Maximum surgical resection and adjuvant intensity-modulated radiotherapy with simultaneous integrated boost for skull base chordoma

Systematic Review and Meta-Analysis of Particle Beam Therapy versus Photon Radiotherapy for Skull Base Chordoma: TRP-Chordoma 2024

[Objective] The aim of this study was to compare the efficacy of particle beam therapy (PT) with photon radiotherapy (RT) for treatment of skull base chordoma. [Methods] A systematic review was conducted for skull base chordoma treated with PT or photon RT reported from 1990 to 2022. Data were extracted for overall survival (OS) and progression-free survival (PFS), late adverse events, age, gender, gross total resection (GTR) rates, tumor volume, total irradiation dose, and treatment modality. Random-effects meta-regression analysis with the treatment modality as an explanatory variable was performed for each outcome to compare the modalities. [Results] A meta-analysis of 30 selected articles found 3- and 5-year OS rates for PT vs. photon RT or combined photon RT/proton beam therapy (PBT) of 90.8% (95% CI: 87.4-93.3%) vs. 89.5% (95% CI: 83.0-93.6%), p = 0.6543; 80.0% (95% CI: 75.7-83.6%) vs. 89.5% (95% CI: 83.0-93.6%), p = 0.6787. The 5-year PFS rates for PT vs. photon RT or photon RT/PBT were 67.8% (95% CI: 56.5-76.7%) vs. 40.2% (95% CI: 31.6-48.7%), p = 0.0004. A random-effects model revealed that the treatment modality (PT vs. photon RT or photon RT/PBT) was not a significant factor for 3-year OS (p = 0.42) and 5-year OS (p = 0.11), but was a significant factor for 5-year PFS (p < 0.0001). The rates of brain necrosis were 8-50% after PT and 0-4% after photon RT or photon RT/PBT. [Conclusion] This study shows that PT results in higher PFS compared to photon RT for skull base chordoma, but that there is a tendency for a higher incidence of brain necrosis with PT. Publication and analysis of further studies is needed to validate these findings.

Assessing survival outcomes and complication profiles following surgical excision and radiotherapy as interventions for skull base chordoma: a systematic review of operative margins and surgical approaches

INTRODUCTION

Despite their precarious behavioral classification (benign and low grade on histopathology yet behaviorally malignant), great strides have been taken to improve prognostication and treatment paradigms for patients with skull base chordoma. With respect to surgical techniques, lateral transcranial (TC) approaches have traditionally been used, however endoscopic endonasal approaches (EEA) have been advocated for midline lesions. Nonetheless, due to the rarity of this pathology (0.2% of all intracranial neoplasms), investigations within the literature remain limited to small retrospective series. Furthermore, radiotherapeutic treatments investigated to date have proven largely ineffective.

METHODS

Accordingly, we performed a systematic review in order to profile surgical and survival outcomes for skull base chordoma. Fixed and random-effect meta-analyses were performed for categorical variables including GTR, STR, 5-year OS, 10-year OS, 5-year PFS, and 10-year PFS. Additionally, we pooled eligible studies for formal meta-analysis to compare outcomes by surgical approach (lateral versus midline). Statistical analyses were performed using R Studio 'metafor' package or Cochrane Review Manager. Furthermore, meta-analysis of pooled mortality rates and sub-analyses of operative margin and surgical complications were used to compare midline versus lateral approaches via the Mantel-Haenszel method. We considered all p-values < 0.05 to be statistically significant.

RESULTS

Following the systematic search and screen, 55 studies published between 1993 and 2022 reporting data for 2453 patients remained eligible for analysis. Sex distribution was comparable between males and females, with a slight predominance of male-identifying patients (0.5625 [95% CI: 0.5418; 0.3909]). Average age at diagnosis was 42.4 ± 12.5 years, while average age of treatment initiation was 43.0 ± 10.6 years. Overall, I2 value indicated notable heterogeneity across the 55 studies [I2 = 56.3% (95%CI: 44.0%; 65.9%)]. With respect to operative margins, the rate of GTR was 0.3323 [95% CI: 0.2824; 0.3909], I2 = 91.9% [95% CI: 90.2%; 93.4%], while the rate of STR was significantly higher at 0.5167 [95% CI: 0.4596; 0.5808], I2 = 93.1% [95% CI: 91.6%; 94.4%]. The most common complication was CSF leak (5.4%). In terms of survival outcomes, 5-year OS rate was 0.7113 [95% CI: 0.6685; 0.7568], I2 = 91.9% [95% CI: 90.0%; 93.5%]. 10-year OS rate was 0.4957 [95% CI: 0.4230; 0.5809], I2 = 92.3% [95% CI: 89.2%; 94.4%], which was comparable to the 5-year PFS rate of 0.5054 [95% CI: 0.4394; 0.5813], I2 = 84.2% [95% CI: 77.6%; 88.8%] and 10-yr PFS rate of 0.4949 [95% CI: 0.4075; 0.6010], I2 = 14.9% [95% CI: 0.0%; 87.0%]. There were 55 reported deaths for a perioperative mortality rate of 2.5%. The relative risk for mortality in the midline group versus the lateral approach group did not indicate any substantial difference in survival according to laterality of approach (-0.93 [95% CI: -1.03, -0.97], I2 = 95%, (p < 0.001).

CONCLUSION

Overall, these results indicate good 5-year survival outcomes for patients with skull base chordoma; however, 10-year prognosis for skull base chordoma remains poor due to its radiotherapeutic resistance and high recurrence rate. Furthermore, mortality rates among patients undergoing midline versus lateral skull base approaches appear to be equivocal.

Fractionated Radiotherapy After Gross Total Resection of Clival Chordoma: A Systematic Review of Survival Outcomes

BACKGROUND

Current treatment guidelines for clival chordomas recommend surgical resection followed by high-dose radiotherapy (RT). However, in patients in whom gross total resection (GTR) is achieved, the benefits of additional RT remain unclear.

OBJECTIVE

To investigate whether RT offers any benefit to progression-free survival (PFS) in patients undergoing GTR of clival chordoma by performing a systematic review of all currently published literature.

METHODS

A total of 5 databases were searched to include all studies providing data on GTR ± RT for clival chordomas (January 1990-June 2021). Qualitative assessment was performed with Newcastle-Ottawa Scale guidelines for assessing quality of nonrandomized studies. Statistical analysis using individualized patient data of PFS was performed.

RESULTS

The systematic search yielded 2979 studies, weaned to 22 full-text articles containing 108 patients. All patients underwent GTR of clival chordoma, with 46 (43%) patients receiving adjuvant RT. Mean PFS for RT patients was 31.09 months (IQR: 12.25-37.75) vs 54.92 months (IQR: 14.00-85.75) in non-RT patients. Overall, RT did not increase PFS (HR 0.320, P = .069) to a value that achieved statistical significance. Stratifying by photon therapy vs particle beam therapy yielded no statistically significant benefit for particle beam therapy for PFS ( P = .300). Of patients with age ≥65 years, RT did not improve outcomes to statistical significance for PFS (HR 0.450, P = .481). Patients age ≥65 years had lower PFS on both bivariate analysis (HR 3.708, P = .007) and multivariate analysis (HR 3.322, P = .018).

CONCLUSION

After achieving GTR of clival chordoma, fractionated RT offers unclear benefit upon survival outcomes.

Pure proton therapy for skull base chordomas and chondrosarcomas: A systematic review of clinical experience

Background

Skull base chordoma and chondrosarcoma are exceptionally rare bone tumors with high propensity for local recurrence. Different postoperative radiation modalities are often used to improve the clinical efficacy. Proton therapy (PT) might be among the most promising ones because of the unique ballistic characteristics of high-energy particles. However, previous meta-analysis often included studies with combined radiation techniques. No systematic review to date has directly analyzed the survival and toxicity of pure PT for these two types of malignancies.

Methods

By following the PRISMA guidelines, a systematic search of three databases was conducted. Articles were screened and data were extracted according to a prespecified scheme. R 4.2.0 software was used to conduct the meta-analysis. Normal distribution test was used for the incidence rate of each subgroup.

Results

A total of seven studies involving 478 patients were included in this analysis. The quality of included articles ranged from moderate to high quality. All patients were histopathologically diagnosed with chordoma or chondrosarcoma, and the follow-up time of the cohort ranged from 21 to 61.7 months. For PT planning, the median target volume ranged from 15 cc to 40 cc, and the administered median dose varied from 63 to 78.4 Gy_RBE at 1.8-2.0 Gy_RBE per fraction. The 1-, 2-, 3-, 5-, and 7-year local control and overall survival rates were 100%, 93%, 87%, 78%, and 68%, and 100%, 99%, 89%, 85%, and 68%, respectively. The late grade 3 or higher toxicities were reported in only two involved articles.

Conclusions

Until now, medical centers worldwide have exerted PT to improve outcomes of skull base chordomas and chondrosarcomas. PT not combined with other radiation modalities showed favorable local control and survival with a low incidence of severe radiation-induced toxicities, which manifests promising clinical benefits. However, high-quality evidence is still limited, requiring future clinical trials and prospective studies in selected patients.

The prognostic significance of different degrees of resection of skull base chordoma

BACKGROUND

Complete resection combined with postoperative radiotherapy is ideal for skull base chordomas. The recent literature suggests that the degree of surgical resection is the most important prognostic factor.

METHODS

We retrospectively analyzed the clinical data of 16 patients with initial chordoma treated at our center between August 2015 and December 2021 and conducted a retrospective study on the prognosis of surgical treatment of skull base chordoma between 2013 and 2022.

RESULTS

According to the Kaplan-Meier method, there was a significant difference in PFS between patients aged > 50 years and < 50 years, and no significant difference was observed in PFS for tumor involvement of the internal carotid artery, dura, or superior or inferior clivus. However, there was still a correlation with prognosis. As observed in the included literature, the 5-year overall survival rate was significantly higher in patients undergoing total skull base chordoma resection than in those undergoing subtotal resection (STR), which in turn was significantly higher than in those undergoing partial resection (PR). Patients undergoing subtotal resection had significantly better 5-year PFS rates than those undergoing PR.

CONCLUSION

Our study shows that gross total resection and STR have better survival in patients with skull base chordomas compared to PR.

Long-term outcome of adjunctive Gamma Knife radiosurgery in skull-base chordomas and chondrosarcomas: An Indian experience

Skull-base chordomas (CD) and chondrosarcomas (CS) are locally-invasive tumors, have similar clinical presentations, while differing in their nature of growth and outcomes. In this study, we compare the long-term outcomes of Gamma Knife Radiosurgery (GKRS) as an adjunctive treatment modality for residual skull-base CD and CS. A retrospective analysis of clinico-radiological, pathological, radiotherapeutic and outcome data was carried out in patients who underwent adjunctive GKRS for residual skull-base CD and CS at P D Hinduja Hospital, Mumbai, between 1997 and 2020. All 27 patients included had either histopathologically proven CD (20 patients) or CS (7 patients). Brachyury immunohistochemistry in CD specimens gave 70.6% positivity. Total sessions of GKRS in CD and CS groups were 22 and 7, respectively. Mean tumor volume and mean margin dose in CD group were 6.53 ± 4.18 cm3 and 15.95 ± 1.49 Gy respectively, while for CS group, they were 4.16 ± 2.79 cm3 and 18.29 ± 3.15 Gy. With mean follow-up periods of 5.25 ± 4.73 years and 6 ± 2.07 years respectively, the CD and CS groups showed 5-year progression free survival (PFS) of 56.8% and 57.1%, and a 5-year overall survival (OS) of 82.1% and 100%. Sub-group analysis in both CD and CS groups revealed a better 5-year PFS with the following factors - CS histopathology, patient age < 45 years, margin dose > 16 Gy, tumor volume < 7 cm3 (p-value < 0.05), gross total resection, and brachyury positivity. Adjunctive radiotherapy for skull-base CD and CS holds promise.

Endoscopic endonasal approach for loco-regional recurrent clivus chordomas

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EEA represents an ideal approach for loco-regional recurrent CCs.

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EEA is well tolerated, with preservation of patients QoL.

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EEA can be considered for patients with perspectives of adjuvant therapies.

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Otherwise, EEA can be considered only in selected cases with a palliative aim.

Mid-term follow-up surgical results in 284 cases of clival chordomas: the risk factors for outcome and tumor recurrence

Objective

Skull base chordoma (SBC) is rare and one of the most challenging diseases to treat. We aimed to assess the optimal timing of adjuvant radiation therapy (RT) and to evaluate the factors that influence resection and long-term outcomes.

Methods

In total, 284 patients with 382 surgeries were enrolled in this retrospective study. Postsurgically, 64 patients underwent RT before recurrence (pre-recurrence RT), and 47 patients underwent RT after recurrence. During the first attempt to achieve gross-total resection (GTR), when the entire tumor was resected, 268 patients were treated with an endoscopic midline approach, and 16 patients were treated with microscopic lateral approaches. Factors associated with the success of GTR were identified using χ² and logistic regression analyses. Risk factors associated with chordoma-specific survival (CSS) and progression-free survival (PFS) were evaluated with the Cox proportional hazards model.

Results

In total, 74.6% of tumors were marginally resected [GTR (40.1%), near-total resection (34.5%)]. History of surgery, large tumor volumes, and tumor locations in the lower clivus were associated with a lower GTR rate. The mean follow-up period was 43.9 months. At the last follow-up, 181 (63.7%) patients were alive. RT history, histologic subtype (dedifferentiated and sarcomatoid), non-GTR, no postsurgical RT, and the presence of metastasis were associated with poorer CSS. Patients with pre-recurrence RT had the longest PFS and CSS, while patients without postsurgical RT had the worst outcome.

Conclusion

GTR is the goal of initial surgical treatment. Pre-recurrence RT would improve outcome regardless of GTR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10143-021-01576-4.

Clivus chordomas: Heterogeneous tumor extension requires adapted surgical approaches

OBJECTIVE

Clivus chordomas are semi-malignant, but infiltratively growing tumors. Currently, a widely-accepted treatment concept encompasses maximal, but safe, surgical resection and radiotherapy. Caused by the size and the tumor extension, different surgical approaches, especially in recurrent cases, might be necessary.

METHODS

Retrospective review of 50 patients on whom 70 surgeries were performed: 29 in primary and 41 in recurrent cases. Based on MRI images, all cases were asserted according to the size and the extension of the tumor. Used surgical approaches were evaluated. Postoperative complications, neurological function prior to and after the surgery, the extent of tumor resection on postoperative MR images were assessed and progression-free survival was calculated.

RESULTS

Tumor size was estimated as small (< 5 cm³) in 8, as medium (5-20 cm³) in 21, as large (20-100 cm³) in 17, and as giant (> 100 cm³) in 4 patients. Most frequently used surgical approaches in primary cases were the transsphenoidal one and midfacial degloving (51.7 % and 17.2 %, respectively). In recurrent cases, dependent on the tumor extension, transsphenoidal (21.9 %), retrosigmoidal (29.3 %), and pterional (19.5 %) approaches, as well as midfacial degloving (17.1 %) were used. Due to the vast tumor extension and infiltration, gross total or near total resection could be achieved in 12 patients (24 %), only. There was no mortality and no major complications in primary cases. In recurrences, however, postoperative hemorrhages and strokes emerged in 4.9 % and 7.1 %. Minor complications occurred in 17.1 % and were dominated by CSF leaks (12.2 %), both in primary in recurrent cases. While most cranial nerve impairments were caused by tumor infiltration of the cavernous sinus, and hence have not improved by treatment, the sixth nerve palsy as a consequence of tumor mass compression, could significantly be improved by surgery. Following surgery, patients were subjected to radiotherapy (68.9 % for primary cases, and 36.6 % for recurrences) mainly with carbon ions. Overall, 5-year progression-free survival was 44.7 %.

CONCLUSION

Caused by the heterogenous pattern of growth of clivus chordomas, surgical approaches should be chosen individually. Vast and infiltrative tumor extension constitute major limitations of surgical resection, and hence result in poor progression-frees survival.

Particle Beam Radiation Therapy for Skull Base Sarcomas

Background: To report the clinical experience of carbon-ion and proton radiation therapy for skull base sarcomas.

Methods: An analysis of the retrospective data registry from the Shanghai Proton and Heavy Ion Center for patients with skull base sarcomas was conducted. The 1-/2-year local relapse-free, distant metastasis-free, progression-free, and overall survival (LRFS, DMFS, PFS, OS) rates as well as associated prognostic indicators were analyzed. Radiotherapy-induced acute and late toxicities were summarized.

Results: Between 7/2014 and 5/2019, 62 patients with skull base sarcomas of various subtypes received carbon-ion radiation therapy (53), proton radiation therapy (5), or proton radiation therapy + carbon-ion boost (4). With a median follow-up of 20.4 (range 2.73–91.67) months, the 1-/2-year OS, LRFS, DMFS, and PFS rates were 91.2%/80.2%, 89.2%/80.2%, 86.0%/81.1%, and 75.8%/62.9%, respectively. Grade 3 mucositis and grade 4 hemorrhage were observed in 1 patient for each. Only grade 1 and grade 2 toxicities were observed except for the same patient with grade 4 acute toxicity died of severe hemorrhage (grade 5). Multivariate analyses revealed the lack of prior RT was an independent favorable prognostic factor for OS, PFS, and LRFS, age under 40 was associated with improved OS, early T-disease (T1/2) showed a significant association with better PFS.

Conclusion: With few observed acute and late toxicities, particle beam radiation therapy provided effective tumor control and overall survival for patients with skull base sarcomas.

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.

Impact of early access to multidisciplinary care on treatment outcomes in patients with skull base chordoma

OBJECTIVE

To determine if early access to multidisciplinary surgical care affects outcomes in patients with skull base chordoma.

METHOD

A retrospective chart review of prospectively collected data was performed on 51 patients treated from 1993 to 2014. The cohort was divided into those presenting (1) for initial management (ID, n = 21) or (2) with persistent/progressive disease after prior biopsy/surgery (PD, n = 30) outside of a multidisciplinary setting. The impact of initial surgical management in a multidisciplinary center on progression-free survival (PFS) was assessed with Kaplan-Meier and log-rank analyses.

RESULTS

Mean follow-up, median PFS, median overall survival (OS), and 10-year OS for the entire cohort was 70 months, 47 months, 159 months, and 19%, respectively. Initial management in a multidisciplinary center resulted in a significant improvement in PFS versus initial surgery with or without radiotherapy (XRT) outside of this setting (64 vs 25 months, p = 0.035). Initial surgical resection outside of a multidisciplinary setting increased the risk of recurrence/progression on univariate (HR, 2.276; p = 0.022) and multivariate analysis (HR, 2.831; p = 0.006), respectively.

CONCLUSIONS

The results from this study emphasize the impact that coordinated multidisciplinary surgical care has on patient outcomes for chordomas of the clivus. Biopsy followed by attempted radical resection at a dedicated center does not affect PFS and, therefore, represents a reasonable first step in management for patients presenting outside of multidisciplinary setting.