Stereotactic Radiotherapy for Oligometastasis

Integrating cine EPID, dynamic delivery, and the off-axis Winston-Lutz test to enhance quality control in multiple brain metastasis stereotactic radiotherapy

PURPOSE

Stereotactic radiotherapy (SRT) has transformed cancer treatment, especially for brain metastases. Ensuring accurate SRT delivery is crucial, with the Winston-Lutz test being an important quality control tool. Off-axis Winston-Lutz (OAWL) tests are designed for accuracy assessment, but most are limited to fixed angles and hampered by local-field shifts caused by suboptimal Multi-Leaf Collimator (MLC) positioning. This study introduces a new OAWL approach for quality control in multi-brain-metastasis SRT. Utilizing cine Electronic Portal Imaging Device (EPID) images, it can be used with dynamic conformal arc (DCA) therapy. However, dynamic OAWL (DOAWL) is prone to more local-field shifts due to dynamic MLC movements. A two-step DOAWL is proposed: step 1 calculates local-field shifts using dynamic MLC movements in the beam-eye view data from the Treatment Planning System (TPS), while step 2 processes cine EPID images with an OAWL algorithm to isolate true deviations.

METHODS

Validation involved an anthropomorphic head phantom with metallic ball-bearings, Varian TrueBeam STx accelerator delivering six coplanar/non-coplanar DCA beams, cine EPID, and ImageJ's OAWL analysis algorithm.

RESULTS

Inherent local-field shifts ranged from 0.11 to 0.49 mm; corrected mean/max EPID-measured displacement was 0.34/1.03 mm. Few points exceeded 0.75/1.0-mm thresholds.

CONCLUSIONS

This two-step DOAWL test merges cine-EPID acquisitions, DCA, OAWL, and advanced analysis and offers effective quality control for multi-brain-metastasis SRT. Its routine implementation may also improve physicist knowledge of the treatment precision of their machines.

Recent progress in radioactive seed implantation brachytherapy of non-small cell lung cancer: a narrative review

Background and Objective

Brachytherapy, a new form of radiation therapy, has been used to treat lung cancer and consists of two main forms of treatment: endobronchial brachytherapy and radioactive seed implantation brachytherapy (RSI-BT), the latter of which is used to treat non-small cell lung cancer (NSCLC). The use of RSI-BT in the treatment of NSCLC at our centre has yielded some positive results.

Methods

To more fully consider the context of this application, we conducted a search of PubMed from 2018 to March 5, 2023. The search included a combination of the MeSH terms: "brachytherapy" and "lung neoplasm".

Key Content and Findings

The majority of NSCLC patients who received RSI-BT achieved positive benefits. Most patients had a progression-free survival (PFS) of between 12 and 18 months. Additionally, radioactive particle stent implantation as a specific RSI-BT has shown therapeutic potential in the treatment of malignant airway obstruction. With the application of new technologies, RSI-BT will become more precise, efficient and inexpensive.

Conclusions

This review demonstrates that RSI-BT can be therapeutic in the treatment of both early and advanced NSCLC with manageable complications. There have also been reports on the combination of RSI-BT with other therapies, but more research is needed on the combination of RSI-BT with them.

Sterotactic Ablative Radiotherapy in a Multicentric Series of Oligometastatic SCLC: The SAMOS Cohort

AIMS

SCLC is the most aggressive lung cancer histology with a 5-year OS <10%. At the diagnosis, almost two-thirds of the SCLC an Extended Disease presentation. Two randomized studies (CASPIAN and ImPower133) demonstrated an OS improvement, when immunotherapy was prescribed as maintenance therapy after standard chemotherapy. To date, SABR has had a limited indication in managing metastatic SCLC, although recent reports proposed it as a valid treatment option in selected patients. We propose a retrospective multicentric analysis of patients treated with SABR for oligometastatic SCLC.

METHOD

Data of patients affected by oligometastatic-SCLC treated with SABR between 2017 and 2022 in 11 Italian centers were collected. Clinical and therapeutic variables together with OS and time to next treatment were analyzed. Univariate analysis with Kaplan-Meier curve were calculated, and log-rank test were applied. Cox proportional hazard model was used for multivariate analysis.

RESULTS

Data from 93 patients and 132 metastatic lesions were analyzed. The median age was 64 years (36-86) and all but 1 had Performance Status 0 or 1. Fifty-two patients presented ED at diagnosis. The first line treatment was radiochemotherapy in 42%, CHT alone in 24% and CHT-IO in 28%, others treatment accounts for 4% and only 2% of patients underwent best supportive care. Of the 132 lesions treated with SBRT 55 were in brain, 27 in lung, 11 in liver, 10 in lymph nodes, 8 in bones and 20 in adrenal gland. Median OS was 14 months, 1 year-OS and 2 years OS were 53% and 27%, respectively. The median TtNT was 14 months for the entire population. Of all the analyzed variables only, the anatomical site of the metastases and their number showed statistical significance in the univariate analysist, confirmed in the subsequent multivariate.

CONCLUSION

SABR seems to play a role in delaying further systemic lines in oligometastatic disease and to extend the use of ongoing treatment in oligoprogressive state. Prospective studies are needed to confirm these findings.

Metabolic factors associated with the prognosis of oligometastatic patients treated with stereotactic body radiotherapy

Over the past two decades, it has been established that cancer patients with oligometastases, i.e., only a few detectable metastases confined to one or a few organs, may benefit from an aggressive local treatment approach such as the application of high-precision stereotactic body radiotherapy (SBRT). Specifically, some studies have indicated that achieving long-term local tumor control of oligometastases is associated with prolonged overall survival. This motivates investigations into which factors may modify the dose-response relationship of SBRT by making metastases more or less radioresistant. One such factor relates to the uptake of the positron emission tomography tracer 2-deoxy-2-[18F]fluoro-D-glucose (FDG) which reflects the extent of tumor cell glycolysis or the Warburg effect, respectively. Here we review the biological mechanisms how the Warburg effect drives tumor cell radioresistance and metastasis and draw connections to clinical studies reporting associations between high FDG uptake and worse clinical outcomes after SBRT for oligometastases. We further review the evidence for distinct metabolic phenotypes of metastases preferentially seeding to specific organs and their possible translation into distinct radioresistance. Finally, evidence that obesity and hyperglycemia also affect outcomes after SBRT will be presented. While delivered dose is the main determinant of a high local tumor control probability, there might be clinical scenarios when metabolic targeting could make the difference between achieving local control or not, for example when doses have to be compromised in order to spare neighboring high-risk organs, or when tumors are expected to be highly therapy-resistant due to heavy pretreatment such as chemotherapy and/or radiotherapy.

Stereotactic body radiotherapy for mediastinal lymph node with CyberKnife®: Efficacy and toxicity

PUPRPOSE

Stereotactic body radiotherapy is more and more used for treatment of oligometastatic mediastinal lymph nodes. The objective of this single-centre study was to evaluate its efficacy in patients with either a locoregional recurrence of a pulmonary or oesophageal cancer or with distant metastases of extrathoracic tumours.

PATIENTS AND METHODS

Patients with oligometastatic mediastinal lymph nodes treated with CyberKnife from June 2010 to September 2020 were screened. The primary endpoint was to assess local progression free survival and induced toxicity. Secondary endpoints were overall survival and progression free survival. The delay before introduction of systemic treatment in the subgroup of patients who did not receive systemic therapy for previous progression was also evaluated.

RESULTS

Fifty patients were included: 15 with a locoregional progression of a thoracic primary tumour (87% pulmonary) and 35 with mediastinal metastasis of especially renal tumour (29%). Median follow-up was 27 months (6-110 months). Local progression free survival at 6, 12 and 18 months was respectively 94, 88 and 72%. The rate of local progression was significantly lower in patients who received 36Gy in six fractions (66% of the cohort) versus other treatment schemes. Two grade 1 acute oesophagitis and one late grade 2 pulmonary fibrosis were described. Overall survival at 12, 18 and 24 months was respectively 94, 85 and 82%. Median progression free survival was 13 months. Twenty-one patients were treated by stereotactic body irradiation alone without previous history of systemic treatment. Among this subgroup, 11 patients (52%) received a systemic treatment following stereotactic body radiotherapy with a median introduction time of 17 months (5-52 months) and 24% did not progress.

CONCLUSION

Stereotactic body irradiation as treatment of oligometastatic mediastinal lymph nodes is a well-tolerated targeted irradiation that leads to a high control rate and delay the introduction of systemic therapy in selected patients.

Clinical utility of liquid biopsy and integrative genomic profiling in early-stage and oligometastatic cancer patients treated with radiotherapy

BACKGROUND

Liquid biopsy and Integrative Genomic Profiling (IGP) are yet to be implemented into routine Radiation Oncology. Here we assess the utility of germline, tumour and circulating cell-free DNA-based genomic analyses for the clinical management of early-stage and oligometastatic cancer patients treated by precision radiotherapy.

METHODS

We performed germline, tissue- and liquid biopsy NGS panels on 50 early-stage/oligometastatic cancer patients undergoing radiotherapy. We also monitored ctDNA variants in serial liquid biopsies collected during radiotherapy and follow-up and evaluated the clinical utility of such comprehensive approach.

RESULTS

The integration of different genomic studies revealed that only 1/3 of the liquid biopsy variants are of tumour origin. Altogether, 55 tumour variants (affecting 3/4 of the patients) were considered potentially actionable (for treatment and prognosis), whereas potential follow-up biomarkers were identified in all cases. Germline cancer-predisposing variants were present in three patients, which would have not been eligible for hereditary cancer testing according to clinical guidelines. The presence of detectable ctDNA variants before radiotherapy was associated with progression-free survival both in oligometastatic patients and in those with early-stage.

CONCLUSIONS

IGP provides both valuable and actionable information for personalised decision-making in Radiation Oncology.

Engineered elastin-like polypeptides: An efficient platform for enhanced cancer treatment

Drug delivery systems (DDSs) have recently gained widespread attention for improving drug loading and delivery efficiency in treating many cancers. Elastin-like polypeptides (ELPs) are synthetic peptides derived from a precursor of elastin (tropoelastin), reserving similar structural and physicochemical properties. ELPs have gained a variety of applications in tissue engineering and cancer therapy due to their excellent biocompatibility, complete degradability, temperature-responsive property, controllable sequence and length, and precisely tuned structure and function. ELPs-based drug delivery systems can improve the pharmacokinetics and biodistribution of therapeutic reagents, leading to enhanced antitumor efficacy. In this review, we summarize the recent application of ELPs in cancer treatment, focusing on the delivery of functional peptides, therapeutic proteins, small molecule drugs, and photosensitizers.

Serum exosomal proteomics analysis of lung adenocarcinoma to discover new tumor markers

BACKGROUND

Among the most aggressive and rapidly lethal types of lung cancer, lung adenocarcinoma is the most common type. Exosomes, as a hot area, play an influential role in cancer. By using proteomics analysis, we aimed to identify potential markers of lung adenocarcinoma in serum.

METHODS

In our study, we used the ultracentrifugation method to isolate serum exosomes. The Liquid chromatography-mass spectrometry (LC-MS) and bioinformatics analysis were used to identify potential serum exosomal proteins with altered expression among patients with advanced lung adenocarcinoma, early lung adenocarcinoma, and healthy controls. A western blot (WB) was performed to confirm the above differential expression levels in a separate serum sample-isolated exosome, and immunohistochemistry (IHC) staining was conducted to detect expression levels of the above differential proteins of serum exosomes in lung adenocarcinoma tissues and adjacent tissues. Furthermore, we compared different expression models of the above differential proteins in serum and exosomes.

RESULT

According to the ITGAM (Integrin alpha M chain) and CLU (Clusterin) were differentially expressed in serum exosomes among different groups as well as tumor tissues and adjacent tissues. ITGAM was significantly and specifically enriched in exosomes. As compared to serum, CLU did not appear to be significantly enriched in exosomes. ITGAM and CLU were identified as serum exosomal protein markers of lung adenocarcinoma.

CONCLUSIONS

This study can provide novel ideas and a research basis for targeting lung adenocarcinoma treatment as a preliminary study.

Discrimination Between Primary Lung Cancer and Lung Metastases by Genomic Profiling

Introduction

In cases of lung tumors that occur after treatment for malignancies in other organs, the tumor may represent either a primary lung cancer or a solitary pulmonary metastasis from the other tumor. Because some lung tumors are difficult to differentiate on the basis of imaging and pathologic findings, treatment selection is often difficult. In this study, we attempted to make a genomic diagnosis of primary and metastatic lung tumors by analyzing tumor samples using next-generation sequencing and evaluated the efficacy and validity of the genomic diagnosis.

Methods

A total of 24 patients with a solitary lung nodule and a history of other malignancies were enrolled in this study. Tumor cells were selected from tissue samples using laser capture microdissection. DNA was extracted from those cells and subjected to targeted deep sequencing of 53 genes.

Results

The driver mutation profiles of the primary lung tumors were discordant from those of the primary tumors in other sites, whereas the mutation profiles of pulmonary metastases and previous malignancies were concordant. In all 24 patients, we could diagnose either primary lung cancer (six patients) or lung metastases (18 patients) on the basis of whether gene mutation profiles were concordant or discordant. In 12 patients (50.0%), discrepancies were observed between the genomic and clinical or histopathologic diagnoses.

Conclusions

In patients with a solitary lung lesion and a history of cancer, tumor-specific mutations can serve as clonal markers, affording a more accurate understanding of the pathological condition and thus possibly improving both treatment selection and patient outcome.

Dissociated Responses in Patients with Metastatic Solid Tumors Treated with Immunotherapy

BACKGROUND

Immune checkpoint inhibitors have been demonstrated to improve overall survival. Atypical patterns of response have been reported, including dissociated response (DR). We evaluated the prevalence of DR.

PATIENTS AND METHODS

Patients had to have a baseline computed tomography (CT) scan and at least one follow-up CT scan and two target lesions (TLs). Three types of DR were evaluated using RECIST1.1: DR1, defined as at least one progressive and one responding TL; DR2, defined as at least one progressive and one stable TL; and DR3, defined as at least one stable and one responding TL.

RESULTS

A total of 1244 measurements of 272 TLs were performed in 100 patients. Forty-nine out of the 272 TLs (18%) had received old or recent radiotherapy, and 42 (15%) had been biopsied. An objective response was observed in 22 patients (22%) and on 52 TLs (19%). DR1 were observed in 8% of patients. At the tumor measurement level, the response rate was lower in the case of prior radiotherapy (29% vs 34%, p = 0.01) and higher in the case of prior biopsy (40% vs 32%, p = 0.02).

CONCLUSIONS

A DR was observed in 8% of patients. Response rate was lower in the case of prior radiotherapy and higher in the case of prior biopsy.

The role of the surgeon in the management of oligometastatic non-small cell lung cancer: a literature review

OBJECTIVE

In this review, we aim to summarize the most recent data on the surgical management of oligometastatic non-small cell lung cancer (NSCLC).

BACKGROUND

Approximately 60-70% of all patients with NSCLC initially present with advanced stages of cancer at time of diagnosis. These patients are generally treated with chemotherapy, radiation therapy, or a combination of these modalities. Patients with late-stage disease are usually not considered to be amenable for curative-intent treatments due to poor prognoses. Despite advances in systemic therapies, 5-year overall survival rates in these patients remain poor. However, technological advances in imaging modalities and new imaging strategies have substantially increased tumor detection rates and have resulted in a shift towards earlier diagnosis of NSCLC, possibly in stages in which metastatic disease is limited and still treatable. Studies in recent years have shown that there is a distinct group of patients with metastatic lesions at one or a few sites, often referred to as oligometastatic disease, that may have better survival outcomes compared to patients with more disseminated diseases. Furthermore, it is suggested that these patients may benefit from a combination of systemic treatment and local treatment aimed at the metastatic site(s). However, the role of surgery in this setting remains a controversial subject, with many unanswered questions.

METHODS

The PubMed/MEDLINE database and the Cochrane database were searched to find relevant articles regarding oligometastatic NSCLC. Specifically, articles regarding definitions of oligometastatic disease, oligometastatic tumor biology, diagnosis, and the treatment of oligometastatic disease were identified.

CONCLUSIONS

Oligometastatic NSCLC represents a wide spectrum of diseases and encompasses a heterogeneous patient population. Current data suggests that local ablative treatment of oligometastatic lesions with surgery or stereotactic body radiation therapy may result in improved overall survival and progression-free survival rates. However, more data from multi-center prospective trials are necessary to shed light on which therapeutic modalities are most suitable for the treatment of oligometastatic NSCLC. Integration of clinical and molecular staging data is necessary to allow for more personalized treatment approaches.

The Impact of Radiation Therapy in Children and Adolescents With Metastatic Rhabdomyosarcoma

PURPOSE

There is limited evidence to define the role of radiation therapy in children with metastatic rhabdomyosarcoma (mRMS). In the international BERNIE study, children with mRMS or non-RMS soft tissue sarcoma were randomized to receive standard chemotherapy with or without bevacizumab, with radiation therapy to all disease sites recommended after chemotherapy cycle 6. We retrospectively evaluated the impact of radiation therapy on survival in the mRMS cohort.

METHODS AND MATERIALS

Patients were grouped according to the radiation therapy they received: radical, partial, or none. Radical irradiation was defined as radiation therapy delivered to all disease sites, unless a site was completely surgically resected. Partial irradiation was defined as radiation therapy to ≥1, but not all, disease sites. Landmark analysis excluded patients with an event before day 221. Overall survival (OS) and event-free survival (EFS) were modeled using Cox proportional hazards models.

RESULTS

Of 102 patients with mRMS, 97 were included in the analysis for OS and 85 for EFS. Overall, 27 patients received radical irradiation, 46 partial irradiation, and 24 no irradiation. EFS was not significantly different among patient groups after adjustment for prognostic factors (hazard ratio [HR] = 0.520; P = .054 for any vs no irradiation). Radiation therapy was associated with improved OS compared with no radiation therapy (adjusted HR = 0.249; P = .00025), with OS being greater for radical versus partial irradiation (HR = 0.245; P = .039). The 3-year OS rate was 84%, 54%, and 23% for patients receiving radical, partial, and no irradiation, respectively. Radical treatment (surgery, irradiation, or both) of the primary site improved EFS and OS compared with no treatment.

CONCLUSIONS

These findings demonstrate variability in the application of radiation therapy for mRMS and support the routine use of radical treatment to the primary site. Radical irradiation to metastatic sites may further improve OS. The burden of such treatment should be balanced against prognosis; further studies are needed.

Efficacy and safety of stereotactic body radiotherapy (SBRT) in oligometastatic/persistent/recurrent ovarian cancer: a prospective, multicenter phase II study (MITO-RT3/RAD)

BACKGROUND

Stereotactic body radiotherapy (SBRT) has shown promising results in the clinical setting of oligometastatic, persistent, or recurrent disease in several malignancies including ovarian cancer.

PRIMARY OBJECTIVE

The MITO-RT3/RAD trial is a prospective, multicenter phase II study aimed at identifying potential predictors of response and clinical outcome after SBRT treatment.

STUDY HYPOTHESIS

Radiotherapy delivered by pre-defined SBRT treatment schedules and shared constraints could improve the rate of complete response.

TRIAL DESIGN

All patients accrued will be treated with a radiotherapy dose in the range of 30-50 Gy by 1, 3, or 5 SBRT daily fractions to all sites of active metastatic disease according to diagnostic imaging. Schedules of treatment and dose prescription have been established before considering target sites and healthy organ dose constraints. Follow-up and monitoring of side effects will be carried out every 3 months for the first year with imaging and clinical evalutation, and every 4 months within the second year; thereafter, surveillance will be carried out every 6 months. The best response on a per lesion basis will be evaluated by computed tomographic (CT) scan, positron emission tomography/CT, or magnetic resonance imaging in case of brain lesions, every 3 months.

MAJOR INCLUSION/EXCLUSION CRITERIA

The study includes patients with oligometastatic, persistent, or recurrent ovarian cancer for which salvage surgery or other local therapies are not feasible due to any relative contra-indication to further systemic therapy because of serious co-morbidities, previous severe toxicity, unavailability of potentially active systemic therapy, or patient refusal.

PRIMARY ENDPOINT

The primary endpoint of the study is the clinical complete response rate to SBRT by imaging on a per lesion basis.

SAMPLE SIZE

Approximately 205 lesions will be treated (90 lymph nodes and 115 parenchyma lesions).

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

Fifty-two centers have expressed their intention to participate. Enrollment should be completed by March 2023 and analysis will be completed in September 2023.

TRIAL REGISTRATION

NCT04593381.

Combination of Immune Checkpoint Inhibitors and Anti-Angiogenic Agents in Brain Metastases From Non-Small Cell Lung Cancer

Brain metastases remain a critical issue in the management of non-small cell lung cancer (NSCLC) because of the high frequency and poor prognosis, with survival rates often measured in just months. The local treatment approach remains the current standard of care, but management of multiple asymptomatic brain metastases always involves systemic therapy. Given that anti-angiogenic agents and immune checkpoint inhibitors (ICIs) both target the tumor microenvironment (TME), this combination therapy has become a promising strategy in clinical practice. Increasing number of preclinical and clinical studies have shown remarkable anti-tumor activity of the combination therapy, but the efficacy in brain metastases is unclear due to the strict selection criteria adopted in most clinical trials. This review briefly summarizes the potential synergistic anti-tumor effect and clinical development of the combination of anti-angiogenic agents and ICIs in NSCLC brain metastases, and discusses the existing challenges and problems.

Feasibility and safety of percutaneous computed tomography guided radiofrequency ablation of lymph nodes in oligometastatic patients: a single center's experience

OBJECTIVES

To retrospectively evaluate feasibility and safety of CT-guided percutaneous radiofrequency ablation (RFA) of metastatic lymph nodes (LN) in terms of achieving local tumor control.

METHODS

Institutional database research identified 16 patients with 24 metastatic LNs who underwent percutaneous CT-guided radiofrequency ablation. Mean patient age was 66.6 ± 15.70 years (range 40-87) and male/female ratio was 8/8. Contrast-enhanced CT or MRI was used for post-ablation follow-up. Patient and tumor characteristics and RFA technique were evaluated. Technical and clinical success on per tumor and per patient basis as well as complication rates were recorded.

RESULTS

Mean size of the treated nodes was 1.78 ± 0.83 cm. The mean number of tumors per patient was 1.5 ± 0.63. The mean procedure time was 56.29 ± 24.27 min including local anesthesia, electrode(s) placement, ablation and post-procedural CT evaluation. Median length of hospital stay was 1.13 ± 0.34 days. On a per lesion basis, the overall complete response post-ablation according to the mRECIST criteria applied was 75% (18/24) of evaluable tumors. Repeat treatment of an index tumor was performed on two patients (three lesions) with complete response achieved in 87.5% (21/24) of evaluable tumors following a second RFA. On a per patient basis, disease progression was noted in 10/16 patients at a mean of 13.9 ± 6.03 months post the ablation procedure.

CONCLUSION

CT-guided percutaneous RFA for oligometastatic LNs is a safe and feasible therapy.

ADVANCES IN KNOWLEDGE

With this percutaneous therapeutic option, metastatic LNs can be eradicated with a very low complication rate.

Intracranial Grade II Meningioma Oligometastatic to the Cervical Spine

For intracranial meningiomas that metastasize extracranially, an oligometastatic state exists that is intermediate between incurable, widely metastatic disease and non-metastatic curable disease. Similar to oligometastatic cancer, aggressive local treatment of meningioma oligometastases is warranted, as it may be curable. We present a patient with multiply recurrent intracranial meningiomas over 19 years, with a transformation from grade I to grade II histology, with oligometastatic disease to the C5 vertebral body. Three years following definitive spinal stereotactic radiosurgery, she remains without evidence of other metastatic diseases. Our case highlights the oncologic concept that metastatic meningioma need not be widely disseminated and provides the clinical rationale for aggressive local treatment of an oligometastatic meningioma.

Metastasis-directed stereotactic body radiation therapy in the management of oligometastatic head and neck cancer

INTRODUCTION

Recently major efforts have been made to define the oligometastatic setting, but for head and neck cancer (HNC) limited data are available. We aimed to evaluate outcome of oligometastatic HNC treated with Stereotactic body radiotherapy (SBRT) as metastasis-directed therapy.

MATERIALS AND METHODS

We analyzed patients treated with SBRT on a maximum of five oligometastases from HNC, in up to two organs. Concomitant treatment was allowed. End points were toxicity, local control of treated metastases (LC), progression-free survival (PFS) and overall survival (OS).

RESULTS

48 consecutive patients and 71 lesions were treated. With a follow-up of 20.2 months, most common primary tumors were larynx (29.2%) and salivary glands (29.2%), while common site of metastases was lung (59.1%). Median dose was 48 Gy (21-75) in 3-8 fractions. Treatment was well tolerated, with two patients reporting mild pain and nausea. LC rates at 1 and 2 years were 83.1% and 70.2%. Previous local therapy (HR 4.97; p = 0.002), oligoprogression (HR 4.07; p = 0.031) and untreated metastases (HR 4.19; p = 0.027) were associated with worse LC. PFS at 1 and 2 years were 42.2% and 20.0%. Increasing age (HR 1.03; p = 0.010), non-adenoid cystic carcinoma (HR 2.57; p = 0.034) and non-lung metastases (HR 2.20; p = 0.025) were associated with worse PFS. One- and 2-years OS were 81.0% and 67.1%. Worse performance status (HR 2.91; p = 0.049), non-salivary primary (HR 19.9; p = 0.005), non-lung metastases (HR 2.96; p = 0.040) were correlated with inferior OS.

CONCLUSIONS

SBRT can be considered a safe metastasis-directed therapy in oligometastatic HNC. Efficacy of the treatment seems to be higher when administered upfront in the management of metastatic disease; however, selection of patients need to be improved due to the relevant risk of appearance of new metastatic site after SBRT.

[Radiotherapy and spinal toxicity: News and perspectives]

Radiation-induced myelopathy is a devastating late effect of radiotherapy. Fortunately, this late effect is exceptional. The clinical presentation of radiation myelopathy is aspecific, typically occurring between 6 to 24 months after radiotherapy, and radiation-induced myelopathy remains a diagnosis of exclusion. Magnetic resonance imaging is the most commonly used imaging tool. Radiation oncologists must be extremely cautious to the spinal cord dose, particularly in stereotactic radiotherapy and reirradiation. Conventionally, a maximum dose of 50Gy is tolerated in normofractionated radiotherapy (1.8 to 2Gy per fraction). Repeat radiotherapies lead to consider cumulative doses above this recommendation to offer individualized reirradiation. Several factors increase the risk of radiation-induced myelopathy, such as concomitant or neurotoxic chemotherapy. The development of predictive algorithms to prevent the risk of radiation-induced myelopathy is promising. However, radiotherapy prescription should be cautious, regarding to ALARA principle (as low as reasonably achievable). As the advent of immunotherapy has improved patient survival data and the concept of oligometastatic cancer is increasing in daily practice, stereotactic treatments and reirradiations will be increasingly frequent indications. Predict the risk of radiation-induced myelopathy is therefore a major issue in the following years, and remains a daily challenge for radiation oncologists.

Role of Surgical Intervention in Unresectable Non-Small Cell Lung Cancer

With the development of systemic treatments with high response rates, including tyrosine kinase inhibitors and immune checkpoint inhibitors, some patients with unresectable lung cancer now have a chance to undergo radical resection after primary treatment. Although there is no general consensus regarding the definition of “unresectable” in lung cancer, the term “resectable” refers to technically resectable and indicates that resection can provide a favorable prognosis to some extent. Unresectable lung cancer is typically represented by stage III and IV disease. Stage III lung cancer is a heterogeneous disease, and in some patients with technically resectable non-small cell lung cancer (NSCLC), multimodality treatments, including induction chemoradiotherapy followed by surgery, are the treatments of choice. The representative surgical intervention for unresectable stage III/IV NSCLC is salvage surgery, which refers to surgical treatment for local residual/recurrent lesions after definitive non-surgical treatment. Surgical intervention is also used for an oligometastatic stage IV NSCLC. In this review, we highlight the role of surgical intervention in patients with unresectable NSCLC, for whom an initial complete resection is technically difficult. We further describe the history of and new findings on salvage surgery for unresectable NSCLC and surgery for oligometastatic NSCLC.

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

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

Adoption of Biologically Effective Dose of the Non-Target Lung Volume to Predict Symptomatic Radiation Pneumonitis After Stereotactic Body Radiation Therapy With Variable Fractionations for Lung Cancer

Background: This study aims to establish lung biologically effective dose (BED)–based uniform dosimetric constraints for minimizing the risk of symptomatic radiation pneumonitis (SRP) from stereotactic body radiation therapy (SBRT) using variable fractionations in patients with lung tumors.

Materials and Methods: A total of 102 patients with primary or oligometastatic lung tumors treated with SBRT in our institution were enrolled into this study. The associations between the clinical and dosimetric parameters and the incidences of SRP were analyzed using univariate and multivariate Cox regression hazard models. The receiver operating characteristic (ROC) curve was generated to evaluate the predictive performance of lung BED on the SRP risk compared with the physical dose.

Results: SRP occurred in 11 patients (10.8%). In univariate analysis, the mean lung dose (p = 0.002), V₅ (p = 0.005), V₂₀ (p < 0.001), and the percentage of non-target normal lung volume receiving more than a BED of 5–170 Gy (V_BED5−170, p < 0.05) were associated with SRP. Multivariate logistic regression analysis showed that there existed a significant statistical correlation between SRP and V_BED70 (p < 0.001), which performed better than V₅ or V₂₀ on the ROC curves, resulting in an optimal cut-off value of lung V_BED70 of 2.22%.

Conclusions: This retrospective study indicated that non-target lung BED may better predict SRP from patients with SBRT-treated lung cancer. Limiting the lung V_BED70 below 2.22% may be favorable to reduce the incidence of SRP, which warranted further prospective validation.

Primary Parotid Merkel Type Small Cell Neuroendocrine Carcinoma with Oligometastasis to the Brain and Adrenal Gland: Case Report and Review of Literature

Oligometastatic disease is a hypothesized intermediate stage of disease between localized and widespread metastatic cancer. Localized treatment of oligometastatic lesions may offer survival advantages in addition to systemic treatment. In this case report, we describe a patient who presented with small cell neuroendocrine carcinoma "Merkel type" (SNECM) of the parotid gland which had metastasized to the brain and adrenal gland. He was treated with chemotherapy followed by stereotactic radiotherapy and volumetric modulated arc therapy for oligometastasis. He maintains good functional status with low burden of disease at 20-months after diagnosis. SNECM is a rare and aggressive parotid cancer with immunohistochemical and morphologic similarities to Merkel cell carcinoma (MCC). There are only 44 cases of parotid SNECM in the English literature. This is the first case to describe management of oligometastatic SNECM and we review literature on management of both SNECM and metastatic MCC.

Oligorecurrence Non-small Cell Lung Cancer After Failure of First-Line Chemotherapy: Computed Tomography-Guided 125I Seed Implantation vs. Second-Line Chemotherapy

Purpose: To compare the efficacy and safety of computed tomography (CT)–guided ¹²⁵I seed implantation with second-line chemotherapy in treatment of oligorecurrence non–small cell lung cancer after failure of first-line chemotherapy.

Methods: Data of oligorecurrence non–small cell lung cancer patients after failure of first-line chemotherapy at two institutions were retrospectively reviewed from January 2013 to July 2018. A total of 53 patients who received the treatment of ¹²⁵I seed implantation or second-line chemotherapy were eligible for this study. In group A, 25 patients, 84 lesions, received CT-guided permanent ¹²⁵I seed implantation, whereas in group B, 28 patients, 96 lesions, received second-line chemotherapy. The outcomes were measured in terms of disease control rate, overall survival, quality of life, and complications.

Results: The median follow-up period was 13 months (range, 5–42 months). Disease control rate in group A was higher than that in group B (70.8 vs. 42.3%, P = 0.042) at 6 months after treatment. The median overall survival was 12.8 months (95% confidence interval, 10.5–15.1 months) in group A and 15.2 months (95% confidence interval, 12.2–18.2 months) in group B, with no significant difference (P = 0.847). Since the fourth month, the number of patients in group A with a non-decreasing Karnofsky Performance Scale score was more than that in group B (P < 0.05). The incidence of grade 3 or higher complications especially hematologic toxicity in group A was significantly lower than that in group B (P < 0.05).

Conclusion: Radioactive ¹²⁵I seed implantation is safe and feasible in selected non–small cell lung cancer patients with oligorecurrence after failure of first-line chemotherapy and seems to provide a better long-term quality of life in these patients compared with second-line chemotherapy.

First statement on preparation for the COVID-19 pandemic in large German Speaking University-based radiation oncology departments

The COVID-19 pandemic is challenging modern radiation oncology. At University Hospitals, we have a mandate to offer high-end treatments to all cancer patients. However, in times of crisis we must learn to prioritize resources, especially personnel. Compromising oncological outcome will blur all statistics, therefore all measures must be taken with great caution. Communication with our neighboring countries, within societies and between departments can help meet the challenge. Here, we report on our learning system and preparation measures to effectively tackle the COVID-19 challenge in University-Based Radiation Oncology Departments.

Effects of oral maintenance chemotherapy and predictive value of circulating EBV DNA in metastatic nasopharyngeal carcinoma

Background/Objectives

Oral maintenance chemotherapy can effectively prolong overall survival (OS) in many types of metastatic cancer, but its role in metastatic nasopharyngeal carcinoma (mNPC) is unclear. In this study, the efficacy of oral maintenance chemotherapy in mNPC and the effectiveness of circulating tumor EBV‐DNA for screening patients were evaluated.

Methods

Between June 2016 and December 2017, 141 patients with mNPC who received platinum‐based systemic chemotherapy were included (median follow‐up time, 21 months). Patients were classified into two groups according to the administration of oral maintenance chemotherapy. Plasma samples were collected before, during, and after treatment for the measurement of circulating EBV DNA.

Results

The 2‐year OS was higher for patients who received maintenance chemotherapy than for patients without maintenance chemotherapy (78.9% vs 62.7%, P = .016). Patients with undetectable posttreatment EBV‐DNA after 4‐6 cycles of systemic chemotherapy (n = 73) had a higher 2‐year OS than that of patients with detectable EBV‐DNA (n = 68) (82.16% vs 51.45%, P = .001). For patients with undetectable posttreatment EBV‐DNA, OS was better for those with maintenance chemotherapy than for those without (86.7% vs 73%, P = .027). For patients with detectable posttreatment EBV‐DNA, maintenance chemotherapy did not improve outcomes (49.5% vs 55.4%, P = .824). The most common acute events were hematological toxicity, and all were tolerable and curable.

Conclusions

Oral maintenance chemotherapy with S1 or capecitabine can improve OS in mNPC. Posttreatment EBV‐DNA was not only an independent prognosis factor for mNPC but also can screen out beneficiaries of maintenance chemotherapy.

Immunosurveillance and Immunoediting of Lung Cancer: Current Perspectives and Challenges

The immune system plays a dual role in tumor evolution-it can identify and control nascent tumor cells in a process called immunosurveillance and can promote tumor progression through immunosuppression via various mechanisms. Thus, bilateral host-protective and tumor-promoting actions of immunity are integrated as cancer immunoediting. In this decade, immune checkpoint inhibitors, specifically programmed cell death 1 (PD-1) pathway inhibitors, have changed the treatment paradigm of advanced non-small cell lung cancer (NSCLC). These agents are approved for the treatment of patients with NSCLC and demonstrate impressive clinical activity and durable responses in some patients. However, for many NSCLC patients, the efficacy of immune checkpoint inhibitors is limited. To optimize the full utility of the immune system for eradicating cancer, a broader understanding of cancer immunosurveillance and immunoediting is essential. In this review, we discuss the fundamental knowledge of the phenomena and provide an overview of the next-generation immunotherapies in the pipeline.

Separating or combining immune checkpoint inhibitors (ICIs) and radiotherapy in the treatment of NSCLC brain metastases

With the advancement of imaging technology, systemic disease control rate and survival rate, the morbidity of brain metastases (BMs) from non-small cell lung cancer (NSCLC) has been riding on a steady upward trend (40%), but management of BMs from NSCLC remains obscure. Systemic therapy is anticipated to offer novel therapeutic avenues in the management of NSCLC BMs, and radiotherapy (RT) and immunotherapy have their own advantages. Recently, it was confirmed that immune checkpoint inhibitors (ICIs) and RT could mutually promote the efficacy in the treatment of BMs from NSCLC. In this paper, we provide a review on current understandings and practices of separating or combining ICIs and RT, which could provide a reference for the coming laboratory and clinical studies and contribute to the development of new approaches in NSCLC BMs.

Individual lymph nodes: "See it and Zap it"

BACKGROUND AND PURPOSE

With magnetic resonance imaging (MRI)-guided radiotherapy systems such as the 1.5T MR-linac the daily anatomy can be visualized before, during and after radiation delivery. With these treatment systems, seeing metastatic nodes with MRI and zapping them with stereotactic body radiotherapy (SBRT) comes into reach. The purpose of this study is to investigate different online treatment planning strategies and to determine the planning target volume (PTV) margin needed for adequate target coverage when treating lymph node oligometastases with SBRT on the 1.5T MR-linac.

MATERIALS AND METHODS

Ten patients were treated for single pelvic or para-aortic lymph node metastases on the 1.5T MR-linac with a prescribed dose of 5x7Gy with a 3 mm isotropic GTV- PTV margin. Based on the daily MRI and actual contours, a completely new treatment plan was generated for each session (adapt to shape, ATS). These were compared with plans optimized on pre-treatment CT contours after correcting for the online target position (adapt to position, ATP). At the end of each treatment session, a post-radiation delivery MRI was acquired on which the GTV was delineated to evaluate the GTV coverage and PTV margins.

RESULTS

The median PTV V35Gy was 99.9% [90.7-100%] for the clinically delivered ATS plans compared to 93.6% [76.3-99.7%] when using ATP. The median GTV V35Gy during radiotherapy delivery was 100% [98-100%] on the online planning and post-delivery MRIs for ATS and 100% [93.9-100%] for ATP, respectively. The applied 3 mm isotropic PTV margin is considered adequate.

CONCLUSION

For pelvic and para-aortic metastatic lymph nodes, online MRI-guided adaptive treatment planning results in adequate PTV and GTV coverage when taking the actual patient anatomy into account (ATS). Generally, GTV coverage remained adequate throughout the treatment session for both adaptive planning strategies. "Seeing and zapping" metastatic lymph nodes comes within reach for MRI-guided SBRT.

Radiation as an In Situ Auto-Vaccination: Current Perspectives and Challenges

Radiotherapy is generally considered to be a local treatment, but there have been reports of rare cases demonstrating abscopal effects in which antitumor effects have been observed in cancer lesions other than the irradiated site. This result is more likely to occur when immune checkpoint inhibitors are used in addition to radiotherapy. Certain radiation-induced chemokines and cytokines have immune-enhancing effects. Immune checkpoint inhibitors may strengthen these effects by stimulating antigen-presenting cells and effector cytotoxic T cells. To date, there is no consensus regarding the applicability of the abscopal effect in the clinical setting, including optimal methods for combining immune checkpoint inhibitors and irradiation. In this review, we highlight the evidence for interactions between cancer immunotherapy and radiotherapy and discuss the potential of such interactions for use in designing novel combination therapies.

Tumor biology and multidisciplinary strategies of oligometastasis in gastrointestinal cancers

More than 70% of gastrointestinal (GI) cancers are diagnosed with metastases, leading to poor prognosis. For some cancer patients with limited sites of metastatic tumors, the term oligometastatic disease (OMD) has been coined as opposed to systemic polymetastasis (PMD) disease. Stephan Paget first described an organ-specific pattern of metastasis in 1889, now known as the "seed and soil" theory where distinct cancer types are found to metastasize to different tumor-specific sites. Our understanding of the biology of tumor metastasis and specifically the molecular mechanisms driving their formation are still limited, in particular, as it relates to the genesis of oligometastasis. In the following review, we discuss recent advances in general understanding of this metastatic behavior including the role of specific signaling pathways, various molecular features and biomarkers, as well as the interaction of carcinoma cells with their tissue microenvironments (both primary and metastatic niches). The unique features that underlie OMD provide potential targets for localized therapy. As it relates to clinical practice, OMD is emerging as treatable with surgical resection and/or other local therapy options. Strategies currently being applied in the clinical management of OMD will be discussed including surgical, radiation-based therapy, ablation procedures, and the results of emerging clinical trials involving immunotherapy.

Liquid Biopsy in Oligometastatic Prostate Cancer-A Biologist's Point of View

Prostate cancer (PCa) is the main cause of cancer-related mortality in males and the diagnosis, treatment, and care of these patients places a great burden on healthcare systems globally. Clinically, PCa is highly heterogeneous, ranging from indolent tumors to highly aggressive disease. In many cases treatment-generally either radiotherapy (RT) or surgery-can be curative. Several key genetic and demographic factors such as age, family history, genetic susceptibility, and race are associated with a high incidence of PCa. While our understanding of PCa, which is mainly based on the tools of molecular biology-has improved dramatically in recent years, efforts to better understand this complex disease have led to the identification of a new type of PCa-oligometastatic PCa. Oligometastatic disease should be considered an individual, heterogeneous entity with distinct metastatic phenotypes and, consequently, wide prognostic variability. In general, patients with oligometastatic disease typically present less biologically aggressive tumors whose metastatic potential is more limited and which are slow-growing. These patients are good candidates for more aggressive treatment approaches. The main aim of the presented review was to evaluate the utility of liquid biopsy for diagnostic purposes in PCa and for use in monitoring disease progression and treatment response, particularly in patients with oligometastatic PCa. Liquid biopsies offer a rapid, non-invasive approach whose use t is expected to play an important role in routine clinical practice to benefit patients. However, more research is needed to resolve the many existing discrepancies with regard to the definition and isolation method for specific biomarkers, as well as the need to determine the most appropriate markers. Consequently, the current priority in this field is to standardize liquid biopsy-based techniques. This review will help to improve understanding of the biology of PCa, particularly the recently defined condition known as "oligometastatic PCa". The presented review of the body of evidence suggests that additional research in molecular biology may help to establish novel treatments for oligometastatic PCa. In the near future, the treatment of PCa will require an interdisciplinary approach involving active cooperation among clinicians, physicians, and biologists.

Additional local consolidative therapy has survival benefit over EGFR tyrosine kinase inhibitors alone in bone oligometastatic lung adenocarcinoma patients

OBJECTIVES

Whether epidermal growth factor receptor tyrosine-kinase inhibitors (EGFR-TKIs) plus local consolidative therapy (LCT) has survival benefit over EGFR-TKIs alone in lung adenocarcinoma patients with EGFR mutation and bone oligometastases remains controversial.

MATERIALS AND METHODS

We conducted a retrospective study to assess the effects of LCT in lung adenocarcinoma patients with bone oligometastases and EGFR mutation. The primary endpoint was overall survival (OS); the secondary endpoints was progression-free survival (PFS).

RESULTS

A total of 127 lung adenocarcinoma patients with EGFR mutation and bone oligometastases were assessed, including 65 patients received EGFR-TKIs alone (monotherapy group) and 62 patients received EGFR-TKIs plus local consolidative therapy (LCT) (combination group). Addition of LCT was associated with significantly longer OS (36.3 vs. 21.0 months, P = 0.01; hazard ratio [HR] = 0.537, 95% confidence interval [CI]: 0.360-0.801, p = 0.01) and PFS (14.0 vs. 8.1 months, P = 0.01; HR = 0.613, 95%CI: 0.427-0.879, p = 0.01) in the whole cohort.

CONCLUSION

In lung adenocarcinoma patients with EGFR-mutation and bone oligometastases, LCT plus EGFR-TKIs therapy is associated with significantly longer OS and PFS compared with EGFR-TKIs therapy alone, indicating that LCT plus EGFR-TKIs therapy might be a better therapeutic option for this patient population.