Five-Fraction Radiosurgery Using a Biologically Equivalent Dose of a Single Fraction of 24 Gy for a 3-cm Parasagittal Para-Central Sulcus Brain Metastasis From Adenocarcinoma of the Cecum

An isolated single brain metastasis (BM) is an extremely rare manifestation of failure in patients with cecal adenocarcinoma (CAC). Total en bloc resection (while preserving function) of a 3-cm BM involving both the primary motor and sensory cortexes presents a conundrum: achieving long-term local control and safety of such a BM is also challenging for stereotactic radiosurgery (SRS). We describe the case of a 3.1-cm BM from CAC in the left parasagittal para-central sulcus region, which was treated using five-fraction SRS with a biologically effective dose (BED) of 81.6 Gy. In the SRS, the gross tumor volume (GTV, 7.14 cm3) was defined based on computed tomography (CT)/T1/T2 matching (enhancing lesion 11.66 cm3), and 98.7% of the GTV (CT/T2 mass) was covered with 43.6 Gy (58% isodose) using volumetric-modulated arcs. The maximum tumor response was partial (19.7% of the prior GTV) and sustained for 15.2 months, leaving minor neurological symptoms. However, the patient developed neurological worsening at six months, attributed to adverse radiation effects with a CT/T1/T2 mismatch, for which medical management, including the addition of bevacizumab (BEV), was effective for one year. Multi-fraction SRS with a high marginal and internal BED and sequential systemic therapy, including BEV, can be a minimally invasive, efficacious, and durable treatment option for a large CAC-BM involving the central sulcus. Early co-administration of BEV following SRS, dose escalation to the GTV boundary, and more than five fractions of SRS may be considered to improve the efficacy and safety further.

Management of sarcomatoid Malignant pleural mesothelioma brain metastases with stereotactic radiosurgery: an Illustrative case

Background: Malignant pleural mesothelioma (MPM) is a rare cancer of the respiratory system that rarely metastasizes to the brain. We report a case of sarcomatoid MPM (SMPM) managed with Stereotactic radiosurgery (SRS) to achieve intracranial tumor control and improve neurological symptoms.Illustrative case: This 67-year-old female patient underwent SRS twice in order to treat a total of 15 brain metastases. One-month follow-up imaging after the first SRS demonstrated local tumor response and seven tumors with symptomatic vasogenic edema that responded to initial corticosteroids followed by bevacizumab. At a three-month follow-up after the first procedure, eight new tumors were detected and required repeat SRS. Although sustained tumor control resulted in improved neurological function, the patient subsequently expired from systemic disease progression 12 months after initial diagnosis and six months after initial SRS for brain metastases despite the concurrent use of systemic immunotherapy and systemic chemotherapy.Conclusions: Although SRS provided overall tumor control of metastatic brain disease, further advances in systemic therapies will be needed to improve survival in this aggressive rare cancer.

Intracerebral and pituitary metastatic eccrine carcinoma: prolonged survival using stereotactic radiosurgery

PURPOSE

Eccrine gland carcinoma (EC) is a rare skin neoplasm that uncommonly spreads to the brain or pituitary gland. We describe the role of multiple stereotactic radiosurgery (SRS) procedures to manage recurrent brain metastases of this rare disease.

MATERIALS AND METHODS

Retrospective chart review was completed to obtain details for this report. The study was performed under IRB study on medical record only and was exempt from patient's consent.

RESULTS AND CONCLUSIONS

A 59-year-old female underwent surgical excision of a right parietal scalp EC. Over the next 13 years, the patient underwent initial fractionated whole brain radiation therapy after she developed multiple brain metastases followed by systemic chemotherapy for extracranial disease. Because of repeated development of new brain disease, three SRS procedures were performed to treat a total of 50 brain metastases and a pituitary metastasis (PM). The patient expired from progressive systemic cancer spread 13 years after her initial surgical excision. Due to the rarity of metastatic EC to the brain, no standard treatment paradigm has emerged. Using multimodality options that included local excision of the original skin tumor, followed by radiation, systemic chemotherapy, and three SRS procedures, long-term survival was possible in this unusual case.

Compactness index: a radiosurgery outcome predictor for patients with unruptured brain arteriovenous malformations

OBJECTIVE

The goal of the study was to define and quantify brain arteriovenous malformation (bAVM) compactness and to assess its effect on outcomes after Gamma Knife radiosurgery (GKRS) for unruptured bAVMs.

METHODS

Unsupervised machine learning with fuzzy c-means clustering was used to differentiate the tissue constituents of bAVMs on T2-weighted MR images. The percentages of vessel, brain, and CSF were quantified. The proposed compactness index, defined as the ratio of vasculature tissue to brain tissue, categorized bAVM morphology into compact, intermediate, and diffuse types according to the tertiles of this index. The outcomes of interest were complete obliteration and radiation-induced changes (RICs).

RESULTS

A total of 209 unruptured bAVMs treated with GKRS were retrospectively included. The median imaging and clinical follow-up periods were 49.2 and 72.3 months, respectively. One hundred seventy-three bAVMs (82.8%) achieved complete obliteration after a median latency period of 43.3 months. The rates of RIC and permanent RIC were 76.1% and 3.8%, respectively. Post-GKRS hemorrhage occurred in 14 patients (6.7%), resulting in an annual bleeding risk of 1.0%. Compact bAVM, smaller bAVM volume, and exclusively superficial venous drainage were independent predictors of complete obliteration. Diffuse bAVM morphology, larger bAVM volume, and higher margin dose were independently associated with RICs.

CONCLUSIONS

The compactness index quantitatively describes the compactness of unruptured bAVMs. Moreover, compact bAVMs may have a higher obliteration rate and a smaller risk of RICs than diffuse bAVMs. This finding could help guide decision-making regarding GKRS treatment for patients with unruptured bAVMs.

Prognostic Factors Analysis for Intracranial Cavernous Malformations Treated with Linear Accelerator Stereotactic Radiosurgery

Stereotactic radiosurgery (SRS) is generally considered a substitute for cranial cavernous malformations (CCMs). However, prognostic factors for post-radiosurgery CCM rebleeding and adverse radiation effects have not been well evaluated, and the effect of timing and optimal treatment remains controversial. Therefore, this study evaluated prognostic factors for post-radiosurgical rebleeding and focal edematous changes in 30 patients who developed symptomatic intracranial hemorrhage due to solitary non-brainstem CCM and received linear accelerator (LINAC) SRS in a single medical center from October 2002 to June 2018. An overall post-radiosurgical annual hemorrhage rate with 4.5% was determined in this study. In addition, a higher marginal dose of >1600 centigray and earlier LINAC SRS intervention were correlated with a significantly lower post-radiosurgical annual hemorrhage rate. A lesion size larger than 3 cm3 and a coexisting developmental venous anomaly were significant risk factors for post-radiosurgical focal brain edema but mostly resulted in no symptoms and were temporary. This study demonstrated the efficacy of LINAC SRS in preventing CCM rebleeding and suggests that earlier radiosurgery treatment with a higher dose for non-brainstem symptomatic CCMs be considered.

Chronic encapsulated expanding hematoma after stereotactic radiosurgery of cerebral arteriovenous malformation

Stereotactic radiosurgery has become excellent alternative treatment for cerebral arteriovenous malformations (AVM). This technique has expanded to treatment of larger AVM which is not amenable to surgical management. However, its variable adverse effects should be also taken into considerations sincerely because of radiobiological characteristics such as delayed onset and progressive neurological deteriorations. Herein, we report a case in which progressively expanding hemorrhagic cyst with repeated bleedings so called chronic encapsulated expanding hematoma was developed on several years after radiosurgery treatment. Neurological and radiological findings were improved by surgical removal.

Although Non-diagnostic Between Necrosis and Recurrence, FDG PET/CT Assists Management of Brain Tumours After Radiosurgery

AIM

To re-evaluate the role of (18)F-fluoro-deoxy-D-glucose (FDG) positron emission tomography/ computer assisted tomography (PET/CT) co-registered with magnetic resonance imaging (MRI) in differentiating adverse radiation effect (ARE) from tumour recurrence after Gamma Knife radiosurgery of brain tumours.

PATIENTS AND METHODS

Twenty-seven PET/CT studies co-registered with MRI were performed on 16 patients after radiosurgery, with 12/16 patients having multiple radiosurgery treatments. Long term follow-up was used for evaluation, with 3/16 patients being histopathologically confirmed.

RESULTS

PET/CT was positive in all studies in 6/16 patients, negative in all studies in 6/16 and changed from negative to positive in one. In 2/16 patients, PET/CT was both positive and negative in separate tumour foci. In 9/16 cases with a positive PET/CT, tumour was confirmed. In 6/16 patients with a negative PET/CT, 3/6 had recurrence and 3/6 ARE. In 1/16, equivocal results became negative after retreatment. PET/CT/MRI identified tumour within ARE. Sensitivity of PET/CT/MRI proved to be 64.7%, and specificity 100%.

CONCLUSION

PET/CT/MRI assists management, by revealing metabolism rather than histology.