We present the case of a 50-year-old male patient reporting intermittent upper abdominal pain throughout 2012 and 2013. In February 2014, the patient experienced breathing difficulties and exacerbation of pain. Fludeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) revealed high FDG uptake in a large, heterogeneous intrathoracic mass in the middle mediastinum abutting the right atrium and the right hemidiaphragm, without evidence of distant metastases. The patient underwent subtotal primary tumor resection in April 2014. The histopathology demonstrated a poorly differentiated thymic carcinoma though without primary malignant manifestation in the gland itself. The patient received three adjuvant chemotherapy sessions (Carboplatine/Vepesid) followed by fractionated radiotherapy (2 Gy/day, 30 sessions = 2 Gy × 30 = 60 Gy) to the right thoracic region (July to September 2014). The patient developed paroxysmal atrial fibrillation after thoracic surgery as well as a series of respiratory infections during and after his radiochemotherapy, though without serious sequelae. His general condition remained otherwise stable. By February 2015, the patient developed progressive expressive dysphasia. A brain magnetic resonance imaging (MRI) in May 2015 showed a 3.5 cm ring-enhancing lesion in the left temporal lobe with extensive edema (metastasis # 1 = M1). Speech impairment resolved shortly after gross total resection (GTR). The histopathology proved the lesion to be a thymic carcinoma metastasis with MIB 1 proliferation index of up to 50%. Postsurgical hypofractionated LINAC-radiotherapy (6 Gy/day, 5 sessions = 30 Gy) was delivered to the surgical cavity in June 2015. CT of the neck, thorax, and abdomen in September 2015 showed no signs of distant metastases. However, a follow-up brain MRI in October 2015 demonstrated three new intracranial lesions – the first a 1.9 cm lesion in the right cerebellar hemisphere (metastasis # 2 = M2), the second, a larger extra-axial left temporal mass measuring 3.9 cm with adjacent edema and mass effect threatening the hippocampus, uncus, and language areas (metastasis # 3 = M3), and the third, a 3.0 cm dural-based left parietal lesion exerting mass effect on the sensory cortex (metastasis # 4 = M4). There was no evidence of recurrence in the surgical cavity (M1). Although M2 was relatively small, M3 and M4 were quite large (≥3 cm) and both threatened eloquent areas of the brain. By this time, the patient once again developed expressive dysphasia and mental fatigue [Karnofsky Performance Score (KPS) 90–100], though without evidence of extracranial tumour proliferation (RPA 1) on prior screening CT scan September 2015; the patient remained free from systemic treatment at this stage and was referred to our unit for further management (October 2015).\nThe radiosurgical plan was designed based on a series of factors – past/present radiological evolution, tumor localization, identification of organs at risk (OAR), tumor volume, histopathological traits of prior resected metastasis (M1), general and neurological health status (KPS/RPA), absence of extracranial tumor activity at the time of radiosurgery, positive outcome after microsurgery, and good response to prior anti-tumoral treatments (including chemotherapy and extra/intracranial radiation). Our strategy aimed to rapidly relieve/salvage the language areas, the hippocampus, and the post-central gyrus from the larger left-sided lesions (M3 and M4) within a time frame of 7 days (treatment time between RS1 and RS3) to 4 weeks (MRI at 1 month). Because of the patient's previous positive response to extra and intracranial radiotherapy, we considered the tumor to be radiosensitive and proceeded to plot a peripheral prescription dose biologically isoeffective to the cranial hypofractionated treatment delivered to the surgical cavity earlier (6 Gy × 5). To achieve maximal probability of local tumor control while minimizing the risk of focal radiation-induced adverse reaction, treatment settings included an adaptive and MRI-guided hypofractionated radiosurgical approach; the procedure would allow tumor bed dose distribution readjustments in relation to local tumor volume variations during the course of treatment. The treatment was structured on three radiosurgeries (RS) delivered every third day i.e., day 1 (RS 1), day 4 (RS 2), and day 7 (RS 3). Cranial fixation was achieved by applying a Leksell Coordinate Frame G (Elekta AB, Stockholm) prior to each RS. A stereotactic MRI was performed before each RS session (s-MRI 1, 2, 3) for proper gross tumor volume (GTV) delineation; we set no margins to the GTV (GTV = CTV = PTV). As described in Tables and , the s-MRI at the onset of treatment (day 1) showed further growth of the tumors with substantial perifocal edema, particularly adjacent to M3 (see for tumor volumes at Day 1). M2 was volumetrically optimal for conventional single dose treatment (volume = 2.7 cc). Its marginal dose (GTV = CTV) was set at 19 Gy at the 50% isodose line []. Because of their volumetric traits, aggressive growth pattern, and critical localization, we chose RRR as the best approach to treat M3 and M4. Using standard biological effective dose calculations, we set the initial GTV-prescription dose (fraction 1) for M3 and M4 to 8 Gy at the 35% isodose line []. Dural tail and peripheral zones of hemorrhage were to be included in the field of treatment. Due to underlying extensive perifocal edema, the patient was to be kept on cortisone during the course of the treatment and approximately 4 weeks thereafter.
We report on a 64-year-old woman who initially presented to the emergency department with complaints of chest pain following a motor vehicle crash. A CT incidentally found renal abnormalities, and a postnephrectomy biopsy confirmed renal cell carcinoma. The patient was asymptomatic at that time and remained so for ten months, after which she visited her primary care physician with complaints of mild intermittent headaches and difficulty with balance. An MRI revealed five cerebellar lesions measuring 1.4 × 1.5 × 1.6 cm, 2.0 × 1.5 × 1.7 cm, 0.7 × 0.7 × 0.7 cm, 0.2 × 0.2 × 0.2 cm, and 0.1 × 0.1 × 0.1 cm, as well as extensive vasogenic edema.\nHer treatment team recommended against resection due to the sensitive location of her tumors. GKRS was recommended over WBRT due to concern that avoiding previous radiation fields from treatment for oropharyngeal carcinoma 14 years earlier would not adequately address her relatively caudal metastatic tumors. The patient then underwent her first GKRS treatment at a dose of 22 Gy at the 50% isodose line (Figures and ). On the day of treatment, her Karnofsky Performance Status score was 100. Following GKRS, she was placed on dexamethasone 2 mg daily. Within several weeks she had experienced significant resolution of symptoms.\nOver the next 51 months, she underwent a subsequent six GKRS treatments, all of which treated between one and four metastases. Many of these metastases were in new locations within the cerebellum, while several appeared in the brainstem itself. 49 months after her initial treatment, she underwent a craniotomy to relieve obstructive hydrocephalus with a ventricular shunt placement. An 8.0 mm cerebellar lesion was successfully resected in the same procedure. Around the same time, she underwent SBRT for liver metastases, which was tolerated well.\nThe patient's most recent GKRS treatment occurred 60 months after the first and was suggested when the patient presented with complaints of consistent falls. A CT demonstrated five lesions, four of which were localized to the cerebellum and one limited to the pons. Three of the lesions had increased in size since her previous CT several months earlier. Three lesions were treated with a dose of 20 Gy at the 50% isodose line, one lesion was treated with 18 Gy at the 75% isodose line, and one was treated with 18 Gy at the 55% isodose line. A posttreatment CT demonstrated reduced dimensions of all lesions. Her most recent CT was taken 5 months later and demonstrated reduced or stable sizes of all lesions. 65 months after her initial diagnosis of brain metastasis, the patient began treatment with Votrient 800 mg for her liver metastases, which was tapered down to 400 mg and eventually held completely for after severe GI side effects and elevated liver enzymes.\nOne month prior to this paper, a PET scan was obtained, showing no new evidence of systemic or metastatic disease. At that time, she remained symptom-free with a high quality of life a total of 72 months after her brain metastases were diagnosed.