Phase I study of tandem high-dose chemotherapy with autologous peripheral blood stem cell rescue for children with recurrent brain tumors: a Pediatric Blood and MarrowTransplant Consortium study.

BACKGROUND: High-dose chemotherapy with autologous stem cell rescue (HDC/SCR) has produced responses and prolonged survival for some children with recurrent brain tumors, but is associated with considerable morbidity and mortality. A Phase I trial of two cycles of HDC/SCR for recurrent brain tumors in children was performed to determine the maximum tolerated doses for a novel regimen. PROCEDURES: Two cycles of HDC/SCR were given. Cycle 1 included thiotepa and carmustine given on days -5, -4, and -3. Four to six weeks later, patients received cycle 2 which included thiotepa and carboplatin given on days -5, -4, and -3. Autologous peripheral blood stem cells (PBSC) were infused on day 0 of each cycle. RESULTS: Thirty-two patients were treated and 25 patients received both cycles of HDC/SCR. Common toxicities included mucositis, emesis, diarrhea, anorexia, and pancytopenia. Eight of 32 (25%) assessable children died from regimen-related toxicity. Pulmonary failure occurred in seven patients. Seven patients had grade 3-4 neurotoxicity. The 3-year event-free survival (EFS) was 25%. CONCLUSIONS: We determined the maximum tolerated regimen to be thiotepa 600 mg/m(2) and carmustine 300 mg/m(2) followed by thiotepa 600 mg/m(2) and carboplatin 1,200 mg/m(2) . Pulmonary toxicity was considerable. The toxic death rate was similar to other trials of HDC/SCR for children with recurrent brain tumors performed during the same time period. The regimen resulted in prolonged time to progression for a significant number of patients and long-term survival for some patients with recurrent medulloblastoma and rhabdoid tumor.

A pilot study of addition of amifostine to melphalan, carboplatin, etoposide, and cyclophosphamide with autologous hematopoietic stem cell transplantation in pediatric solid tumors-A pediatric blood and marrow transplant consortium study.

Limited information is available regarding the use of amifostine in pediatric hematopoietic stem cell transplant (HSCT) patients. Melphalan, carboplatin, etoposide +/- cyclophosphamide is a commonly used preparatory regimen in pediatric solid tumor HSCT. Therefore, we decided to determine the feasibility of the addition of amifostine (750 mg/m b.i.d. x 4 d) to melphalan (200 mg/m), carboplatin (1200 mg/m), and etoposide (800 mg/m) (level 1) and escalating doses of cyclophosphamide (3000 mg/m and 3800 mg/m, levels 2 and 3, respectively) followed by autologous HSCT. Thirty-two patients with a variety of pediatric solid tumors were studied. Seventeen patients were accrued at level 1, 9 at level 2, and 6 at level 3. Major toxicities during the administration of the preparatory regimen were hypocalcemia, emesis, and hypotension. Hypocalcemia required aggressive calcium supplementation during the conditioning phase. No dose limiting toxicities were encountered at level 3. Amifostine at 750 mg/m b.i.d. for 4 days can be administered with a double alkylator regimen consisting of melphalan (200 mg/m), cyclophosphamide (up to 3800 mg/m), carboplatin (1200 mg/m), and etoposide (800 mg/m) with manageable toxicities.

Orbital rhabdomyosarcoma.

BACKGROUND: Although rhabdomyosarcoma (RMS) is a rare tumor among the entire group of mesenchymal malignancies, it is a relatively common lesion and significant challenge for the ocular oncologist in terms of its diagnosis and management. METHODS: A comprehensive literature search of articles published over the past 30 years in PubMed was conducted. RESULTS: Orbital RMS usually presents as a space-occupying lesion in the orbit during the first decade and may mimic other neoplastic or inflammatory masses. The tumor has predilection for the superior nasal quadrant of the orbit. The clinical manifestations depend on the location of the tumor within the orbit and its rate of growth. The common histopathologic types are embryonal and alveolar varieties. CT and MR imaging are important in the evaluation of this tumor. Particular attention should be placed on the bone invasion and extension of the tumor into the intracranial cavity and paranasal sinuses. Treatment usually consists of a combination of chemotherapy and radiation therapy following excisional biopsy. CONCLUSIONS: Survival of orbital RMS has improved due to advances in chemotherapy and radiotherapy. Posttreatment complications, including side effects of radiotherapy and secondary orbital malignancies, as well as visual dysfunction, occur more often and present new challenges due to improved long-term survival.

Bacillus cereus central line infection in an immunocompetent child with hemophilia.

Bacillus species are increasingly recognized as pathogens in immunocompromised patients. The authors report a case of Bacillus cereus infection of a central line in an immunocompetent patient with hemophilia, which required line removal for complete cure.

Neuronal stem cells biology and plasticity.

Recent studies have suggested that stem cells are able to cross primordial tissue barriers. Their ability to respond to unrelated microenvironmental signals strongly suggest that they have greater potential than previously imagined especially for their future clinical use for the regeneration of tissues or even perhaps organ systems. In particular there is an intriguing reciprocal relationship between the hematopoietic and neuronal stem cell systems. Both stem cell pools appear to respond to microenvironmental signals that are not developmental related. These intriguing observations have led to a number of studies that have attempted to explore this apparent phenomenon of plasticity associated with both hematopoietic and neuronal stem cell populations.