Stereotactic Radiosurgery and Stereotactic Body Radiotherapy in the Management of Oligometastatic Disease

Stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT) represent non-invasive, efficacious and safe radiation treatments for the ablation of intracranial and extracranial metastases. Although the use of SRS has been established by level 1 evidence for patients presenting with up to three or four brain metastases for at least a decade, the paradigm of ablating a limited number of extracranial metastases (typically up to five, known as oligometastatic disease) has yet to be proven beyond the few reported but highly encouraging phase II randomised trials. In this overview, we summarise the phase III randomised controlled trials evaluating SRS for intact brain metastases and postoperative surgical cavities and introduce the limited literature and future concepts for treating patients with more than five intracranial metastases. Next, we summarise the published phase II randomised controlled trials specific to SBRT and oligometastatic disease, while briefly describing and contrasting the technical principles and biological mechanisms of SBRT versus conventional radiation. Phase III evidence for SBRT is needed, and we summarise ongoing trials in this overview. Ultimately, SRS and SBRT have become cornerstone therapeutic options for patients with oligometastatic disease and the future is bright for these patients, considering that not so long ago they were considered incurable and relegated to palliation alone.     

Stereotactic Pelvic Reirradiation for Locoregional Cancer Relapse

AimsUp to 40% of patients who have received radiation for a pelvic malignancy will develop locoregional recurrence in the previously irradiated volume. Stereotactic body radiotherapy (SBRT) has been used in the oligometastatic setting, and provides an ablative approach ideal for reirradiation. The purpose of this study was to evaluate the outcomes after SBRT reirradiation of extraosseous recurrences in the pelvis.Materials and methodsThis single institution retrospective study evaluated patients treated with SBRT reirradiation in the pelvis from January 2011 to February 2018. Patients with more than five oligometastatic lesions, >7 cm in size, and recurrence within the prostate were excluded.ResultsIn total, 30 patients were treated with SBRT with a median follow-up of 29.4 months. The primary tumour sites were most commonly rectum (30.8%) and prostate (30.8%). The median time interval between irradiation for the primary and SBRT reirradiation was 48 months (3–245). The typical reirradiation treatment was 35 Gy in five fractions, the median gross tumour volume size was 10.2 (0.3–110.5) ml and the most common target was the iliac nodes (40%). There were three (10%) acute grade 3 toxicities and no late grade 3 or more toxicities. At 12/24 months, local relapse-free survival, metastasis-free survival, progression-free survival and overall survival were 67.7%/50.7%, 67%/41.7%, 34.8%/14.9% and 83.2%/62.5%, respectively. On univariate analysis, improved local control was associated with low gross tumour volume (<10 ml) (P = 0.003) and prostate primary (P = 0.02), but was no longer significant on multivariate analysis. The proximity of organ at risk to the target did not significantly correlate with worse toxicity (P = 0.14) or tumour coverage (gross tumour volume: P = 0.8, planning target volume: P = 0.4).ConclusionSBRT pelvic reirradiation in oligometastatic patients is a safe and effective treatment modality. Careful consideration should be taken with larger tumour size, as it may be associated with worse oncological and toxicity outcome.     

X线立体定向放射治疗29例体部恶性肿瘤近期疗效观察

目的　探讨立体定向放射治疗体部恶性肿瘤的近期疗效。方法　单用立体定向放射治疗者 ,每次 4 .0～6 .0GY ,治疗 6～ 1 0次 ;肺癌应用立体定向放疗作为追加剂量者 ,每次 3 .5～ 5 .0GY ,治疗 4～ 7次。结果　总有效率 68.9% ,5例死亡。结论　立体定向放射治疗体部恶性肿瘤可得到较理想的姑息甚至根治性疗效 ,可降低正常组织的损伤 ,大幅度提高肿瘤局部剂量     

立体定向适形放射治疗体部恶性肿瘤的临床分析

目的：对62例体部恶性肿瘤实体定向适形放射治疗，并作临床分析。方法：自1997年5月至2001年5月治疗62例颅外肿瘤（89个病变部位），并进行了随访。肿瘤的临床靶体积（CTV）为0.2-254.2cm^3(平均为28.7cm^3)，计划靶体积处方剂量为3-12Gy(平均5.38Gy)，分3-10次照射。结果：治疗过程中无1例死亡。患者一般状况评分（KPS评分）：治疗前10-90分（平均60分），治疗后20-100分（平均82分）。近期疗效按实体瘤疗效标准：完全缓解（CR）6例，部分缓解(PR)34例，无变化（NC）15例，进展（PD）7例，肿瘤控制有效率为64.5%。结论：立体定向适形放射治疗颅外肿瘤有较好疗效。     

大垂体肿瘤的立体定向放射治疗

目的 探讨大垂体肿瘤立体定向放射治疗(stereotatic radiotherapy,SRT)的效果和视力保护问题。方法 11例大垂体肿瘤患者,肿瘤中位直径为4 cm,2例垂体肿瘤距视神经或视交叉的距离≥2 mm,其余患者肿瘤则紧贴视神经或视交叉。本组患者用X线分次立体定向放射治疗,每次剂量为5～7 Gy,每周2～3次,总剂量为40 Gy。做计划时使80％等剂量线避开视神经或视交叉。结果 肿瘤经分次SRT后体积明显缩小90.9％(10/11),视力有改善者占90.9％(10/11)。结论 SRT治疗大垂体肿瘤是有效的,对于肿瘤距视神经或视交叉的距离≤2 mm的垂体肿瘤,只要掌握好合适的分割剂量和次数,不会出现视力障碍。     

胸部肿瘤的立体定向放射治疗

目的：胸部肿瘤立体定向放疗的应用研究。方法：1999年11月至2001年1月期间共治疗41例患者45个病灶。进行分次立体定向适形放疗。射野一般4-8个，每日1次，连续照射，共5-12次，每次治疗时根据85%-95%剂量曲线确定处方剂量：4-7Gy，总量为25-60Gy。结果：41例45个病灶根据CT复查肿瘤消退情况确定CR为37.8%，PR为37.8%，总有效率为75.6%。结论：立体定向放疗治疗胸部较小的原发性肺癌和孤立转移瘤是一种局部控制好、疗程短、疗效显著、无痛苦的新疗法；是常规大野放疗后局部追加剂量的最好方式；对于肺癌术后或放疗后复发，是减少肿瘤周围正常组织接受剂量，避免损伤，提高肿瘤局部控制率的有效手段。后期不良反应及无期疗效有待进一步观察。     

Stereotactic radiotherapy for intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive malignancy with an increasing incidence worldwide and poor prognosis, despite several advances and continuous efforts to develop effective treatments. Complete surgical resection is the mainstay of treatment and offers a potentially curative option, but is only possible in less than a third of patients, owing to advanced disease. Chemotherapy is a well-established treatment in the adjuvant and palliative setting, however, confers limited benefit. Conventional radiotherapy is challenging due to local toxicity. With recent advances in stereotactic ablative radiotherapy (SABR), it is now possible to focus ablative beams of radiotherapy precisely aimed at tumours to minimise damage to surrounding viscera. This review details the history, technical background and application of SABR to iCCA, with directions for future research suggested.     

Stereotactic fractionated radiotherapy for Klatskin tumours

Background and purpose

In spite of various efforts perihilar cholangiocellular carcinoma (Klatskin tumour) has still a bad prognosis. The treatment of patients with inoperable Klatskin tumours by stereotactic fractionated radiotherapy (SFRT) was analysed retrospectively.

Patients, methods and materials

In our department 13 patients were treated for Klatskin tumours by SFRT (32-56 Gy, 3 × 4 Gy/week) from 1998 to 2008. The treatment technique was developed from stereotactic body frame radiotherapy to image guided (IGRT) stereotactic radiotherapy with control of patient positioning by cone beam computer tomography (CBCT). 6/13 patients received additional chemotherapy before or after SFRT.

Results

A median survival of 33.5 (6.6-60.4) months after diagnosis was reached by SFRT. The median time of freedom from tumour progression was 32.5 (6.1-60.4, last patient died without tumour progression) months. The therapy was tolerated very well. Nausea was the most common side effect. 5/13 patients suffered from recurrent cholangitis caused and enhanced by the primary tumour and drainages or stents in the bile ducts.

Conclusions

In the context of reaching local control being still the main problem of Klatskin tumour patients, SFRT seems to be a very promising method for the treatment of these tumours.     

Stereotactic body radiation therapy for lung metastases

Introduction

Stereotactic body radiation therapy (SBRT) has an emerging role in patients affected with pulmonary metastases. Purpose of this study was to evaluate efficacy and tolerability of SBRT in a cohort of patients treated between 2003 and 2009 at our institution.

Methods

A total of 61 patients with oligometastatic lung tumors (single pulmonary nodules in 73.7%) were included in the study. SBRT was performed with a stereotactic body frame and a 3D-conformal technique. Fifty-one patients received 26 Gy in 1 fraction, 22 a dose of 45 Gy in 3 fractions and 3 a dose of 36 Gy in 4 fractions. Primary tumor was lung cancer in 45.7% of patients, colorectal cancer in 21.3% and a variety of other origins in 33%. The primary endpoint was local control, secondary endpoints were survival and toxicity.

Results

After a median follow-up interval of 20.4 months, local control rates at 2 and 3 years were 89% and 83.5%, overall survival 66.5% and 52.5%, cancer-specific survival 75.4% and 67%, progression-free survival 32.4% and 22.3%. Tumor volume was significantly associated to survival, with highest rates in patients with single small tumors. Median survival time was 42.8 months, while median progression-free survival time was 11.9 months. Toxicity profiles were good, with just one case of grade III toxicity (pneumonitis).

Conclusion

This study shows that SBRT is an effective and safe local treatment option for patients with lung metastases. Definitive results are strictly correlated to clinical selection of patients.     

立体定向放射治疗非小细胞肺癌45例临床分析

目的探讨立体定向放射治疗对失去手术机会的非小细胞肺癌近期疗效及临床意义.方法对45例失去手术机会的非小细胞肺癌患者实施立体定向放射治疗,采用CT模拟定位技术和立体定向适形技术,6MV-X线放射源,单次靶剂量5～10GY,隔日照射,共4～8次,疗程7～15天.结果治疗结束后6～8周考核疗效.CR11/45、PR26/45、NR6/45、PD2/45,有效率(CR+PR)82.2%,患者治疗后症状和体征改善,KPS评分提高.结论初步认为立体定向放射治疗可提高非小细胞肺癌局部控制率并能改善治疗后生活质量,近期疗效满意.     

Whole Brain Radiotherapy Combined with Stereotactic Radiosurgery versus Stereotactic Radiosurgery Alone for Brain Metastases

Background: The aim of this study was to evaluate the effect of whole brain radiotherapy (WBRT) combined with streotactic radiosurgery versus stereotactic radiosurgery (SRS) alone for patients with brain metastases. Materials and Methods: This was a retrospective study that evaluated the results of 46 patients treated for brain metastases at Dr. Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital, Radiation Oncology Department, between January 2012 and January 2015. Twenty-four patients were treated with WBRT+SRS while 22 patients were treated with only SRS. Results: Time to local recurrence was 9.7 months in the WBRT+SRS arm and 8.3 months in SRS arm, the difference not being statistically significant (p= 0.7). Local recurrence rate was higher in the SRS alone arm but again without significance (p=0,06). Conclusions: In selected patient group with limited number (one to four) of brain metastases SRS alone can be considered as a treatment option and WBRT may be omitted in the initial treatment.     

垂体瘤的立体定向放射治疗进展

垂体瘤是常见的颅内肿瘤,分为功能性和无功能性两种。控制肿瘤体积及激素水平为其治疗的两大目标。立体定向放射治疗作为垂体瘤二线治疗方案,获得了良好的肿瘤控制率及激素缓解率。但仍不可避免地存在一些治疗后并发症,最主要的为放疗相关垂体功能减退。本文总结近几年关于立体定向放疗治疗垂体瘤的文献,将国内外学者的共识及争议点加以综述。     

立体定向适形放射治疗肺癌的临床研究

42例肺癌患者接受立体定向放疗 ,4～ 8Gy/次 ,1次 /d ,总量 3 0～ 45Gy。结果治疗后 ,CR为 14 3 % ( 6/4 2 ) ,CR PR 76 2 % ( 3 2 /4 2 ) ,NC 16 7% ( 7/4 2 )。主要不良反应为放射性食管炎及放射性肺炎 ,反应程度较轻。初步研究结果提示 ,立体定向适形放疗治疗肺癌近期疗效令人满意。     

立体定向放射治疗脊柱转移瘤疗效分析

目的观察立体定向放射治疗脊柱转移瘤的疗效与不良反应。方法应用全身伽玛刀治疗脊柱转移瘤24例，肿瘤组织照射剂量38．2～46．8Gy，10～13分次，13～17天完成。结果放疗后疼痛完全缓解（CR）7例，部分缓解（PR）12例，轻微疗效（MR）2例，止痛有效率90．5％。骨转移灶完全消失3例，明显缩小13例，治疗后生活质量评分较治疗前明显改善，消化道反应和骨髓抑制等不良反应轻微。结论立体定向放射治疗脊柱转移瘤止痛效果迅速持久，能明显改善患者的生活质量，控制肿瘤效果满意，值得推广。