Ascending myelitis after intensive chemotherapy and radiation therapy in children with cranial parameningeal sarcoma

[Radiotherapy and spinal toxicity: News and perspectives]

Radiation-induced myelopathy is a devastating late effect of radiotherapy. Fortunately, this late effect is exceptional. The clinical presentation of radiation myelopathy is aspecific, typically occurring between 6 to 24 months after radiotherapy, and radiation-induced myelopathy remains a diagnosis of exclusion. Magnetic resonance imaging is the most commonly used imaging tool. Radiation oncologists must be extremely cautious to the spinal cord dose, particularly in stereotactic radiotherapy and reirradiation. Conventionally, a maximum dose of 50Gy is tolerated in normofractionated radiotherapy (1.8 to 2Gy per fraction). Repeat radiotherapies lead to consider cumulative doses above this recommendation to offer individualized reirradiation. Several factors increase the risk of radiation-induced myelopathy, such as concomitant or neurotoxic chemotherapy. The development of predictive algorithms to prevent the risk of radiation-induced myelopathy is promising. However, radiotherapy prescription should be cautious, regarding to ALARA principle (as low as reasonably achievable). As the advent of immunotherapy has improved patient survival data and the concept of oligometastatic cancer is increasing in daily practice, stereotactic treatments and reirradiations will be increasingly frequent indications. Predict the risk of radiation-induced myelopathy is therefore a major issue in the following years, and remains a daily challenge for radiation oncologists.

Parameningeal rhabdomyosarcoma: outcomes and opportunities

PURPOSE

To examine patterns of failure in patients with parameningeal rhabdomyosarcoma (PM-RMS) treated with intensity modulated radiation therapy (IMRT).

METHODS AND MATERIALS

Forty-seven patients with PM-RMS received chemotherapy and IMRT for definitive treatment. The median age was 9 years (range, 0.5-35 years). The high-risk features were as follows: 40% alveolar histology, 72% group III and 26% group IV disease, 57% either intracranial extension (ICE) (n=25) or cranial neuropathy (n=21). The median time to RT from the start of chemotherapy was 15 weeks (range, 2-54 weeks). Patients received 50.4 Gy in 1.8-Gy fractions to the primary tumor by use of IMRT. Thirteen patients aged≥14 years with alveolar histology received 36 Gy prophylactic nodal irradiation (PNI) to bilateral cervical nodes. Events were defined as local, regional (nodal), central nervous system (CNS), or distant failures.

RESULTS

With a median follow-up time of 3.3 years (range, 0.5-12.8 years), 18 patients experienced failure: 5 local, 2 regional, 6 distant, and 7 CNS. The 5-year local failure-free survival was 86%. Age, histology, and time to RT did not influence the risk of local failure. The 5-year regional failure-free survival was 92%: 100% for embryonal and 74% for alveolar (P=.03). However, there were no lymph node failures in patients with alveolar histology who were given PNI. The 5-year CNS failure-free survival was 83%: 100% without and 70% with ICE (P=.01); 95% without and 69% with cranial neuropathy (P=.02). The estimated 5-year event-free survival and overall survival were 61% for group III and 58% for group IV patients.

CONCLUSIONS

Distant failure was the most common type of failure among group IV patients. Patients with alveolar histology seem to benefit from PNI. The presence of ICE or cranial neuropathy portends a high risk of CNS failure, the most common pattern of failure among non-group IV patients. These patients may benefit from the addition of novel CNS-directed therapy.

Increased vulnerability of the spinal cord to radiation or intrathecal chemotherapy during adolescence: A report from the Children's Oncology Group

PURPOSE

To assess the rate of spinal cord toxicity in adolescents resulting from chemoradiotherapy of parameningeal sarcoma.

METHODS AND MATERIALS

Of 152 patients with parameningeal sarcoma treated per the Intergroup Rhabdomyosarcoma Study Group protocol from 1977 through 1989, eight developed paralyzing ascending myelitis after intrathecal chemotherapy with cytosine arabinoside, methotrexate, and hydrocortisone administered during and after radiation therapy to volumes that included part of the spinal cord. The eight cases include three not previously published.

RESULTS

Of eight patients who developed CNS toxicity after intrathecal chemotherapy and radiotherapy for parameningeal rhabdomyosarcoma, all but one were between 13 and 18 years of age when treated. This severe toxicity occurred in one quarter of 28 adolescents treated with the regimen in comparison with one of 123 children 12 years of age or less (P < 0.0001), a rate that was as much as 30 times higher in the adolescents. Lengthening of the spinal cord during the pubertal growth spurt may account for the apparent increased vulnerability.

CONCLUSIONS

Chemoradiotoxicity-associated spinal cord injury appears to be more likely to occur in adolescents than in younger or older ages. This observation appears to reverse a conventional wisdom in which the central nervous system is thought to become more resistant to the neurotoxic effects of chemoradiotherapy as it matures.

Myelopathy After Radiation Therapy and Chemotherapy with Capecitabine and Gemcitabine

This article describes a woman with metastatic upper gastrointestinal cancer who developed thoracic myelopathy unexpectedly after standard dosage and fractionation radiotherapy. She also was receiving capecitabine and gemcitabine concomitantly. There are few reported cases of chemotherapy potentiation of spinal cord radiation toxicity. These agents are known radiosensitizers, making it likely that they contributed to this adverse outcome. As these agents are increasingly incorporated into clinical trials of combined therapy, caution will be necessary in both trial design and clinical management.

Physical models and simpler dosimetric descriptors of radiation late toxicity

Predicting radiation damage to specific organs is becoming ever more challenging with the use of intensity-modulated beams, nonuniform dose distributions, partial organ irradiation, and interpatient and even intraorgan variations in radiation sensitivity. Data-based physical models can be of use in summarizing complicated dose-volume data to help describe clinical outcomes and ultimately aid in the prediction of clinical toxicity. This article attempts to provide a brief overview of the use of normal tissue complication probability (NTCP) models and other simple dose/volume metrics to describe a few clinically significant complications (either frequent or serious) associated with radiation therapy of the head and neck, thorax, and abdominal-pelvic regions. Specifically, it reviews the application of these methods for late toxicities of the parotid, lung, heart, spinal cord, liver, and rectum. It focuses on organ-specific NTCP parameters as well as simple dosimetric descriptors that might be used to help treatment plan evaluation in clinical practice.

Local intracerebral administration of Paclitaxel with the paclimer delivery system: toxicity study in a canine model

INTRODUCTION

Paclitaxel, a microtubule binding agent with potent anti-glioma activity in vitro, exhibits poor penetrance to the CNS when delivered systemically. To minimize toxicity and reach therapeutic concentrations in the CNS, paclitaxel was previously incorporated into biodegradable microspheres (Paclimer), and the efficacy of Paclimer was determined in a rat model of malignant glioma. In this study we report the safety of intracranial Paclimer in a canine dose escalation toxicity study to prepare its translation into clinical scenarios.

METHODS

Twelve normal beagle dogs underwent a right parieto-occipital craniectomy and were randomized to receive either Paclimer at 2-mg/kg (n=5), empty microspheres at 2-mg/kg (n=1), Paclimer at 20-mg/kg (n=5), or empty microspheres at 20-mg/kg (n=1). Post-operatively, dogs were observed daily for signs of neurotoxicity. Complete blood counts and plasma levels of paclitaxel were obtained weekly. CSF levels and MRI scans were obtained on days 14-120. Paclitaxel concentrations were quantified by LC-MS.

RESULTS

Animals treated with 20-mg/kg Paclimer had minimal paclitaxel levels in plasma (range 0-7.84 ng/ml) and CSF (range 0-1.16 ng/ml). Animals treated with 2 mg/kg Paclimer had undetectable levels of paclitaxel in plasma, CSF was not obtained to minimize animal suffering. All animals exhibited normal behavior and weight gain, and were alive post-operatively through the last day of the study (day 60-120) without signs of neurological toxicity. There was no evidence of systemic toxicity or myelosuppression. MR imaging was comparable between Paclimer animals and controls. Adverse effects included wound infections and a brain abscess, all of which responded to antibiotic therapy, and one ventriculomegaly due to communicating hydrocephalus.

CONCLUSIONS

Paclimer-based delivery of paclitaxel is safe for intraparenchymal delivery at the tested doses in normal dogs.

Fatal radiation myelopathy after high-dose busulfan and melphalan chemotherapy and radiotherapy for Ewing's sarcoma: a review of the literature and implications for practice

Radiation myelopathy is a rare, devastating, late effect of radiotherapy to the spinal cord. Spinal cord tolerance is currently accepted as about 50 Gy in 1.8-2 Gy fractions. However, the effect of chemotherapy on cord tolerance is unclear. This issue is important, given the increasing use of chemotherapy in combination with radiotherapy. We describe the case of a 17-year-old boy with a right apical paraspinal Ewing's tumour in the neck treated with induction chemotherapy, high-dose chemotherapy (busulfan and melphalan) with peripheral stem-cell rescue and, 4 months later, radiotherapy to the primary tumour site (cervical cord received 50 Gy in 30 fractions). After a latent period of 4 months, he developed a progressive, severe and ultimately fatal radiation myelopathy, which we suggest was due to a synergistic interaction between the high-dose chemotherapy and the radiotherapy. The use of such chemotherapy regimens in Ewing's tumours should be carefully considered, particularly when radiotherapy encompassing the spinal cord is an essential component of management.

Widespread intratumoral virus distribution with fractionated injection enables local control of large human rhabdomyosarcoma xenografts by oncolytic herpes simplex viruses

Novel methods of local control for sarcomas are needed. We investigated the antitumor effect of two related herpes simplex virus (HSV) mutants, NV1020 and NV1066, on human rhabdomyosracoma cells and xenografts. Cell death correlated with virus replication and apoptosis in cultured cells and tumors. Complete regression was seen in all tumors <250 mm(3) following a single injection, yet only half of tumors >250 mm(3) showed a complete response. Fractionation of the virus dose into five injection sites did not increase transduction efficiency, transgene expression, or virus production, but did yield more widespread intratumoral distribution. Despite the same total dose of virus, improved control of large tumors was seen using fractionated injections as all large tumors (500-700 mm(3)) had durable, complete regression. Our data suggest that oncolytic HSVs may be useful for local control of bulky rhabdomyosarcoma tumors and that fractionated virus administration results in a more widespread virus infection and better tumor control. Therefore, strategies to maximize intratumoral virus distribution at initial delivery should be sought.

Influence of radiation therapy parameters on outcome in children treated with radiation therapy for localized parameningeal rhabdomyosarcoma in Intergroup Rhabdomyosarcoma Study Group trials II through IV

PURPOSE

To evaluate the impact of radiation treatment parameters on cancer control outcomes for children with parameningeal rhabdomyosarcoma (PM-RMS) treated on Intergroup Rhabdomyosarcoma Study Group protocols II through IV (including IRS-IV pilot).

MATERIALS AND METHODS

Radiation therapy (RT) treatment quality was assessed by contemporary review of portal radiographs, simulation films, treatment plans, and, in most cases, cross-sectional diagnostic imaging data for patients treated on Intergroup Rhabdomyosarcoma Study Group protocols II through IV. Five hundred ninety-five patients with PM-RMS were registered on these 4 studies between 1978 and 1997. Most of these patients (95%) had Group III disease. Radiation doses varied over the span of these trials with protocol doses ranging from 40 Gy to 50.4 Gy on IRS-II and IRS-III and 50.4 Gy to 59.4 Gy (hyperfractionated) on IRS-IV pilot and IRS-IV. Patients with high-risk signs of meningeal impingement, including cranial nerve palsy (CNP) or cranial base bone erosion (CBBE) with or without intracranial extension (ICE), were required to start radiotherapy at the time of study entry (Day 0). Among 595 patients reviewed, 385 (65%) had diagnostic images submitted to the Quality Assurance Review Center for assessment of target volume coverage. Only 123 (21%) patients, 49 (40%) of whom were treated on IRS-II, received whole brain RT.

RESULTS

The estimated overall survival and failure-free survival rates were 73% and 69% at 5 years, respectively. The estimated 5-year local failure (LF) rate was 17%. The detection of ICE increased from 24% to 41% as more cross-sectional diagnostic images became available. For patients with any sign of meningeal impingement, starting RT <2 weeks after diagnosis (n = 315) had 18% LF compared to 33% LF if started >2 weeks after diagnosis (n = 43) (p = 0.03). For patients with ICE, starting RT <2 weeks after diagnosis (n = 177) resulted in LF in 16% compared to 37% among those who started >2 weeks after (n = 19) (p = 0.07). For patients with CNP and/or CBBE, starting RT <2 weeks after diagnosis (n = 138) resulted in 21% LF compared to 30% among those that started >2 weeks (n = 23) (p = 0.23). In none of these circumstances was the 5-year failure-free survival significantly impacted by this increase in LF. The estimated 3-year survival after local failure was 17% (95% CI, 10%-25%). For patients without signs of meningeal impingement, there was no difference in local control whether they started radiation therapy earlier or later than 10 weeks. Patients with large (> or =5 cm) Group III tumors had an LF rate of 35% if they received less than 47.5 Gy compared to an LF rate of 18% in patients who received less than 47.5 Gy with smaller tumors or a rate of 15% if they received more than 47.5 Gy, irrespective of tumor size (p = 0.14). There was no evidence that whole brain radiation therapy affected LF or reduced central nervous system (CNS) relapse. Multivariate analysis of RT parameters and clinical factors demonstrated that a radiation dose of >47.5 Gy was associated with lower LF. The presence of ICE, CNP, or CBBE and age >10 years at diagnosis were significantly associated with higher rates of local failure.

CONCLUSIONS

The availability of cross-sectional diagnostic images (CT or MRI) has improved detection of ICE. Starting radiation therapy within 2 weeks of diagnosis for patients with signs of meningeal impingement was associated with lower rates of local failure. When no signs of meningeal impingement were present, delay of radiation therapy for more than 10 weeks did not impact local failure rates. Whole brain radiation therapy is unnecessary in PM-RMS. A dose of at least 47.5 Gy seems to be associated with lower rates of local failure, especially when tumor diameter is > or =5 cm.

Radiation myelitis in a 5-year-old girl

Myelopathy is an uncommon complication of radiotherapy, particularly in the pediatric age group. A 5-year-old girl with acute lymphoblastic leukemia developed a severe but transient radiculopathy after intrathecal administration of methotrexate and cytarabine for an isolated central nervous system relapse. Chemotherapy was then given through an intraventricular catheter. Owing to a second central nervous system recurrence, she was treated with craniospinal radiation. The whole brain down to the level of C2 received a dose of 2400 cGy. Two months after completion of radiation, the child developed a progressive tetraparesis, and magnetic resonance imaging revealed an enhancing lesion involving the medulla and upper cervical cord. A biopsy was consistent with a treatment-related necrotizing leukoencephalopathy. This case suggests that patients who develop neurologic dysfunction when treated with methotrexate can also be particularly susceptible to radiation-related injury.

Treatment of children and adolescents with localized parameningeal sarcoma: experience of the Intergroup Rhabdomyosarcoma Study Group protocols IRS-II through -IV, 1978-1997

BACKGROUND

We reviewed 611 patients with parameningeal sarcoma entered on Intergroup Rhabdomyosarcoma Study Group (IRSG) Protocols-II through IV (1978-1997), to delineate treatment results and evaluate prognostic factors.

PROCEDURE

Primary sites were the middle ear/mastoid (N = 138), nasopharynx/nasal cavity (N = 235), paranasal sinuses (N = 132), parapharyngeal region (N = 29), and the pterygopalatine/infratemporal fossa (N = 77). Treatment was initial biopsy or surgery followed by multiagent chemotherapy and radiation therapy (XRT). Beginning in 1977, patients with cranial nerve palsy, cranial base bony erosion, and/or intracranial extension at diagnosis were considered as having meningeal involvement. They received triple intrathecal medications, whole brain XRT, and then spinal XRT. These treatments were successively eliminated from 1980 to 1991.

RESULTS

The 611 patients' overall survival rate at 5 years was 73% (95% confidence interval, 70-77%). Favorable prognostic factors were: age 1-9 years at diagnosis; primary tumor in the nasopharynx/nasal cavity, middle ear/mastoid, or parapharyngeal areas; no meningeal involvement; and non-invasive tumors (T1). Thirty-five of 526 patients (6.7%) with information about presence/absence of meningeal involvement at diagnosis developed central nervous system (CNS) extension at 5-164 weeks (median, 46 weeks) after starting therapy. The estimated 5-year cumulative incidence rate of CNS extension during the study period was 5-7% (P = 0.88).

CONCLUSIONS

Biopsy, XRT to the target volume, and systemic chemotherapy are successful treatments for the large majority of patients with localized parameningeal sarcoma. Carefully defining and irradiating the initial volume should reduce the risk of CNS failure. Aggressive initial surgical management of these patients is unnecessary.

Progress in the diagnosis and treatment of rhabdomyosarcoma and related soft tissue sarcomas

Advances in the diagnosis and treatment of rhabdomyosarcoma and related soft tissue sarcomas continue in the Intergroup Rhabdomyosarcoma Study Group (IRSG) and European cooperative groups. The use of molecular biology techniques in soft tissue sarcomas are redefining the classic pathology of these small blue cell tumors. Improvements in imaging, radiotherapy, and surgery, in part, deserve credit for the better survival seen in all cooperative trials. These advances confound the interpretation of consecutively run chemotherapy trials using historical comparisons. The IRSG has reported improvement in the prognosis of both nonmetastatic and metastatic embryonal rhabdomyosarcoma as attributable to three, three-drug regimens that use cyclophosphamide at 2.2 g/m2 in either maintenance or induction and maintenance therapy. Patients of any age with metastatic, nonembryonal, and those over 10 years of age with metastatic embryonal rhabdomyosarcoma continue to have a poor prognosis, which even megatherapy has failed to change. The doublet of ifosfamide and etoposide in combination with vincristine, actinomycin D, and cyclophosphamide at 2.2 g/m2 achieved a remarkable 3-year survival of 58% in patients with metastatic rhabdomyosarcoma and undifferentiated soft tissue sarcoma. The topoisomerase I inhibitor, topotecan, has recently been found by the IRSG to have a 57% overall response rate in patients with metastatic alveolar rhabdomyosarcoma. Topotecan has completed testing with cyclophosphamide in a phase II window study in newly diagnosed patients with metastatic disease and has been incorporated into a randomized trial in intermediate risk patients in IRSG-V. Molecular studies in IRSG-V will be applied in the detection of occult bone marrow metastases and the evaluation of resection margins at initial and second-look surgery. Long-term follow-up will be required in patients with gross residual sarcoma randomized to conventional and hyperfractionated radiotherapy in IRSG-IV to assess late effects. Although older patients with unfavorable histology and metastatic disease continue to have a poor prognosis, the overall 5-year survival of children and adolescents with nonmetastatic and metastatic rhabdomyosarcoma is approaching 80%. As molecular discoveries advance the diagnosis and detection of rhabdomyosarcoma, it is hoped that the futuristic molecular based treatment strategies in development and early testing will further improve survival in high-risk patients with metastatic soft tissue sarcoma.

Role of radiation therapy in parameningeal rhabdomyosarcoma

Radiation therapy plays a crucial role in the management of children with parameningeal rhabdomyosarcomas. Because of the close proximity to the skull base, most lesions are not amenable to complete surgical resection without mutilation, and treatment has primarily been chemoradiation. Adequate radiotherapy dose, coverage of the tumor, and knowledge of potential areas of invasion are of paramount importance as demonstrated by early data from the Intergroup Rhabdomyosarcoma Study Group. The timing, dose, and treatment volume for parameningeal rhabdomyosarcomas have evolved in the last 25 years in a continuous effort to find ways of maximizing local control while reducing possible late sequelae. Hyperfractionated radiation therapy is currently being tested against conventional dose radiation therapy for group III tumors. At present, approximately 70% of children treated for parameningeal rhabdomyosarcoma on the Intergroup Rhabdomyosarcoma Study are alive at 5 years compared with a 25% survival before the formation of multi-institutional cooperative group studies.

Soft tissue sarcomas in children

In childhood, soft tissue sarcomas comprise a complex group of malignancies of varied histologic subtypes, the prognoses of which depend on the histology, age, site, extent of involvement and a variety of other factors. This paper discusses the varieties of tumors classified as soft tissue sarcomas in childhood and the multimodal approach taken to cure these tumors, with particular attention to the details of difficult surgical problems.

Growth hormone deficiency following radiotherapy for orbital and parameningeal sarcomas

Growth hormone deficiency (GHD) is a recognized late effect of successful treatment of tumors requiring cranial irradiation. Growth after treatment was assessed in 16 patients with sarcomas of the orbital and parameningeal regions. Median age at diagnosis was 6.35 years and median follow-up was 7.2 years. Treatment consisted of combination chemotherapy and radical radiotherapy, conventionally fractionated with a median dose 4500 cGy; the hypothalamic/pituitary region received a median dose of 4163 cGy. Height was measured every 6 months and 13/16 patients underwent tests of GH function. At GH testing median height standard deviation score (SDS) was -0.7, a median decrease of -0.55 since tumor diagnosis. Seven patients were treated with human GH (hGH) at a median of 3.7 years from tumor diagnosis and followed for a median of 2.7 years. Treatment with hGH resulted in a median increase in height SDS of 0.9. Careful surveillance with timely introduction of GH replacement is required for treatment of GHD following treatment of orbital and parameningeal sarcomas.

[Combined chemoradiotherapy of tumors in the child]

The high chemosensitivity of pediatric tumors along with their natural propensity for an early distant dissemination have stimulated the interest for chemo-radiation combinations in children since the mid 50s. Following the early experiments in nephroblastomas on the interaction of Actinomycin-D and radiotherapy, multiple national and international studies have been conducted since the mid 70s with considerable success: nowadays most pediatric tumors enjoy a long term survival in excess of 70%. Like their adult counterparts, these associations aim to induce an early control of the primary tumor and distant spreading (spatial cooperation) but also, more specifically in children, to limit the toxicity on normal tissues when treatment intensity can be further reduced. The association of an initial chemotherapy followed by local radiation at a dose and in a volume adapted to the response to chemotherapy along with associated prognostic factors has become widely tested in national and international studies conducted in Hodgkin's disease, Ewing's sarcoma, medulloblastomas, and brain tumors in the very young. Conversely, concomitant associations have remained limited to high-risk subgroups (parameningeal rhabdomyosarcomas for example) due to their potential hazards.

Excessive spinal cord toxicity from intensive central nervous system-directed therapies

BACKGROUND

Intrathecal chemotherapy, radiation therapy, and systemic chemotherapy are used for both prophylaxis and treatment of central nervous system (CNS) disease in hematologic malignancies. Twenty-three cases of myelopathy that occurred in patients who received intensive CNS-directed therapy were evaluated to identify the determinants of this severe CNS toxicity.

METHODS

Nine cases treated by the authors and 14 collected from the literature are discussed. Twelve had Burkitt's leukemia/lymphoma. Patient ages ranged from 3 to 30 years (median, 15 years). The dose intensity of CNS-directed therapies, including intrathecal cytosine arabinoside (ara-C), intrathecal methotrexate (MTX), systemic high dose (HD) MTX, systemic HD ara-C, systemic thiotepa, and CNS radiation, was evaluated by the determination of single drug doses and cumulative total drug or irradiation doses over elapsed treatment durations.

RESULTS

Central nervous system treatment was prophylactic in 10 cases; active CNS disease was being treated in 13 cases. One patient received only intrathecal ara-C before toxicity occurred; other received intrathecal ara-C and varying combinations of intrathecal MTX, HD ara-C, HD MTX, CNS radiation, and systemic thiotepa. Eight patients died of toxicity, of whom 6 had autopsy-proven cord necrosis; 3 were ventilator-dependent; 10 had persistent paraplegia or paraparesis; and 2 recovered completely.

CONCLUSION

Both highly intensive, short CNS treatment sequences and lower intensity, long term cumulative treatments may result in this rare but severe myelopathy. The cause is multifactorial, with systemic chemotherapy, intrathecal chemotherapy, and radiation therapy contributing to toxicity. Multiple intrathecal ara-C and/or MTX doses given at frequent (daily) intervals should be avoided. Concurrent intrathecal ara-C and systemic HD ara-C also appear to be especially toxic. Intrathecal hydrocortisone given with intrathecal ara-C does not protect against myelopathy. Multiple, frequently spaced courses of CNS-directed therapies must be avoided, especially in patients who have received prior CNS radiation.

Acute ascending myelitis and encephalopathy after intrathecal cytosine arabinoside and methotrexate in an adolescent boy with acute lymphoblastic leukemia

A 14-year-old boy with acute lymphoblastic leukemia developed acute ascending myelitis followed by encephalopathy after intrathecal administration of methotrexate 15 mg and cytosine arabinoside 50 mg. The patient had none of the risk factors noted previously in other patients with intrathecal therapy (IT) induced neurotoxicity. The doses administered were within the standard scales, and toxicity developed in the second boost of IT 20 days after the first one. There may not be any parameters to predict the occurrence of such severe and rare form of CNS neurotoxicity attributed to IT.

Primary intraspinal soft-tissue sarcoma in childhood: report of two cases with a review of the literature

Two young children who presented with lower spinal cord dysfunction manifested by bilateral leg weakness and urinary retention were diagnosed with intraspinal soft-tissue sarcoma. Neither patient had a significant extradural mass. Both tumors had histochemical features of rhabdomyosarcoma. Temporary responses were noted after combination chemotherapy either with vincristine, actinomycin D, and cyclophosphamide or with ifosfamide/mesna and etoposide. However, both patients developed uncontrollable cerebrospinal fluid (CSF) dissemination of tumor and died within 6 months of diagnosis, despite intrathecal chemotherapy and irradiation for one and very high-dose intravenous methotrexate (33 g/m2) for the other. This rare tumor can respond to parenteral antisarcoma chemotherapy, but better strategies are needed to prevent CSF spread and ultimate demise. Early institution of intrathecal cytostatic agents may retard or prevent CSF dissemination and prolong survival.