Efficacy of Dose-Escalated Hypofractionated Radiosurgery for Arteriovenous Malformations

There is considerable controversy about the management of arteriovenous malformations (AVMs) that are high risk for surgical resection. Stereotactic radiosurgery (SRS) has a reported success rate of less than 50% with unacceptably high rates of radiation necrosis with larger AVM volumes. Neither volume staging nor hypo-fractionated SRS have conclusively been demonstrated to improve results. We hypothesized that the failure of previous hypo-fractionation SRS trials was due to an insufficient biologically effective dose (BED) of radiation. We initiated a pilot study of treating AVM patients with a total dose divided into three or five fractions designed to deliver the equivalent BED of 20 Gy in a single fraction (α/β =3). We performed a retrospective analysis of 37 AVM patients who had a minimum of two years of follow-up or underwent obliteration. Patients were treated with 30 Gy/3 fractions, 33 Gy/3 fractions, or 40 Gy/5 fractions using a CyberKnife device (Accuracy Incorporated, Madison, Wisconsin, United States). The primary endpoint was complete AVM obliteration, determined by MRA imaging. Most obliterations were confirmed with diagnostic cerebral angiography. Secondary endpoints were post-radiosurgery hemorrhage and radiation-related necrosis. Kaplan-Meier analysis was used to determine obliteration rates. From 2013 to 2021, 37 patients fitting inclusion criteria were identified (62% male, average age at treatment = 48.88 years). Fifteen (41%) patients had prior treatment (surgery, radiosurgery, embolization) for their AVM, 32 (86%) had AVMs in eloquent locations, 17 (46%) had high-risk features, and 14 (38%) experienced AVM rupture prior to treatment. The average modified radiosurgery-based AVM score (mRBAS) was 1.81 (standard deviation (SD)= 0.52), and the mean AVM volume was 6.77 ccs (SD = 6.09). Complete AVM obliteration was achieved in 100% of patients after an average of 26.13 (SD = 14.62) months. The Kaplan-Meier analysis showed AVM obliteration rates at one, two, and three years to be 16.2%, 46.9%, and 81.1%, respectively. Post-operative AVM rupture or hemorrhage occurred in one (2.7%) patient, after nine months. Radiation necrosis occurred in four (11%) patients after an average period of 17.3 (SD =14.7) months. The SRS dose used in this study is the highest BED of any AVM hypofractionation trial in the published literature. This study suggests that dose-escalated hypofractionated radiosurgery can be a successful strategy for AVMs with acceptable long-term complication rates. Further investigation of this treatment regimen should be performed to assess its efficacy.

Meningioma Presenting With Intratumoral Hemorrhage on Active Surveillance

Meningiomas are relatively common primary adult brain tumors. They are slow-growing, highly vascular, and graded according to histology, phenotypic and genotypic features. We present a case of a 66-year-old male with a history of tongue squamous cell carcinoma, which presented multiple risk factors for cardiovascular and thromboembolic events. A brain lesion was initially detected on a computed tomography (CT) scan and later characterized by magnetic resonance imaging (MRI). The multidisciplinary team decided to maintain surveillance due to the lack of associated symptoms. Upon expansion in size and acute intralesional hemorrhage seen on follow-up imaging, the patient was submitted to surgical excision. The histopathological testing determined it to be an atypical meningioma. Two months later, the patient received stereotactic radiotherapy, and a post-surgical MRI showed no evidence of tumor recurrence. This case report describes a rare occurrence of intratumoral hemorrhage in a meningioma during surveillance, highlighting the importance of vigilant monitoring and consideration of potential risk factors for hemorrhagic events.

Stereotactic Radiotherapy or Whole-Brain Irradiation Plus Simultaneous Integrated Boost After Resection of Brain Metastases

BACKGROUND/AIM

Most patients with resected brain metastases receive post-operative radiotherapy. This study investigated outcomes of fractionated stereotactic radiotherapy (FSRT) alone or whole-brain irradiation plus simultaneous integrated boost (WBI+SIB) in the post-operative setting.

PATIENTS AND METHODS

Forty-four patients receiving FSRT alone (n=32) or WBI+SIB (n=12) after resection of 1-3 brain metastases from 2014-2022 were analyzed. Twelve factors were evaluated for local control (LC), distant brain control (DBC), and overall survival (OS).

RESULTS

On univariate and multivariate analyses, single brain metastasis was associated with improved LC and DBC. Longer interval between tumor diagnosis and radiotherapy, single brain metastasis, and Karnofsky performance score >80 were associated with improved OS. WBI+SIB showed a trend towards better DBC.

CONCLUSION

Several independent predictors of outcomes after FSRT or WBI+SIB following resection of brain metastases were identified. Given similar survival in the post-operative setting between FSRT and WBI+SIB, potential toxicity remains a significant factor in treatment recommendations.

Radiation Necrosis Following Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy with High Biologically Effective Doses for Large Brain Metastases

In Radiation Therapy Oncology Group 90-05, the maximum tolerated dose of single-fraction radiosurgery (SRS) for brain metastases of 21-30 mm was 18 Gy (biologically effective dose (BED) 45 Gy₁₂). Since the patients in this study received prior brain irradiation, tolerable BED may be >45 Gy₁₂ for de novo lesions. We investigated SRS and fractionated stereotactic radiotherapy (FSRT) with a higher BED for radiotherapy-naive lesions. Patients receiving SRS (19-20 Gy) and patients treated with FSRT (30-48 Gy in 3-12 fractions) with BED > 49 Gy₁₂ for up to 4 brain metastases were compared for grade ≥ 2 radiation necrosis (RN). In the entire cohort (169 patients with 218 lesions), 1-year and 2-year RN rates were 8% after SRS vs. 2% and 13% after FSRT (p = 0.73) in per-patient analyses, and 7% after SRS vs. 7% and 10% after FSRT (p = 0.59) in per-lesion analyses. For lesions ≤ 20 mm (137 patients with 185 lesions), the RN rates were 4% (SRS) vs. 0% and 15%, respectively, (FSRT) (p = 0.60) in per-patient analyses, and 3% (SRS) vs. 0% and 11%, respectively, (FSRT) (p = 0.80) in per-lesion analyses. For lesions > 20 mm (32 patients with 33 lesions), the RN rates were 50% (SRS) vs. 9% (FSRT) (p = 0.012) in both per-patient and per-lesion analyses. In the SRS group, a lesion size > 20 mm was significantly associated with RN; in the FSRT group, lesion size had no impact on RN. Given the limitations of this study, FSRT with BED > 49 Gy₁₂ was associated with low RN risk and may be safer than SRS for brain metastases > 20 mm.

Stereotactic Body Radiotherapy as an Effective Treatment for Pancreatic Cancer

Background Stereotactic body radiotherapy (SBRT) allows the delivery of an ablative radiation dose to the tumor with minimal toxicity. Although magnetic resonance imaging (MRI)-guided SBRT appears to be a promising approach in the modern era, X-ray image-guided SBRT is still used worldwide for pancreatic cancer. This study aims to evaluate the results of X-ray image-guided SBRT in patients with locally advanced pancreatic cancer (LAPC). Methodology Medical records of 24 patients with unresectable LAPC who underwent X-ray image-guided SBRT between 2009 and 2022 were retrospectively evaluated. SPSS version 23.0 (IBM Corp., Armonk, NY, USA) was utilized for all analyses. Results The median age was 64 years (range = 42-81 years), and the median tumor size was 3.5 cm (range = 2.7-4 cm). The median total dose of SBRT was 35 Gy (range = 33-50 Gy) in five fractions. After SBRT, 30% of patients showed complete and 41% showed partial response, whereas 20% had stable disease and 9% had progression. Median follow-up was 15 months (range = 6-58 months). During follow-up, four (16%) patients had local recurrence, one (4%) had a regional recurrence, and 17 (70%) had distant metastasis (DM). The two-year local control (LC), local recurrence-free survival (LRFS), overall survival (OS), and DM-free survival (DMFS) rate was 87%, 36%, 37%, and 29%, respectively. In univariate analysis, a larger tumor size (>3.5 cm) and higher cancer antigen 19-9 level (>106.5 kU/L) significantly decreased the OS, LRFS, and DMFS rates. No severe acute toxicity was observed. However, two patients had severe late toxicity as intestinal bleeding. Conclusions X-ray image-guided SBRT provides a good LC rate with minimal toxicity for unresectable LAPC. However, despite modern systemic treatments, the rate of DM remains high which plays a major role in survival.

Salvage Surgical Resection after Linac-Based Stereotactic Radiosurgery for Newly Diagnosed Brain Metastasis

Background: This study aimed to assess the clinical outcomes of salvage surgical resection (SSR) after stereotactic radiosurgery and fractionated stereotactic radiotherapy (SRS/fSRT) for newly diagnosed brain metastasis. Methods: Between November 2009 and May 2020, 318 consecutive patients with 1114 brain metastases were treated with SRS/fSRT for newly diagnosed brain metastasis at our hospital. During this study period, 21 of 318 patients (6.6%) and 21 of 1114 brain metastases (1.9%) went on to receive SSR after SRS/fSRT. Three patients underwent multiple surgical resections. Twenty-one consecutive patients underwent twenty-four SSRs. Results: The median time from initial SRS/fSRT to SSR was 14 months (range: 2–96 months). The median follow-up after SSR was 17 months (range: 2–78 months). The range of tumor volume at initial SRS/fSRT was 0.12–21.46 cm³ (median: 1.02 cm³). Histopathological diagnosis after SSR was recurrence in 15 cases, and radiation necrosis (RN) or cyst formation in 6 cases. The time from SRS/fSRT to SSR was shorter in the recurrence than in the RNs and cyst formation, but these differences did not reach statistical significance (p = 0.067). The median survival time from SSR and from initial SRS/fSRT was 17 and 74 months, respectively. The cases with recurrence had a shorter survival time from initial SRS/fSRT than those without recurrence (p = 0.061). Conclusions: The patients treated with SRS/fSRT for brain metastasis need long-term follow-up. SSR is a safe and effective treatment for the recurrence, RN, and cyst formation after SRS/fSRT for brain metastasis.

Fractionated stereotactic radiotherapy for uveal melanoma: Long-term outcome and control rates

Purpose

The aim of our study is to evaluate local tumour control rates, radiation side‐effects, visual preservation and disease‐free survival (DFS) of uveal melanoma (UM) patients treated with fractionated stereotactic radiotherapy (fSRT).

Methods

A retrospective study of UM patients, who were treated with fSRT (N = 189), was performed by the Rotterdam Ocular Melanoma Study group (ROMS), the Netherlands, between 1999 and 2014 with a follow‐up of at least 5 years.

Results

The 1‐, 3‐, 5‐, 10‐ and 15‐year local tumour control rates were as follows: 99.4%, 92.8%, 92.2%, 89.3% and 89.3%, respectively. Cataract (67.8%) was the most common side‐effect of fSRT followed by retinopathy (35.1%), maculopathy (23.8%), vitreous haemorrhage (20.1%), neovascular glaucoma (NVG) (20.0%) and optic neuropathy (12.4%). Patients with anterior located UMs developed cataract more frequently (p = 0.047, multivariable analysis). By multivariable analysis, significant factors for secondary enucleation were tumour recurrence (p < 0.001) and NVG (p < 0.001). In multivariable analysis, risk factors for a worse DFS were larger UM (p = 0.024) and tumours with subretinal fluid (SRF) at baseline (p = 0.038). The 5‐year DFS was 77.0% and the best corrected visual acuity decreased significantly after treatment. After 5 years, 22.0% of patients and after 10 years 17.6% of patients had a visual acuity of ≤0.3 logMAR.

Conclusion

Fractionated stereotactic radiotherapy is a good treatment option for small‐, medium‐ and large‐sized tumours with 5‐year local tumour control of 92.2%. After 5 years, 22.0% of the patients had a good vision. Independently of tumour location, the visual acuity decreased significantly after treatment. Overall, the 5‐year DFS was 77.0%.

Does Combined Fractionated Stereotactic Radiotherapy and Immunotherapy Change the Outcome of Recurrent High-Grade Gliomas?

Background

Radiotherapy (RT) with immune checkpoint inhibitors (ICI) has yielded good responses in many cancers. We aimed to report the results of combined fractionated stereotactic radiotherapy (FSRT) and ICI in patients with recurrent high-grade glioma.

Methodology

Patients were treated with FSRT and nivolumab which were continued until progression or toxicity. The Response Assessment in Neuro-oncology and Immunotherapy Response Assessment in Neuro-oncology criteria were used to assess treatment response on magnetic resonance imaging. Treatment-related toxicity was noted in all patients.

Results

A total of eight patients were included. Recurrence was detected after a median of 5.8 months following the first RT, all in the treatment field. FSRT (3 × 8 Gy) was applied with neoadjuvant, concurrent, and adjuvant nivolumab. After a median follow-up of 21.3 months from diagnosis and 12.6 months from recurrence, one patient was alive and seven succumbed to the disease. The median overall survival was 20.9 months after diagnosis and 12.9 months after recurrence. The median progression-free interval was 2.3 months after FSRT. The local control (LC) rate was 62.5% with a median local recurrence-free survival of nine months. Progression in other regions of the brain was observed in four patients with a median progression-free survival of 2.1 months. Acute toxicity was not observed. ICI-related grade 3 late pneumonitis was observed in two patients, and grade 1 late thyroid toxicity in two patients. One patient with pneumonitis also developed osteoporosis and radiation necrosis.

Conclusions

A high LC rate was achieved with concurrent FSRT and ICI with a severe late toxicity rate of 25%. This combination can be an option in recurrent high-grade gliomas.

Survival After Stereotactic Radiosurgery (SRS) or Fractionated Stereotactic Radiotherapy (FSRT) for Cerebral Metastases in the Elderly

BACKGROUND/AIM

Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) have gained popularity especially for treating 1-3 cerebral metastases. Elderly patients benefit from treatment personalisation. A specific survival score was created to facilitate this approach.

PATIENTS AND METHODS

Ten characteristics were retrospectively analysed for survival in 104 elderly patients with 1-3 cerebral metastases receiving SRS or FSRT alone using a linear accelerator or Cyberknife®.

RESULTS

On multivariate analysis, better survival was significantly associated with KPS of 90-100 (p=0.049), single lesion (p=0.036), maximum cumulative diameter of all lesions <16 mm (p=0.026) and supratentorial involvement only (p=0.047). Three groups were formed with 12-14 points (n=22), 15-16 points (n=33) and 17-19 points (n=49) with 12-month survival rates of 7%, 34% and 58% (p<0.0001), respectively. Positive predictive values for predicting death ≤12 months and survival ≥12 months were 95% and 54%.

CONCLUSION

The new score showed very high accuracy in predicting death ≤12 months, but not in predicting survival ≥12 months.

Dosimetric comparison of Gamma Knife® IconTM and linear accelerator-based fractionated stereotactic radiotherapy (FSRT) plans for the re-irradiation of large (>14 cm3) recurrent glioblastomas

Our objective is to investigate dosimetric differences between clinically deliverable Gamma Knife^® (GK) Icon™ and linac-based FSRT plans on the basis of normal brain dose sparing for large (>14 cm³) recurrent glioblastomas (GBM). Sixteen patients with large, recurrent GBM were treated using re-irradiation via linac-based FSRT, 35 Gy in 10 fractions. For each patient, a new GK FSRT plan was created in Leksell GammaPlan^® V11 (LGP). To maintain clinical deliverability, the LGP optimization included a planning goal of treatment time <20 minutes per fraction. Dosimetric comparison of coverage and normal brain dose between the linac and GK treatment plans was performed in MIM. The GK FSRT plans had significantly (p < 0.05) lower mean normal brain dose values (-8.85%), mean values of normal brain V20 (-32.4%) and V12 (-25.9%), and a lower mean V4 (-10.0%). GK FSRT plans have the potential to reduce the risk of radiation-related toxicities.

Apatinib and fractionated stereotactic radiotherapy for the treatment of limited brain metastases from primary lung mucoepidermoid carcinoma: A case report

RATIONALE

Apatinib is a novel anti-angiogenic agent that targets vascular endothelial growth factor receptor-2, thereby inhibiting tumor angiogenesis, and is effective in the treatment of brain metastases (BM) and peritumoral brain edema (PTBE). There are no previous reports of combination therapy with apatinib and fractionated stereotactic radiotherapy (FSRT) for BM from primary lung mucoepidermoid carcinoma (MEC).

PATIENT CONCERNS

A 63-year-old man underwent left lower lobectomy and mediastinal lymph node dissection in April 2018.

DIAGNOSES

Postoperative pathology demonstrated high-grade MEC. The patient developed 3 BM with PTBE 3 months after undergoing surgery.

INTERVENTIONS

The patient received a combination of FSRT and apatinib (250-500 mg/d) as maintenance therapy.

OUTCOMES

The 3 BM showed nearly complete responses, and the PTBE areas shrank visibly. A new BM lesion occurred 7 months after the first FSRT and was treated with a second dose of FSRT. The patient developed extensive metastasis and atelectasis 9 months later. He died of pulmonary infection in December 2019. The overall survival time was 20 months.

LESSONS

Limited BM from primary lung MEC may be treated effectively with combination therapy with apatinib and FSRT when chemotherapy alone is not effective or tolerated. Further studies are needed to investigate the clinical outcomes and toxicities associated with the treatment.

FSRT vs. SRS in Brain Metastases-Differences in Local Control and Radiation Necrosis-A Volumetric Study

Background: While the role of stereotactic radiotherapy for brain metastases is increasing, evidence on the comparative efficacy and safety of fractionated stereotactic radiotherapy (FSRT) and single-session radiosurgery (SRS) is scarce.

Methods: Longitudinal volumetric analysis was performed in a consecutive cohort of 120 patients and 190 brain metastases (>0.065 cm³ in volume / > ~5 mm in diameter) treated exclusively with FSRT (n = 98) and SRS (n = 92), respectively. A total of 972 tumor segmentations was used, averaging 5.1 time points per metastasis. Progression was defined using a volumetric extension of the RANO-BM criteria. Local control and radionecrosis were compared for lesions treated with FSRT and SRS, respectively.

Results: Metastases treated with FSRT were significantly larger at baseline (mean, 4.66 vs. 0.40 cm³, p < 0.001). Biologically effective dose (BED) for metastases (α/β = 12, linear-quadratic-cubic model) was significantly associated with local control, whereas BED for normal brain (α/β = 2, linear-quadratic model) was significantly associated with radionecrosis. Median time to local progression was 22.9 months in the FSRT group compared to 14.5 months in the SRS group (p = 0.022). Overall radionecrosis rate at 12 months was 3.4% for FSRT and 14.8% for SRS (p = 0.010). Radionecrosis °IV requiring resection with histologic proof of radiation necrosis also was significantly reduced in the FSRT group (FSRT 0.0% vs. SRS 3.9%, p = 0.041). In multivariate analysis, FSRT was associated with reduced risk of progression (HR 0.47, p = 0.015) and reduced risk of radionecrosis (HR 0.18, p = 0.045).

Conclusions: This volumetric study provides initial evidence that the improvements in therapeutic ratio expected for FSRT in larger brain metastases, might equally extend into the domain of smaller metastases, traditionally less considered for fractionated treatment. FSRT might constitute an important tool to further increase local control and reduce radionecrosis risk in stereotactic radiotherapy for brain metastases, that should be assessed in randomized intervention trials.

Predicting the Risk of Subsequent Distant Brain Metastases After Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy in Elderly Patients

BACKGROUND/AIM

Treatment for elderly patients with few brain metastases is controversial. A score was generated to predict distant brain metastases (DBMs) after stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT).

PATIENTS AND METHODS

Ten characteristics were retrospectively analyzed for freedom from new DBMs in 104 elderly patients receiving SRS or FSRT alone for 1-3 brain metastases. Characteristics that were significant or showed a trend on multivariate analysis were used for the score.

RESULTS

On multivariate analysis, favorable histology (p=0.026) and single brain metastasis (p=0.006) showed significant associations with freedom from DBMs. A trend was found for supra-tentorial location only (p=0.065). Three groups were designed, 10-14, 16-20 and 21-25 points, with 6-month rates of freedom from DBMs of 10%, 54% and 95%, respectively (p<0.0001). Positive predictive values to predict DBMs and freedom from DBMs at 6 months were 91% and 94%.

CONCLUSION

This new score provided high accuracy in predicting DBMs and freedom from DBMs.

Fractionated Stereotactic Sequential Boost in a Selected Cohort of Glioblastoma Patients: A Mono-institutional Analysis

AIM

To retrospectively assess toxicity and survival in 15 selected Glioblastoma patients treated with a sequential fractionated stereotactic radiotherapy (FSRT) boost after chemo-radiotherapy (CHT-RT) and compare their survival outcomes with a control group.

PATIENTS AND METHODS

Toxicity was assessed with the CTCAE 3.0 scale. The Kaplan-Meier method was used to design survival curves, log-rank test for bivariate analysis and Cox proportional hazard regression model for multivariate analysis.

RESULTS

The median follow-up was 16 months (range=5-60). One case of headache and one of radionecrosis (RN) occurred. Median overall survival (OS) was 25 months in the boost group vs. 14 in the no-boost group (p=0.004). Median progression-free survival (PFS) was 15 months in the boost group versus 8 in the no-boost group (p=0.046). At multivariate analysis FSRT boost resulted significantly associated with OS and PFS.

CONCLUSION

In our series a sequential FSRT boost resulted in safe outcomes and significantly associated with survival.

The risk/benefit ratio of radiotherapy in pituitary tumors

Radiation therapy (RT) is an effective treatment for patients with either nonfunctioning or secreting pituitary adenomas unsuccessfully treated by surgery and/or medical therapy, resulting in local control of 90-95% at 5-10 years and variable normalization of hormonal hypersecretion for patients with GH-, ACTH-, and prolactin-secreting adenomas in the range of 40-80% at 5 years; however, its use has been limited because of concerns regarding potential late toxicity of radiation and delayed efficacy in normalization of hormone hypersecretion. In the last decades, there have been advances in all aspects of radiation treatment, including more accurate immobilization, imaging, treatment planning and dose delivery. RT has evolved with the development of highly conformal stereotactic techniques and new planning and dose delivery techniques, including intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). All these new techniques allow precise and sharply focused radiation delivery reducing the dose to surrounding critical neurovascular and brain structures, and potentially limiting the long-term consequences of radiation treatments. In this review, we present a critical analysis of the more recent available literature on the use of RT in patients with both nonfunctioning and secreting pituitary adenomas, focussing particularly on the risk/benefit ratio of modern radiation techniques.

Quality of life: fractionated stereotactic radiotherapy versus enucleation treatment in uveal melanoma patients

PURPOSE

To report the quality of life and visual functioning in uveal melanoma patients treated with enucleation or fractionated stereotactic radiation therapy (fSRT).

METHODS

Uveal melanoma (UM) patients treated with fSRT (n = 65) or enucleation (n = 48) participated in this prospective study. Questionnaires to measure anxiety (State-Trait Anxiety Inventory), subjective distress (Impact of Event Scale) and quality of life (EORTC-QLQ-C30 and National Eye Institute Visual Function Questionnaire (VFQ-25)) were obtained before treatment and 2, 6, 12, 24, 36 and 48 months after treatment.

RESULTS

Less peripheral vision was observed until 3 years (p = 0.026) posttreatment in enucleated patients compared to irradiated patients. From 2 months until 3 years posttreatment irradiated patients increase in role functioning-score (p = 0.005), while enucleated patients decrease in score (p = 0.012). Regardless of their treatment, for all patients we measured a reduction in physical functioning (p = 0.035), insomnia (p < 0.001) and in state anxiety from pretreatment until 2 years posttreatment (p < 0.001). An increase in pain overall (p = 0.023) and in emotional functioning is observed 1 year posttreatment (p < 0.001). At baseline, patients with metastases (independent of their treatment) have more subjective distress (p = 0.037) than patients without metastases. The mean 'global health score' overall, without effect of time, was 76.4 (SD: 13.6).

CONCLUSION

Enucleated patients had more difficulty working or performing household tasks 2 months posttreatment compared to irradiated patients. Enucleated patients had diminished peripheral vision until 3 years compared to irradiated patients. Overall quality of life is not significantly different between both treatment groups.

Validation of a Survival Score for Patients Receiving Radiosurgery or Fractionated Stereotactic Radiotherapy for 1 to 3 Brain Metastases

BACKGROUND/AIM

We developed a scoring system to predict 1-year survival after radiosurgery for 1-3 brain metastases. This study aimed to validate this system.

PATIENTS AND METHODS

Seventy-six new patients were included in this validation study. Like in the original scoring-system, three factors (age, performance status, extra-cranial metastases) were used. For each factor, 1-year survival rates in % were divided by 10, and the three scoring-points were added for each patient.

RESULTS

Patient's scores were 10, 11, 13, 14, 16 or 17 points with 1-year survival rates ranging between 31% and 80%. Two groups, 10-14 and 16-17 points were formed. In the 14-16 points group, 1-year survival was 47% (versus 33% in the preceding study, p=0.060). In the 16-17 points group, 1-year survival rates were 75% versus 77% (p=0.79).

CONCLUSION

In the more favorable group, the scoring-system was very reproducible. In the less favorable group, the difference was larger, but also not signficant.

Predicting the Risk of Developing New Cerebral Lesions After Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy for Brain Metastases from Renal Cell Carcinoma

AIM

To create an instrument for estimating the risk of new brain metastases after stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) alone in patients with renal cell carcinoma (RCC).

PATIENTS AND METHODS

In 45 patients with 1-3 brain metastases, seven characteristics were analyzed for association with freedom from new brain metastases (age, gender, performance score, number and sites of brain metastases, extra-cerebral metastasis, interval from RCC diagnosis to SRS/FSRT).

RESULTS

Lower risk of subsequent brain lesions after RT was associated with single metastasis (p=0.043) and supratentorial involvement only (p=0.018). Scoring points were: One metastasis=1, 2-3 metastases=0, supratentorial alone=1, infratentorial with/without supratentorial=0. Scores of 0, 1 and 2 points were associated with 6-month rates of freedom from subsequent brain lesions of 25%, 74% and 92% (p=0.008). After combining groups with 1 and 2 points, 6-month rates were 25% for those with 0 points and 83% for those with 1-2 points (p=0.002).

CONCLUSION

Two groups were identified with different risks of new brain metastases after SRS or FSRT alone. High-risk patients may benefit from additional whole-brain irradiation.

A Score to Identify Patients with Brain Metastases from Colorectal Cancer Who May Benefit from Whole-brain Radiotherapy in Addition to Stereotactic Radiosurgery/Radiotherapy

AIM

To design a tool to predict the probability of new cerebral lesions after stereotactic radiosurgery/radiotherapy for patients with 1-3 brain metastases from colorectal cancer.

PATIENTS AND METHODS

In 21 patients, nine factors were evaluated for freedom from new brain metastases, namely age, gender, Karnofsky performance score (KPS), tumor type, number, maximum total diameter of all lesions and sites of cerebral lesions, extra-cranial metastases, and time from cancer diagnosis to irradiation.

RESULTS

Freedom from new lesions was positively associated with KPS of 90-100 (p=0.013); maximum total diameter ≤15 mm showed a trend for positive association (p=0.09). Points were assigned as: KPS 70-80=1 point, KPS 90-100=2 points, maximum diameter ≤15 mm=2 points and maximum diameter >15 mm=1 point. Six-month rates of freedom from new lesions were 29%, 45% and 100% for those with total scores of 2, 3 and 4 points, respectively, with corresponding 12-month rates of 0%, 45% and 100% (p=0.027).

CONCLUSION

This study identified three risk groups regarding new brain metastases after stereotactic irradiation. Patients with 2 points could benefit from additional whole-brain radiotherapy.

Rapid recovery of vision following early intervention with fractionated stereotactic radiotherapy for optic nerve sheath meningioma

Purpose

To report the outcomes of early intervention with fractionated stereotactic radiotherapy (FSRT) in a patient with primary optic nerve sheath meningioma (ONSM).

Patient and methods

A male patient in his early 40s underwent 5-beam FSRT at a prescribed dose of 50 Gy in 25 fractions over 35 days. The patient had an 11-month history of progressive visual impairment at the time of FSRT.

Results

On day 14 of treatment, the patient reported early improvement in his vision. Two weeks after the completion of FSRT, his left eye visual acuity and field recovered completely. However, the tumor regressed only slightly in the 2 years of follow-up.

Conclusion

Early intervention with FSRT for optic nerve sheath meningioma resulted in a rapid response and complete improvement of visual impairment.

Radiosurgery and stereotactic radiotherapy with cyberknife system for meningioma treatment

Objective The aim of this work was to evaluate the impact of stereotactic radiosurgery/fractionated stereotactic radiotherapy with the Cyberknife system on local disease control, clinical outcome and toxicity in patients with meningioma, according to the site and histological grade of lesion. From January 2013 to April 2017, 52 patients with intracranial meningiomas were treated with the Cyberknife system. Twenty-four patients had undergone previous surgery: 38% gross total resection, 10% subtotal resection; 27 patients underwent no surgery; 22 patients had a recurrence of meningioma. Methods Radiosurgery was used for lesions smaller than 2 cm, stereotactic radiotherapy for lesions larger than 2 cm, or smaller but close to a critical site such as the optical chiasm, optic pathway or brainstem. Results Local control and clinical outcomes were analysed. Median follow-up was 20 months: six patients died, one after re-surgery died from post-surgical sepsis, three from heart disease. Progression-free survival had a mean value of 38.3 months and overall survival of 41.6 months. We evaluated at 12 months 28 patients (100% local control); at 24 months 19 patients (89% local control); at 36 months nine patients (89% local control). At baseline, 44/52 patients (85%) were symptomatic: 19 visual disorders, 17 motor disorders, six hearing disorders, 10 headache and six epilepsy. Visual symptoms remained unchanged in 52%, improved in 32%, resolved in 16%. Headache was improved in 40%, resolved in 10%, unchanged in 50%. Epilepsy was resolved in 17%, unchanged in 33%, worsened in 33%. Conclusions Stereotactic radiosurgery/fractionated stereotactic radiotherapy with Cyberknife provides a good local disease control, improving visual, hearing and motor symptoms.

Impact of Cochlear Dose on Hearing Preservation following Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy for the Treatment of Vestibular Schwannoma

Objective  The objective of this study was to examine the effect of cochlear dose on hearing preservation in stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (fSRT) for vestibular schwannoma (VS). Design  This is a retrospective case-control study. Setting  This study was completed at the Ronald Reagan UCLA Medical Center, a university-affiliated tertiary care center. Participants  Patients who underwent SRS (marginal dose of 12 Gy) or fSRT (marginal dose of 50.4 Gy) procedures for VS were included in the study. Main Outcome Measures  The main outcome measure was hearing preservation. Audiometric data, when available, were used to determine the level of hearing according to the Gardner Robertson scale. Results  A total of 38 patients (14 SRS and 24 fSRT) were analyzed. SRS patients with decreased hearing received a significantly higher minimum cochlear dose (7.41 vs. 4.24 Gy, p  = 0.02) as compared with those with stable hearing. In fSRT patients, there were no significant differences in cochlear dose for patients with decreased hearing as compared with those with stable hearing. For SRS patients, who received a minimum cochlear dose above 6 Gy, there was a significant risk of decreased hearing preservation (odds ratio: 32, p  = 0.02). Conclusion  Higher minimum cochlear dose was predictive of decreased hearing preservation following SRS. Though the study is low powered, the radiation dose to the cochlea should be a parameter that is considered when planning SRS or fSRT therapies for patients with VS.

Management of Chordoma and Chondrosarcoma with Fractionated Stereotactic Radiotherapy

OBJECTIVE

To evaluate the efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) for chordoma and chondrosarcoma.

METHODS

Twenty consecutive patients with a histopathologic diagnosis of chordoma (n = 16) or chondrosarcoma (n = 4) treated between 2010 and 2016 were retrospectively identified. All patients underwent FSRT in five fractions to a median dose of 37.5 Gy (range: 25-40 Gy) and followed with serial magnetic resonance imaging. Overall survival (OS), local recurrence-free survival (LRFS), and event-free survival (EFS) were estimated using the Kaplan-Meier method.

RESULTS

With a median follow-up of 28 months after FSRT and 40 months after initial surgery, crude OS and LRFS were 90%. Nine patients (45%) reported grade 1-3 acute toxicity, and two patients (10%) experienced grade 4, 5 late toxicity. One patient previously treated with proton therapy died from radiation vasculopathy 9 months after FSRT. The use of FSRT for recurrent disease or in patients with prior radiation therapy was associated with significantly decreased EFS.

CONCLUSION

FSRT for chordoma and chondrosarcoma is associated with high rates of OS and local control. Although many patients experience acute toxicity, there is a low incidence of late toxicity or irreversible treatment related morbidity despite the frequency of prior radiotherapy in this population. FSRT is an effective adjuvant or salvage treatment for chordoma and chondrosarcoma.

Target volume geometric change and/or deviation from the cranium during fractionated stereotactic radiotherapy for brain metastases: potential pitfalls in image guidance based on bony anatomy alignment

INTRODUCTION

This study sought to evaluate the potential geometrical change and/or displacement of the target relative to the cranium during fractionated stereotactic radiotherapy (FSRT) for treating newly developed brain metastases.

METHODS

For 16 patients with 21 lesions treated with image-guided frameless FSRT in 5 or 10 fractions using a 6-degree-of-freedom image guidance system-integrated platform, the unenhanced computed tomography or T2-weighted magnetic resonance images acquired until the completion of FSRT were fused to the planning image datasets for comparison. Significant change was defined as ≥3-mm change in the tumour diameter or displacement of the tumour centroid.

RESULTS

FSRT was started 1 day after planning image acquisition. Tumour shrinkage, deviation and both were observed in 2, 1 and 1 of the 21 lesions, respectively, over a period of 7-13 days. Tumour shrinkage or deviation resulted in an increase or decrease in the marginal dose to the tumour, respectively, and a substantial increase in the irradiated volume for the surrounding tissue irrespective of the pattern of alteration. No obvious differences in the clinical and treatment characteristics were noted among the populations with or without significant changes in tumour volume or position.

CONCLUSION

Target deformity and/or deviation can unexpectedly occur even during relatively short-course FSRT, inevitably leading to a gradual discrepancy between the planned and actually delivered doses to the tumour and surrounding tissue. To appropriately weigh the treatment outcome against the planned dose distribution, target deformity and/or deviation should also be considered in addition to the immobilisation accuracy, as image guidance with bony anatomy alignment does not necessarily guarantee accurate target localisation until completion of FSRT.

Early manifestation of communicating hydrocephalus after fractionated stereotactic radiotherapy for aggressive giant atypical prolactinoma

Aggressive giant invasive pituitary adenomas refractory to standard surgical or medical treatment remain a genuine challenge. In addition, communicating hydrocephalus (CH) attributed to malabsorption of cerebrospinal fluid (CSF) developing after radiotherapy for pituitary adenomas has not been previously reported. Herein, we describe the case of a 48-year-old male presenting with a giant atypical prolactinoma refractory to previous therapies, including pharmacotherapy and repetitive surgery. He underwent image-guided fractionated stereotactic radiotherapy in 28 fractions, resulting in early manifestation of CH associated with undisputed, both radiological and hormonal response. He recovered well after a shunt placement, with otherwise favorable consequences such as sustained tumor regression, decreasing prolactin level, and retained visual function for a 22-month follow-up. Fractionated stereotactic radiotherapy would provide a viable treatment alternative for these refractory cases, while caution should be exercised regarding the possibility of iatrogenic CH.

Fractionated stereotactic radiotherapy using CyberKnife for the treatment of large brain metastases: a dose escalation study

AIMS

To evaluate the toxicity and efficacy of fractionated stereotactic radiotherapy (FSRT) with doses of 18-30 Gy in three fractions and 21-35 Gy in five fractions against large brain metastases.

MATERIALS AND METHODS

Between 2005 and 2012, 61 large brain metastases (≥ 2.5 cm in maximum diameter) of a total of 102 in 54 patients were treated with FSRT as a first-line therapy. Neurological symptoms were observed in 47 of the 54 patients before FSRT. Three fractions were applied to tumours with a maximum diameter ≥ 2.5 cm and <4 cm, and five fractions were used for brain metastases ≥ 4 cm. After ensuring that the toxicities were acceptable (≤ grade 2), doses were escalated in steps. Doses to the large brain metastases were as follows: level I, 18-22 Gy/three fractions or 21-25 Gy/five fractions; level II, 22-27 Gy/three fractions or 25-31 Gy/five fractions; level III, 27-30 Gy/three fractions or 31-35 Gy/five fractions. Level III was the target dose level.

RESULTS

Overall survival rates were 52 and 31% at 6 and 12 months, respectively. Local tumour control rates of the 102 total brain metastases were 84 and 78% at 6 and 12 months, respectively. Local tumour control rates of the 61 large brain metastases were 77 and 69% at 6 and 12 months, respectively. Grade 3 or higher toxicities were not observed.

CONCLUSIONS

The highest dose levels of 27-30 Gy/three fractions and 31-35 Gy/five fractions seemed to be tolerable and effective in controlling large brain metastases. These doses can be used in future studies on FSRT for large brain metastases.

Intensity-modulated fractionated stereotactic radiotherapy with reduced margin for high grade gliomas: dosimetric analysis of sparing optic nerve & chiasm

The aim of this study was to evaluate the potential advantage of intensity modulation fractionated stereotactic radiotherapy (IM-FSRT) for sparing the optic nerve and chiasm in the management of anaplastic astrocytoma (AA) or glioblastoma (GBM). Clinical data of 16 patients with high grade gliomas were retrospectively reviewed. All patients had tumors close to the optic chiam that prohibited the full dose radiation therapy. The patients were treated with either IM-FSRT in conjunction with external beam radiation or IM-FSRT only to a total dose of 60 Gy. The final dosimetric analysis was performed. The estimated average maximum optic nerve and chiasm dose 48.6±5.0 Gy (range, 34.2-55.9). Conformity index reached as high as 0.98, and inhomogeneity coefficient was low enough to deliver the prescribed radiation dose. IM-FSRT showed excellent dose conformality to the target volume with superior normal tissue sparing effect. High precision therapy such as IM-FSRT could be a reliable treatment technique for the patients with AA or GBM for a maximal sparing of optic apparatus.

Fractionated stereotactic radiotherapy in the treatment of pituitary macroadenomas

Background

The use of fractionated stereotactic radiotherapy (fsrt) has evolved with technical advances in noninvasive immobilization, radiation delivery, and image guidance. The application of fsrt to pituitary tumours is aimed at reducing toxicity through improved dose conformality and reduced treatment margins. The aim of the present paper is to report our own experience and to review the published data on fsrt for pituitary macroadenomas.

Methods

Between September 2000 and October 2005, 13 patients with pituitary macroadenoma underwent fsrt at our institution. In 12 patients, radiotherapy treatment followed surgical resection (transsphenoidal resection in 8, frontal craniotomy in 3, and multiple transsphenoidal resections followed by craniotomy in 1). In 4 patients, the tumours were functional (2 adrenocorticotropic hormone–secreting, 1 prolactinoma, and 1 growth hormone–secreting); the tumours in the remaining patients were clinically non-secretory. Before radiation, 3 patients had panhypopituitarism, and 6 patients had visual field defects. All patients were treated with fsrt using non-coplanar micro–multileaf collimation portals. A median dose of 50.4 Gy (range: 45–60 Gy) was prescribed to the 76.9%–95.2% isodose surface and delivered in 1.8-Gy fractions. The median planning target volume (gross tumour plus 3 mm) was 33.5 cm3 (range: 3.2–75 cm3).

Results

After a median follow-up of 24 months (range: 6–60 months), local control was 100%. One patient achieved clinical complete response. Treatment was well tolerated acutely for all patients. Neither radiation-induced optic neuropathy nor any radiation-related endocrine dysfunction was observed in our patients.

Conclusions

In accordance with published series, we found fsrt to be safe and effective in the management of large pituitary macroadenomas.

Fractionated stereotactic radiotherapy for parasellar meningiomas: a preliminary report of visual outcomes

BACKGROUND/AIM

Fractionated stereotactic radiotherapy (FSRT) is a new treatment for brain tumours that are close to critical structures, such as the visual apparatus. This study aims to assess the visual outcomes for patients with parasellar meningioma following FSRT.

METHODS

A retrospective, non-comparative case series of 13 patients with parasellar meningiomas who were treated in one institution with FSRT between January 1995 and January 2001.

RESULTS

13 patients (26 eyes) were followed for a mean of 2 years. Visual acuity improved in four eyes (12.5%), remained stable in 18 eyes (75%), and worsened in three eyes (12.5%). Visual field improved in 15 eyes (57%), remained stable in six eyes (23%), and worsened in four eyes (15%). No adverse visual outcome occurred as a result of radiation.

CONCLUSION

These preliminary findings suggest that FSRT is a safe and effective treatment for parasellar meningiomas.