Fractionated stereotactic radiotherapy to the post-operative cavity for radioresistant and radiosensitive brain metastases

Stereotactic radiotherapy following surgery for brain metastasis: Predictive factors for local control and radionecrosis

PURPOSE

To evaluate local control and adverse effects after postoperative hypofractionated stereotactic radiosurgery in patients with brain metastasis.

METHODS

We reviewed patients who had hypofractionated stereotactic radiosurgery (7.7Gy×3 prescribed to the 70% isodose line, with 2mm planning target volume margin) following resection from March 2008 to January 2014. The primary endpoint was local failure defined as recurrence within the surgical cavity. Secondary endpoints were distant failure rates and the occurrence of radionecrosis.

RESULTS

Out of 95 patients, 39.2% had metastatic lesions from a non-small cell lung cancer primary tumour. The median Graded Prognostic Assessment score was 3 (48% of patients). One-year local control rates were 84%. Factors associated with improved local control were no cavity enhancement on pre-radiation MRI (P<0.00001), planning target volume less than 12cm³ (P=0.005), Graded Prognostic Assessment score 2 or above (P=0.009). One-year distant cerebral control rates were 56%. Thirty-three percent of patients received whole brain radiation therapy. Histologically proven radionecrosis of brain tissue occurred in 7.2% of cases. The size of the preoperative lesion and the volume of healthy brain tissue receiving 21Gy (V₂₁) were both predictive of the incidence of radionecrosis (P=0.010 and 0.036, respectively).

CONCLUSION

Adjuvant hypofractionated stereotactic radiosurgery to the postoperative cavity in patients with brain metastases results in excellent local control in selected patients, helps delay the use of whole brain radiation, and is associated with a relatively low risk of radionecrosis.

Hypofractionated Stereotactic Radiosurgery and Radiotherapy to Large Resection Cavity of Metastatic Brain Tumors

OBJECTIVE

To evaluate the efficacy of postoperative fractionated stereotactic radiosurgery (FSRS) and hypofractionated stereotactic radiotherapy (SRT) to large surgical cavities after gross total resection of brain metastases.

METHODS

A retrospective analysis of 41 patients who had received tumor-bed FSRS (5 fractions) or SRT (10 fractions) after resection of brain metastasis between 2005 and 2015 was performed. All resection cavities were treated with a frameless linear accelerator-based system. Patients who underwent subtotal resection, single-dose SRS to the resection cavity, or were treated with a fractionation schedule other than 5 or 10 fractions, were excluded.

RESULTS

Twenty-six patients were treated with 5 fractions and 15 patients with 10 fractions. The median planning target volume was 19.78 cm³ (12.3-28 cm³) to the 5-fraction group and 29.79 cm³ (26.3-47.6 cm³) to the 10-fraction group (P = 0.020). The 1-year and 2-year local control rates for all patients were 89.4% and 77.1%, respectively, and 89.6% and 78.6% were free from distant intracranial progression, respectively. No difference was observed in local control or freedom from distant intracranial progression between the 5-fraction or 10-fraction groups. The median overall survival was 28.27 months (95% confidence interval, 19.42-37.12) for all patients. No patient developed necrosis at the resection cavity.

CONCLUSIONS

Fractionation offers the potential to exploit the different biological responses between neoplastic and normal tissues to ionizing radiation. The use of 5 daily doses of 5-6 Gy or 10 daily doses of 3 Gy is a good strategy to have a reasonable local control and avoid neurotoxicity.

Adjuvant hypofractionated partial-brain radiation therapy for pediatric Ewing sarcoma brain metastases: case report

This case report demonstrates that hypofractionated partial-brain radiation therapy with limited margins is a reasonable approach following gross tumor resection of Ewing sarcoma metastases to the brain. The patient presented with 2 intracranial metastases treated with gross-total resection followed by radiation therapy to 30 Gy in 5 fractions. The patient experienced symptomatic treatment-related inflammatory changes with resolution after receiving dexamethasone. He remains alive at 21 months of follow-up with no evidence of disease.

HFSRT of the resection cavity in patients with brain metastases

PURPOSE

Aim of this single center, retrospective study was to assess the efficacy and safety of linear accelerator-based hypofractionated stereotactic radiotherapy (HFSRT) to the resection cavity of brain metastases after surgical resection. Local control (LC), locoregional control (LRC = new brain metastases outside of the treatment volume), overall survival (OS) as well as acute and late toxicity were evaluated.

PATIENTS AND METHODS

46 patients with large (> 3 cm) or symptomatic brain metastases were treated with HFSRT. Median resection cavity volume was 14.16 cm(3) (range 1.44-38.68 cm(3)) and median planning target volume (PTV) was 26.19 cm(3) (range 3.45-63.97 cm(3)). Patients were treated with 35 Gy in 7 fractions prescribed to the 95-100 % isodose line in a stereotactic treatment setup. LC and LRC were assessed by follow-up magnetic resonance imaging.

RESULTS

The 1-year LC rate was 88 % and LRC was 48 %; 57% of all patients showed cranial progression after HFSRT (4% local, 44% locoregional, 9% local and locoregional). The median follow-up was 19 months; median OS for the whole cohort was 25 months. Tumor histology and recursive partitioning analysis score were significant predictors for OS. HFSRT was tolerated well without any severe acute side effects > grade 2 according to CTCAE criteria.

CONCLUSION

HFSRT after surgical resection of brain metastases was tolerated well without any severe acute side effects and led to excellent LC and a favorable OS. Since more than half of the patients showed cranial progression after local irradiation of the resection cavity, close patient follow-up is warranted. A prospective evaluation in clinical trials is currently being performed.

Role of radiation therapy in melanomas: Systematic review and best practice in 2016

Radiotherapy has been used for skin cancers since early after the discovery of X-rays. The introduction of sophisticated surgery techniques and information of the general population on potential late radiation-induced toxicity and carcinogenesis have led to limiting indications in the dermatologist community. However, radiotherapy (RT) has undergone considerable developments, essentially including technological advances, to sculpt radiation delivery, with demonstration of the benefit either alone or after adding concomitant cytotoxic agents or targeted therapies. Although side effects due to high doses and/or the use of old RT techniques have been significantly decreased, the risk of atrophic scars, ulcerations or secondary cancers persist. In this systematic review, we aim to discuss indications for RT in melanomas with focus on new advances that may lead to rehabilitating this treatment option according to the tumor radiosensitivity and clinical benefit/risk ratio. Melanomas have been considered as radioresistant tumors for many years.

Stereotactic fractionated radiotherapy of the resection cavity in patients with one to three brain metastases

OBJECTIVES

The goal of this study is to evaluate the role of stereotactic fractionated radiotherapy (SFRT) in patients with one to three brain metastases after surgical resection.

METHODS AND MATERIALS

We performed a retrospective single-institutional study in patients undergoing SFRT of surgical cavity after resection of ≤3 brain metastases. 60 patients with newly diagnosed brain metastases treated with SFRT following resection were included. The total irradiation dose was 30 Gy (5 Gy/d, BED 45 Gy) after complete macroscopical resection and 35 Gy (5 Gy/d, BED 52.5 Gy) in patients with macroscopic residual tumour after surgery. Macroscopic residual tumour was defined as contrast enhancement next to the resection cavity on the postoperative T1-MRI. The gross tumour volume (GTV) encompassing the residual tumour was delineated on the T1-MRI, the clinical target volume (CTV) encompassed the surgical cavity plus 1mm and the planning target volume (PTV) the CTV plus 2mm.

RESULTS

Eight of 60 patients had no imaging follow-up due to morbidity/mortality. Two of 52 (3.8%) patients experienced local failures only, 25 of 52 (48.1%) patients experienced distant intracranial failures only and 4 (7.7%) patients experienced both local and distant intracranial failures. In summary, there were 6 (11.5%) local failures and 29 (55.8%) distant failures. Age was significant for local control in the Cox regression test (p=0.046). Thirty-seven of 60 (61.7%) patients died during follow-up. Median follow-up was 8 months. Median overall survival was 15 months. Cox regression for survival was significant for KPS score ≤70% and size of PTV. No severe side effects were seen. Patients undergoing whole brain radiation therapy (WBRT) as salvage therapy in case of progression had no severe side effects either.

CONCLUSION

In the light of encouraging local control rates, SFRT could be an alternative to WBRT after surgical resection of ≤3 brain metastases. Due to the high rate of distant intracranial failure regular follow-up with MRI is mandatory.

Frameless LINAC-based stereotactic radiation therapy to brain metastasis resection cavity without whole-brain radiation therapy: A systematic review

PURPOSE

The aim of this systematic review was to summarize the findings from the published data of frameless stereotactic radiation therapy (RT) to the resection cavity delivered with nonrobotic linear accelerator in patients with brain metastases.

METHODS

The studies cited in this systematic review were identified through a search of the PubMed database, using the search terms: "stereotactic [Title/Abstract]" and "Brain [Title/Abstract]," and "Metas* [Title/Abstract]." The search was unlimited to language and publication year.

RESULTS

A total of 9 studies were included in our review. Stereotactic RT to the resection cavity appears to provide excellent local control rates that are comparable to framed stereotactic RT. There are various factors that influence local control. Distant intracranial control rates are poor with the use of postoperative stereotactic RT compared with local treatment (surgery or stereotactic RT) plus whole-brain RT.

CONCLUSIONS

Stereotactic RT to the resection cavity appears to provide good local control rates and poor distant intracranial control. Postoperative treatment should be discussed by a multidisciplinary team and tailored to each case individually.

Treatment of brain oligometastases with hypofractionated stereotactic radiotherapy utilising volumetric modulated arc therapy

Stereotactic radiosurgery (SRS) is commonly used to treat brain metastases, particularly in the oligometastatic setting. This study analyses our initial experience in treating oligometastatic brain disease using Volumetric Modulated Arc Therapy (VMAT) to deliver hypofractionated stereotactic radiotherapy (HFSRT). Sixty-one patients were treated with HFSRT with a median dose of 24 Gy (range 22-40 Gy) in a median of three fractions (range 2-10 fractions). With a median follow-up of 23 months, the local control rate was 74 % for the entire cohort. Local control was 87 % for patients who had surgery with no radiological evidence of residual disease followed by HFSRT compared with 69 % in patients treated with HFSRT alone. The overall median time post radiotherapy to local failure was 8.6 months and to extracranial failure was 7.9 months. The mean time to distant brain failure was 9.9 months. Twenty-two patients (36 %) died during the study with median time to death of 4.4 months. Median overall survival (OS) from treatment was 21 months and 12 month OS was 60 %. Our experience with HFSRT using VMAT for oligometastatic brain metastases in the post-operative setting demonstrates comparable local control and survival rates compared with international published data. In the intact brain metastasis setting, local control using the dose levels and delivery in this cohort may be inferior to radio-surgical series. Local control is independent of histology. Careful selection of patients remains critical.

Resection Followed by Involved-Field Fractionated Radiotherapy in the Management of Single Brain Metastasis

Introduction

We expanded upon our previous experience using involved-field fractionated radiotherapy (IFRT) as an alternative to whole brain radiotherapy or stereotactic radiosurgery for patients with surgically resected brain metastases (BM).

Materials and methods

All patients with single BM who underwent surgical resection followed by IFRT at our institution from 2006 to 2013 were evaluated. Local recurrence (LR)-free survival, distant failure (DF)-free survival, and overall survival (OS) were determined. Analyses were performed associating clinical variables with LR and DF. Salvage approaches and toxicity of treatment for each patient were also assessed.

Results

Median follow-up was 19.1 months. Fifty-six patients were treated with a median dose of 40.05 Gy/15 fractions with IFRT to the resection cavity. LR-free survival was 91.4%, DF-free survival was 68.4%, and OS was 77.7% at 12 months. No variables were associated with increased LR; however, melanoma histopathology and infratentorial location were associated with DF on multivariate analysis. LRs were salvaged in 5/8 patients, and DFs were salvaged in 24/29 patients. Two patients developed radionecrosis.

Conclusion

Adjuvant IFRT is feasible and safe for well-selected patients with surgically resected single BM. Acceptable rates of local control and salvage of distal intracranial recurrences continue to be achieved with continued follow-up.

New developments in intracranial stereotactic radiotherapy for metastases

Brain metastases are common and the prognosis for patients with multiple brain metastases treated with whole brain radiotherapy is limited. As systemic disease control continues to improve, the expectations of radiotherapy for brain metastases are growing. Stereotactic radiosurgery (SRS) as a high precision localised irradiation given in a single fraction prolongs survival in patients with a single brain metastasis and functional independence in those with up to three brain metastases. SRS technology has become commonplace and is available in many radiation oncology and neurosurgery departments. With increasing use there is a need for appropriate patient selection, refinement of dose-fractionation and safe integration of SRS with other treatment modalities. We review the evidence for current practice and new developments in the field, with a specific focus on patient-relevant outcomes.

Hypofractionated radiosurgery has a better safety profile than single fraction radiosurgery for large resected brain metastases

The purpose of this study is to compare the safety and efficacy of single fraction radiosurgery (SFR) with hypofractionated radiosurgery (HR) for the adjuvant treatment of large, surgically resected brain metastases. Seventy-five patients with 76 resection cavities ≥ 3 cm received 15 Gray (Gy) × 1 SFR (n = 40) or 5-8 Gy × 3-5 HR (n = 36). Cumulative incidence of local failure (LF) and radiation necrosis (RN) was estimated accounting for death as a competing risk and compared with Gray's test. The effect of multiple covariates was evaluated with the Fine-Gray proportional hazards model. The most common HR dose-fractionation schedules were 6 Gy × 5 (44%), 7-8 Gy × 3 (36%), and 6 Gy × 4 (8%). The median follow-up was 11 months (range 2-71). HR patients had larger median resection cavity volumes (24.0 vs. 13.3 cc, p < 0.001), planning target volumes (PTV) (37.7 vs. 20.5 cc, p < 0.001), and cavity to PTV expansion margins (2 vs. 1.5 mm, p = 0.002) than SFR patients. Cumulative incidence of LF (95% CI) at 6 and 12-months for HR versus SFR was 18.9% (0.07-0.34) versus 15.9% (0.06-0.29), and 25.6% (0.12-0.42) versus 27.2% (0.14-0.42), p = 0.80. Cumulative incidence of RN (95% CI) at 6 and 12 months for HR vs. SFR was 3.3% (0.00-0.15) versus 10.7% (0.03-0.23), and 10.3% (0.02-0.25) versus 19.2% (0.08-0.34), p = 0.28. On multivariable analysis, SFR was significantly associated with an increased risk of RN, with a HR of 3.81 (95% CI 1.04-13.93, p = 0.043). Hypofractionated radiosurgery may be the more favorable treatment approach for radiosurgery of cavities 3-4 cm in size and greater.