Optimization of radiotherapy for patients with cranial chordoma. A review of dose-response ratios for photon techniques

Clival chordomas and chondrosarcomas in Denmark-Outcomes in 33 patients following the national centralization of treatment in 2010

PURPOSE

This 13-year consecutive case series aims to provide a comprehensive overview of all patients operated for clival chordomas and clival chondrosarcomas in Denmark since the centralization of treatment in 2010, comparing outcomes to international series.

METHODS

This was a retrospective review of 33 patients with clival tumors, comprising 22 chordomas and 11 chondrosarcomas, who were treated at Copenhagen University Hospital between years 2010 and 2023. Data were collected from digital patient records and pathology reports.

RESULTS

The symptoms leading to diagnosis primarily included double vision, headaches, and dizziness. In general, patients were in good health, with a mean Charlson Comorbidity Index score of 1.6. The complication rate of the index surgery was 51.5%. Adjuvant radiotherapy was applied in 51.5% of the cases. In patients with clival chordomas, the mean age was 51.1 years, ranging from 16 to 83 years. At the time of diagnosis, the mean tumor volume was 20.9 cm3 and the five-year overall survival rates were 79.1% (95% confidence interval (CI): 62.4-100). In patients with chondrosarcomas, the mean age was 48.2 years, ranging from 15 to 76 years. At the time of diagnosis, the mean tumor volume was 22.3 cm3 and the five-year overall survival 90% (95% CI: 73.2-100).

CONCLUSION

The centralized treatment of clival tumors in Denmark demonstrates incidence, survival, and complication rates comparable to those found in other international series. Given the variations in treatment strategies, tumor localizations across series, and small sample sizes, the further analysis of larger compiled multicenter datasets for clival tumors could provide more solid evidence regarding the management of these rare tumors.

Predicting overall survival in chordoma patients using machine learning models: a web-app application

OBJECTIVE

The goal of this study was to evaluate the efficacy of machine learning (ML) techniques in predicting survival for chordoma patients in comparison with the standard Cox proportional hazards (CoxPH) model.

METHODS

Using a Surveillance, Epidemiology, and End Results database of consecutive newly diagnosed chordoma cases between January 2000 and December 2018, we created and validated three ML survival models as well as a traditional CoxPH model in this population-based cohort study. Randomly, the dataset was divided into training and validation datasets. Tuning hyperparameters on the training dataset involved a 1000-iteration random search with fivefold cross-validation. Concordance index (C-index), Brier score, and integrated Brier score were used to evaluate the performance of the model. The receiver operating characteristic (ROC) curves, calibration curves, and area under the ROC curves (AUC) were used to assess the reliability of the models by predicting 5- and 10-year survival probabilities.

RESULTS

A total of 724 chordoma patients were divided into training (n = 508) and validation (n = 216) cohorts. Cox regression identified nine significant prognostic factors (p < 0.05). ML models showed superior performance over CoxPH model, with DeepSurv having the highest C-index (0.795) and the best discrimination for 5- and 10-year survival (AUC 0.84 and 0.88). Calibration curves revealed strong correlation between DeepSurv predictions and actual survival. Risk stratification by DeepSurv model effectively discriminated high- and low-risk groups (p < 0.01). The optimized DeepSurv model was implemented into a web application for clinical use that can be found at https://hust-chengp-ml-chordoma-app-19rjyr.streamlitapp.com/ .

CONCLUSION

ML algorithms based on time-to-event results are effective in chordoma prediction, with DeepSurv having the best discrimination performance and calibration.

Long-term outcomes of high dose carbon-ion radiation therapy for unresectable upper cervical (C1-2) chordoma

Background

Chordoma is a rare, locally invasive neoplasm of the axial skeleton. Complete resection is often difficult, especially for the upper‐cervical (C1‐2) spine. We evaluated the efficacy and safety of carbon‐ion radiotherapy (CIRT) for unresectable C1‐2 chordoma.

Methods

Patients with C1‐2 chordoma treated with definitive CIRT (60.8 Gy [RBE] in 16 fractions) were retrospectively analyzed. We evaluated OS, LC, PFS, and toxicity.

Results

Nineteen eligible patients all completed the planned course of CIRT. With the median follow‐up 68 months (range: 29–144), median OS was 126 months (range: 36‐NA). Five‐year OS, LC, and PFS were 68.4% (95% CI, 42.8%–84.4%), 75.2% (46.1%–90.0%), and 64.1% (36.3%–82.3%), respectively. Regarding acute toxicity of grade ≥3, there was only one grade 3 mucositis. Late toxicity included radiation‐induced myelitis (grade 3 in 1 patient; 5.3%), and compression fractures (n = 5; 26.3%).

Conclusions

High‐dose CIRT is a promising treatment option for unresectable upper cervical chordoma.

Multivariate Analysis and Validation of the Prognostic Factors for Skull Base Chordoma

Background: Skull base chordoma is a rare tumor with low-grade malignancy and a high recurrence rate, the factors affecting the prognosis of patients need to be further studied. For that, we investigated prognostic factors of skull base chordoma through the database of the Surveillance, Epidemiology, and End Results (SEER) program, and validated in an independent data set from the Xiangya Hospital.

Methods: Six hundred and forty-three patients diagnosed with skull base chordoma were obtained from the SEER database (606 patients) and the Xiangya Hospital (37 patients). Categorical variables were selected by Chi-square test with a statistical difference. Survival curves were constructed by Kaplan–Meier analysis and compared by log-rank test. Univariate and multivariate Cox regression analyses were used to explore the prognostic factors. Propensity score matching (PSM) analysis was undertaken to reduce the substantial bias between gross total resection (GTR) and subtotal resection (STR) groups. Furthermore, clinical data of 37 patients from the Xiangya Hospital were used as validation cohorts to check the survival impacts of the extent of resection and adjuvant radiotherapy on prognosis.

Results: We found that age at diagnosis, primary site, disease stage, surgical treatment, and tumor size was significantly associated with the prognosis of skull base chordoma. PSM analysis revealed that there was no significant difference in the OS between GTR and STR (p = 0.157). Independent data set from the Xiangya Hospital proved no statistical difference in OS between GTR and STR groups (p = 0.16), but the GTR group was superior to the STR group for progression-free survival (PFS) (p = 0.048). Postoperative radiotherapy does not improve OS (p = 0.28), but it can prolong PFS (p = 0.0037). Nomograms predicting 5- and 10-year OS and DSS were constructed based on statistically significant factors identified by multivariate Cox analysis. Age, primary site, tumor size, surgical treatment, and disease stage were included as prognostic predictors in the nomograms with good performance.

Conclusions: We identified age, tumor size, surgery, primary site, and tumor stage as main factors affecting the prognosis of the skull base chordoma. Resection of the tumor as much as possible while ensuring safety, combined with postoperative radiotherapy may be the optimum treatment for skull base chordoma.

Treatment of Chordomas and Chondrosarcomas With CyberKnife Robotic Hypofractionated Radiosurgery: A Single Institution Experience

Introduction

The aim of this study is to determine the efficacy and safety of CyberKnife® (Accuray, Inc., Sunnyvale, CA) hypofractionated radiosurgery (HfRS) in the treatment of chordomas and chondrosarcomas.

Methods

A total of 24 patients retrospectively identified with chordomas (19 patients) or chondrosarcomas (five patients) were treated between 2012 and 2019 with HfRS as monotherapy or an adjuvant, rescue, or combination therapy. Tumors were located in the skull base (75%) and vertebral spine (25%). Of these, 19 patients underwent previous partial resection and four patients received previous conventional external beam radiation therapy (EBRT) (60-74 Gy). Exclusive or rescue HfRS (20 patients) was administered in five fractions with a median dose of 37.5 Gy (30-40 Gy). Combined tomotherapy-EBRT treatment (median dose: 54 Gy) and HfRS (16.5-30 Gy in 3-12 fractions) were performed in four patients with bulky chordomas.

Results

The median follow-up from HfRS was 28 months. During clinical follow-up, no deaths were registered with overall survival (OS) of 100% and the actuarial local recurrence-free survival (LRFS) was 93% at one year, 85% at three years, and 68% at five years. Acute toxicity related to HfRS was present in a single patient.

Conclusions

It is seen that HfRS is effective and safe for chordomas and chondrosarcomas, with rates of LRFS comparable to other radiation modalities.

Chordomas and chondrosarcomas of the skull base: treatment and outcome analysis in a consecutive case series of 24 patients

Background

We present our 9-year consecutive case series of skull base chordomas and chondrosarcomas from a UK tertiary referral centre, discussing treatments offered and outcomes. This was carried out to improve understanding around current treatment and to better inform the management of future patients.

Methods

Consecutive case series over a 9-year period (2007–2016). Retrospective data analysis from the electronic skull base multidisciplinary team database and the digital patient records at a UK tertiary referral centre

Results

Twenty-four patients were identified (11 chordomas, 13 chondrosarcomas, mean age 52). Nineteen had proton beam therapy (PBT) postoperatively; two had intensity-modulated radiotherapy; two had no further treatment. One patient was lost to follow-up. All chordomas were resected via a transnasal endoscopic approach. Of the 19 patients undergoing resection with PBT, 13 were disease free at latest follow-up, and six patients had local recurrence, of which two died (mean follow up 7.4 years). Of the three patients treated with surgery then IMRT/TomoTherapy, one died 4 years post-treatment, and the other two are alive after 4 and 5 years of follow-up respectively. Of the two patients treated with surgery alone, one was lost to follow-up, and the other is alive after more than 8 years. Chondrosarcoma 5-year survival was 91.6%, and chordoma 4-year survival was 75%.

Conclusion

Skull base chordomas and chondrosarcomas can be challenging to resect, and most cases require adjuvant therapy to achieve control. Where complete resection is not possible, it is critical to undertake sufficient resection to permit high-dose radiation.

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.

Long-term outcomes of skull base chordoma treated with high-dose carbon-ion radiotherapy

Background

We evaluated the long‐term efficacy and safety of carbon‐ion radiotherapy (C‐ion RT) for skull base chordoma, a rare neoplasm.

Methods

Thirty‐four patients with skull base chordoma who were treated with C‐ion RT were prospectively enrolled and analyzed retrospectively. C‐ion RT was delivered with 60.8 Gy (relative biological effectiveness [RBE]) in 16 fractions at four fractions per week.

Results

The median follow‐up period was 108 months. The 5‐ and 9‐year local control rates were 76.9% and 69.2%, respectively. The 5‐ and 9‐year overall survival rates were 93.5% and 77.4%, respectively. Regarding grade 3 or more severe late reactions, one patient developed a grade 3 mucosal ulcer, two developed grade 4 ipsilateral optic nerve injuries, and one developed a grade 5 mucosal ulcer at 9 years and 3 months after C‐ion RT.

Conclusion

C‐ion RT with 60.8 Gy (RBE)/16 fractions is a promising treatment option for inoperable skull base chordoma.

Radiation tolerance of the optic pathway in patients treated with proton and photon radiotherapy

INTRODUCTION

Radiation-induced optic neuropathy (RION) is a complication of radiation therapy (RT) that causes blindness. We aimed to define the tolerance of the anterior optic pathway to fractionated RT and identify risk factors for RION.

MATERIALS/METHODS

Patients with chordoma or chondrosarcoma of the skull base treated with proton and photon therapy between 1983 and 2013, who received a minimum of 30 Gy (relative biologic effectiveness [RBE]) to the anterior optic pathway were assessed. Optic neuropathy with radiographic correlation occurring ≥6 months after completion of RT in the absence of tumor recurrence or other probable cause was diagnosed as RION.

RESULTS

Of 514 patients, 17 developed RION. With median follow-up of 4.8 years, cumulative incidence of RION was 1% among patients receiving <59 Gy (RBE) and 5.8% among patients receiving ≥60 Gy (RBE) to the optic pathway. Higher maximum point dose to the optic pathway (subhazard ratio [SHR] = 1.2, 95% CI 1.05-1.2, p = 0.001), older age (SHR = 1.1, 95% CI 1.02-1.08, p < 0.0005), and female sex (SHR = 16.3, 95% CI 2.2-122.4, p = 0.007) were statistically significant risk factors for RION in multivariate analysis.

CONCLUSION

In our study cohort, rates of RION were very low with conventionally fractionated RT up to 59 Gy. At doses ≥60 Gy, there is an increased risk of RION, with greater risk for women and older patients.

Proton therapy for skull base tumors: A review of clinical outcomes for chordomas and chondrosarcomas

BACKGROUND

Skull base chordomas and chondrosarcomas are rare tumors traditionally treated by surgical resection and adjuvant radiation therapy (RT). We will discuss data evaluating clinical outcomes of proton therapy in the treatment of skull base chordomas and chondrosarcomas.

METHODS

A literature review was performed using a MEDLINE search from January 1990 to January 2017.

RESULTS

The published data suggest that the dose intensification allowed by proton therapy has resulted in good clinical outcomes and a tolerable toxicity profile.

CONCLUSION

Proton therapy is a modern RT technique that has demonstrated improved preliminary clinical outcomes in the treatment of skull base chordomas and chondrosarcomas compared to conventional radiotherapy, and comparable to other advanced photon-based RT techniques.

Feasibility of Intensity-Modulated Radiation Therapy in the Treatment of Advanced Cervical Chordoma

Aims and Background

Postoperative radiation is often given in cases of cervical chordoma because of the high incidence of local recurrence. The tumor mass usually surrounds the spinal cord and infiltrates vertebral bone. A combined technique using protons or electrons to boost the initial photon fields is generally applied. We evaluated the use of dynamic intensity-modulated radiation therapy as an alternative technique for treating advanced cervical chordoma.

Methods and Study Design

A female patient with incomplete resection of a vertebral chordoma surrounding C2-C3 was irradiated with a total dose of 58 Gy (ICRU point) in 2 Gy daily fractions for 29 days between December 2001 and January 2002. Beam arrangement consisted of seven 6 MV non-opposed coplanar fields. Pretreatment quality assurance included checking of the absolute dose at reference points and 2D dose map analysis. Treatment was delivered with a 120-leaf collimator in sliding window mode. To verify the daily setup, portal images at 0° and 90° were compared with the simulation images before treatment delivery (manual matching) and after treatment delivery (automatic anatomy matching).

Results and Conclusions

The mean dose to the planning target volume (PTV) was 57.6 ± 2.1 Gy covering 95% of the PTV per 95% isodose. The minimum dose to the PTV (D99) was 53.6 Gy in the overlapping area between the PTV and the spinal cord planning organ at risk volume (PRV). The maximum dose to the spinal cord was 42.2 Gy and to the spinal cord PRV (8 mm margin) 53.7 Gy. The mean dose to the parotid glands was 37.4 Gy (homolateral gland) and 19.5 Gy (contralateral gland). Average deviation in setup was -1.1 ± 2.5 mm (anterior-posterior), 2.4 ±1.3 mm (latero-lateral), 0.7 ± 0.9 mm (craniocaudal) and -0.43 ± 1° (rotation).

Conclusions

In the treatment of chordomas surrounding the spinal cord, intensity-modulated radiotherapy can provide high dose homogeneity and PTV coverage. Frequent digital portal image-based setup control is able to reduce random positioning errors for head and neck cancer patients immobilized with conventional thermoplastic masks.

Gamma Knife Management of Skull Base Chordomas: Is it a Choice?

Background:

Skull base chordomas are locally invasive tumors which able to extend in different directions with skull base invasion. Although they are histologically benign, they have invasive nature makes total resection virtually impossible to achieve in most cases and this lead to residual tumors after surgery. To decrease postoperative surgical resection morbidity of these tumors, gamma knife radiosurgery (GKRS) was performed as alternative management for these residual chordomas to evaluate its safety and efficacy.

Materials and Methods:

A retrospective study was made on eight residual skull base chordomas treated with GKRS between 2011 and 2015. The mean patient age was 49 years (range 30–73 years). Four patients harboring chordoma were male, and four patients were females with 1:1 ratio. All patients had undergone one prior surgery. Patients were treated with peripheral dose ranged between 12–15 gray (Gy) (mean 13.75 Gy) usually at 35% to 50% isodose curve (mean 38.8%). The maximum dose to the adjacent brain stem area ranged between 10 and 12 Gy. All patients were followed up from 8 to 39 months (mean 18 months).

Results:

The tumor control rate was 50% and 25% after 18 and 36 months, respectively, but we found that their wasdeclined in the tumor control rate with long follow-up time. Four tumors were stable in their size just for 18 months, and then there two of these tumors were progressed in their size, the other four patients showed progression in their tumors in their 1^st year of treatment without sign of central tumor necrosis.

Conclusion:

Skull base chordoma patients complained from symptoms due to tumor mass effect which were not prospected to respond to GKRS alone as the aim of this type of treatment was the local tumor control, the tumor control rate declined with long follow-up time and this correlated with radioresistant nature of skull base chordoma. We advise a gross total resection to decrease the tumor volume, and this making gamma knife a reasonable treatment modality.

Management of Chordoma and Chondrosarcoma with Fractionated Stereotactic Radiotherapy

OBJECTIVE

To evaluate the efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) for chordoma and chondrosarcoma.

METHODS

Twenty consecutive patients with a histopathologic diagnosis of chordoma (n = 16) or chondrosarcoma (n = 4) treated between 2010 and 2016 were retrospectively identified. All patients underwent FSRT in five fractions to a median dose of 37.5 Gy (range: 25-40 Gy) and followed with serial magnetic resonance imaging. Overall survival (OS), local recurrence-free survival (LRFS), and event-free survival (EFS) were estimated using the Kaplan-Meier method.

RESULTS

With a median follow-up of 28 months after FSRT and 40 months after initial surgery, crude OS and LRFS were 90%. Nine patients (45%) reported grade 1-3 acute toxicity, and two patients (10%) experienced grade 4, 5 late toxicity. One patient previously treated with proton therapy died from radiation vasculopathy 9 months after FSRT. The use of FSRT for recurrent disease or in patients with prior radiation therapy was associated with significantly decreased EFS.

CONCLUSION

FSRT for chordoma and chondrosarcoma is associated with high rates of OS and local control. Although many patients experience acute toxicity, there is a low incidence of late toxicity or irreversible treatment related morbidity despite the frequency of prior radiotherapy in this population. FSRT is an effective adjuvant or salvage treatment for chordoma and chondrosarcoma.

Hyperfractionated high-dose proton beam radiotherapy for clival chordomas after surgical removal

OBJECTIVE

To evaluate the hyperfractionated high-dose proton beam therapy (PBT) for patients with clival chordomas.

METHODS

Records for 19 patients with pathologically verified clival chordomas treated with surgery followed by hyperfractionated PBT were retrospectively reviewed. The first 9 consecutive patients were treated with 77.44 cobalt gray equivalents (CGEs) in 64 fractions, and the latter 10 patients were treated with 78.4 CGE in 56 fractions.

RESULTS

The median follow-up period of all 19 cases was 61.7 months with a range from 31.5 to 115.4 months. At 5 years, the local control, cause-specific and overall survival rates for all 19 cases were 75%, 94% and 83.2%, respectively. Whereas the 5-year local control, cause-specific and over all survival rates of the latter 10 cases were 100%, 100% and 88.9%, respectively, with a median follow-up period of 59.5 months. One of the first nine patients demonstrated bilateral temporal lobe radiation necrosis, who were successfully treated conservatively. In the latter cohort, two cases showed transient neurological symptoms probably due to brain stem ischaemia, but both cases recovered completely with conservative treatment.

CONCLUSION

The hyperfractionated high-dose scheme combined with maximum surgical removal was shown to be efficient for patients with clival chordomas.

ADVANCES IN KNOWLEDGE

High-dose proton beam radiotherapy using a hyperfractionation scheme yielded a more favourable outcome than previous reports.

Enigmatic entity in childhood: clival chordoma from a tertiary center's perspective

PURPOSE

Chordoma is a rare neoplasm that arises from embryonic notochordal remnants along the axial skeleton (i.e., clivus, sacrum) and the vertebral bodies. They comprise less than 1 % of CNS tumors and 1-4 % of all bone malignancies. It rarely affects children and adolescents (<5 %). Chordomas are locally aggressive and highly recurrent. Their management is challenging for clinicians.

METHODS

This retrospective study includes six pediatric patients with pathological evidence of clival chordoma. These cases were identified over a period of 15 years in a tertiary care institute.

RESULTS

There were two boy and four girls with a mean age of 10.6 years (range, 4-16 years). The chief complaint was due to cranial nerve palsy (or dysfunction), mostly affecting lower cranial nerves (66.6 %), followed by diplopia and headache. One patient had obstructive sleep apnea. All patients were operated and a total of 15 surgeries were performed (mean, 2.5). Tumor recurrence was observed in four patients (67 %). Two-year and 5-year progression-free survivals (PFS) were 67 and 33 %, respectively. None of the patients were lost either during the surgery or the follow-up period (6.9 years: 1-14 years).

CONCLUSIONS

Clival chordomas are challenging tumors in neurosurgical practice. A multidisciplinary approach is warranted in each patient. Today, the best management strategy seems to be surgical resection followed by radiotherapy. Chemotherapy should be considered in selective and preference basis. Sharing institutional experiences will provide future insights in prognosis of these rare tumors. Implementing newer surgical instruments, endoscope in particular, is encouraged in management of the clival chordomas.

Characterization of T gene sequence variants and germline duplications in familial and sporadic chordoma

Chordoma is a rare bone cancer that is believed to originate from notochordal remnants. We previously identified germline T duplication as a major susceptibility mechanism in several chordoma families. Recently, a common genetic variant in T (rs2305089) was significantly associated with the risk of sporadic chordoma. We sequenced all T exons in 24 familial cases and 54 unaffected family members from eight chordoma families (three with T duplications), 103 sporadic cases, and 160 unrelated controls. We also measured T copy number variation in all sporadic cases. We confirmed the association between the previously reported variant rs2305089 and risk of familial [odds ratio (OR) = 2.6, 95% confidence interval (CI) = 0.93, 7.25, P = 0.067] and sporadic chordoma (OR = 2.85, 95% CI = 1.89, 4.29, P < 0.0001). We also identified a second common variant, rs1056048, that was strongly associated with chordoma in families (OR = 4.14, 95% CI = 1.43, 11.92, P = 0.0086). Among sporadic cases, another common variant (rs3816300) was significantly associated with risk when jointly analyzed with rs2305089. The association with rs3816300 was significantly stronger in cases with early age onset. In addition, we identified three rare variants that were only observed among sporadic chordoma cases, all of which have potential functional relevance based on in silico predictions. Finally, we did not observe T duplication in any sporadic chordoma case. Our findings further highlight the importance of the T gene in the pathogenesis of both familial and sporadic chordoma and suggest a complex susceptibility related to T.

Treatment and Outcome of Patients with Skull Base Chordoma: A Meta-analysis

Objective Chordoma is a locally aggressive tumor. The aim of this study was to assess the efficacy of different surgical approaches and adjuvant radiation modalities used to treat these patients. Design Meta-analysis. Main Outcome Measures Overall survival (OS), disease-specific survival (DSS), and progression-free survival (PFS). Results The 5-year OS and PFS rates of the whole cohort (n = 467) were 86% and 65.7%, respectively. The 5-year DSS for patients who underwent open surgery and endoscopic surgery was 45% and 49%, respectively (p = 0.8); PFS was 94% and 79%, respectively (p = 0.11). The 5-year OS of patients treated with surgery followed by adjuvant radiotherapy was 90% compared with 70% of those treated by surgery alone (p = 0.24). Patients undergoing partial resection without adjuvant radiotherapy had a 5-year OS of 41% and a DSS of 45%, significantly lower than in the total-resection group (p = 0.0002 and p = 0.01, respectively). The complication rates were similar in the open and endoscopic groups. Conclusions Patients undergoing total resection have the best outcome; adjuvant radiation therapy improves the survival of patients undergoing partial resection. In view of the advantages of minimally invasive techniques, endoscopic surgery appears an appropriate surgical approach for this disease.

Prognostic Factors in the Operative Management of Dedifferentiated Sacral Chordomas

BACKGROUND:

Dedifferentiated chordomas are rare high-grade malignant spinal tumors for which there is minimal information to help guide treatment.

OBJECTIVE:

To identify prognostic factors associated with increased risk of local recurrence, metastases, and reduced survival in a cohort of patients undergoing sacrectomy for de novo dedifferentiated sacral chordoma.

METHODS:

Ten patients undergoing sacrectomy for histologically confirmed dedifferentiated chordoma at a specialist center were reviewed. There were 6 male and 4 female patients with a mean age of 66.7 years (range, 57-80 years) and mean follow-up of 36.7 months (range, 3-98 months). Data on prognostic factors were collected.

RESULTS:

The commonest presenting symptom was lumbar/gluteal pain. Mean duration of preoperative symptoms was 3.6 months (range, 2-7 months). Local recurrence was seen in 7 patients; metastases occurred in 5 patients. After sacrectomy, 7 patients died at a mean of 41 months (range, 3-98 months). Tumor size &gt;10 cm in diameter, amount of dedifferentiation within the conventional chordoma, sacroiliac joint infiltration, and inadequate resection margins were associated with increased risk of recurrence and reduced survival. Surgical approach, cephalad extent of primary tumor, and adjuvant radiotherapy did not affect oncological outcomes.

CONCLUSION:

Dedifferentiated chordomas are aggressive malignant tumors with a higher risk of local recurrence, metastases, and early mortality than conventional chordomas. Tumor diameter &gt;10 cm, marginal resection, and sacroiliac joint infiltration may be associated with increased risk of local recurrence and mortality. Those with a smaller burden of dedifferentiated disease (&lt;1 cm2) within the primary chordoma have a better prognosis. Patients should be counseled about these risks before surgery and should have regular follow-up for the detection of local recurrence and metastases.

A review of the surgical management of sacral chordoma

BACKGROUND

Sacral chordomas are rare low-to-intermediate grade malignant tumours, which arise from remnants of the embryonic notochord. This review explores prognostic factors in the management of sacral chordomas and provides guidance on the optimal treatment regimens based on the current literature.

PATIENTS AND METHODS

Electronic searches were performed using MEDLINE, Embase and the Cochrane library to identify studies on prognostic factors in the management of sacral chordomas published between January 1970 and December 2013. The literature search and review process identified 100 articles that were included in the review article. This included both surgical and non-surgical studies on the management of sacral chordomas.

RESULTS

Sacrectomy with wide resection margins forms the mainstay of treatment but is associated with high risk of disease recurrence and reduced long-term survival. Adequate resection margins may require sacrifice of adjacent nerve roots, musculature and ligaments leading to functional compromise and mechanical instability. Large tumour size (greater than 5-10 cm in diameter), dedifferentiation and greater cephalad tumour extension are associated with increased risk of disease recurrence and reduced survival. Chordomas are poorly responsive to conventional radiotherapy and chemotherapy.

CONCLUSION

Operative resection with wide resection margins offers the best long-term prognosis. Inadequate resection margins, large tumour size, dedifferentiation, and greater cephalad chordoma extension are associated with poor oncological outcomes. Routine long-term follow-up is essential to enable early detection and treatment of recurrent disease.

Proton therapy for skull base chordomas: an outcome study from the university of Florida proton therapy institute

Objectives Skull base chordoma is a rare, locally aggressive tumor located adjacent to critical structures. Gross total resection is difficult to achieve, and proton therapy has the conformal advantage of delivering a high postoperative dose to the tumor bed. We present our experience using proton therapy to treat 33 patients with skull base chordomas. Design Retrospective outcomes study. Setting University of Florida Proton Therapy Institute; 2007 to 2011. Participants A total of 33 patients with skull base chordomas received postoperative three-dimensional conformal proton therapy. The patients were 79% male and 6% diabetic; 27% had received a gross total resection. Main Outcome Measures The gross tumor/tumor bed received a dose between 77.4 CGE and 79.4 CGE. Local control and overall survival were tracked, and radiation toxicity was assessed using a modified Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme. Results Median follow-up for all patients was 21 months. Local control and overall survival rates at 2 years were 86% and 92%, respectively. Grade 2 toxicity was observed in 18% of our cohort in the form of unilateral hearing loss partially corrected with a hearing aid. No grade 2 or higher optic or brainstem toxicities were observed. Conclusions Proton therapy is an effective treatment modality for skull base chordomas.

Fractionated stereotactic radiosurgery treatment results for skull base chordomas

Chordomas are uncommon neoplasms and there is still controversy regarding establishment of diagnosis and management. The aim of this study was to evaluate efficacy and toxicity of fractionated stereotactic radiosurgery (FSRS) in skull base chordomas. There were 4 female (36%) and 7 male (64%) patients. FSRS was delivered with CyberKnife (Accuray Inc., Sunnyvale, CA). The median tumor volume was 14.7 cc (range, 3.9-40.5 cc). The median marginal tumor dose was 30 Gy (range, 20-36 Gy) in a median 5 fractions (range, 3-5 fractions). The median follow-up time was 42 months (range, 17-63 months). At the time of analysis, 10 (91%) patients were alive and 1 (9%) had died due to tumor progression. Of 10 patients, 8 (73%) had stable disease and the remaining 2 (18%) had progressive disease. The actuarial overall survival (OS) after FSRS was 91% at two-years. Two patients developed radiation-induced brain necrosis as a complication in the 8th and 28th months of follow-up, respectively. Our results with robotic FSRS in skull base chordomas are promising for selected patients. However, due to the slow growth pattern of skull base chordomas, a longer follow-up is required to determine exact treatment results and late morbidity.

Skull base chordomas: clinical features, prognostic factors, and therapeutics

Chordomas of the skull base are one of the rarest intracranial malignancies that arise from ectopic remnants of embryonal notochod. The proximity of many chordomas to neurovascular structures makes gross total resection difficult, and the tendency for recurrence leads to the routine use of adjuvant postoperative radiation. Several surgical approaches are used ranging from extensive craniotomies to minimally invasive endonasal endoscopic approaches. In this review, the histopathology and epidemiology, imaging characteristics, surgical approaches, adjuvant therapies, prognostic factors, and molecular biology of chordomas are described.

Current comprehensive management of cranial base chordomas: 10-year meta-analysis of observational studies

OBJECT

The role of surgery and adjuvant radiation therapy for cranial base chordomas is not well established. This meta-analysis measures the relationship of complete resection and type of adjuvant radiation therapy to 5-year progression-free survival (PFS) and overall survival (OS) of cranial base chordomas.

METHODS

A systematic MEDLINE search (1999-present) yielded 23 observational studies and 807 patients who fit inclusion criteria. The following analyses were performed: 1) Kaplan-Meier 5-year PFS and OS compared based on the extent of resection and type of adjuvant radiation therapy using the log-rank method; 2) a random-effects model comparing 5-year PFS with complete or incomplete resection; and 3) paired z-test comparisons of weighted average 5-year OS and PFS grouped by type of adjuvant radiation therapy.

RESULTS

The weighted average follow-up was 53.6 months. The weighted average 5-year PFS and OS were 50.8% and 78.4%, respectively. Complete resection conferred a higher 5-year PFS than incomplete resection from the random effects model (mean difference in PFS 20.7%; 95% CI 6.57%-34.91%). Patients with incomplete resection were 3.83 times more likely to experience a recurrence (95% CI 1.63-9.00) and 5.85 times more likely to die (95% CI 1.40-24.5) at 5 years versus patients with complete resection. There was no difference in 5-year OS by type of adjuvant radiation, although 5-year PFS was lower in patients receiving Gamma Knife surgery relative to carbon ion radiotherapy (p = 0.042) on paired z-test. No survival difference occurred between radiation therapy techniques on Kaplan-Meier analysis of compiled patient data.

CONCLUSIONS

Patients with complete resection of cranial base chordomas have a prolonged 5-year PFS and OS. Adjuvant proton-beam, carbon ion, and modern fractionated photon radiation therapy techniques offered a similar rate of PFS and OS at 5 years.

A retrospective clinicopathological study of 37 patients with chordoma: a danish national series

Purpose. There are, in general, few published series on chordoma. It is a rare disease and further data are still needed.

Patients/methods. The data of 37 patients with chordoma were retrospectively analyzed. Treatment was surgical excision in 11, radical radiotherapy in 9 and a combination of the two in 16 cases. The male to female ratio was 2.7 : 1. Median age was 59 years (range 1–89 years).

Results. The most common symptoms at diagnosis were pain (98%), neurological disturbances (42%) and incontinence (33%). The tumours were located in the sacro-coccygeal region in 68%, the spheno-occipital region in 16% and the vertebrae in 16% of the patients. Median tumour.size was 7 cm (range 1–30 cm). Local recurrence occurred in 21/36 treated cases and distant metastases developed in eight patients (23%). The median time to recurrence/progression after primary treatment was 2 years (range 1–10 years). The actuarial 5-year rates of overall, progression-free and symptom-free survival were 40%, 31% and 20%, respectively. The corresponding 10-year rates were 26%, 21% and 14%, respectively. At the time of analysis, seven patients were alive, six without evidence of disease. Four of the six patients without active disease were symptom free. A univariate analysis showed that age, sex, tumour size, histopathology, surgical safety margin, treatment modality and radiation dose did not significantly affect overall, progression-free or symptom-free survival. Only turnout site had a prognostic value with turnouts in the spheno-occipital region carrying the worst prognosis.

Discussion. We conclude that effective treatment against chordomas is still lacking and a prospective multi-institutional registration study may provide more information on the optimal work-up and treatment of this rare disease.

The role of chemotherapy in pediatric clival chordomas

The purpose of this retrospective study was to review the role of chemotherapy in the treatment, management and outcome of children diagnosed with clival chordomas. The medical records of six pediatric chordoma patients diagnosed at Childrens Hospital Los Angeles between 1995 and 2005 were reviewed. Of the six patients reviewed, all underwent an initial surgical resection. Following resection, three received a combination of chemotherapy and radiation therapy, two received chemotherapy alone and one patient refused both forms of therapy; this patient expired of progressive tumor. One patient developed acute monoblastic leukemia (M5a subtype) and died of intracranial hemorrhage during induction chemotherapy, 39 months after initial diagnosis. MRI of brain and spine showed disease progression shortly before his death. Two patients who received chemotherapy only after surgery, one patient who received chemotherapy at relapse following irradiation and one patient who received irradiation followed by chemotherapy are alive with stable radiographic abnormalities at a median follow-up of 9 years from diagnosis (range: 6-13 years). Chemotherapeutic agents included ifosfamide and etoposide in all four surviving patients. Chemotherapy with ifosfamide and etoposide may have a role in the treatment of pediatric clival chordomas when used alone or in combination with irradiation.

Proton beam radiation therapy for head and neck malignancies

Proton beam radiation therapy (PBRT) has unique physical properties (e.g., Bragg Peak) that limit the amount of normal tissue irradiated in the head and neck region while maximizing the radiation delivered to the tumor. Radiation therapy is commonly used in both the primary and adjuvant setting for many head and neck malignancies. Limiting the unnecessary radiation to normal tissues within the head and neck region can result in a profound improvement in quality of life during and after treatment. Although PBRT was initially developed in the 1950s, recent technological advances have permitted the development of hospital-based facilities for proton delivery. PBRT has been shown to improve outcomes for patients with sinonasal tumors, chordomas, chondrosarcomas, ocular, and periocular malignancies. Further development of intensity-modulated proton therapy will permit comprehensive treatment for head and neck tumors.

State of the art management in spine oncology: a worldwide perspective on its evolution, current state, and future

STUDY DESIGN

A review of the past and current status of the evolving field of spine oncology.

OBJECTIVE

To provide a framework of reference for developments in the field, particularly the rapidly evolving field of molecular biology, as well as contemporary practice in the management of spine tumors.

METHODS

Literature review of the surgical treatment of spine tumors in the past and present, the emerging radiologic and biologic technologies, as well as the field of targeted therapy in cancer and the economic implications of technological advances.

RESULTS

A vast contemporary literature is currently available that provides a clear rational basis for treatment. Most treatment recommendations are currently based on retrospective data and small Phase II prospective studies. Treatment paradigms continue to evolve without their relative merits being evaluated by randomized controlled trials. The current lack of randomized trials in spine oncology reflect both the rarity of spine tumors and strongly held biases based on retrospective studies and institutional bias.

CONCLUSION

Spine oncology is a rapidly evolving field with contributions in surgery, radiation therapy, and targeted chemotherapy resulting in overall improvement in quality of life and survival in patients with spine tumors. However, the economic consequences of these improvements are substantial and need to be kept in proper perspective.

Challenges of local recurrence and cure in low grade malignant tumors of the spine

STUDY DESIGN

Systematic review and ambispective multicenter cohort study.

OBJECTIVE

1. To compare the effects of wide/marginal (en bloc) resection with intralesional resection on local recurrence and survival for chordomas and chondrosarcomas of the spine. 2. To determine the influence of radiation therapy in the management of chordomas and chondrosarcomas.

SUMMARY OF BACKGROUND DATA

Chordomas and chondrosarcomas of the spine are prone to local recurrence and death despite being low-grade malignant tumors. No study to date has enough numbers or adequate scientific rigor to determine the influence of resection or radiation therapy on outcome.

METHODS

A systematic review was performed to evaluate the 2 objectives. In addition an ambispective multicenter cohort analysis of chordomas and chondrosarcomas was performed. The GRADE system of analysis integrating the results of the systematic review, the multicenter cohort study and the expert opinion of the Spine Oncology Study Group (SOSG) was used to arrive at treatment recommendations.

RESULTS

A total of 63 articles were included in the systematic reviews. Evidence was low quality. En bloc resection appeared to improve both local recurrence and disease free survival in Chordoma and Chondrosarcoma. Radiation therapy had a positive impact on the management of Chordoma and Chondrosarcoma with predictably low side effects. The cohort analysis showed significantly decreased local recurrence for Chordoma (P < 0.0001) and Chondrosarcoma (P < 0.0001) with en bloc resection, and significantly decreased death for both Chordoma (P = 0.0001) and Chondrosarcoma (P = 0.0015) with en bloc resection.

CONCLUSION

When wide or marginal margins (en bloc) are achieved in surgical resection of chordomas and chondrosarcomas of the spine there is a decrease in local recurrence and mortality. Therefore, en bloc resection should be undertaken for the treatment of chordomas and chondrosarcomas of the spine. Strong Recommendation, Moderate Quality Evidence.Radiation therapy of at least 60 to 65 Gy equivalents is indicated as an adjuvant treatment for chordoma and chondrosarcoma of the spine when there has been incomplete resection or an intralesional margin. Weak Recommendation, Low Quality Evidence.

Proton therapy in chordoma of the base of the skull: a systematic review

Chordoma is a rare, slow-growing, locally aggressive, primary bone tumor that arises from the skull base region in approximately 25-35% of cases. The therapeutic approach to chordoma has traditionally been surgery, followed by radiation therapy. The advent of charged particle radiotherapy has let us consider protons as the postoperative treatment of choice, but no controlled studies have yet confirmed the superiority of protons over photons. During January 2008, two independent researchers conducted a systematic review of the current data on the treatment of base of the skull chordoma C with proton therapy (PT) and, for comparison, with other irradiation techniques (conventional radiation therapy, ion therapy, fractionated stereotactic radiation therapy, and radiosurgery). Two hundred and ten reports in total were retrieved (81 concerning PT). According to the inclusion criteria, 47 articles were considered in the analysis. There were no prospective trials (randomized or nonrandomized) but just seven uncontrolled single-arm studies for PT, providing clinical outcomes for 416 patients in total; these reports were mainly related to advanced inoperable or incompletely resected tumors. The therapeutic approach to chordoma of the base of the skull has traditionally relied on surgical control. Radiation therapy has demonstrated to be a valuable modality for local control in the postoperative setting, particularly with the advent of charged particle radiotherapy. The use of protons has shown better results in comparison to the use of conventional photon irradiation, resulting in the best long-term (10 years) outcome for this tumor with relatively few significant complications considering the high doses delivered with this therapeutic modality.

Treatment of chordomas with CyberKnife: georgetown university experience and treatment recommendations

OBJECTIVE

To determine the efficacy and safety of chordoma treatment with CyberKnife (Accuray, Inc., Sunnyvale, CA) stereotactic radiosurgery (CK/SRS).

METHODS

Eighteen patients with chordoma were treated with CK/SRS as a primary adjuvant (17 patients) or the only treatment (1 patient). The series included 24 lesions (28 treatments). The median age of the patients was 60 years (range, 24-85 years). Forty-four percent of the tumors were located in the mobile spine, 39% inside the cranium, and 17% in the sacral region. The male-to-female ratio was 1:1. The mean tumor volume was 128.0 mL (range, 12.0-457.3 mL), and the median dose of 35 Gy (range, 24.0-40.0 Gy) was delivered in 5 sessions. The median follow-up period was 46 months (range, 7-65 months).

RESULTS

There were 3 significant complications in patients with previous irradiation, including infection in the surgical/radiation site (2 patients) and decreased vision (1 patient). Improvement in pain and quality of life did not reach statistical significance (alpha = 0.05). Seven patients experienced recurrence at a median of 10 months (range, 5-38 months), and 4 patients with disseminated disease died 7 to 48 months after therapy. Two patients had a partial response, whereas 9 others had stable disease. The local control rate at 65 months was 59.1%, with an overall survival of 74.3% and disease-specific survival of 88.9%. We estimated an alpha/beta ratio of 2.45 for chordomas, which supports hypofractionation.

CONCLUSION

The CK/SRS safety and efficacy profile compares favorably with those of other treatment delivery systems. CK/SRS appears to reduce tumor volume, given an adequate dose. The authors recommend treatment with 40 Gy in 5 sessions to the clinical treatment volume, which includes the gross tumor volume and at least a 1-cm margin.

NEAR-COMPLETE PATHOLOGICAL RESPONSE OF CHORDOMA TO HIGH-DOSE SINGLE-FRACTION RADIOTHERAPY

OBJECTIVE

High-dose, single-fraction radiotherapy, also known as radiosurgery, has theoretical advantages for the treatment of chordoma, which is considered resistant to conventional radiation therapy. Demonstration of biological effectiveness, as indicated by pathological response of a chordoma specimen after such radiotherapy, has not previously been reported.

CLINICAL PRESENTATION

A 72-year-old man presented with lower back pain and was found to have an L3 vertebral mass. Open biopsy yielded chordoma. He was considered for en bloc resection, but definitive radiation therapy was preferred owing to medical comorbidities and concern for field contamination from the previous biopsy.

INTERVENTION

The patient underwent single-fraction, high-dose, image-guided radiation therapy to the tumor. Two months later, he underwent kyphoplasty because of recurrent pain. A core biopsy performed at that time showed viable chordoma. Four months after treatment, he underwent L3 corpectomy because of symptoms of mechanical instability. Pathology now showed near-complete necrosis of the resected chordoma.

CONCLUSION

Preoperative, single-fraction radiotherapy for chordoma induced a near-complete pathological response in this patient. That the effect was seen at 4 months but not 2 months after treatment suggests a time-dependent effect. This case suggests a promising role for single-fraction, image-guided radiation therapy in the treatment of chordoma.

Primary malignant tumors of the spine

Primary malignant tumors of the spine account for less than 5% of primary bone tumors. Data from the SEER program suggest that the most common bone sarcomas are osteosarcoma, chondrosarcoma, Ewing's sarcoma, chordoma, and malignant fibrous histiocytoma/fibrosarcoma. During the last two decades, tremendous progress has been made in clinical aspects, surgical approaches, and reconstruction with instrumentation at all levels of the spine. Stabilization procedures, including vertebroplasty and kyphoplasty, have further allowed palliation of pain and symptom relief from compression fractures. Improved radiation techniques have offered the potential for improved local control. This article reviews the changes in surgical philosophy in the management of malignant spinal tumors during the past two decades.

Chordoma: the nonsarcoma primary bone tumor

Chordomas are rare, slowly growing, locally aggressive neoplasms of bone that arise from embryonic remnants of the notochord. These tumors typically occur in the axial skeleton and have a proclivity for the spheno-occipital region of the skull base and sacral regions. In adults, 50% of chordomas involve the sacrococcygeal region, 35% occur at the base of the skull near the spheno-occipital area, and 15% are found in the vertebral column. Craniocervical chordomas most often involve the dorsum sella, clivus, and nasopharynx. Chordomas are divided into conventional, chondroid, and dedifferentiated types. Conventional chordomas are the most common. They are characterized by the absence of cartilaginous or additional mesenchymal components. Chondroid chordomas contain both chordomatous and chondromatous features, and have a predilection for the spheno-occipital region of the skull base. This variant accounts for 5%-15% of all chordomas and up to 33% of cranial chordomas. Dedifferentiation or sarcomatous transformation occurs in 2%-8% of chordomas. This can develop at the onset of the disease or later. Aggressive initial therapy improves overall outcome. Patients who relapse locally have a poor prognosis but both radiation and surgery can be used as salvage therapy. Subtotal resection can result in a stable or improved status in as many as 50% of patients who relapse after primary therapy. Radiation therapy may also salvage some patients with local recurrence. One series reported a 2-year actuarial local control rate of 33% for patients treated with proton beam irradiation.

Tumor-biology and current treatment of skull-base chordomas

Chordomas are rare, slow growing tumors of the axial skeleton, which derive from the remnants of the fetal notochord. They can be encountered anywhere along the axial skeleton, most commonly in the sacral area, skull base and less commonly in the spine. Chordomas have a benign histopathology but exhibit malignant clinical behavior with invasive, destructive and metastatic potential. Genetic and molecular pathology studies on oncogenesis of chordomas are very limited and there is little known on mechanisms governing the disease. Chordomas most commonly present with headaches and diplopia and can be readily diagnosed by current neuroradiological methods. There are 3 pathological subtypes of chordomas: classic, chondroid and dedifferentiated chordomas. Differential diagnosis from chondrosarcomas by radiology or pathology may at times be difficult. Skull base chordomas are very challenging to treat. Clinically there are at least two subsets of chordoma patients with distinct behaviors: some with a benign course and another group with an aggressive and rapidly progressive disease. There is no standard treatment for chordomas. Surgical resection and high dose radiation treatment are the mainstays of current treatment. Nevertheless, a significant percentage of skull base chordomas recur despite treatment. The outcome is dictated primarily by the intrinsic biology of the tumor and treatment seems only to have a secondary impact. To date we only have a limited understanding this biology; however better understanding is likely to improve treatment outcome. Hereby we present a review of the current knowledge and experience on the tumor biology, diagnosis and treatment of chordomas.

Chordoma

PURPOSE OF REVIEW

To review developments in chordoma treatment.

RECENT FINDINGS

Recent series with prolonged follow-up show that adequate margins are necessary for surgery to be curative. Safe margins are often difficult to obtain due to the anatomical sites of chordoma: sacrum, skull base and spine. Tumors in these sites are problematic for radiation therapy as well, and this adds to the need for high doses. Hadrons have therefore been used in addition to, or instead of, photons. New photon beam techniques, e.g. intensity modulated radiation therapy and stereotactic procedures, have recently been evaluated. Although less available than photons, hadrons possess certain advantages. While chemotherapy is poorly active, recent interest has focused on molecular-targeted agents. Imatinib was shown to be active, providing mainly nondimensional tissue responses in a significant proportion of patients, which may improve symptoms and progression-free interval. Epidermal growth factor receptor targeting, anti-angiogenics, and the combination of targeted agents with chemotherapy and radiation therapy are also under scrutiny.

SUMMARY

Two major issues about local treatment remain unresolved: when to complement surgery with radiation therapy, and how best to deliver high doses of radiation therapy to the tumor tissue. Regarding systemic treatment, there is ongoing research into how to exploit molecular-targeted therapies.

Gamma Knife surgery for skull base chordomas and chondrosarcomas

Object

The purpose of this study was to evaluate radiosurgical outcomes in skull base chordomas and chondrosarcomas, and to determine which tumors are appropriate for stereotactic radiosurgery as adjuvant therapy following maximum tumor resection.

Methods

Thirty-seven patients (48 lesions) were treated using Gamma Knife surgery (GKS); 27 had chordomas, seven had chondrosarcomas, and three had radiologically diagnosed chordomas. The mean tumor volume was 20 ml, and the mean maximum and marginal doses were 28 and 14 Gy, respectively. The mean follow-up period was 97 months from diagnosis and 59 months from GKS.

Results

The actuarial 5- and 10-year survival rates after GKS were 80 and 53%, respectively. The actuarial 5- and 10-year local tumor control (LTC) rates after single or multiple GKS sessions were 76 and 67%, respectively. All patients with low-grade chondrosarcomas achieved good LTC. A tumor volume of less than 20 ml significantly affected the high rate of LTC (p = 0.0182). No patient had adverse radiation effects, other than one in whom facial numbness worsened despite successful tumor control.

Conclusions

As an adjuvant treatment after resection, GKS is a reasonable option for selected patients harboring skull base chordomas or chondrosarcomas with a residual tumor volume of less than 20 ml. Dose planning with a generous treatment volume to avoid marginal treatment failure should be made at a marginal dose of at least 15 Gy to achieve long-term tumor control.

High-dose Radiotherapy in the Management of Chordoma and Chondrosarcoma of the Skull Base and Cervical Spine: Part 1 — Clinical Outcomes

AIMS

Patients with chordoma and chondrosarcoma in the skull base present a complex multidisciplinary problem. These tumours are rare and occur in difficult anatomical regions. We reviewed the local control and survival of patients treated in our centre.

MATERIALS AND METHODS

Between 1996 and 2005, 12 adult cases of chordoma (nine) and chondrosarcoma (three) in the skull base or cervical spine were treated in our centre. The median follow-up is currently 38 months. One patient was treated with palliative intent. In 10 cases the prescription dose was 65 Gy in 39 fractions. The target volumes were measured, and the target maximum and minimum doses and the equivalent uniform dose (EUD) for the phase I plans were recorded.

RESULTS

Local control was achieved in 11 of 12 cases. One chordoma patient failed locally, and one other died of metastatic disease despite local control. The 3- and 5-year cause-specific survival for the series was 88 and 75%, respectively. The mean phase I planning target volume (PTV) was 120.4 cm(3). The median minimum dose in the phase I PTV was 81.0%. The median EUD (expressed as a percentage of the prescribed dose) for the phase I PTV, calculated using a value for the exponent a of -15, was 98.3%. The phase I EUD was below 80% in two of the 12 cases.

CONCLUSIONS

Our results confirm a need for aggressive local surgery and high-dose radiotherapy, and endorse multidisciplinary working. Although charged particle therapy is accepted as providing optimal treatment plans, in eight of our patients travel abroad would not have been feasible. This series provides encouraging results for carefully planned photon conformal radiotherapy, carried out in close collaboration with a specialist surgical team.

Chordoma: 6 years' experience at a tertiary centre

Nine patients with a histologically proven diagnosis of chordoma seen at the Department of Radiation Oncology, Maulana Azad Medical College and Lok Nayak Hospital between January 1999 and December 2004 were retrospectively reviewed with respect to age, sex, presentation, location of tumour, treatment, response, recurrence, metastasis and follow up. Chordoma constituted 0.07% of total cancer cases registered over 6 years. Out of nine patients, eight were males and one was female with median age at time of diagnosis 52 years (range 34-68 years). All had sacrococcygeal lesions except one who had a spheno-occipital lesion. Seven patients had undergone either subtotal or gross total resection whereas only biopsy had been carried out in two of them. All patients received radiation therapy, seven in a postoperative setting and two for palliation. Follow-up period ranged from 2 to 50 months. Four patients died--the first after fourth fraction of radiation, second after 10 days of treatment, third of progressive lesion in sphenoidal region despite resection and radiation and fourth of local recurrence in the sacrococcyx. One patient developed distant metastases in the lungs and subcutaneous tissue over the scalp along with local recurrence; he is still alive. Two patients are locally free of disease whereas the other two were lost to follow up. The present analysis was undertaken to review our institutional experience with an aim to provide a practical approach to these tumours. In this report, these cases are discussed and the published works have been reviewed for the optimal management of patients with chordoma.

Less Common Indications for Stereotactic Radiosurgery or Fractionated Radiotherapy for Patients with Benign Brain Tumors

Microsurgical resection remains the mainstay of treatment for truly benign brain tumors that can be safely resected because of the potential for permanent cure with most histologic findings, including most of the histologic findings discussed in this article. Physicians must keep in mind the indolent nature of many of the benign brain tumors and realize that many patients are likely to live out normal life spans if tumor control is achieved. Therefore, it is not sufficient simply to consider local tumor control rates and short-term toxicity risks when choosing between surgery, stereotactic radiosurgery, and fractionated radiotherapy. Patients need to be apprised of all therapeutic options and to make their decisions with all information required to evaluate the risks and benefits. For benign brain tumors, these decisions may have consequences that last for decades.