A risk-based approach to identifying oligometastatic disease on imaging

Recognition of <3 metastases in <2 organs, particularly in cancers with a known predisposition to oligometastatic disease (OMD) (colorectal, prostate, renal, sarcoma and lung), offers the opportunity to focally treat the lesions identified and confers a survival advantage. The reliability with which OMD is identified depends on the sensitivity of the imaging technique used for detection and may be predicted from phenotypic and genetic factors of the primary tumour, which determine metastatic risk. Whole-body or organ-specific imaging to identify oligometastases requires optimization to achieve maximal sensitivity. Metastatic lesions at multiple locations may require a variety of imaging modalities for best visualisation because the optimal image contrast is determined by tumour biology. Newer imaging techniques used for this purpose require validation. Additionally, rationalisation of imaging strategies is needed, particularly with regard to timing of imaging and follow-up studies. This article reviews the current evidence for the use of imaging for recognising OMD and proposes a risk-based roadmap for identifying patients with true OMD, or at risk of metastatic disease likely to be OM.     

Cost-Effectiveness Analysis of Stereotactic Ablative Body Radiation Therapy Compared With Surgery and Radiofrequency Ablation in Two Patient Cohorts: Metastatic Liver Cancer and Hepatocellular Carcinoma

AimsTo compare the cost-effectiveness of stereotactic ablative body radiation therapy (SABR) with radiofrequency ablation and surgery in adult patients with metastatic liver cancer and hepatocellular carcinoma (HCC).Materials and methodsTwo patient cohorts were assessed: liver oligometastases and HCC. For each patient cohort, a decision analytic model was constructed to assess the cost-effectiveness of interventions over a 5-year horizon. A Markov process was embedded in the decision model to simulate the possible prognosis of cancer. Data on transition probabilities, survival, side-effects, quality of life and costs were obtained from published sources and the SABR Commissioning through Evaluation (CtE) scheme. The primary outcome was the incremental cost-effectiveness ratio with respect to quality-adjusted life-years. The robustness of the results was examined in a sensitivity analysis. Analyses were conducted from a National Health Service and Personal Social Services perspective.ResultsIn the base case analysis, which assumed that all three interventions were associated with the same cancer progression rates and mortality rates, SABR was the most cost-effective intervention for both patient cohorts. This conclusion was sensitive to the cancer progression rate, mortality rate and cost of interventions. Assuming a willingness-to-pay threshold of £20 000 per quality-adjusted life-year, the probability that SABR is cost-effective was 57% and 50% in liver oligometastases and HCC, respectively.ConclusionsOur results indicate a potential for SABR to be cost-effective for patients with liver oligometastases and HCC. This finding supports further investigation in clinical trials directly comparing SABR with surgery and radiofrequency ablation.     

Distinct Outcomes of Oropharyngeal Squamous Cell Carcinoma Patients after Distant Failure According to p16 Status: Implication in Therapeutic Options

Introduction: Recent modifications in the epidemiology of oropharyngeal squamous cell carcinoma (OSCC) have led to the increase of Human papillomavirus (HPV) related metastatic head and neck cancer patients with high life expectancy even at advanced stage, low comorbidity and still restricted systemic therapy opportunities. In the recent era of ablative therapies’ development, oligometastatic HPV OSCC patients are indubitably good candidates for intensified treatment. However, data related to outcomes after optimised management of metastatic sites are dramatically missing. Materials and patients: In our cohort of 186 unselected consecutive OSCC patients treated with curative intent at our institution between 2009 and 2013, we analysed the incidence, treatment and outcomes of distant metastatic (DM) failure according to p16 status. Results: After a median follow-up of 4.2 years (95% CI: 3.8–4.4) from primary diagnosis of OSCC, 21/95 p16− patients (22.1%) vs. 8/91 (8.8%) p16+ patients presented DM failure with a median interval of 11 (range 0–46) and 28 months (range 0–71), respectively (p = 0.10). Overall survival (OS) after DM failure was significantly higher in p16+ patients with a two-year OS rate of 75% and 15% for p16+ and p16−, respectively (p = 0.002). In eight HPV-related metastatic patients, three underwent ablative lung metastasis treatment and are still complete responders four to five years later. Conclusion: This study highlights distinct outcomes of metastatic HPV-related OSCC patients emphasised by three long-term complete responders after lung ablative treatment. In patients with high life expectancy and limited tumour burden, the question of ablative treatment such as metastasectomy or stereotactic ablative radiotherapy (SBRT) should be addressed.     

Stereotactic ablative radiotherapy before resection to avoid delay for early-stage lung cancer or oligometastases during the COVID-19 pandemic: Pathologic outcomes from the SABR-BRIDGE protocol

Background

During coronavirus disease 2019 (COVID-19)–related operating room closures, some multidisciplinary thoracic oncology teams adopted a paradigm of stereotactic ablative radiotherapy (SABR) as a bridge to surgery, an approach called SABR-BRIDGE. This study presents the preliminary surgical and pathological results.

Methods

Eligible participants from four institutions (three in Canada and one in the United States) had early-stage presumed or biopsy-proven lung malignancy that would normally be surgically resected. SABR was delivered using standard institutional guidelines, with surgery >3 months following SABR with standardized pathologic assessment. Pathological complete response (pCR) was defined as absence of viable cancer. Major pathologic response (MPR) was defined as ≤10% viable tissue.

Results

Seventy-two patients underwent SABR. Most common SABR regimens were 34 Gy/1 (29%, n = 21), 48 Gy/3–4 (26%, n = 19), and 50/55 Gy/5 (22%, n = 16). SABR was well-tolerated, with one grade 5 toxicity (death 10 days after SABR with COVID-19) and five grade 2–3 toxicities. Following SABR, 26 patients underwent resection thus far (13 pending surgery). Median time-to-surgery was 4.5 months post-SABR (range, 2–17.5 months). Surgery was reported as being more difficult because of SABR in 38% (n = 10) of cases. Thirteen patients (50%) had pCR and 19 (73%) had MPR. Rates of pCR trended higher in patients operated on at earlier time points (75% if within 3 months, 50% if 3–6 months, and 33% if ≥6 months; p = .069). In the exploratory best-case scenario analysis, pCR rate does not exceed 82%.

Conclusions

The SABR-BRIDGE approach allowed for delivery of treatment during a period of operating room closure and was well-tolerated. Even in the best-case scenario, pCR rate does not exceed 82%.     

Métastases osseuses : les nouvelles techniques d’irradiation et traitements combinés ablatifs décalent-ils les standards ?

IntroductionIrradiation of bone metastases primarily aims at alleviating pain, preventing fracture in the short term. The higher doses and more conformal dose distribution achievable while saving healthy tissue with new irradiation techniques have induced a paradigm shift in the management of bone metastases in a growing number of clinical situations.Materials and MethodsA search of the English and French literature was conducted using the keywords: bone metastases, radiotherapy, interventional radiology, vertebroplasty, radiofrequency, chemoembolization.Results-discussionStereotactic irradiation yields pain relief rates greater than 90% in Phase I/II and retrospective studies. IMRT (static, rotational, helical) and stereotactic irradiation yield local control rates of 75-90% at 2 years. Some situations previously evaluated as palliative are currently treated more aggressively with optimized radiation sometimes combined modality interventional radiology.ConclusionA recommendation can only be made for stereotactic irradiation in vertebral oligometastases or reirradiation. In the absence of a sufficient level of evidence, the increasing use of conformal irradiation techniques can only reflect the daily practice and the patient benefit while integrating economic logic care. The impact of these aggressive approaches on survival remains to be formally demonstrated by interventional prospective studies or observatories including quality of life items and minimal 2-year follow-up.     

单纯脑寡转移的初治非小细胞肺癌患者预后相关因素分析

目的　分析单纯脑寡转移的初治非小细胞肺癌患者临床特征及治疗模式,探讨影响患者预后的相关因素。方法　收集2005年1月至2014年12月大连医科大学附属第一医院治疗的晚期非小细胞肺癌患者,均为初诊单纯脑寡转移病例41例。对年龄、性别、KPS评分、GPA评分、原发病灶病理类型、脑转移病灶数量、脑转移病灶最大径、脑转移灶局部治疗模式、肺内病灶控制情况、全身治疗模式等因素应用Log-rank检验进行单因素分析,多因素分析采用Cox回归模型,Kaplan-Meier法分析生存情况。结果　全组患者中位生存时间8.9个月,1年、2年生存率分别为41.5%、14.6%。单因素分析提示：脑转移病灶数量、脑转移治疗模式、全身治疗模式与预后相关,多因素分析结果提示靶向治疗是唯一独立预后相关因素。结论　对于初诊即存在脑寡转移的非小细胞肺癌患者,寡转移病灶的数量、脑转移治疗模式、全身治疗模式为预后相关因素,其中全身治疗模式即是否应用靶向治疗为唯一独立预后相关因素。     

A prospective pilot study of curative-intent stereotactic body radiation therapy in patients with 5 or fewer oligometastatic lesions

BACKGROUND: It is hypothesized that oligometastatic disease represents a state of potentially curable, limited metastases. Stereotactic body radiation therapy (SBRT) is an option for patients who are not amenable to or do not want resection. METHODS: From 2001 to 2006, 121 patients with < or =5 detectable metastases were enrolled in 2 prospective studies that used curative-intent SBRT. Most patients were treated with 10 fractions of 5 Gray. Stereotactic radiosurgery was offered to patients with brain metastases. RESULTS: The 2-year overall survival (OS), progression-free survival (PFS), local control (LC), and distant control (DC) rates were 50%, 26%, 67%, and 34%, respectively; and the respective 4-year rates values were 28%, 20%, 60%, and 25%. A greater net tumor volume predicted significantly worse OS, PFS, LC, and DC. Patients with breast cancer fared significantly better with respect to OS, PFS, LC, and DC; and patients with adrenal metastases had significantly worse OS, PFS, and DC despite the small number of such patients enrolled. Neither the number of metastatic lesions nor the number of organs involved was a significant predictor of outcome. Among 45 patients who remained alive at the last follow-up, 29 patients had no evidence of disease, including 23 patients with > or =2 years of follow-up. CONCLUSIONS: Oligometastatic disease is a potentially curable state of distant cancer spread. In this hypothesis-generating analysis, patients with less volume burden of their metastatic disease and those with primary breast cancer fared better. SBRT delivered with curative intent in patients with limited metastases should be investigated further. The Southwest Oncology Group is developing a prospective protocol to treat women who have limited breast cancer metastases with SBRT.