Proton beam therapy for skull base chordomas: a systematic review of tumor control rates and survival rates.

The management of base of skull (BS) chordomas is a neurosurgical conundrum owing to their close proximity to the critical neurovascular structures. Surgical resection is the gold standard treatment followed by adjuvant radiotherapy which includes photon therapy, proton beam therapy (PBT), gamma knife radiosurgery, etc. PBT has become an unparalleled therapeutic modality in the management of BS chordomas. The aim of this systematic review was to assess the outcomes in BS chordoma patients who received PBT as a primary or adjuvant therapy. PubMed and Cochrane databases were screened till May 2022. Following the PRISMA guidelines, studies were reviewed thoroughly, and the data of the included study was extracted. Statistical analysis was performed using the SAS 9.4 with P value < .05 considered as significant. Sixteen studies with 752 patients were included. The majority of the patients were adults (> 18 years) with a male:female ratio of 1.2. The most common clinical features were cranial nerve (3rd, 6th, or 12th) palsy and hearing impairment. Ninety-five percent of the patients underwent surgical resection before PBT. The mean PBT dose received was 74.02 cGe (cobalt gray equivalent). Eighty percent of the patients showed a positive response to the therapy defined in terms of tumor regression. Five-year local control (LC), overall survival (OS), and progression-free survival (PFS) were calculated as 76.6%, 79.6%, and 89%, respectively. Statistical analysis revealed none of the factors had any significant association with 5-year LC. PBT is a growing therapeutic technique that has revolutionized the treatment of BS chordomas.

Localisation of the petrous internal carotid artery relative to the vidian canal on computed tomography: a case-control study evaluating the impact of petroclival chondrosarcoma.

BACKGROUND: The vidian canal (VC) is normally a reliable anatomical landmark for locating the petrous internal carotid artery (pICA). This study determined the influence of petroclival chondrosarcoma on the relationship between the VC and pICA. METHODS: Nine patients (3 males, 6 females; median age 49) with petroclival chondrosarcoma, and depiction of the pICA on contrast-enhanced CT, were retrospectively studied. CT-based measurements were performed by two observers, both in the presence of the petroclival chondrosarcoma (case) and on the contralateral control side. The antero-posterior (AP) and craniocaudal (CC) measurements from the posterior VC to the pICA, whether the pICA was in the trajectory of the VC, and the coronal relationship of the pICA anterior genu with the VC were recorded. RESULTS: Chondrosarcoma usually displaced the pICA anteriorly (8/9 cases) and superiorly (6/9 cases) relative to the normal side with mean AP and CC measurements of 3.9 mm v 7.2 mm (p = 0.054) and 4.4 mm v 1.4 mm (p = 0.061). The VC trajectory less frequently intersected the pICA cross-section in the presence of chondrosarcoma however it was in the line of the eroded dorsal VC in one case. The anterior genu of the pICA was displaced more laterally by chondrosarcoma but usually remained superior to the VC. CONCLUSION: Petroclival chondrosarcoma variably influences the anatomical relationship between the VC and the pICA, hence requiring an individualised approach. The pICA is usually anterosuperiorly displaced, and the anterior genu remains superior to the VC, however it may be located in the line of the canal.

Cavernous sinus fungal infection: a rare case.

Intracranial fungal infection of the cavernous sinus is a condition that usually affects immunocompromised individuals and is rarely seen in immunocompetent individuals. It is a potentially life threatening condition which requires prompt treatment. Here we present a case of an immunocompetent patient with a fungal infection of the cavernous sinus.

Effectiveness of base-of-skull immobilization system in a compact proton therapy setting.

PURPOSE: The purpose of this study was to investigate daily repositioning accuracy by analyzing inter- and intra-fractional uncertainties associated with patients treated for intracranial or base of skull tumors in a compact proton therapy system with 6 degrees of freedom (DOF) robotic couch and a thermoplastic head mask indexed to a base of skull (BoS) frame. MATERIALS AND METHODS: Daily orthogonal kV alignment images at setup position before and after daily treatments were analyzed for 33 patients. The system was composed of a new type of thermoplastic mask, a bite block, and carbon-fiber BoS couch-top insert specifically designed for proton therapy treatments. The correctional shifts in robotic treatment table with 6 DOF were evaluated and recorded based on over 1500 planar kV image pairs. Correctional shifts for patients with and without bite blocks were compared. RESULTS: Systematic and random errors were evaluated for all 6 DOF coordinates available for daily vector corrections. Uncertainties associated with geometrical errors and their sources, in addition to robustness analysis of various combinations of immobilization components were presented. CONCLUSIONS: Analysis of 644 fractions including patients with and without a bite block shows that the BoS immobilization system is capable of maintaining intra-fraction localization with submillimeter accuracy (in nearly 83%, 86%, 95% of cases along SI, LAT, and PA, respectively) in translational coordinates and subdegree precision (in 98.85%, 98.85%, and 96.4% of cases for roll, pitch, and yaw respectively) in rotational coordinates. The system overall fares better in intra-fraction localization precision compared to previously reported particle therapy immobilization systems. The use of a mask-attached type bite block has marginal impact on inter- or intra-fraction uncertainties compared to no bite block.

Chordomas and chondrosarcomas-The role of radiation therapy.

Achieving negative surgical margins can be challenging for skull base and spinal/paraspinal sarcomas. Data shows that pre- or post-operative radiation therapy improves local control. Delivery of sufficient dose of radiation can be difficult because of the proximity to normal organs/tissues that are sensitive to radiation therapy and therefore dose-limiting. A comprehensive literature search was conducted using PubMed search engine. The scarcity of prospective, randomized data limits the ability to generate definitive treatment recommendations. J. Surg. Oncol. 2016;114:564-569. © 2016 Wiley Periodicals, Inc.

Clinical Signs of Base of Skull Fracture in the South Indian Population.

Objective The clinical signs of base of skull fracture (BSF) are often ambiguous and difficult to identify, but are often used to make decisions on early medical interventions. This study aimed to assess the prevalence of the clinical signs of BSF, their dependency to diagnose this injury and to assess the correlation between the presence of these clinical signs and the severity of head injury and patient outcome. Materials and Methods A cross-sectional study was conducted in a tertiary care hospital in South India over a period of 3 years (2020-2023). Patients older than 18 years, with radiological or surgical evidence of BSF were monitored for developing the clinical signs including Battle's signs, raccoon's sign, otorrhea, and rhinorrhea. The presence of these clinical signs was correlated with demographical characteristics, patient presentation, complications, and their outcome. Results A total of 292 patients were included in the study. The mean age of the cohort was 36.27 ± 18.68 years. A total of 55 (18.8%) showed at least one of the four signs of BSF. Raccoon's sign was seen in 9.5% cases, Battle's sign in 5.5%, otorrhea in 5.5%, and rhinorrhea in 2.4% cases. Patients with frontal ( p = 0.021) or ethmoid (0.049) fractures and ENT bleeding ( p = 0.022) were significantly more likely to present with at least one sign of BSF. The patients who presented with clinical signs were more likely to have a complication during the course of the hospital stay ( p = 0.024) than those without clinical signs, including cranial nerve palsy ( p < 0.001) and cerebrospinal fluid leak ( p < 0.001). The outcome of the patient did not change based on the presence of clinical signs ( p = 0.926). Conclusion These study results indicate a limited diagnostic value of BSF clinical signs in the South Indian population. Thus, other modalities should be considered for the diagnosis when suspected. These results also discourage the use of the nasal route in all patients with suspected head injury and emphasize that during the nasal aspiration procedure, the use of a rigid device is fundamental to avoid false passage of the aspiration tube from the nasal to the intracranial region.

Minimally invasive approach for skull base meningiomas.

INTRODUCTION: Skull base meningiomas constitute a complex group of skull base tumors. The endoscopic endonasal approaches (EEA) and endoscopic Keyhole have a minimally invasive philosophy with high effectiveness, safety, and a significant decrease in postoperative morbidity in these tumors. OBJECTIVE: To describe the results of the use of minimally invasive approaches to skull base meningiomas. METHOD: A descriptive, retrospective study was carried out in 140 patients at the "Hermanos Ameijeiras" Hospital who underwent surgery for cranial base meningiomas using minimally invasive approaches to the cranial base. The degree of tumor resection, tumor recurrence, reinterventions, and complications were evaluated. RESULTS: ESA were used in 72.8% of the study, while endoscopic Keyholes were used in 26.4% and combined approaches in 0.7%. In relation to total tumor resection, 91.9% was generally achieved. Overall tumor recurrence and reinterventions were less than 8.5% and 4%, respectively. Complications in ESA were: cerebrospinal fluid (CSF) fistula (2.1%), diabetes insipidus, hydrocephalus, cerebral infarction, surgical site hematoma, worsening of cranial nerves I-IV (1.4%) respectively. While in the Keyhole type approaches: seizures (2.9%), hydrocephalus (1.4%), CSF fistula (1.4%), worsening of Nerves IX-XII (0.7%). CONCLUSIONS: The following study reaffirms that minimally invasive approaches for skull base meningiomas constitute advanced surgical techniques for these tumors, associated with a low rate of postoperative complications.

Intra-operative interstitial brachytherapy in a novel infra-zygomatic approach for partially resectable head and neck cancers around the base of skull: A technical note.

Purpose: To report an intra-operative catheter insertion technique into the base of skull tumor bed following surgical resection for maxillary tumors. Material and methods: A 42-year-old male patient diagnosed with carcinoma of the maxilla was treated with neoadjuvant chemotherapy followed by chemo-radiation using external beam technique combined with brachytherapy boost to post-operative bed. Brachytherapy was delivered via intra-operative catheter placement at the base of skull to residual disease, which was surgically unresectable. Initially, catheters were placed cranio-caudally. This was later changed into an infra-zygomatic approach to improve planning and dose coverage. High-risk clinical tumor volume (CTV) was generated with a 3 mm margin to residual gross tumor. Planning was done using Varian Eclipse brachytherapy planning system, and an optimal plan was generated. Conclusions: An innovative, beneficial, and safe brachytherapy approach is necessary in a difficult and critical area, such as the base of skull. Our novel method of implant insertion through infra-zygomatic approach resulted in a safe and successful procedure.

Proton Beam Therapy in the Reirradiation Setting of Brain and Base of Skull Tumour Recurrences.

The therapeutic management of local tumour recurrence after a first course of radical radiotherapy is always complex. Surgery and reirradiation carry increased morbidity due to radiation-induced tissue changes. Proton beam therapy (PBT) might be advantageous in the reirradiation setting, thanks to its distinct physical characteristics. Here we systematically reviewed the use of PBT in the management of recurrent central nervous system (CNS) and base of skull (BoS) tumours, as published in the literature. The research question was framed following the Population, Intervention, Comparison and Outcomes (PICO) criteria: the population of the study was cancer patients with local disease recurrence in the CNS or BoS; the intervention was radiation treatment with PBT; the outcomes of the study focused on the clinical outcomes of PBT in the reirradiation setting of local tumour recurrences of the CNS or BoS. The identification stage resulted in 222 records in Embase and 79 in Medline as of March 2023. Sixty-eight duplicates were excluded at this stage and 56 were excluded after screening as not relevant, not in English or not full-text articles. Twelve full-text articles were included in the review and are presented according to the site of disease, namely BoS, brain or both brain and BoS. This review showed that reirradiation of brain/BoS tumour recurrences with PBT can provide good local control with acceptable toxicity rates. However, reirradiation of tumour recurrences in the CNS or BoS setting needs to consider several factors that can increase the risk of toxicities. Therefore, patient selection is crucial. Randomised evidence is needed to select the best radiation modality in this group of patients.

Carbon Ion Radiotherapy: An Evidence-Based Review and Summary Recommendations of Clinical Outcomes for Skull-Base Chordomas and Chondrosarcomas.

Skull-base chordoma and chondrosarcoma are rare radioresistant tumors treated with surgical resection and/or radiotherapy. Because of the established dosimetric and biological benefits of heavy particle therapy, we performed a systematic and evidence-based review of the clinical outcomes of patients with skull-base chordoma and chondrosarcoma treated with carbon ion radiotherapy (CIRT). A literature review was performed using a MEDLINE search of all articles to date. We identified 227 studies as appropriate for review, and 24 were ultimately included. The published data illustrate that CIRT provides benchmark disease control outcomes for skull-base chordoma and chondrosarcoma, respectively, with acceptable toxicity. CIRT is an advanced treatment technique that may provide not only dosimetric benefits over conventional photon therapy but also biologic intensification to overcome mechanisms of radioresistance. Ongoing research is needed to define the magnitude of benefit, patient selection, and cost-effectiveness of CIRT compared to other forms of radiotherapy.

A Rare Occurrence of an Extensive Sino-Nasal Solitary Fibrous Tumour.

Introduction: Solitary fibrous tumours are uncommon in head and neck region, especially in the nasal cavities and paranasal sinuses, with most cases reported in the thoracic region in the pleura. It is often considered a borderline or low-grade malignant soft tissue tumour. Complete surgical resection is currently the treatment of choice, though intracranial and orbital extension of these lesions must be carefully evaluated and navigated to ensure a safe outcome. Case Report: A 36 years-old lady presented with a long one-year history of left-sided nasal obstruction with facial pain, headaches and mild visual disturbances. She had been treated for sinusitis for a prolonged period. Clinically, there was a left nasal mass obliterating the ostiomeatal complexes and the roof of the nasal cavity. MRI showed heterogeneously enhancing mass occupying the left ethmoid sinuses extending laterally eroding the left lamina papyracea to the orbit, medially towards the right nasal cavity eroding the nasal septum, and superiorly to extend intracranially. After inconclusive biopsies were performed, the mass was excised with a combined endoscopic and open lateral rhinotomy approach with left medial maxillectomy and reconstruction of the skull base defect. The tumour was eventually reported as a solitary fibrous tumour. Conclusions: Solitary fibrous tumour is a rare differential of tumours in the sino-nasal region, diagnosed via histopathology. Although generally slow-growing, these lesions may extend the adjacent structures namely the orbit and skull base. Definitive treatment via surgical resection may be performed safely after careful radiological assessment and multidisciplinary consideration.

Notochordal Tumors.

This review provides an overview of the spectrum of tumors showing notochordal differentiation. This spectrum encompasses benign entities that are mostly discovered incidentally on imaging, reported as benign notochordal cell tumor, usually not requiring surgical intervention; slowly growing and histologically low-grade tumors referred to as conventional chordoma but associated with a significant metastatic potential and mortality; and more aggressive disease represented by histologically higher-grade tumors including dedifferentiated chordoma, a high-grade biphasic tumor characterized by a conventional chordoma juxtaposed to a high-grade sarcoma, usually with a spindle or pleomorphic cell morphology, and associated with a poor prognosis and poorly differentiated chordoma.

Primary osteosarcoma of the sphenoid wing in a middle-aged woman with extensive intracranial extension: A case report.

Primary osteosarcomas involving the base of the skull in middle-aged patients are rare. We describe the case of a 59-year-old Asian woman presenting with lethargy, epistaxis, left maxillary and mandibular pain, and headache. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large left greater sphenoid wing tumour with extensive local infiltration and intracranial extension. The tumour was diagnosed as osteosarcoma based on histological examination. In this report, we discuss the clinical presentations, radiological features, and imaging differential diagnoses of this case.

Cost-effectiveness of proton therapy in treating base of skull chordoma.

While proton beam therapy (PBT) can offer increased sparing of healthy tissue, it is associated with large capital costs and as such, has limited availability. Furthermore, it has not been well established whether PBT has significant clinical advantages over conventional volumetric modulated arc therapy (VMAT) for all tumour types. PBT can potentially offer improved clinical outcomes for base of skull chordoma (BOSCh) patients compared with photon (X-ray) therapy, however the cost-effectiveness of these treatments is unclear. In this study, the cost-effectiveness of PBT in the treatment of BOSCh patients is assessed, based on an analysis of comparative radiotherapy treatment plans using a radiobiological Markov model. Seven BOSCh patients had treatment plans for the delivery of intensity modulated proton therapy and VMAT retrospectively analysed. The patient outcome (in terms of tumour local control and normal tissue complications) after receiving each treatment was estimated with a radiobiological Markov model. In addition, the model estimated the cost of both the primary treatment and treating any resultant adverse events. The incremental cost-effectiveness ratio (ICER) was obtained for each patient. PBT was found to be cost-effective for 5 patients and cost-saving for 2. The mean ICER was AUD$1,990 per quality adjusted life year gained. Variation of model parameters resulted in the proton treatments remaining cost-effective for these patients. Based on this cohort, PBT is a cost-effective treatment for patients with BOSCh. This supports the inclusion of PBT for BOSCh in the Medicare Services Advisory Committee 1455 application.

Intensity-modulated radiotherapy for paranasal sinuses and base of skull tumors.

Paranasal sinus and skull base tumors are rare aggressive head and neck cancers, and typically present in the locally advanced stages. As a result, achieving wide surgical resection with clear margins is a challenge for these tumors, and radiotherapy is thus usually indicated as an adjuvant modality following surgery to optimize local control. Given the integral role of radiotherapy in the management of this subgroup of head and neck tumors, the advent of intensity-modulated radiotherapy (IMRT) has led to substantial improvement of clinical outcomes for these patients. This is primarily driven by the improvement in radiation dosimetry with IMRT compared to conventional two dimensional (2D)- and 3D-techniques, in terms of ensuring dose intensity to the tumor target coupled with minimizing dose exposure to critical organs. Consequently, the evident clinical benefits of IMRT have been in reduction of normal tissue toxicities, ranging from critical neurological symptoms to less debilitating but bothersome symptoms of eye infections and radiation-induced skin changes. Another domain where IMRT has potential clinical utility is in the management of a subset of non-resectable T4 paranasal sinus and skull base tumors. For these inoperable lesions, the steep dose-gradient between tumor and normal tissue is even more advantageous, given the crucial need to maintain dose intensity to the tumor. Innovative strategies in this space also include the use of induction chemotherapy for patient selection. In this review, we summarized the data for the aforementioned topics, including specific discussions on the different histologic subtypes of paranasal sinus and skull base tumors.

Myositis in the head and neck: challenges in diagnosis and management.

Myositis in the head and neck may present with non-specific symptoms, and radiographically may mimic malignancy. Multidisciplinary management is often essential, and we describe the challenges in an effort to raise awareness of the condition.

Definitive proton beam therapy for adenoid cystic carcinoma of the nasopharynx involving the base of skull.

OBJECTIVES: Management of unresectable adenocystic carcinoma (ACC) of the nasopharynx is challenging given the high dose required for tumor control while respecting dose constraints. We evaluated long-term outcomes and toxicity in patients with unresectable ACC of the nasopharynx treated with definitive proton beam therapy. METHODS: Between 2000 and 2013, 14 patients with ACC of the nasopharynx were treated. Ninety-three percent had T4 disease. All had involvement of the skull base. Seventy-nine percent and 21% of patients underwent biopsy and endoscopic debulking surgery, respectively. Median dose was 73.8Gy (RBE). Fifty percent of patients received concurrent chemotherapy. Locoregional control and overall survival probabilities were estimated by the Kaplan-Meier method. Treatment toxicity was scored by the Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Median follow-up of surviving patients was 69months. There were 3 local, 1 regional, and 4 distant failures. Median time of local failures was 69months (range: 63-161). All local recurrences were within previous high-dose regions. Four patients developed metastatic disease at a median of 30months (range: 4-64). Five-year overall survival was 59%. The most common cause of death was due to metastatic disease. There was one acute grade 3 toxicity. No patient required gastrostomy tube or hospitalization. Three patients developed grade 3 or higher late toxicity. Two of these patients received combined modality treatment. With 176months follow-up, no second cancer was observed. CONCLUSION: Proton beam therapy results in promising local control with acceptable toxicity in patients with unresectable ACC of the nasopharynx. As late recurrence is common, longer follow-up is necessary to confirm our findings.

An Automated, Gravity-driven CSF Drainage System Decreases Complications and Lowers Costs.

BACKGROUND: FlowSafeTM (BeckerSmith Medical, Irvine, CA, USA) is a novel, robotic, external lumbar drainage (ELD) system, which was designed to control cerebrospinal fluid (CSF) drainage, reduce complications, and decrease treatment costs. METHODS:  Forty-seven consecutive neurosurgical patients requiring ELD were treated using the FlowSafe system. RESULTS: In 39 of 40 patients with traumatic and surgical dural openings, potential CSF leaks were avoided. In seven patients with suspected normal pressure hydrocephalus, post-infectious ventriculomegaly, or pseudotumor cerebrum, we were able to assess the likelihood of improvement with shunting. The system, therefore, produced what we considered to be the "desired result" in 46 of 47 patients (98%). Our one treatment failure (2%) involved a patient with unrecognized hydrocephalus who, following a Chiari repair with a dural patch graft, was drained for six days. A persistent CSF leak eventually required a reoperation. Two patients (4%) described low-pressure headaches during treatment. Both responded to temporarily suspending or reducing the drainage rate. We saw no complications. Required nursing interventions were minimal.  Conclusions: The FlowSafe system was safe and effective. In our experience, there were fewer complications compared to currently available ELD systems. The FlowSafe was well tolerated by our patients. The near elimination of nursing interventions should allow lumbar drainage to be delivered in less costly, non-intensive care unit settings. Larger trials will be needed.

Plasmacytoma of the Skull Base: A Meta-Analysis.

Objective Extramedullary plasmacytomas are rare tumors. In the current study we aim to characterize its clinical course at the skull base and define the most appropriate therapeutic protocol. Methods We conducted a meta-analysis of articles in the English language that included data on the treatment and outcome of plasmacytoma of the base of skull. Results The study cohort consisted of 47 patients. The tumor originated from the clivus and sphenoclival region in 28 patients (59.5%), the nasopharynx in 10 patients (21.2%), the petrous apex in 5 patients (10.6%), and the orbital roof in 4 patients (8.5%). The chief complaints at presentation included recurrent epistaxis and cranial nerve palsy, according to the site of tumor. Twenty-two patients (46.8%) had surgical treatment; 25 (53.2%) received radiation therapy. Adjuvant therapy was administered in 11 cases (50%) with concurrent multiple myeloma. The 2-year and 5-year overall survival rates were 78% and 59%, respectively. Clear margin resection was achieved in a similar proportion of patients who underwent endoscopic surgery and open surgery (p = 0.83). A multivariate analysis of outcome showed a similar survival rate of patients treated surgically or with radiotherapy. Conclusions The mainstay of treatment for plasmacytoma is based on radiation therapy, but when total resection is feasible, endoscopic resection is a valid option.

Multiple Cerebrovascular Complications due to Sphenoid Sinusitis.

Sphenoiditis is of particular interest because the sphenoid sinus has thin wall and its special anatomical location facilitate dissemination of infection to many intracranial structures including vascular structures. The main objective of this report is to gain insight into patterns of presentation and imaging findings in cerebrovascular complications of sphenoid sinusitis and to emphasize the need of reviewing Brain Computed Tomography Scan in all windows. This is a report of 32-year-old young female presented with fever and headache who was diagnosed to have sphenoid sinusitis after radiological examination. Sphenoid sinusitis may involve several intracranial structures, with potentially severe or even fatal complications. Prompt diagnosis and antibiotic/antifungal therapy is essential to minimize mortality and morbidity.