Treatment of Peripheral Non-Small Cell Lung Carcinoma with Stereotactic Body Radiation Therapy

Stereotactic body radiation therapy (SBRT) is an effective and well-tolerated noninvasive treatment for medically inoperable patients with peripheral non–small cell lung carcinoma. The term “peripheral” refers to lesions that lie 2 cm or more from the mediastinum and proximal bronchial tree and was instituted based on results from a specific dose and fractionation schedule. Improvements in immobilization, respiratory motion management, and image guidance have allowed for SBRT'S highly conformal and accurate delivery of large radiation doses per fraction. Results from prospective and retrospective studies suggest that lung SBRT has superior outcomes when compared with conventionally fractionated treatments and is comparable with surgical resection. Investigations into the optimal SBRT dosing regimen for peripheral lesions are ongoing, with recent trials suggesting comparable efficacy between single and multiple fraction schedules. Chest wall toxicity after peripheral treatment is common, but it usually resolves with conservative management. Pneumonitis is less often observed after treatment of peripheral lesions, and changes in pulmonary function tests are minimal. Studies in the frail and elderly suggest that neither baseline pulmonary function tests nor age should preclude treatment. Recent technical developments have reduced delivery time and resulted in more conformal treatments. This review is on behalf of the IASLC Advanced Radiation Technology Committee.     

CBCT图像引导下SBRT治疗肺部原发灶或转移灶的初步研究

[目的]评价CBCT图像引导技术下SBRT治疗原发性肺癌或肺转移瘤的安全性和初步疗效。[方法]2012年8月至2013年10月共9例患者在浙江省肿瘤医院接受CBCT图像引导下SBRT胸部放疗,中位年龄68岁。每次照射前行KV级CBCT扫描并在线配准。每次照射剂量5．0～12．5Gv．每日1次,中位照射次数8次（4～10次）;BED76．8～112．5Gy（中位96Gy）。[结果]9例患者均安全完成放疗,总有效率为77．8％。其中CR1例（11．1％）,PR6例（66．7％）,SD2例（22．2％）,无PD患者,未出现3度以上放射性毒副反应。中位随访8．8个月（1．3～14．6个月）,1年局部控制率及总生存率分别为88．9％和100％。[结论]CBCT图像引导下SBRT治疗早期肺癌或肺转移瘤近期疗效明确．毒副反应低．远期疗效有待进一步随访。     

Adjuvant Systemic Therapy in Patients With Early-Stage NSCLC Treated With Stereotactic Body Radiation Therapy

Introduction

Stereotactic body radiation therapy (SBRT) is commonly used to treat nonsurgical patients with early-stage NSCLC. There are no prospective data on the role of adjuvant chemotherapy in this setting.

三维适形放疗联合立体定向放疗加量对局部晚期周围型非小细胞肺癌的疗效观察

目的 观察三维适形放射治疗(3DCRT)结合立体定向放射治疗(SBRT)方法推量的照射方法,对局部晚期周围型非小细胞肺癌的疗效.方法 对47例局部进展期周围型非小细胞肺癌患者,采用CT模拟定位,TPS计划上勾画靶区,常规3～5野照射,PTV剂量达到46～60 Gy后,针对肺部病灶采用立体定向放射治疗方法加量5～6 Gy ×3F～4F,肺部肿瘤等效生物剂量(BED)达到72 ～ 86 Gy.结果 47例患者全部完成治疗,仅1例出现Ⅲ度放射性肺炎,无严重晚期放射性肺炎发生.完全缓解率为78.7％(CR 37例),部分缓解率为14.9％(PR 7例),稳定率6.4％(NC 3例),总有效率(CR +PR)为93.6％.1年局控率为95.7％ (45/47),2年局控率为80.9％ (38/47).1、2、3年总生存率分别为76.6％、51.1％、31.9％.结论 局部晚期周围型非小细胞肺癌,采用3DCRT结合SBRT的放射治疗方式,发生严重放射性肺炎几率低,局控率好.     

Predicting 2-Year Survival for Radiation Regimens in Advanced Non-small Cell Lung Cancer

AimsTotal dose, dose per fraction, number of fractions and treatment time are important determinants of the biological effect of a radiation regimen. Several randomised clinical trials (RCTs) have tested a variety of dosing regimens in advanced unresected non-small cell lung cancer, but survival remains poor. This work used past RCT data to develop and validate a predictive model that could help in designing new radiation regimens for successful testing in RCTs.Materials and methodsEleven RCTs that compared radiation regimens alone were used to define the relationship between radiation regimens and 2-year survival. On the basis of this relationship, predictive models were developed. Predicted values were internally and externally validated against observed values from the same 11 RCTs and 21 other RCTs. Scatter plots and Pearson's correlation coefficient (r) were used for validation. Finally, regimens were explored that could improve survival.ResultsIncrements in the total dose, dose per day and the number of treatment days were associated with improved survival; increments in dose-squared and treatment weeks were associated with reduced survival. The observed and predicted values were similar on internal (r = 0.96) and external validation (r = 0.76). Regimens that delivered a higher total dose over a shorter time had higher survival rates compared with the standard (60 Gy, 30 fractions, 6 weeks); survival may be improved by delivering the standard treatment in 5 weeks rather than 6 weeks.ConclusionThe developed model can predict the effect of thoracic radiation on survival in advanced non-small cell lung cancer patients. It is a useful tool for designing new radiation regimens for clinical trials.     

Impact of Pretreatment Interstitial Lung Disease on Radiation Pneumonitis and Survival in Patients Treated With Lung Stereotactic Body Radiation Therapy (SBRT)

Introduction

The purpose of this study was to determine the impact of interstitial lung disease (ILD) on radiation pneumonitis (RP) and overall survival (OS) in lung stereotactic body radiation therapy (SBRT).

Radiosensitivity of Lung Metastases by Primary Histology and Implications for Stereotactic Body Radiation Therapy Using the Genomically Adjusted Radiation Dose

Introduction

We assessed the radiosensitivity of lung metastases on the basis of primary histologic type by using a validated gene signature and model lung metastases for the gnomically adjusted radiation dose (GARD).

Current Evidence for Stereotactic Body Radiotherapy in Lung Metastases

Lung metastases are the second most common malignant neoplasms of the lung. It is estimated that 20–54% of cancer patients have lung metastases at some point during their disease course, and at least 50% of cancer-related deaths occur at this stage. Lung metastases are widely accepted to be oligometastatic when five lesions or less occur separately in up to three organs. Stereotactic body radiation therapy (SBRT) is a noninvasive, safe, and effective treatment for metastatic lung disease in carefully selected patients. There is no current consensus on the ideal dose and fractionation for SBRT in lung metastases, and it is the subject of study in ongoing clinical trials, which examines different locations in the lung (central and peripheral). This review discusses current indications, fractionations, challenges, and technical requirements for lung SBRT.     

Stereotactic, high single-dose irradiation of stage I non-small cell lung cancer (NSCLC) using four-dimensional CT scans for treatment planning

We reviewed response rates, local control, survival and side effects after non-fractionated stereotactic high single-dose body radiation therapy for lung tumors.

Forty patients with stage I non-small cell lung cancer (NSCLC) underwent radiosurgery involving single-dose irradiation. The standard dose prescribed to the isocenter was 30 Gy with an axial safety margin of 10 mm and a longitudinal safety margin of 15 mm. The planning target volume (PTV) was defined using three CT scans with reference to the phases of respiration so that the movement span of the clinical target volume (CTV) was enclosed.

The volume of the bronchial carcinomas varied from 4.2 to 130 cm³ (median: 19.5 cm³), and the PTV derived from four-dimensional CT (4D-CT) scans using image fusion ranged from 15.6 to 390.5 cm³ (median: 101 cm³). Tumor size ranged from 1.7 to 10 cm at largest focuses. Follow-up periods varied from 6.0 to 61.5 months (median: 20 months). We observed three local tumor recurrences, resulting in an actuarial local tumor control of 81% at 3 years. With the exception of two rib fractures, no serious late toxicity was observed. The overall survival probability rates were: 2 years: 66%, 3 years: 53% (median overall survival: 37 months). Cancer-specific survival probability was: 2 years: 71%, 3 years: 57%.

Non-fractionated high single-dose SBRT for NSCLC is more convenient for the patient and less time-consuming than hypofractionated SBRT, but data dealing with this method are still scanty. This alternative treatment results in favourable local control and acceptable toxicity.