Proton beam therapy in the management of skull base chordomas: systematic review of indications, outcomes, and implications for neurosurgeons

Adjuvant Stereotactic Radiosurgery With or Without Postresection Fractionated Radiation Therapy for the Management of Clival Chordomas in Adults: An International Multicenter Case Series

BACKGROUND

Clival chordomas are challenging because of their proximity to critical neurovascular structures. Stereotactic radiosurgery (SRS) has been proven effective with minimal adverse effects.

OBJECTIVE

To compare the outcomes of histologically confirmed primary clival chordomas in adults who underwent SRS alone (SRS group) vs SRS after fractionated radiotherapy (FRT+SRS group).

METHODS

We collected patient data from 10 institutions affiliated with the International Radiosurgery Research Foundation. We evaluated overall survival, tumor control, and freedom from additional treatment (FFAT).

RESULTS

Fifty-seven (77%) patients were included in the SRS group and 17 (23%) in the FRT+SRS group. The median radiological follow-up was 48 months (IQR, 24-85) in the SRS group and 36 months (IQR, 25-41) in the FRT+SRS group. During the follow-up, 8 SRS and 2 FRT+SRS patients died ( P = .80). The groups had comparable 10-year overall survival (SRS: 76% vs FRT+SRS: 80%; logrank test, P = .75) and tumor control rates (SRS: 34% vs FRT+SRS: 45%; logrank test, P = .29). The SRS group had a superior 10-year FFAT rate (40%) compared with FRT+SRS (23%; logrank test, P = .02). This finding persisted in the multivariate analysis of the Cox proportional hazards illustrating a 2.40-fold increase in the relative risk of requiring additional treatment among the FRT+SRS group ( P = .04).

CONCLUSION

Adjuvant FRT with subsequent boost SRS did not provide superior overall survival or tumor control compared with patients who underwent adjuvant SRS alone. Further studies are required to refine management guidelines among adults with clival chordomas.

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.

Cervical Paraspinal Chordoma: A Literature Review with a Novel Case Report

Chordomas are rare malignant neoplasms, accounting for 1–4% of all primary bone tumors. Most spinal chordomas occur in the sacrococcygeal region and the base of the skull; however, 6% of chordomas are observed in the cervical spine. In these cases, the lesion is mainly located in the midline. These tumors slowly grow before becoming symptomatic and encase the surrounding vascular and nerve structures. Patients with advanced chordoma have a poor prognosis due to local recurrence with infiltration and destruction of adjacent bone and tissues. Systemic chemotherapy options have not been fully effective in these tumors, especially for recurrent chordomas. Thus, new combinations of currently available targeted molecular and biological therapies with radiotherapy have been proposed as potential treatment modalities. Here, the present paper describes the case of a 41-year-old male with a C2–C4 chordoma located paravertebrally, who underwent surgical resection with a debulking procedure for a cervical chordoma. Computed tomography angiography revealed a paraspinal mass with bone remodeling and the MRI showed a paravertebral mass penetrating to the spinal canal with a widening of the intervertebral C2–C3 foramen. Initially, the tumor was diagnosed as schwannoma based on its localization and imaging features; however, the histopathology specimen confirmed the diagnosis of chordoma. This case study highlights the effectivity of radical surgical resection as a mainstay treatment for chordomas, discusses neuroimaging, diagnosis, and the use of currently available targeted therapies and forthcoming treatment strategies, as alternative treatment options for chordoma.

Systematic Review Comparing Open versus Endoscopic Surgery in Clival Chordomas and a 10-Year Single-Center Experience

Objectives Chordomas are rare, slow-growing, and osteo-destructive tumors of the primitive notochord. There is still contention in the literature as to the optimal management of chordoma. We conducted a systematic review of the surgical management of chordoma along with our 10-year institutional experience.

Design A systematic search of the literature was performed in October 2020 by using MEDLINE and EMBASE for articles relating to the surgical management of clival chordomas. We also searched for all adult patients surgically treated for primary clival chordomas at our institute between 2009 and 2019.

Participants Only articles describing chordomas arising from the clivus were included in the analysis. For our institution experience, only adult primary clival chordoma cases were included.

Main Outcome Measures Patients were divided into endoscopic or open surgery. Rate of gross total resection (GTR), recurrence, and complications were measured.

Results Our literature search yielded 24 articles to include in the study. Mean GTR rate among endoscopic cases was 51.9% versus 41.7% for open surgery. Among the eight cases in our institutional experience, we found similar GTR rates between endoscopic and open surgery.

Conclusion Although there is clear evidence in the literature that endoscopic approaches provide better rates of GTR with fewer overall complications compared to open surgery. However, there are still situations where endoscopy is not viable, and thus, open surgery should still be considered if required.

The benefits of inferolateral transtubercular route on intradural surgical exposure using the endoscopic endonasal transclival approach

BACKGROUND

Surgical access to the ventral pontomedullary junction (PMJ) can be achieved through various corridors depending on the location and extension of the lesion. The jugular tubercle (JT), a surgically challenging obstacle to access the PMJ, typically needs to be addressed in transcranial exposures. We describe the endoscopic endonasal transclival approach (EETCA) and its inferolateral transtubercular extension to assess the intradural surgical field gained through JT removal. We also complement the dissections with an illustrative case.

METHODS

EETCA was surgically simulated, and the anatomical landmarks were assessed in eight cadaveric heads. Microsurgical dissections were additionally performed along the endoscopic surgical path. Lastly, we present an intraoperative video of the trans-JT approach in a patient with lower clival chordoma.

RESULTS

The EETCA allowed adequate extracranial visualization and removal of the JT. The surgical bony window-obtained along the clivus and centered at the JT via the EETCA-measured 11 × 9 × 7 mm. Removal of the JT provided an improved intradural field within the lower third of the cerebellopontine cistern to expose an area bordered by the cranial nerves VII/VIII and flocculus superior and anterior margin of the lateral recess of the fourth ventricle and cranial nerves IX-XI inferiorly, centered on the foramen of Luschka.

CONCLUSIONS

Removal of the JT via EETCA improves exposure along the lower third of the cerebellopontine and upper cerebellomedullary cisterns. The inferolateral transtubercular extension of the EETCA provides access to the lateral recess of the fourth ventricle, in combination with the ventral midline pontomedullary region.

A Review of Particle Therapy for Skull Base Tumors: Modern Considerations and Future Directions

Skull base tumors constitute one of the established indications for particle therapy, specifically proton therapy. However, a number of prognostic factors, practical clinical management issues, and the emerging role of carbon ion therapy remain subjects of active clinical investigation. This review summarizes these topics, assesses the present status, and reflects on future research directions focusing on the management of chordomas, one of the most aggressive skull base tumors. In addition, the role of particle therapy for benign tumors of the skull base, including pituitary adenoma and acoustic neuroma, is reviewed.

Chordoma of the sacrum and mobile spine: a narrative review

Chordoma is a notochord-derived primary tumor of the skull base and vertebral column known to affect 0.08 to 0.5 per 100,000 persons worldwide. Patients commonly present with mechanical, midline pain with or without radicular features secondary to nerve root compression. Management of these lesions has classically revolved around oncologic resection, defined by en bloc resection of the lesion with negative margins as this was found to significantly improve both local control and overall survival. With advancement in radiation modalities, namely the increased availability of focused photon therapy and proton beam radiation, high-dose (>50 Gy) neoadjuvant or adjuvant radiotherapy is also becoming a standard of care. At present chemotherapy does not appear to have a role, but ongoing investigations into the ontogeny and molecular pathophysiology of chordoma promise to identify therapeutic targets that may further alter this paradigm. In this narrative review we describe the epidemiology, histopathology, diagnosis, and treatment of chordoma.

Recent advances in understanding and managing chordomas: an update

Chordomas are rare and difficult-to-treat tumors arising from the embryonic notochord. While surgery is the mainstay of treatment, and despite new techniques aimed at maximizing total tumoral resection, recurrence remains high and the probability of disease-free survival low. New breakthroughs in genetics, targeted molecular therapy, and heavy-particle beam therapy offer some promise as adjuvant treatments in addition to surgical resection. A multidisciplinary approach encompassing genetics, immunotherapy, radiation therapy, and surgery, at a facility experienced in the management of this complex disease, offers the best chance of survival and quality of life to patients while limiting the intrinsic morbidity of these treatments.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Outcomes, Prognostic Factors and Salvage Treatment for Recurrent Chordoma After Pencil Beam Scanning Proton Therapy at the Paul Scherrer Institute

AIMS

The outcome of chordoma patients with local or distant failure after proton therapy is not well established. We assessed the disease-specific (DSS) and overall survival of patients recurring after proton therapy and evaluated the prognostic factors affecting DSS.

MATERIALS AND METHODS

A retrospective analysis was carried out of 71 recurring skull base (n = 36) and extracranial (n = 35) chordoma patients who received adjuvant proton therapy at initial presentation (n = 42; 59%) or after post-surgical recurrence (n = 29; 41%). The median proton therapy dose delivered was 74 GyRBE (range 62-76). The mean age was 55 ± 14.2 years and the male/female ratio was about one.

RESULTS

The median time to first failure after proton therapy was 30.8 months (range 3-152). Most patients (n = 59; 83%) presented with locoregional failure only. There were only 12 (17%) distant failures, either with (n = 5) or without (n = 7) synchronous local failure. Eight patients (11%) received no salvage therapy for their treatment failure after proton therapy. Salvage treatments after proton therapy failure included surgery, systemic therapy and additional radiotherapy in 45 (63%), 20 (28%) and eight (11%) patients, respectively. Fifty-three patients (75%) died, most often from disease progression (47 of 53 patients; 89%). The median DSS and overall survival after failure was 3.9 (95% confidence interval 3.1-5.1) and 3.4 (95% confidence interval 2.5-4.4) years, respectively. On multivariate analysis, extracranial location and late failure (≥31 months after proton therapy) were independent favourable prognostic factors for DSS.

CONCLUSION

The survival of chordoma patients after a treatment failure following proton therapy is poor, particularly for patients who relapse early or recur in the skull base. Although salvage treatment is administered to most patients with uncontrolled disease, they will ultimately die as a result of disease progression in most cases.

Patient Prioritization for Proton Beam Therapy in a Cost-neutral Payer Environment: Use of the Clinical Benefit Score for Resource Allocation

Objectives There has been a rapid increase in the number of one- and two-room proton beam therapy (PBT) centers, which may be limited in the number of patients they can treat. The objective of this study was to analyze the impact of the 'clinical benefit score' (CBS), utilized as a method for treatment prioritization for PBT operating in a 'cost-neutral' proton-photon payer environment. Materials & methods This study includes patients considered for PBT at a center that initially had only one or two treatment rooms available for clinical use. Patients were prospectively scored using the CBS, and higher scores were prioritized. The outcome was receipt of PBT and the independent variable was CBS. Crude and adjusted analyses were performed using logistic regression. Results There were 2163 patients evaluated. A total of 205 patients (9.5%) were deemed candidates for PBT, which was received by 122 (5.6%) patients. In patients considered for PBT, the mean CBS was 18.7. Patients who were <21 years old, female, non-Caucasian, receiving re-irradiation, and those with Medicare had a higher CBS. Multivariate analysis adjusting for insurance status revealed both CBS and insurance to be significant predictors for receiving PBT. A unit increase in CBS was associated with 1.04 times increased odds of receiving PBT (OR=1.04, 95%CI: 1.01-1.07, p=0.0145) and having Medicare was associated with 3.13 times increased odds of receiving PBT (OR=3.13, 95%CI: 1.57-6.26, p=0.0012). Subgroup analysis, which only included patients enrolled prior to opening the second gantry, showed 1.05 times increased odds of receiving PBT per unit increase in CBS (OR=1.05, 95%CI: 1.00-1.10, p=0.03) and 2.87 times increased odds of receiving PBT in patients with Medicare (OR=2.87, 95%CI: 1.04-7.92, p=0.04). Conclusion  The CBS utilized was significantly associated with the receipt of PBT in a cost-neutral payer setting. Physicians may consider the use of CBS as a resource allocation tool.

Proton therapy- the modality of choice for future radiation therapy management of Prostate Cancer?

BACKGROUND

Proton Therapy (PR) is an emerging treatment for prostate cancer (Pca) patients. However, limited and conflicting data exists regarding its ability to result in fewer bladder and rectal toxicities compared to Photon Therapy (PT), as well as its cost efficiency and plan robustness.

MATERIALS AND METHODS

An electronic literature search was performed to acquire eligible studies published between 2007 and 2018. Studies comparing bladder and rectal dosimetry or Gastrointestinal (GI) and Genitourinary (GU) toxicities between PR and PT, the plan robustness of PR relative to motion and its cost efficiency for Pca patients were assessed.

RESULTS

28 studies were eligible for inclusion in this review. PR resulted in improved bladder and rectal dosimetry but did not manifest as improved GI/GU toxicities clinically compared to PT. PR plans were considered robust when specific corrections, techniques, positioning or immobilisation devices were applied. PR is not cost effective for intermediate risk Pca patients; however PR may be cost effective for younger or high risk Pca patients.

CONCLUSION

PR offers improved bladder and rectal dosimetry compared to PT but this does not specifically translate to improved GI/GU toxicities clinically. The robustness of PR plans is acceptable under specific conditions. PR is not cost effective for all Pca patients.

Prospective validation of a molecular prognostication panel for clival chordoma

OBJECTIVE

There are currently no reliable means to predict the wide variability in behavior of clival chordoma so as to guide clinical decision-making and patient education. Furthermore, there is no method of predicting a tumor's response to radiation therapy.

METHODS

A molecular prognostication panel, consisting of fluorescence in situ hybridization (FISH) of the chromosomal loci 1p36 and 9p21, as well as immunohistochemistry for Ki-67, was prospectively evaluated in 105 clival chordoma samples from November 2007 to April 2016. The results were correlated with overall progression-free survival after surgery (PFSS), as well as progression-free survival after radiotherapy (PFSR).

RESULTS

Although Ki-67 and the percentages of tumor cells with 1q25 hyperploidy, 1p36 deletions, and homozygous 9p21 deletions were all found to be predictive of PFSS and PFSR in univariate analyses, only 1p36 deletions and homozygous 9p21 deletions were shown to be independently predictive in a multivariate analysis. Using a prognostication calculator formulated by a separate multivariate Cox model, two 1p36 deletion strata (0%-15% and > 15% deleted tumor cells) and three 9p21 homozygous deletion strata (0%-3%, 4%-24%, and ≥ 25% deleted tumor cells) accounted for a range of cumulative hazard ratios of 1 to 56.1 for PFSS and 1 to 75.6 for PFSR.

CONCLUSIONS

Homozygous 9p21 deletions and 1p36 deletions are independent prognostic factors in clival chordoma and can account for a wide spectrum of overall PFSS and PFSR. This panel can be used to guide management after resection of clival chordomas.

Gamma knife surgery efficacy in controlling postoperative residual clival chordoma growth

OBJECTIVE

This study primarily aims to evaluate the efficacy of gamma knife surgery in controlling growth progression rate of residual clival chordoma through retrospective outcome analysis of 12 consecutive patients.

PATIENTS AND METHODS

Data for 12 consecutive patients underwent GKS for post-operative residual histologically verified clival chordoma at our institution (IMC - Cairo- Egypt) from 2006 through end of 2017 were retrospectively reviewed and analyzed with mean follow-up period of 45 months (range12-120 months).

RESULTS

In the last follow up MR, tumor growth control was achieved in 33.3% of patients (mean treated tumors volume was 2.7cc with mean peripheral prescription dose of 16 Gy), and 66.7% of patients reported lost tumor growth control (mean treated tumor volume was 9.2 cc with mean peripheral dose was 13.5 Gy). The overall tumor free progression with mean follow up period of 45mos was 33.3%. The Actuarial 2, 3 and 5 year tumor control rates after initial GKS was 35%, 30% and 25% respectively.

CONCLUSION

Without satisfactory maximum tumor reduction and sufficient high peripheral prescription radiation tumor dose, it should not be expected that GKS could efficiently control the progression of residual clival chordoma, especially for long term.

Protein phosphatase 2A inhibition enhances radiation sensitivity and reduces tumor growth in chordoma

Background

Standard therapy for chordoma consists of surgical resection followed by high-dose irradiation. Protein phosphatase 2A (PP2A) is a ubiquitously expressed serine/threonine phosphatase involved in signal transduction, cell cycle progression, cell differentiation, and DNA repair. LB100 is a small-molecule inhibitor of PP2A designed to sensitize cancer cells to DNA damage from irradiation and chemotherapy. A recently completed phase I trial of LB100 in solid tumors demonstrated its safety. Here, we show the therapeutic potential of LB100 in chordoma.

Methods

Three patient-derived chordoma cell lines were used: U-CH1, JHC7, and UM-Chor1. Cell proliferation was determined with LB100 alone and in combination with irradiation. Cell cycle progression was assessed by flow cytometry. Quantitative γ-H2AX immunofluorescence and immunoblot evaluated the effect of LB100 on radiation-induced DNA damage. Ultrastructural evidence for nuclear damage was investigated using Raman imaging and transmission electron microscopy. A xenograft model was established to determine potential clinical utility of adding LB100 to irradiation.

Results

PP2A inhibition in concert with irradiation demonstrated in vitro growth inhibition. The combination of LB100 and radiation also induced accumulation at the G2/M phase of the cell cycle, the stage most sensitive to radiation-induced damage. LB100 enhanced radiation-induced DNA double-strand breaks. Animals implanted with chordoma cells and treated with the combination of LB100 and radiation demonstrated tumor growth delay.

Conclusions

Combining LB100 and radiation enhanced DNA damage-induced cell death and delayed tumor growth in an animal model of chordoma. PP2A inhibition by LB100 treatment may improve the effectiveness of radiation therapy for chordoma.

Four-Level Vertebrectomy for En Bloc Resection of a Cervical Chordoma

BACKGROUND

Chordomas are locally aggressive tumors that can involve multiple levels of the spine and are difficult to resect. We present our technique for 4-level en bloc cervical spondylectomy for a locally aggressive chordoma.

CASE DESCRIPTION

A 37-year-old woman presented with a 6-month history of dysphagia and a large indurated cervical mass. Imaging showed an enhancing lesion involving C3-6. Needle biopsy confirmed the diagnosis of chordoma. En bloc resection was chosen to maximize her chances of disease-free survival. A 360° approach was deemed necessary. We posteriorly disconnected the vertebral bodies and skeletonized the bilateral vertebral arteries and nerve roots. The interspinous and yellow ligaments and the spinous processes were spared to maintain a solid posterior tension band, as previously described approaches that had sacrificed these elements had a high rate of instrumentation failure. After posterior instrumentation, a wide anterior approach enabled us to resect the tumor attached to the vertebral bodies of C3-6 as 1 specimen. A 4-level corpectomy cage and plate were used for anterior instrumentation. The patient tolerated the surgery well. She needed a temporary gastrostomy, and she had a right C5 palsy that progressively recovered. Follow-up imaging showed no tumor recurrence and good bony fusion.

CONCLUSIONS

En bloc resection as part of a multidisciplinary team approach remains the mainstay of spinal chordoma treatment. Modern instrumentation and careful dissection can provide good results even in locally advanced cases.

[Extended endoscopic endonasal surgery for clival chordoma and chondrosarcoma: Our experience in 14 cases]

OBJECTIVE

To report our experience in the management of chordoma and chondrosarcoma with extended endoscopic endonasal surgery.

METHOD

We performed a retrospective analysis of a series of 14 patients with clival chordoma or chondrosarcoma who had extended endoscopic endonasal surgery from 2008 to 2016 performed by the same multidisciplinary team.

RESULTS

We had fourteen patients (male/female 2:1), with a mean age of 49years for chordoma and 32 for chondrosarcoma. The most common clinical presentation was diplopia in 78.5% of cases, followed by dysphagia in 28.6%. Histologically, 71.4% were chordomas and 28.6% were chondrosarcomas. In addition, invasion of at least two thirds or more of the clivus was found in 81% of the cases; in 57.1% there was intradural invasion, and in 35.7% invasion of the sella turcica. In 42.8% of cases, the degree of resection was total and in 21.5% subtotal. The most common complication was CSF fistula, occurring in 28.6% of the cases, with only one case requiring surgery to repair it. Adjuvant treatment with Proton Beam was performed in 35.7% of cases and with conventional radiotherapy in 21.5%. Mean follow-up was 53.5months and tumour recurrence or progression was found in 21.5% of the cases, two of which had not received adjuvant treatment. There were no deaths.

CONCLUSION

The extended endoscopic endonasal approach (EEEA) performed by an experienced team is a good alternative for the management of these lesions. Intradural invasion may be related to an increased risk of complications and worse clinical presentation, in addition to a lower rate of total resection.

Recent advances in radiation oncology

Radiotherapy (RT) is very much a technology-driven treatment modality in the management of cancer. RT techniques have changed significantly over the past few decades, thanks to improvements in engineering and computing. We aim to highlight the recent developments in radiation oncology, focusing on the technological and biological advances. We will present state-of-the-art treatment techniques, employing photon beams, such as intensity-modulated RT, volumetric-modulated arc therapy, stereotactic body RT and adaptive RT, which make possible a highly tailored dose distribution with maximum normal tissue sparing. We will analyse all the steps involved in the treatment: imaging, delineation of the tumour and organs at risk, treatment planning and finally image-guidance for accurate tumour localisation before and during treatment delivery. Particular attention will be given to the crucial role that imaging plays throughout the entire process. In the case of adaptive RT, the precise identification of target volumes as well as the monitoring of tumour response/modification during the course of treatment is mainly based on multimodality imaging that integrates morphological, functional and metabolic information. Moreover, real-time imaging of the tumour is essential in breathing adaptive techniques to compensate for tumour motion due to respiration. Brief reference will be made to the recent spread of particle beam therapy, in particular to the use of protons, but also to the yet limited experience of using heavy particles such as carbon ions. Finally, we will analyse the latest biological advances in tumour targeting. Indeed, the effectiveness of RT has been improved not only by technological developments but also through the integration of radiobiological knowledge to produce more efficient and personalised treatment strategies.

Distinctive Head and Neck Bone and Soft Tissue Neoplasms

Benign and malignant primary bone and soft tissue lesions of the head and neck are rare. The uncommon nature of these tumors, combined with the complex anatomy of the head and neck, pose diagnostic challenges to pathologists. This article describes the pertinent clinical, radiographic, and pathologic features of selected bone and soft tissue tumors involving the head and neck region, including angiofibroma, glomangiopericytoma, rhabdomyosarcoma, biphenotypic sinonasal sarcoma, chordoma, chondrosarcoma, and osteosarcoma. Emphasis is placed on key diagnostic pitfalls, differential diagnosis, and the importance of correlating clinical and radiographic information, particularly for tumors involving bone.

Recent advances in understanding and managing chordomas

Chordomas are rare primary bone tumors arising from embryonic remnants of the notochord. They are slow-growing, locally aggressive, and destructive and typically involve the axial skeleton. Genetic studies have identified several mutations implicated in the pathogenesis of these tumors. Treatment poses a challenge given their insidious progression, degree of local invasion at presentation, and high recurrence rate. They tend to respond poorly to conventional chemotherapy and radiation. This makes radical resection the mainstay of their treatment. Recent advances in targeted chemotherapy and focused particle beam radiation, however, have improved the management and prognosis of these tumors.