and size of the oligometastases. A comment on the synergistic combination of medical treatment and radiotherapy is also made, projecting on future steps in this specific clinical setting.

Local Control Following Stereotactic Body Radiation Therapy for Liver Oligometastases: Lessons from a Quarter Century

The utilization of stereotactic body radiation therapy for the treatment of liver metastasis has been widely studied and has demonstrated favorable local control outcomes. However, several predictive factors play a crucial role in the efficacy of stereotactic body radiation therapy, such as the number and size (volume) of metastatic liver lesions, the primary tumor site (histology), molecular biomarkers (e.g., KRAS and TP53 mutation), the use of systemic therapy prior to SBRT, the radiation dose, and the use of advanced technology and organ motion management during SBRT. These prognostic factors need to be considered when clinical trials are designed to evaluate the efficacy of SBRT for liver metastases.

Advances and Challenges in Trials of Local Therapy for Patients With Oligometastatic or Oligoprogressive Disease

The paradigm of oligometastatic disease (OMD), characterized by a limited number of metastases potentially amenable to local therapies, presents unique opportunities and challenges in clinical trial design and implementation. Although local ablative therapies, such as stereotactic body radiation therapy, have shown promise in improving outcomes for patients with OMD, there is a lack of large-scale randomized phase III trials supporting their widespread use. This paper outlines the key challenges in trial design and implementation in the oligometastatic setting, including appropriate patient selection, the definition of the oligometastatic state, trial design considerations, endpoint selection, and logistical considerations related to enrollment and follow-up. We suggest potential strategies to address these challenges, emphasizing the importance of a comprehensive, patient-centric approach, and the integration of multidisciplinary teams in trial design and implementation. The aim is to encourage the design of well-structured clinical trials, ultimately refining best practices and enhancing patient outcomes in the management of OMD.

The pattern of failure after Stereotactic Radiation Therapy (SRT) for oligo-metastases: predictive factors for poly-progression

PURPOSE

Patients with oligo-metastatic disease (OMD) can be safely treated with Stereotactic Radiation Therapy (SRT). Further disease progression is common in these patients. In most cases, patients relapse again with oligo-metastases, however some can experience a poly-progression after a local ablative treatment (LAT). The purpose of this study was to retrospectively identify factors associated with poly-progression in patients receiving SRT for OMD.

METHODS

Data from a monocentric database were retrospectively analyzed. Patients treated with SRT for OMD and who developed progression after LAT were selected. Patients were categorized as oligo- or poly-progressive according to the number of new/progressing metastases (≤ or > 5). Herein, we analyzed data about patients' characteristics, oligo-metastatic presentation and radiation treatment characteristics to evaluate their relationship with progression type.

RESULTS

From 2013 to 2021, data on 700 patients progressing after LAT were analyzed. Among them, 227 patients (32.4%) experienced a poly-progression; the median time to poly-progression was 7.72 months (range 1-79.6). Five variables associated with poly-progression were found to be statistically significant in the univariate analysis: performance status (p < 0.001), site of the primary tumor (p = 0.016), ablative dose (p = 0.002), treated site (p = 0.002), single or double organ (p = 0.03). Of those, all but the number of involved organs retained their significant predictive value on the multivariate analysis.

CONCLUSION

Our study identified four independent factors associated with poly-progression in patients with OMD receiving SRT. Our data may support comprehensive characterization of OMD, better understanding of factors associated with progression.

[Results of a nationwide survey on the treatment of salivary gland diseases in German hospitals]

BACKGROUND

Salivary gland diseases are an important part of the work of ENT physicians in hospitals. The treatment strategies depend, among other things, on the doctrine at the respective location.

OBJECTIVE

The aim of this questionnaire-based study was to assess the current diagnostic workup and therapeutic strategies for salivary gland diseases in German otorhinolaryngology departments.

MATERIALS AND METHODS

A survey was performed using a 25-question online questionnaire sent to all German otorhinolaryngology department directors.

RESULTS

The questionnaire was answered by 92 of 175 otorhinolaryngology departments (52.6%). In the diagnosis of salivary gland tumors, a dominance of sonography and MRI was shown. Fine- and core-needle aspiration were not performed by more than 50% of the clinics. The dominant technique for parotidectomy was under microscopic control (82%). In 99% of clinics, EMG was used during resection of the parotid gland for intraoperative monitoring of the facial nerve. There was a trend towards performing partial parotidectomies (85%), lateral parotidectomies (70%), and extracapsular dissections (57%) for benign tumors of the parotid gland. The treatment concepts for malignant tumors were inconsistent.

CONCLUSION

In particular, the treatment strategy and extent of surgery for benign and malignant salivary gland tumors differed depending on location. The choice of palliative (drug) therapy was also diverse. Prospective multicenter studies could help to develop evidence-based treatment strategies.

Stereotactic body radiation therapy in the treatment of cancer patients with oligometastatic disease: a real world study

PURPOSE

Stereotactic body radiation therapy (SBRT) is a treatment modality with curative intent for oligometastatic cancer patients, commonly defined by a low-burden metastatic disease with 1-5 systemic metastases. Better knowledge of the clinical profile and prognostic factors in oligometastatic cancer patients could help to improve the selection of candidates who may obtain most benefits from SBRT. The objective of this study was to describe the clinical data and outcome in term of overall survival (OS) of patients with oligometastatic disease treated with SBRT over a 6-year period.

METHODS

From 2013 to 2018, 284 solid tumor cancer patients with 1-5 oligometastases underwent SBRT at a large university-affiliated oncological center in Barcelona, Spain. Variables related to the patient profile, tumor, oligometastatic disease, and treatment were evaluated.

RESULTS

A total of 327 metastatic tumors were treated with SBRT. In 65.5% of cases, metachronous tumors were diagnosed at least 1 year after diagnosis of the primary tumor. The median age of the patients was 73.9 years and 66.5% were males. The median follow-up was 37.5 months. The most common primary tumors were lung and colorectal cancer, with lung and bone as the most commonly treated metastatic sites. Ninety-three percent of patients showed a Karnofsky score (KPS) between 80 and 100. Adenocarcinoma was the most common histological type. The median overall survival was 53.4 months, with 1-, 2- and 5-year survival rates of 90.5%, 73.9% and 43.4%, respectively. Overall survival rates of breast (67.6 months, 95% CI 56.4-78.9), urological (63.3 months, 95% CI 55.8-70.8), and colorectal (50.8 months, 95% CI 44.2-57.4) tumors were higher as compared with other malignancies (20 months, 95% CI 11.2-28.8 months) (p < 0.001). Patients with Karnofsky score (KPS) of 90 and 100 showed a significantly better survival than those with impaired performance status (p = 0.001).

CONCLUSION

SBRT appears to be well tolerated and safe approach in oligometastatic patients. Patients with good performance status and with primary breast, urological and colorectal cancer have higher OS compared with other malignancies. More studies are necessary to evaluate the prognostic factors in oligometastatic disease (OMD) in order to select patients who could benefit more from this therapeutic approach.

The oligometastatic paradigm and the role of radiotherapy

Most cancer-related deaths are due to metastatic disease. There is now an emerging evidence base suggesting that a subgroup of metastatic patients benefit significantly from local resection (surgery) or ablation (stereotactic ablative body radiation, SABR) of their metastatic sites. These patients are in what has been termed the 'oligometastatic state', a transitional window between local and disseminated disease where locally ablative, metastasis-directed therapy prolongs progression-free survival, improves overall survival and sometimes achieves cure. Appropriately selecting those who fit this oligometastatic phenotype, while integrating advances in ablative technologies such as SABR with modern systemic treatments, is an evolving challenge for oncologists.

A critical review on oligometastatic disease: a radiation oncologist's perspective

Since the first definition by Hellman and Weichselbaum in 1995, the concept of OligoMetastatic Disease (OMD) is a growing oncology field. It was hypothesized that OMD is a clinical temporal window between localized primary tumor and widespread metastases deserving of potentially curative treatment. In real-world clinical practice, OMD is a "spectrum of disease" that includes a highly heterogeneous population of patients with different prognosis. Metastasis directed therapy with local ablative treatment have proved to be a valid alternative to surgical approach. Stereotactic body radiation therapy demonstrated high local control rate and increased survival outcomes in this setting with a low rate of toxicity. However, there is a lack of consensus regarding many clinical, therapeutic, and prognostic aspects of this disease entity. In this review, we try to summarize the major critical features that could drive radiation oncologists toward a better selection of patients, treatments, and study endpoints. With the help of a set of practical questions, we aim to integrate the literature discussion.

[Radiation therapy of malignant salivary gland tumors]

Due to their rarity, histologic heterogeneity, and localization, treatment of malignant salivary gland tumors requires an interdisciplinary approach. First-line treatment includes complete tumor resection. Postoperative radiation therapy is advised in patients with risk factors, i.e., incomplete tumor resection, high-grade tumors, or perineural invasion. Definitive radiation therapy is only advised for inoperable tumors because of significantly lower local control and survival rates when compared to combined surgery and radiation therapy. In radiation oncology, modern techniques such as intensity-modulated radiation therapy (IMRT) or particle therapy with heavy ions (i.e., C12) have led to improved outcomes in the treatment of head and neck tumors, especially of adenoid cystic carcinomas. Given the biological and physical benefits of particles, particle therapy, particularly carbon ion radiation, is a promising therapeutic approach for salivary gland tumors that will be further investigated in prospective clinical studies.

Stereotactic ablative radiotherapy for pulmonary oligometastases from primary hepatocellular carcinoma: a multicenter and retrospective analysis (KROG 17-08)

OBJECTIVE

Hypofractionated radiotherapy has recently been applied to treat pulmonary metastases of hepatocellular carcinoma. However, there is no definite evidence on its safety and efficacy. We evaluate the clinical outcomes of hypofractionated radiotherapy for oligo pulmonary metastases of hepatocellular carcinoma in the multicenter and retrospective study.

METHODS

From March 2011 to February 2018, 58 patients with fewer than five pulmonary metastases of hepatocellular carcinoma who underwent hypofractionated radiotherapy in nine tertiary university hospitals were analyzed retrospectively. The primary endpoint was the local control rate. The secondary endpoints were overall survival, progression-free survival, prognostic factors affecting the treatment outcomes and treatment-related side effects.

RESULTS

The local tumor response rate including complete and partial response was 77.6% at 3 months after hypofractionated radiotherapy. The median survival and progression-free survival times were 20.9 and 5.3 months, respectively. The 1-year overall survival and progression-free survival rates were 65.5 and 22.4%, respectively. The good treatment response after hypofractionated radiotherapy (P = 0.001), the absence of intrahepatic tumor (P = 0.004) and Child-Pugh class A (P = 0.010) were revealed as significant prognostic factors for overall survival in the multivariate analysis. A progression-free interval of <6 months (P = 0.009) was a negative prognostic factor for overall survival in the multivariate analysis. Of 58 patients, five (8.6%) had grade 2 or higher radiation pneumonitis after hypofractionated radiotherapy.

CONCLUSIONS

The favorable local control rate and acceptable toxicity indicate the clinical usefulness of hypofractionated radiotherapy for hepatocellular carcinoma patients who have less than five pulmonary metastases.

Oligoscore: a clinical score to predict overall survival in patients with oligometastatic disease treated with stereotactic body radiotherapy

BACKGROUND

to find clinical features that can predict prognosis in patients with oligometastatic disease treated with stereotactic body radiotherapy (SBRT).

MATERIAL AND METHODS

Patients with less than 5 metastases in less than 3 different body sites were included in the analysis. Various clinical and treatment parameters were analyzed to create a Cox proportional hazard model for Overall Survival (OS). Subsequently, significant variables were used to create a score.

RESULTS

997 patients were analyzed. Median OS was 2.61 years, 1 and 3 years OS was respectively 85% and 43%. Location of the primary tumor, performance status, site of irradiated metastases, presence of extratarget non irradiated lesions and RT dose were significant prognostic factors for OS. These parameters were used to create a score and to distinguish three different classes, with median OS of 5.67 years in low risk, 2.47 years in intermediate risk and 1.82 years in high risk group.

CONCLUSION

moving from easily accessible clinical parameters, a score was created to help the physician's decision about the better treatment or combination of treatments for the individual patient.

Long-term survival following definitive radiation therapy for recurrence or oligometastases in gynecological malignancies: A landmark analysis

OBJECTIVE

Radiation therapy (RT) may improve outcomes for patients with oligometastatic cancer. We sought to determine if there are long-term survivors treated with definitive RT for recurrent or oligometastatic gynecological cancer (ROMGC), and to evaluate the clinical and disease characteristics of these patients.

METHODS

We performed a landmark analysis in 48 patients with ROMGC who survived for ≥5 years following definitive RT of their metastasis. Patient characteristics were extracted from the medical record. DFS was modeled using the Kaplan-Meier method.

RESULTS

This cohort included 20 patients (42%) with ovarian cancer, 16 (33%) with endometrial cancer, 11 (23%) with cervical cancer, and one (2%) with vaginal cancer. The sites of ROMGC were the pelvic (46%), para-aortic (44%), supraclavicular (7%), mediastinal (4%), axillary (4%) lymph nodes and the lung (5.5%). Median total RT dose and fractionation were 62.1 Gy and 2.1 Gy/fraction; one patient was treated with SBRT. 32 patients (67%) received chemoradiation; these patients had higher rates of median DFS than those treated with RT alone (93 vs. 34 months, P = 0.05). At median follow-up of 11.7 years, 11 (23%) patients had progression of disease. 20 (42%) patients had died, 9 (19%) died from non-gynecologic cancer and 8 (17%) from gynecologic cancer (three were unknown). 25 (52%) patients were alive and disease-free (10 initially had endometrial cancer [63% of these patients], eight had cervical cancer [73%], six had ovarian cancer [30%], one had vaginal cancer [100%]).

CONCLUSIONS

Long-term survival is possible for patients treated with definitive RT for ROMG, however randomized data are needed to identify which patients derive the most benefit.

Knowing When to Use Stereotactic Ablative Radiation Therapy in Oligometastatic Cancer

Oligometastatic patients are a heterogeneous and yet not well-defined population. The actual definition identifies as oligometastatic, patients with 1-5 metastases in 1-3 different organs. However, only a proportion of these patients are "true" oligometastatic and therefore derive some kinds of benefit from local ablative approaches like stereotactic ablative radiation therapy (SABR). Since SABR is an easily accessible, effective and well-tolerated treatment, it is widely employed in the oligometastatic scenarios, without a particular focus on selection criteria. However, it should be crucial to identify predictive and prognostic features that could be clinically implemented. Therefore, we conducted this narrative review of the available literature to summarize all clinical, radiomic, genetic and epigenetic features found to be predictive of overall survival, progression-free survival or local control of oligometastatic patients treated with SABR.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Metastatic salivary gland carcinoma: A role for stereotactic body radiation therapy? A study of AIRO-Head and Neck working group

OBJECTIVES

The role of radiotherapy (RT) for oligometastases is currently established in different oncological settings but data on salivary gland cancer (SGC) are lacking. We evaluated the role of RT in oligometastatic SGC patients, focusing on stereotactic body radiation therapy (SBRT).

MATERIALS AND METHODS

We performed a retrospective, multicentric study of oligometastatic SGC treated with palliative RT or SBRT. Endpoints included response evaluation and local control (LC).

RESULTS

Between 2006 and 2016, 64 patients were collected from 9 Italian Cancer Centers, on behalf of the Italian Association of Radiotherapy and Clinical Oncology (AIRO) Head and Neck Working Group. 37 patients (57.8%) were suffering from adenoid cystic carcinoma (ACC) and 27 patients (42.2%) had non-ACC. Thirty-four patients underwent palliative RT (53,1%), and 30 received SBRT (46,9%). Most common metastatic sites were bone for palliative RT and lung for SBRT. Among patients treated with SBRT, an objective response or a stability was observed in all treated lesions. After a median follow-up of 29.2 months (range 2.3-117.1), LC at 12 months was 57.5% for patients treated with SBRT and was higher in ACC subgroup.

CONCLUSION

We confirmed the potential role of SBRT in the management of oligometastatic SGC patients to control limited burden of disease considering the absence of effective systemic therapies.

Stereotactic body radiation therapy for oligometastatic gynecologic malignancies: A systematic review

OBJECTIVE

To assess the efficacy and safety of stereotactic body radiation therapy (SBRT) for oligometastatic gynecologic malignancies.

METHOD

A comprehensive search of the PubMed, Medline, and EMBASE databases was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. "Oligometastatic" was defined as a limited number of uncontrolled/untreated metastatic lesions (typically ≤ 5), including regional nodal metastases. Primary outcomes were response rate (complete response or partial response), local control of oligometastatic lesions, and toxicity.

RESULTS

Of 716 screened records, 17 studies (13 full length articles, 4 conference abstracts) were selected and analyzed as 16 unique studies. A total of 667 patients were treated with ~1071 metastatic lesions identified. Primary sites included ovarian (57.6%), cervical (27.1%), uterine (11.1%), vaginal (0.4%), vulvar (0.3%), and other/unspecified (3.4%). Most patients (65.4%) presented with a single metastatic lesion. Metastatic lesion sites included the abdomen (44.2%), pelvis (18.8%), thorax (15.5%), neck (4.6%), central nervous system (4.3%), bone (1.6%), and other/unspecified (11%). Of the lesions, 64% were nodal. Response rate (among 8 studies) ranged from 49% to 97%, with 7/8 studies reporting > 75% response rate. Local control ranged from 71% to 100%, with 14/16 studies reporting ≥ 80% local control. No grade ≥ 3 toxicities were observed in 9/16 (56%) studies. Median progression-free survival (PFS) (among 10 studies) ranged from 3.3 months to 21.7 months. Disease progression most commonly occurred outside of the SBRT radiation field (79% to 100% of failures).

CONCLUSIONS

SBRT for oligometastatic gynecologic malignancies is associated with favorable response and local control rates but a high rate of out-of-field progression and heterogeneous PFS. Additional study into rational combinations of SBRT and systemic therapy appears warranted to further improve patient outcomes.

Phase II trial of high dose stereotactic body radiation therapy for lymph node oligometastases

Lymph nodes are common sites of oligometastases for several primaries. Stereotactic body radiation therapy (SBRT) represents an effective treatment but no consensus exists regarding dose and fractionation. Aim of this trial was to evaluate safety and efficacy of high-dose SBRT. We included patients with 1 to 3 lymph node metastases. Primary end-point was safety, while secondary end-points were in-field local control (LC), out-field lymph nodal progression free survival (LPFS), distant metastasis free survival (DMFS), progression free survival (PFS) and overall survival (OS). 64 lesions in 52 patients were treated from 2015 to 2019. Most common primary tumor was genitourinary cancer (75%), in particular prostate cancer (65.4%). With a median follow-up of 24.4 months (range 3-49), treatment was very well tolerated, with only 4 (7.7%) patients reporting acute side effects, all classified as grade 1, in the form of pain, fatigue, nocturia and dysuria. No toxicity ≥ grade 2 were reported. Rates of LC at 1, 2 and 3 years were 97.9%, 82.1% and 82.1%. Male sex (HR 0.12, p value 0.014) was associated with improved LC. LPFS at 1, 2 and 3 years were 69.6%, 49.6% and 46.1%, respectively, and DMFS was 81.74%, 67.5% and 58.5%, respectively. Presence of lesions in other organs was correlated with inferior DMFS (HR 3.82, p = 0.042). PFS at 1, 2 and 3 years were 67.4%, 42.4% and 31.86%, respectively. OS at 1, 2 and 3 years were 97.3%, 94.2%, 84%, respectively and significantly correlated with in-field recurrence (HR 8.72, p = 0.000). Our prospective trial confirms safety and efficacy of SBRT in the management of lymph node metastases. Registered Clinical trial NCT02570399.

Pulmonary oligometastases treated by stereotactic body radiation therapy (SBRT): a single institution's experience

Background

To investigate the effect of stereotactic body radiation therapy (SBRT) on pulmonary oligometastases and to analyze the clinical factors and dose parameters affecting local recurrence-free survival (LRFS) and overall survival (OS).

Methods

This study retrospectively enrolled a total of 84 patients (148 lesions) treated in our department from May 2015 to November 2018. Pulmonary oligometastases was defined as up to 5 metastatic lesions in the lung and with both the primary tumor and any extra-thoracic metastases being controlled. Patients receiving a BED₁₀ (biological effective dose, α/β =10) of SBRT ≥75 Gy and a dose/fraction ≥4 Gy were enrolled. The patient group consisted of 52 men (61.9%) and 32 women (38.1%), with a median age 56 years (range, 29-80 years). Median tumor diameter was 1.71cm (range, 1.2-5.0 cm). The BED₁₀ was 75-119 Gy in 4-15 fractions. Univariate and multivariate Cox regression analyses were performed on factors predicting the outcomes.

Results

All patients completed the treatment as planned, and the median follow-up time was 20.3 months. The median OS for the entire group was 34.3 months, with an actuarial 1-, 2-, 3- and 5-year OS of 74.7%, 59.4%, 49.7%, and 36.8%, respectively. Among the 148 lesions in the whole group, 19 (12.8%) lesions had local recurrence (LR). The median LRFS time for all patients was 56.9 months. The LRFS rate was 93.6%, 83.5%, 81.4%, and 76.6% at 1, 2, 3, and 5 years, respectively. No patient developed acute grade 3 or 4 toxicity. On univariate analysis, age ≥63 years old, primary site of colorectal cancer, BED₁₀ <85.2 Gy, pathological type of adenocarcinoma, planning target volume (PTV) min BED₁₀ <76.6 Gy, and gross tumor volume (GTV) ≥8.8 cc, were significantly associated with poorer LRFS. Multivariate analysis showed that age ≥63 years old, primary site of colorectal cancer, and PTV min BED₁₀ <76.6 Gy were significant risk factors affecting LRFS.

Conclusions

SBRT is feasible for pulmonary oligometastasis with favorable local control and minimal toxicity. Multiple dose parameters, instead of a prescription dose only, in combination with clinical parameters, should be considered for optimal local control.

Stereobody radiotherapy for nodal recurrences in oligometastatic patients: a pooled analysis from two phase I clinical trials

Stereotactic body radiotherapy (SBRT) has been shown to achieve high local control rates in limited metastatic burden of disease. Few papers reported on the efficacy of SBRT in nodal oligometastases. The primary aim of the present paper was to analyze the treatment outcome in this setting. Data from DESTROY-1 and SRS-DESTROY-2 phase I clinical trials were reviewed and analyzed. These trials were based on a 5 fractions and a single fraction regimens, respectively. End-points of this analysis were toxicity rates, overall response rate (ORR), and local control (LC). Patients treated between December 2003 and January 2018, with any metastatic site, and primary tumor type and histology were included. One hundred-eighty-one patients (M/F: 93/88; median age: 67, range 37-88) treated with SBRT on 253 nodal lesions were analyzed. Initially, the used technique was 3D-CRT (20.9%), while subsequently treatments were delivered by VMAT (79.1%). The total dose to the PTV ranged between 12 Gy/single fraction to 50 Gy/5 fractions. With a median follow-up of 21 months (2-124), no grade 3 acute or late toxicity was recorded. ORR based on functional imaging was 92.5% with a complete response rate of 76%. Two- and three-year actuarial LC were 81.6% and 76.0%, respectively. Our large pooled analysis confirms the efficacy and safety of SBRT/SRS in patients with nodal metastases and identifies clinical and treatment variables able to predict complete response and local control rate.

Stereotactic Radiotherapy for Ultra-Central Lung Oligometastases in Non-Small-Cell Lung Cancer

Background: Stereotactic body radiotherapy (SBRT) in ultra-central (UC) lung tumors, defined in the presence of planning target volume (PTV) overlap or direct tumor abutment to the central bronchial tree or esophagus, may be correlated to a higher incidence of severe adverse events. Outcome and toxicity in oligometastatic (≤3 metastases) non-small-cell lung cancer (NSCLC) patients receiving SBRT for UC tumors were evaluated. Methods: Oligometastatic NSCLC patients treated with SBRT for UC were retrospectively reviewed. Local control (LC), distant metastasis-free survival (DMFS), progression-free survival (PFS) and overall survival (OS) were calculated. Incidence and grade of toxicity were evaluated. Statistical analysis was performed to assess the impact of clinical and treatment-related variables on outcome and toxicity occurrence. Results: Seventy-two patients were treated to a median biologically effective dose (BED) of 105 (75–132) Gy¹⁰. Two-year LC, DMFS, PFS, and OS were 83%, 46%, 43%, and 49%. BED>75 Gy¹⁰ was correlated to superior LC (p = 0.02), PFS (p = 0.036), and OS (p < 0.001). Grade ≥3 toxicity rate was 7%, including one fatal esophagitis. No variables were correlated to DMFS or to occurrence of overall and grade ≥3 toxicity. Conclusions: SBRT using dose-intensive schedules improves outcome in NSCLC patients. Overall toxicity is acceptable, although rare but potentially fatal toxicities may occur.

Stereotactic Body Radiation Therapy for Extracranial Oligometastatic Non-small-cell Lung Cancer: A Systematic Review

Stereotactic body radiation therapy (SBRT) has emerged as a treatment modality for selected patients with oligometastatic non-small-cell lung cancer (NSCLC). The objectives of this systematic review were to explore the benefits and risks of SBRT for extracranial oligometastatic NSCLC. The MEDLINE, Embase, PubMed, and CENTRAL databases were searched for relevant articles from January 1, 2000 to July 23, 2019. Fully published phase III or phase II trials of any sample size were included. Retrospective series published in manuscript form with at least 50 patients were also included. Four prospective phase II randomized trials (total, 188 participants), 4 prospective non-randomized studies (total, 140 participants), and eleven retrospective studies (total, 1288 participants) were included in this systematic review. A variety of dose fractionation schemes were used. The median overall survival (OS) ranged from 13.5 to 55 months. Progression-free survival (PFS) ranged from 4.4 to 14.7 months. Quality of life outcomes were reported in 2 studies. None of the studies reported symptom control outcomes. There are no fully completed phase III randomized trials that clarify the risks and benefits of SBRT for oligometastatic NSCLC. Higher PFS and OS with SBRT were reported in 4 phase II randomized studies. The results from mature phase III randomized data regarding whether SBRT for oligometastatic NSCLC benefits patients in terms of OS, PFS, quality of life, and symptom control are needed.

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

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

[Radiotherapy of oligometastases: Sequences and interactions with systemic therapies, example of kidney cancer]

This article is a review of the literature that aims to clarify the place of systemic and locoregional treatments, with a focus on radiotherapy and surgery in the management of patients with oligometastatic kidney cancer. We have selected articles of interest published in Medline indexed journals. We have also analysed the related guidelines: National Comprehensive Cancer Network (NCCN) 2019, European Association of Urology (EAU) 2019, European Society of Medical Oncology (ESMO) 2019, Association française d'urologie (Afu) 2018 as well as some abstracts of international congresses. The main treatments evaluated were surgery and radiotherapy. We defined the different scenarios conventionally encountered in clinical practice. The evolution of systemic therapies (increased overall survival and response rate) is likely to increase the number of patients potentially accessible to locoregional treatments. The complete analysis of the literature underlines the place of locoregional treatments whatever the scenarios mentioned. Data on stereotactic radiotherapy found a local control rate consistently above 70% in all studies with a maintained response and positive impact on overall survival and progression-free survival. The improvement of overall survival by sequential use of the various therapeutic classes confirms the need for optimization of locoregional treatments in the model of oligometastatic kidney cancer. The dogma of radioresistance must definitely be set aside with current irradiation techniques.