Radiation therapy for chordomas of the base of skull and cervical spine: patterns of failure and outcome after relapse

Spot scanning proton therapy for malignancies of the base of skull: treatment planning, acute toxicities, and preliminary clinical outcomes

PURPOSE

To describe treatment planning techniques and early clinical outcomes in patients treated with spot scanning proton therapy for chordoma or chondrosarcoma of the skull base.

METHODS AND MATERIALS

From June 2010 through August 2011, 15 patients were treated with spot scanning proton therapy for chordoma (n=10) or chondrosarcoma (n=5) at a single institution. Toxicity was prospectively evaluated and scored weekly and at all follow-up visits according to Common Terminology Criteria for Adverse Events, version 3.0. Treatment planning techniques and dosimetric data were recorded and compared with those of passive scattering plans created with clinically applicable dose constraints.

RESULTS

Ten patients were treated with single-field-optimized scanning beam plans and 5 with multifield-optimized intensity modulated proton therapy. All but 2 patients received a simultaneous integrated boost as well. The mean prescribed radiation doses were 69.8 Gy (relative biological effectiveness [RBE]; range, 68-70 Gy [RBE]) for chordoma and 68.4 Gy (RBE) (range, 66-70) for chondrosarcoma. In comparison with passive scattering plans, spot scanning plans demonstrated improved high-dose conformality and sparing of temporal lobes and brainstem. Clinically, the most common acute toxicities included fatigue (grade 2 for 2 patients, grade 1 for 8 patients) and nausea (grade 2 for 2 patients, grade 1 for 6 patients). No toxicities of grades 3 to 5 were recorded. At a median follow-up time of 27 months (range, 13-42 months), 1 patient had experienced local recurrence and a second developed distant metastatic disease. Two patients had magnetic resonance imaging-documented temporal lobe changes, and a third patient developed facial numbness. No other subacute or late effects were recorded.

CONCLUSIONS

In comparison to passive scattering, treatment plans for spot scanning proton therapy displayed improved high-dose conformality. Clinically, the treatment was well tolerated, and with short-term follow-up, disease control rates and toxicity profiles were favorable.

[Chordoma]

PURPOSES

To review in the literature, all the epidemiological, clinical, radiological, histological and therapeutic data regarding chordomas as well as various notochordal entities: ecchordosis physaliphora, intradural and intraparenchymatous chordomas, benign notochordal cell tumors, parachordomas and extra-axial chordomas. To identify different types of chordomas, including familial forms, associations with tuberous sclerosis, Ollier's disease and Maffucci's syndrome, forms with metastasis and seeding. To assess the recent data regarding molecular biology and progress in targeted therapy. To compare the different types of radiotherapy, especially protontherapy and their therapeutic effects. To review the largest series of chordomas in their different localizations (skull base, sacrum and mobile spine) from the literature.

MATERIALS

The series of 136 chordomas treated and followed up over 20 years (1972-2012) in the department of neurosurgery at Lariboisière hospital is reviewed. It includes: 58 chordomas of the skull base, 47 of the craniocervical junction, 23 of the cervical spine and 8 from the lombosacral region. Similarly, 31 chordomas in children (less than 18 years of age), observed in the departments of neurosurgery of les Enfants-Malades and Lariboisière hospitals, are presented. They were observed between 1976 and 2010 and were located intracranially (n=22 including 13 with cervical extension), 4 at the craniocervical junction level and 5 in the cervical spine.

METHODS

In the entire Lariboisière series and in the different groups of localization, different parameters were analyzed: the delay of diagnosis, of follow-up, of occurrence of metastasis, recurrence and death, the number of primary patients and patients referred to us after progression or recurrence and the number of deaths, recurrences and metastases. The influence of the quality of resection (total, subtotal and partial) on the prognosis is also presented. Kaplan-Meier actuarial curves of overall survival and disease free survival were performed in the entire series, including the different groups of localization based on the following 4 parameters: age, primary and secondary patients, quality of resection and protontherapy. In the pediatric series, a similar analysis was carried-out but was limited by the small number of patients in the subgroups.

RESULTS

In the Lariboisière series, the mean delay of diagnosis is 10 months and the mean follow-up is 80 months in each group. The delay before recurrence, metastasis and death is always better for the skull base chordomas and worse for those of the craniocervical junction, which have similar results to those of the cervical spine. Similar figures were observed as regards the number of deaths, metastases and recurrences. Quality of resection is the major factor of prognosis with 20.5 % of deaths and 28 % of recurrences after total resection as compared to 52.5 % and 47.5 % after subtotal resection. This is still more obvious in the group of skull base chordomas. Adding protontherapy to a total resection can still improve the results but there is no change after subtotal resection. The actuarial curve of overall survival shows a clear cut in the slope with some chordomas having a fast evolution towards recurrence and death in less than 4 years and others having a long survival of sometimes more than 20 years. Also, age has no influence on the prognosis. In primary patients, disease free survival is better than in secondary patients but not in overall survival. Protontherapy only improves the overall survival in the entire series and in the skull base group. Total resection improves both the overall and disease free survival in each group. Finally, the adjunct of protontherapy after total resection is clearly demonstrated. In the pediatric series, the median follow-up is 5.7 years. Overall survival and disease free survival are respectively 63 % and 54.3 %. Factors of prognosis are the histological type (atypical forms), localization (worse for the cervical spine and better for the clivus) and again it will depend on the quality of resection.

CONCLUSIONS

Many different pathologies derived from the notochord can be observed: some are remnants, some may be precursors of chordomas and some have similar features but are probably not genuine chordomas. To-day, immuno-histological studies should permit to differentiate them from real chordomas. Improving knowledge of molecular biology raises hopes for complementary treatments but to date the quality of surgical resection is still the main factor of prognosis. Complementary protontherapy seems useful, especially in skull base chordomas, which have better overall results than those of the craniocervical junction and of the cervical spine. However, we are still lacking an intrinsic marker of evolution to differentiate the slow growing chordomas with an indolent evolution from aggressive types leading rapidly to recurrence and death on which more aggressive treatments should be applied.

Proton therapy for reirradiation of progressive or recurrent chordoma

PURPOSE

To report the results in patients reirradiated with proton therapy for recurrent or progressive chordoma, with or without salvage surgery.

METHODS AND MATERIALS

A retrospective review of 16 consecutive patients treated from 2005 to 2012 was performed. All patients had received at least 1 prior course of radiation therapy to the same area, and all but 1 patient had at least 1 surgical resection for disease before receiving reirradiation. At the time of recurrence or progression, half of the patients underwent additional salvage surgery before receiving reirradiation. The median prior dose of radiation was 75.2 Gy (range, 40-79.2 Gy). Six patients had received prior proton therapy, and the remainder had received photon radiation. The median gross tumor volume at the time of reirradiation was 71 cm(3) (range, 0-701 cm(3)). Reirradiation occurred at a median interval of 37 months after prior radiation (range, 12-129 months), and the median dose of reirradiation was 75.6 Gy (relative biological effectiveness [RBE]) (range. 71.2-79.2 Gy [RBE]), given in standard daily fractionation (n=14) or hyperfractionation (n=2).

RESULTS

The median follow-up time was 23 months (range, 6-63 months); it was 26 months in patients alive at the last follow-up visit (range, 12-63 months). The 2-year estimate for local control was 85%, overall survival 80%, chordoma-specific survival 88%, and development of distant metastases 20%. Four patients have had local progression: 3 in-field and 1 marginal. Late toxicity included grade 3 bitemporal lobe radionecrosis in 1 patient that improved with hyperbaric oxygen, a grade 4 cerebrospinal fluid leak with meningitis in 1 patient, and a grade 4 ischemic brainstem stroke (out of radiation field) in 1 patient, with subsequent neurologic recovery.

CONCLUSIONS

Full-dose proton reirradiation provided encouraging initial disease control and overall survival for patients with recurrent or progressive chordoma, although additional toxicities may develop with longer follow-up times.

Incidence and relative survival of chordomas: the standardized mortality ratio and the impact of chordomas on a population

BACKGROUND

Chordomas are rare bone tumors arising from remnants of the embryonic notochord.

METHODS

Data for this study were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute (1973-2009) to calculate the incidence, relative survival (RS), and standardized mortality ratio (SMR) of patients diagnosed with intracranial and extracranial chordomas and to assess the effects of age and sex on this disease.

RESULTS

The overall incidence of extracranial and intracranial chordomas was 8.4 per 10 million population. The median overall survival of patients with chordoma patients was 7.7 years. The median survival was 7.7 years for male patients and 7.8 years for female patients. Younger patients (aged <40 years) survived longer compared with older patients (10-year RS, 68% vs 43%). The estimated age-standardized 5-year, 10-year, and 20-year RS rates was 72%, 48%, and 31%, respectively. The SMR in the overall cohort was 4.6 (95% confidence interval, 4.22-5.0) or 21.0 (95% confidence interval, 16.6-27.2) in young adult patients and 3.0 (95% confidence interval, 2.6-3.4) in elderly patients.

CONCLUSIONS

The elderly had a more aggressive form of this disease; and, other than the incidence, sex did not influence outcome in this disease. The study of chordomas presents a good case for the contribution that the SMR can have on measuring the impact of a disease on a population of patients. Although the younger population has better survival rates, the impact (SMR) in the younger age groups is much higher than in older populations.

Risk of incisional recurrence after midface and anterior skull base surgery in sinonasal malignancies

We sought to determine the risk of tumor incisional recurrence in patients receiving surgery and postoperative radiation therapy for locally advanced sinonasal malignancies. Medical records for 70 patients newly diagnosed with nonmetastatic American Joint Committee on Cancer stage II to stage IV sinonasal malignancies between 1991 and 2003 were retrospectively reviewed. Patient demographics and tumor variables were recorded. All patients underwent upfront surgical resection with postoperative three-dimensional conformal proton beam radiotherapy. Recurrence and survival-related outcomes were recorded. Two patients with squamous cell carcinoma had pathologically confirmed tumor recurrence at the incision site. The actuarial risk of incisional recurrence for the entire group at 1 year was 3%. One of the two patients had a maxillary sinus tumor and developed isolated skin recurrence along the transfacial incision. The other patient with an ethmoid sinus tumor developed isolated dural recurrence along the craniotomy incision. Both patients underwent multiple courses of salvage surgery and radiation therapy. One was successfully salvaged locally but developed distant metastases and the other died of local recurrence. Tumor seeding following transfacial and craniotomy surgery can occur, especially for squamous cell carcinoma. Sound oncological surgical technique, even when utilizing these difficult surgical approaches, is important to minimize incisional recurrence.

Chordoma: current concepts, management, and future directions

Chordoma is a rare bone cancer that is aggressive, locally invasive, and has a poor prognosis. Chordomas are thought to arise from transformed remnants of notochord and have a predilection for the axial skeleton, with the most common sites being the sacrum, skull base, and spine. The gold standard treatment for chordomas of the mobile spine and sacrum is en-bloc excision with wide margins and postoperative external-beam radiation therapy. Treatment of clival chordomas is unique from other locations with an enhanced emphasis on preservation of neurological function, typified by a general paradigm of maximally safe cytoreductive surgery and advanced radiation delivery techniques. In this Review, we highlight current standards in diagnosis, clinical management, and molecular characterisation of chordomas, and discuss current research.

Tumours of the atlas and axis: a 37-year experience with diagnosis and management

PURPOSE

This paper presents a single institution's longterm experience regarding the incidence and management of tumours of the atlas and axis and discusses clinical and imaging findings and treatment options.

MATERIALS AND METHODS

We searched the registry of the Istituto Ortopedico Rizzoli for patients admitted and treated for tumours of the upper cervical spine. We identified 62 patients over 37 years, from July 1973 to October 2010. There were 39 male and 23 female patients, with a mean age of 39.5 (range 5-77) years. For each patient, we collected data on clinical presentation, imaging and treatment. Mean follow-up was 10 years.

RESULTS

Benign bone tumours were diagnosed in 24 (39%) and malignant tumours in 38 (61%) patients. The most common tumours were bone metastases, followed by osteoid osteomas and chordomas. The atlas was involved in six and the axis in 52 patients; in four patients, both the atlas and axis were involved. The most common clinical presentation was pain, torticollis, dysphagia and neurological deficits. Surgical treatment was performed in 35 patients and conservative treatment, including intralesional methylprednisolone injections and halo-vest immobilisation with or without radiation therapy, chemotherapy or embolisation, in the remaining patients. One patient with osteoblastoma of the atlas had local recurrence. All patients with metastatic bone disease had local recurrence; four of the eight patients with plasmacytoma progressed to multiple myeloma within 1-4 years. All patients with chordomas had two to four local recurrences. Patients with osteosarcomas and chondrosarcoma died owing to local and distant disease progression.

CONCLUSIONS

Bone tumours of the cervical spine are rare. However, they should be kept in mind when examining patients with neck pain or neurological symptoms at the extremities. In most cases, only intralesional surgery can be administered. Combined radiation therapy and chemotherapy is indicated for certain tumour histologies.

Ectopic pineal chordoma

Background:

Chordomas are rare tumors that arise from the remnants of embryonic notochord anywhere along the neuroaxis. Even though they may occur in an extraosseous intradural location, the most common sites include the sacrococcygeal and clivus regions. The authors report a unique presentation encompassing the pineal region with metastasis to the peritoneum after a ventriculoperitoneal (VP) shunt procedure and review the current knowledge about their pathophysiology and management. The presentation and clinical history endorse the idea that intradural extraosseous chordomas may be distinct from ecchordosis physaliphora and probably do not derive from it.

Case Description:

An 18-year-old male with previous history of VP shunt presented to the emergency room with pain and abdominal distension. Computed tomography (CT) scans revealed a mass in the pineal region and in the abdominal cavity. Histopathologic exams showed chordoma in both abdominal and cranial samples. The patient died due to systemic complications.

Conclusion:

The authors hypothesized that notochord remnants may subsist within the brain and occasionally may generate a neoplastic lesion.

In vitro characterization of cells derived from chordoma cell line U-CH1 following treatment with X-rays, heavy ions and chemotherapeutic drugs

Background

Chordoma, a rare cancer, is usually treated with surgery and/or radiation. However, very limited characterizations of chordoma cells are available due to a minimal availability (only two lines validated by now) and the extremely long doubling time. In order to overcome this situation, we successfully derived a cell line with a shorter doubling time from the first validated chordoma line U-CH1 and obtained invaluable cell biological data.

Method

After isolating a subpopulation of U-CH1 cells with a short doubling time (U-CH1-N), cell growth, cell cycle distribution, DNA content, chromosome number, p53 status, and cell survival were examined after exposure to X-rays, heavy ions, camptothecin, mitomycin C, cisplatin and bleocin. These data were compared with those of HeLa (cervical cancer) and U87-MG (glioblastoma) cells.

Results

The cell doubling times for HeLa, U87-MG and U-CH1-N were approximately 18 h, 24 h and 3 days respectively. Heavy ion irradiation resulted in more efficient cell killing than x-rays in all three cell lines. Relative biological effectiveness (RBE) at 10% survival for U-CH1-N was about 2.45 for 70 keV/μm carbon and 3.86 for 200 keV/μm iron ions. Of the four chemicals, bleocin showed the most marked cytotoxic effect on U-CH1-N.

Conclusion

Our data provide the first comprehensive cellular characterization using cells of chordoma origin and furnish the biological basis for successful clinical results of chordoma treatment by heavy ions.

Chordomas of the skull base and cervical spine: clinical outcomes associated with a multimodal surgical resection combined with proton-beam radiation in 40 patients

Previous studies of chordoma have focused on either surgery, radiotherapy, or particular tumor locations. This paper reviewed the outcomes of surgery and proton radiotherapy with various tumor locations. Between 2001 and 2008, 40 patients with chordomas of the skull base and cervical spine had surgery at our hospital. Most patients received proton therapy. Their clinical course was reviewed. Age, sex, tumor location, timing of surgery, extent of resection, and chondroid appearance were evaluated in regard to the progression-free survival (PFS) and overall survival (OS). The primary surgery (PS) group was analyzed independently. The extensive resection rate was 42.5%. Permanent neurological morbidity was seen in 3.8%. Radiotherapy was performed in 75% and the mean dose was 68.9 cobalt gray equivalents. The median follow-up was 56.5 months. The 5-year PFS and OS rates were 70% and 83.4%, respectively. Metastasis was seen in 12.5%. The tumor location at the cranio-cervical junction (CCJ) was associated with a lower PFS (P = 0.007). In the PS group, a younger age and the CCJ location were related to a lower PFS (P = 0.008 and P < 0.001, respectively). The CCJ location was also related to a lower OS (P = 0.043) and it was more common in young patients (P = 0.002). Among the survivors, the median of the last Karnofsky Performance Scale score was 80 with 25.7% of patients experiencing an increase and 11.4% experiencing a decrease. Multimodal surgery and proton therapy thus improved the chordoma treatment. The CCJ location and a younger age are risks for disease progression.

Degenerative Pannus Mimicking Clival Chordoma Resected via an Endoscopic Transnasal Approach

Lesions of the lower clivus represent a technically challenging subset of skull base disease that requires careful treatment. A 75-year-old woman with tongue atrophy was referred for resection of a presumed clival chordoma. The lesion was resected via an endoscopic transnasal transclival approach with no complications. Pathology revealed only chronic inflammatory tissue consistent with a degenerative pannus. Degenerative pannus should be included in the differential diagnosis of lower clival extradural lesions. The endoscopic transnasal transclival corridor should be considered for resection of such lesions as an alternative to larger, more morbid, traditional skull base approaches.

The treatment outcome depending on the extent of resection in skull base and spinal chordomas

PURPOSE

The authors tried to assess the treatment outcomes depending on the extent of resection in axial chordomas and compare the outcome of two adjunctive therapies (external beam radiation therapy vs. stereotactic radiosurgery) following incomplete tumour resection in terms of local tumour control.

PATIENTS AND METHODS

We retrospectively reviewed 30 consecutive patients with chordoma involving skull base, sacrum and mobile spine between 1993 and 2008. Their initial treatments had different extent of resection. Wide resection was performed for 12 (40%), subtotal resection and adjunctive radiotherapy/radiosurgery for 12 (40%), while six patients (20%) were solely treated with radiotherapy/radiosurgery. For these three groups, overall and progression-free survival rate were compared.

RESULTS

The overall survival rate was 96% at 5 years and 67% at 10 years. Tumour progression-free survival (PFS) rates were 73% and 43% at 5 and 10 years, respectively. Local tumour progression was seen in 67% in all patients, 58% in wide resection group, 67% in subtotal resection plus radiotherapy/radiosurgery group, and 75% in radiotherapy/radiosurgery group; however, this was not statistically significant (P = 0.69). Neither the extent of resection nor tumour location significantly influenced overall and progression-free survival (P > 0.05). With regard to the type of radiotherapy, tumour progression occurred in all lesions treated with external photon beam radiation therapy (EBRT) but only 38% of lesions treated with stereotactic radiosurgery (SRS) (P = 0.003).

CONCLUSIONS

Adjunctive radiotherapy/radiosurgery following subtotal resection showed comparable local control and survival to wide resection. SRS offered superior local tumour control compared to EBRT.

Pediatric epidural tumors of the spine--experience of a decade from the Kashmir Valley

We present our experience after analyzing retrospectively the clinicopathological characteristics, surgical approaches, immediate and long-term postoperative complications and survival outcome of pediatric spinal epidural tumors treated over a period of 10 years from 2000 to 2009 in a tertiary-care hospital. Our study included benign and malignant tumors. The majority of our patients were boys (14:8). The duration of symptoms was longer in benign lesions. Non-Hodgkin's lymphoma was the commonest malignant tumor and aneurysmal bone cyst was the commonest benign tumor. The mean duration of follow-up was 19 months (range 3-48 months). Most of the patients improved in their neurological grade after surgery; however, the degree of excision had no bearing on the length of survival for malignant lesions.

Clival chordomas: clinical management, results, and complications in 71 patients

Object

Chordomas are rare malignant neoplasms arising predominantly at the sacrum and skull base. They are uniformly lethal unless treated with aggressive resection and proton beam irradiation. The authors present results of the surgical management of a large number of patients with clivus chordomas. Factors that influence the surgeon's ability to achieve radical tumor resection are also evaluated.

Methods

Between 1991 and 2005, 71 patients with clivus chordomas underwent surgery. The average follow-up was 66 months (median 60 months, range 3–189 months). Sixty-five patients had complete records that were analyzed in the present report. Thirty-five percent of them had undergone surgery before being treated by the authors. They were evaluated with MR imaging and CT scanning and underwent surgery utilizing a variety of skull base techniques aimed at achieving radical excision. Many also underwent postoperative radiation, usually in the form of proton beam therapy. The patients were followed up with serial imaging at regular intervals as well as with neurological evaluation.

Results

Radical tumor resection was achieved in 58% of the group. The overall 5-year survival rate was 75%. Radical resection had a positive impact on survival. The ability to achieve radical resection was dependent on the preoperative tumor volume and the number of anatomical areas involved by the tumor. Cranial nerve impairment and CSF leakage were the most frequent postoperative complications.

Conclusions

Radical excision is the ideal surgical goal in the treatment of clival chordomas and can be achieved with reasonable risks. Several different surgical approaches may be necessary to accomplish this.

Long-term control of clival chordoma with initial aggressive surgical resection and gamma knife radiosurgery for recurrence

PURPOSE

Chordomas are locally destructive tumors with high rates of recurrence, and therapeutic strategies remain controversial. This study analyzed long-term outcomes for clival chordomas after initial aggressive surgical resection and gamma knife radiosurgery for recurrence and investigated clinical factors predicting recurrence.

METHODS

Clinical records were reviewed for 19 consecutive patients (11 men, 8 women; mean age, 43.1 years) with clival chordoma who underwent initial surgical resection using skull base approaches (mean follow-up after surgical resection, 87.2 months). All tumors were aggressively removed, along with the surrounding bone. Four patients were treated with radiotherapy after surgical resection.Recurrent lesions were treated with gamma knife radio surgery or reoperation. Factors predicting tumor recurrence were analyzed, including age, tumor extension, extent of resection and MIB-1 labeling index. Patient status was evaluated using the Karnofsky performance scale (KPS).

RESULTS

Tumor resection was total, subtotal and partial in 14, 4 and 1 patients, respectively. Tumors recurred in 11 patients. Overall, 2- and 5-year progression-free survival rates were 77.9% and 47.9%, respectively. The MIB-1 labeling index was independently associated with recurrence.The optimum cutoff point for the MIB-1 labeling index was 3.44%. All recurrent tumors were totally resected or controlled by gamma knife (mean follow-up after recurrence, 71.2 months). All patients survived and were active (mean KPS at final follow-up, 89.5%).

CONCLUSION

Long-term control of clival chordomas was achieved. Recurrent tumors were controlled with gamma knife radiosurgery, since lesions were localized and small after initial aggressive resection. The MIB-1 labeling index can provide important information for predicting tumor recurrence.

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.

Diagnosis and management of sacral tumors

Sacral tumors pose significant challenges to the managing physician from diagnostic and therapeutic perspectives. Although these tumors are often diagnosed at an advanced stage, patients may benefit from good clinical outcomes if an aggressive multidisciplinary approach is used. In this review, the epidemiology, clinical presentation, imaging characteristics, treatment options, and published outcomes are discussed. Special attention is given to the specific anatomical constraints that make tumors in this region of the spine more difficult to effectively manage than those in the mobile portions of the spine.

Optimal treatment planning for skull base chordoma: photons, protons, or a combination of both?

PURPOSE

We compared dosimetry of proton (PR), intensity modulated radiation therapy (IMRT) photon (PH), and combined PR and IMRT PH (PP) irradiation of skull base chordomas to determine the most optimal technique.

METHODS AND MATERIALS

Computed tomography simulation scans of 5 patients with skull base chordoma were used to generate four treatment plans: an IMRT PH plan with 1-mm planning target volume (PTV; PH1) for stereotactic treatment, an IMRT PH plan with 3-mm PTV (PH3) for routine treatment, a PR plan with beam-specific expansion margins on the clinical target volume, and a PP plan combining PR and PH treatment. All plans were prescribed 74 Gy/Cobalt Gray equivalents (CGE) to the PTV. To facilitate comparison, the primary objective of all plans was 95% or greater PTV prescribed dose coverage. Plans then were optimized to limit dose to normal tissues.

RESULTS

PTVs ranged from 4.4 to 36.7 cc in size (mean, 21.6 cc). Mean % PTV receiving 74 Gy was highest in the PP plans (98.4%; range, 96.5-99.2%) and lowest in the PH3 plans (96.1%; range, 95.1-96.7%). PR plans were the least homogeneous and conformal. PH3 plans had the highest mean % volume (V) of brain, brainstem, chiasm, and temporal lobes greater than tolerance doses. The PH1 plans had the lowest brainstem mean % V receiving 67 Gy (V(67Gy); 2.3 Gy; range, 0-7.8 Gy) and temporal lobe mean % V(65Gy) (4.3 Gy; range, 0.1-7.7 Gy). Global evaluation of the plans based on objective parameters revealed that PH1 and PP plans were more optimal than either single-modality PR or PH3 plans.

CONCLUSIONS

There are dosimetric advantages to using either PH1 or PP plans, with the latter yielding the best target coverage and conformality.

Emerging role of proton beam radiation therapy for chordoma and chondrosarcoma of the skull base

Chordomas and chondrosarcomas of the skull base are rare, indolent tumors with a natural history of locally invading their surroundings. Safe, maximal resection is the mainstay of treatment, followed by adjuvant radiation therapy. Even with multimodality therapy, local recurrence remains the most common failure pattern, translating to an adverse overall survival. Compared with other forms of radiation therapy, proton beam therapy has been used to increase the dose delivered to the tumor while elegantly sparing dosing to adjacent critical normal structures.

Solitary lymph node metastasis without local recurrence of primary chordoma

Chordoma is a malignant neoplasm believed to arise from notochord remnants. Its incidence is highest in the sixth decade and is generally regarded as a locally aggressive tumor with slow progression growth rate. Its metastatic incidence ranges from 5 to 40%, and it is generally believed that metastases without local recurrence of primary neoplasm are extremely rare. We report a case of a 38-year-old male patient with solitary inguinal lymph node metastasis without local recurrence of a previously surgically treated primary sacrococcygeal chordoma.

Neuronavigation using an image-guided endoscopic transnasal-sphenoethmoidal approach to clival chordomas

OBJECTIVE

Surgical approaches described for resection of clival tumors have been complicated, extensive, traumatic, and invasive. They are also associated with significant mortality and morbidity rates. We describe a minimally invasive, endoscopic transsphenoidal surgical treatment for clival tumors.

METHODS

Three men, aged 43, 46, and 66 years, each presented with a history of headaches, diplopia, and multiple cranial nerve deficits. All preoperative magnetic resonance imaging scans showed large clival tumors. A neuronavigational image-guided endoscopic transnasal-sphenoethmoidal approach was performed to resect the clival tumors.

RESULTS

All three patients had near-total removal of clival tumors using this method, and the histology revealed chordomas. They underwent postoperative adjuvant radiotherapy. No complications were encountered. All patients were able to resume their usual activities on the same day after surgery. Furthermore, this technique greatly reduced patient discomfort, hastened recovery, and shortened the hospital stay.

CONCLUSION

The neuronavigation image-guided transsphenoidal approach is a viable, minimally invasive alternative for surgical treatment of clival tumors.

The Etiology of Recurrent Chordoma Presenting as a Neck Mass: Metastasis vs. Surgical Pathway Seeding

Chordomas are rare tumors of notochordal origin that arise along the vertebral axis. These slowly growing yet highly destructive tumors are associated with an alarming rate of recurrence, although surgical resection followed by proton, proton/photon, or conventional radiotherapy has been somewhat successful in terms of recurrence-free survival. Still, recurrent disease as a result of metastasis or surgical pathway seeding does occur. We retrospectively reviewed the case of a 64-year-old woman who presented with a left neck mass at level II. She had a history of recurrent chordomas involving the occipital portion of the clivus that had been treated with multiple resections and proton-beam irradiations over a period of several years. The new mass was found to have infiltrated the superior end of the sternocleidomastoid muscle. Neck dissection was performed. Pathology revealed no lymphoid tissue in the main specimen and no evidence of chordoma in any of the lymph nodes. We believe that this latest clival chordoma might have occurred as a result of surgical pathway seeding during a previous operation anterior to the sternocleidomastoid muscle, although metastasis cannot be ruled out. We also review the literature on clival and skull base chordomas as it relates to recurrence, metastasis, and seeding.

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.

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.

Proton therapy - a systematic review of clinical effectiveness

BACKGROUND AND PURPOSE

Proton therapy is an emerging treatment modality for cancer that may have distinct advantages over conventional radiotherapy. This relates to its ability to confine the high-dose treatment area to the tumour volume and thus minimizing radiation dose to surrounding normal tissue. Several proton facilities are currently operating or under planning world-wide - in the United States, Asia and Europe. Until now no systematic review assessing the clinical effectiveness of this treatment modality has been published.

MATERIALS AND METHODS

A systematic review of published studies that investigated clinical efficacy of proton therapy of cancer.

RESULTS

We included 54 publications: 4 randomized controlled trials (RCTs) reported in 5 publications, 5 comparative studies and 44 case series. Two RCTs addressed proton irradiation as a boost following conventional radiation therapy for prostate cancer, where one demonstrated improved biochemical local control for the highest dose group without increased serious complication rates. Proton therapy has been used to treat a large number of patients with ocular tumours, but except for one low quality RCT, no proper comparison with other treatment alternatives has been undertaken. Proton therapy offers the option to deliver higher radiation doses and/or better confinement of the treatment of intracranial tumours in children and adults, but reported studies are heterogeneous in design and do not allow for strict conclusions.

CONCLUSION

The evidence on clinical efficacy of proton therapy relies to a large extent on non-controlled studies, and thus is associated with low level of evidence according to standard heath technology assessment and evidence based medicine criteria.

Advanced radiation therapy technologies in the treatment of rectal and anal cancer: intensity-modulated photon therapy and proton therapy

Intensity-modulated photon radiation therapy (RT; IMRT) and proton therapy are advanced radiation technologies that permit improved conformation of radiation dose to target structures while limiting irradiation of surrounding normal tissues. Application of these technologies in the treatment of rectal and anal cancer is attractive, based on the potential reduction in radiation treatment toxicities that are frequently incurred in the pelvis and perineum. Furthermore, conformal RT might also allow for dose escalation to target areas, leading to improved tumor control. This review discusses the underlying principles of IMRT. In addition, the rationale and clinical data regarding the efficacy of radiation dose escalation for rectal and anal cancer will be highlighted, as well as tolerance of pelvic organs to RT and chemotherapy. Finally, preliminary results of IMRT in the treatment of lower gastrointestinal tract cancers will be reviewed. The potential and rationale for proton therapy in treatment of these malignancies are also discussed.

Modern radiation treatment planning and delivery--from Röntgen to real time

The field of radiation oncology has advanced exponentially since the discovery of X-rays just over 100 years ago. With the advent of three-dimensional treatment planning, the therapeutic index was increased by dose escalation and more accurate shielding of normal tissues. Now, even greater advances are under way with IMRT, image-guided radiation therapy, delineation and control of organ motion, and real-time imaging. Similarly, the use of particle therapies such as protons has the potential to effect even more accurate dose distributions. Clinical studies investigating these modalities will likely further increase the efficacy of radiation in years to come.

The challenges of revision skull base surgery

Because the skull base is an anatomically complex structure, skull base tumors can hide easily in the crevices that interconnect the intra- and extracranial spaces and intermingle with important neurovascular structures. Often, total surgical resection of these tumors is not possible, and even with postoperative adjuvant radiotherapy, some recurrences after treatment are inevitable. Early detection of recurrent skull base tumors requires clinical vigilance and periodic imaging studies. The management of recurrent skull base tumors presents many challenges beyond those associated with primary procedures. A multidisciplinary setting that includes modern microsurgery and stereotactic radiation therapy provides patients with optimal care.

Extra-axial chordoma

A chordoma which occurs as a primary tumour outside the axial skeleton is known as an extra-axial chordoma, parachordoma or chordoma periphericum. It is extremely rare and therefore survival, recurrence and the rates of metastasis are not known. Whilst few recurrences have been described, the extra-axial chordoma has the potential for late recurrence at up to 12 years. Metastases are even less frequent.

We report the case of a 56-year-old woman who developed an extra-axial chordoma of the right thoracic wall in close relationship with the tenth rib. The tumour was completely removed and the prognosis is excellent.

Chordomas of the base of the skull and upper cervical spine. One hundred patients irradiated by a 3D conformal technique combining photon and proton beams

To define the prognostic factors for local control and overall survival among 100 consecutive patients with chordoma of the base of skull or upper cervical spine treated by fractionated irradiation combining proton and photon beams. Between December 1993 and August 2002, 100 patients (median age: 53 years [8 - 85], M/F sex ratio: 3/2) were treated by a combination of high-energy photons and protons. The proton component was delivered at the Centre de Protonthérapie d'Orsay (CPO) by a 201 MeV beam. The median total dose delivered to the tumor volume was 67 GyECo. With a median follow-up of 31 months [range: 0 - 87], 25 tumours relapsed locally. The 2- and 4-year local control rates were 86.3% (+/-3.9%) and 53.8% (+/-7.5%), respectively. According to multivariate analysis, at least 95% of the tumor volume encompassed by the 95% isodose (p = 0.048; RR: 3.4 95%CI [1.01 - 11.8]) and a minimal dose delivered into the tumor volume <56 GyECo (p = 0.042; RR: 2.3 95%CI [1.03 - 5.2]) were independent prognostic factors of local control. Ten patients died. The 2- and 5-year overall survival rates were 94.3% (+/-2.5%) and 80.5% (+/-7.2%), respectively. According to multivariate analysis, local tumor control (p = 0.005; RR: 21 95%CI [2.2 - 200]) was a prognostic factor of overall survival. For chordomas of the base of the skull and upper cervical spine treated by surgery and irradiation combining photons and protons, the quality of irradiation, reflected by homogeneity of the dose into the tumor volume, is a major factor of local control. Close attention must be paid to minimize the underdosed areas close to critical organs. The role of surgical resection remains paramount, and a trial of dose escalation would have to consider an increase in the dose to critical organs, especially as current results indicate the low toxicity of this treatment.

Recurrent and metastatic clivus chordoma: systemic palliative therapy retards disease progression

We report on a male patient with progressive and metastatic clivus chordoma treated over a period of 9 years by a multidisciplinary approach. Within the first 4 years, the patient underwent surgery four times. Thereafter, he received radiotherapy and subsequent chemotherapy. Stabilization of disease was achieved repeatedly for variable periods under local radiotherapy, systemic chemotherapy, immunomodulatory and anti-angiogenic therapy with isotretinoin and interferon-alpha, followed by thalidomide. Due to the occurrence of brain and lung metastases 8 years after initial diagnosis, liposomal doxorubicin was added to thalidomide. At the last follow-up control the patient had stable disease, with no progression of the intracranial tumor and regression of pulmonary metastases. He is in a good physical, psychological and neurological condition with a Karnofsky score of 80. Our observations show that multimodal therapy including a systemic palliative approach is associated with long quiescent intervals in recurrent chordoma and with regression of its metastases. Use of substances with high efficacy on tumor tissue and low toxicity, allowing long-term administration, seems promising in similar situations.

Radiotherapeutic factors in the management of cervical-basal chordomas and chondrosarcomas

OBJECTIVE

To define prognostic factors for local control and survival in 90 consecutive patients treated by fractionated photon and proton radiation for chordoma or chondrosarcoma of the cranial base and upper cervical spine.

METHODS

Between December 1995 and December 2000, 90 patients (median age, 51.3 yr; range, 10-85 yr; male/female ratio, 3:2) were treated by a combination of high-energy photons and protons. Sixty-four patients had a chordoma, and 26 had a chondrosarcoma. The proton component was delivered by the 201-MeV proton beam of the Centre de Protontherapie d'Orsay. The median total dose delivered to the gross tumor volume (GTV) was 67 cobalt Gray equivalents (range, 22-70 cobalt Gray equivalents).

RESULTS

With a median follow-up of 34 months (range, 3-74 mo), treatment of 25 tumors failed locally. The 3-year local control rates were 69.2% (+/-6.0%) and 91.6% (+/-8.4%) for chordomas and chondrosarcomas, respectively. According to multivariate analysis, a small tumor volume excluded from the 95% isodose line (P = 0.032; relative risk [RR], 0.098; 95% confidence interval [CI], 0.01-0.81) and a controlled tumor (P = 0.049; RR, 0.19; 95% CI, 0.04-0.99) were independent favorable prognostic factors for overall survival. On multivariate analysis, a high minimum dose (P = 0.02; RR, 2.8; 95% CI, 1.2-6.6), a high tumor control probability (P = 0.02; RR, 3.8; 95% CI, 1.2-12.5), a high dose delivered to 95% of the GTV (P = 0.03; RR, 3.4; 95% CI, 1.15-10.2), a high GTV encompassed by the 90% isodose line (P = 0.01; RR, 3.29; 95% CI, 1.29-8.44), and a small GTV excluded from the 90% isodose line (P = 0.036; RR, 0.4; 95% CI, 0.1-0.9) were independent favorable prognostic factors for local control.

CONCLUSION

In chordomas and chondrosarcomas of the cranial base and cervical spine treated by surgical resection and then by high-dose photon and proton irradiation, local control is mainly dependent on the quality of radiation, especially dose uniformity within the GTV. Special attention must be paid to minimize underdosed areas because of the close proximity of critical structures and to redefine and possibly escalate dose constraints to tumor targets in future studies in view of the low toxicity observed to date.

Les chordomes de la base du crâne et du rachis cervical haut. À propos d'une série de 100 patients irradiés selon une technique conformationnelle 3D par une association de faisceaux de photons et de protons

OBJECTIVE

To define prognostic factors for local control and survival in 100 consecutive patients treated by fractionated photon and proton radiation for chordoma of the skull base and upper cervical spine.

PATIENTS AND METHODS

Between December 1995 and August 2002, 100 patients (median age: 53 years, range: 8-85, M/F sex-ratio: 3/2), were treated by a combination of high-energy photons and protons. The proton component was delivered by the 201 MeV proton beam of the Centre de Protonthérapie d'Orsay (CPO). The median total dose delivered to the gross tumour volume was 67 Cobalt Gray Equivalent (CGE) (range: 60-71). A complete surgery, incomplete surgery or a biopsy was performed before the radiotherapy in 16, 75 and 9 cases, respectively.

RESULTS

With a median follow-up of 31 months (range: 1-87), 25 tumours failed locally. The 2 and 4-year local control rates were 86.3% (+/-3.9%) and 53.8% (+/-7.5%), respectively. According to multivariate analysis, less than 95% of the tumour volume encompassed by the 95% isodose line (P=0.048; RR: 3.4 IC95% [1.01-11.8]) and a minimal dose less than 56 CGE (p=0.042; RR: 2.3 IC95% [1.03-5.2]) were independent prognostic factors of local control. Ten patients died. The 2 and 5-year overall survival rates were 94.3% (+/-2.5%) and 80.5% (+/-7.2%). According to multivariate analysis, a controlled tumour (P=0.005; RR: 21 IC95% [2.2-200]) was the lonely independent favourable prognostic factor for overall survival.

CONCLUSION

In chordomas of the skull base and upper cervical spine treated by surgical resection followed by high-dose photon and proton irradiation, local control is mainly dependent on the quality of radiation, especially dose-uniformity within the gross tumour volume. Special attention must be paid to minimise underdosed areas due to the close proximity of critical structures and possibly escalate dose-constraints to tumour targets in future studies, in view of the low toxicity observed to date.

Radiosurgery for Cranial Base Chordomas and Chondrosarcomas

OBJECTIVE:

To evaluate the efficacy and toxicity of radiosurgery in the treatment of cranial base chordoma and chondrosarcoma.

METHODS:

We reviewed 29 patients with cranial base chordoma (n = 25) or chondrosarcoma (n = 4) who underwent stereotactic radiosurgery between September 1990 and December 2002. The median patient age was 45 years (range, 10–81 yr). Nineteen patients also had radiation therapy before or in conjunction with radiosurgery (median dose, 50.4 Gy). The median tumor volume was 14.4 cm3 (range, 0.6–65.1 cm3). The median tumor margin dose was 15 Gy (range, 10–20 Gy); the median maximum radiation dose was 30 Gy (range, 20–40 Gy). Median clinical and imaging follow-up periods were 4.8 and 4.5 years, respectively.

RESULTS:

Seven chordoma patients (28%) had tumor progression (in-field, n = 3; out-of-field, n = 4), whereas 18 had stable disease or tumor shrinkage. No patient with a chondroid chordoma had tumor enlargement. The actuarial tumor control rates were 89 and 32% at 2 and 5 years, respectively. All 4 patients with chondrosarcoma had tumor control. Clinically, 7 patients (24%) had improvement of pretreatment symptoms, 16 (55%) remained stable, and 6 (21%) worsened. Three patients with tumor progression died. Ten patients (34%) had radiation-related complications. Complications included cranial nerve deficits (n = 6), radiation necrosis (n = 5), and pituitary dysfunction (n = 3). Patients having radiosurgery alone had no toxicity.

CONCLUSION:

Cranial base chordomas and chondrosarcomas remain a formidable management challenge. Radiosurgery as an adjunct to surgical resection provides in-field tumor control for some patients, but radiation-related complications are relatively high, especially when radiosurgery is combined with fractionated radiation therapy.

Clinical and research validity of hadrontherapy with ion beams

Clinical results obtained with hadrontherapy have been extremely positive for various tumours, with percentages of local control and survival higher than those ascribed to conventional radiotherapy. Most clinical data obtained with charged particles are related to protontherapy but the implementation of carbon ion therapy has demonstrated to be of great interest in the last decade. These results, accompanied by the new performances in accelerator technology and calculation systems of the delivered doses, have determined over the past years an increased interest for the development of hadrontherapy, with the construction of new centres provided with equipment entirely dedicated to clinical activity (LLUMC, Loma Linda and NPTC, Boston in USA, HIMAC-NIRS, Chiba, PROBEAT, Tsukuba, and Hyogo Beam Medical Centres in Japan). A revision of the clinical indications specifically focused on ion therapy is presented as well as the results obtained in the different centres. With hadrontherapy, it is finally possible to increase the spectrum of treatments allowing preserving the organ and its functionality, with positive impacts from a social and economic point of view.