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Farzin Eftekhari
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ABSTRACT: Osteosarcoma is an aggressive tumor of mesenchymal origin, capable of producing osteoid and immature bone. It is the most frequent primary malignant skeletal neoplasm in children and adolescents. Imaging studies play a major role in initial diagnosis, staging, and assessment of tumor response to chemotherapy. Conventional radiography is the prime imaging modality for diagnosis of bony tumors. Radionuclide bone scan is used in detection of metastatic lesions in the other bones. Computed tomography may be used as an adjunct to conventional radiography, but its main role is detection of pulmonary metastasis. The standard magnetic resonance imaging is the most specific modality for local staging and monitoring response to chemotherapy, and distinguishing postsurgical changes from residual tumor. Dynamic contrast-enhanced magnetic resonance imaging has been introduced to quantify the percentage of tumor necrosis, identify early responders, and thus predict survival. The role of 18F fluorodeoxyglucose positron emission tomography (PET) in the staging and management of osteosarcoma is evolving. It has the advantage of total body imaging and may have an overall role in tumor staging and grading, detection of early response, and therefore, in the prognosis and detection of recurrence.
Cancer treatment and research 01/2010; 152:33-62.
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Pediatric Radiology 11/2008; 39(1):90. · 1.67 Impact Factor
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ABSTRACT: Hematopoietic stem cell transplantation (HSCT) is the only curative therapy for autosomal recessive infantile malignant osteopetrosis, an otherwise fatal disease. HSCT has also been utilized in patients with the less severe autosomal recessive intermediate form in an attempt to correct hematologic abnormalities and halt cranial nerve deficits caused by progressive cranial foraminal stenosis. Successful engraftment is accompanied by rapid normalization of radiographic signs of osteopetrosis.
Skeletal Radiology 07/2007; 36 Suppl 1:S34-7. · 1.54 Impact Factor
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ABSTRACT: Our aim was to formulate appropriate MDCT chest and abdominopelvic CT scan protocols for pediatric patients.
Surface radiation dose measurements from a set of anthropomorphic phantoms (nominal 1 year old, 5 year old, and 10 year old) and an adult phantom were compared with standard CT dose index measurements. Image-noise values on axial 5-mm-thick anthropomorphic phantom images were obtained as a measure of image quality.
Peripheral CT dose index values obtained with the standard 16-cm acrylic phantom were within approximately 10% of the CT surface dose measurements for the pediatric anthropomorphic phantoms for both chest and abdominopelvic scan protocols. The noise value for the adult phantom image acquired using a typical clinical CT technique was identified, and targeting this level of noise for pediatric CT examinations resulted in a decrease in dose of 60-90%. Initially, 80 kVp was selected for use with very small children; however, beam-hardening artifacts were severe enough to cause us to abandon this option. Current pediatric protocols at M. D. Anderson Cancer Center rely on 100- and 120-kVp settings. The display field-of-view parameter can be used as a surrogate for patient size to develop clinical pediatric CT protocol charts.
CT dose index measurements obtained using the 16-cm standard acrylic phantom are sufficiently accurate for estimating chest and abdominopelvic CT entrance exposures for pediatric patients of the same approximate size as the anthropomorphic phantoms used in this study. Image-noise measurements can be used to adjust chest and abdominopelvic CT techniques for pediatric populations, resulting in a decrease in measured entrance dose by 60-90%.
American Journal of Roentgenology 05/2004; 182(4):849-59. · 2.78 Impact Factor
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ABSTRACT: Contemporary therapy for osteosarcoma is comprised of initial treatment with chemotherapy and surgical extirpation of the primary tumor in the affected bone. In view of the major advances forged by chemotherapy in the treatment of the primary tumor, an attempt was made to destroy the tumor exclusively with this therapeutic modality and abrogate surgery.
Thirty-one consecutive patients were treated. All had localized disease (absence of metastases) at the time of diagnosis. Initial treatment with chemotherapy was comprised of high-dose methotrexate and leucovorin rescue (MTX-LF) in 3 patients and intraarterial cisplatin in 28 patients. Clinical, radiologic, angiographic, radionuclide, and histologic investigations were utilized to assess the efficacy of treatment. After a response at 3 months, entry into the study was permitted and treatment was maintained for a total of 18-21 months with a combination of agents comprised of MTX-LF, intraarterial cisplatin, and doxorubicin. Patients were monitored closely for disease recurrence with the investigations outlined earlier. Two informed consents were required: one at the time of diagnosis and another at 3 months after the initial response had been attained.
Only 3 of 31 patients were cured with the administration of chemotherapy alone. Local recurrence and pulmonary metastases were not reported to develop in these 3 patients during a follow-up period of 204+ to 225+ months. Four other patients also possibly were cured with chemotherapy alone. At their request, several months after the cessation of chemotherapy, they underwent surgical extirpation of the tumor. No evidence of viable tumor was found. These patients remained free of disease for 192+ to 216+ months. Thus, only seven patients did not develop local recurrence and/or pulmonary metastases. Among the remaining 24 patients, 9 developed local recurrences without pulmonary metastases 14-74 months (median, 30 months) after the initial response. Eight of the nine patients were rendered tumor free by extirpation of the local recurrence. Two of these eight patients subsequently died, one of the acquired immunodeficiency syndrome (AIDS) and the other of varicella septicemia. The ninth patient refused amputation and died of metabolic complications. Three other patients developed local recurrences 20-69 months and pulmonary metastases 10-98 months after achievement of the initial response. These patients were rendered tumor free by extirpation of the local recurrence and metastasectomy. One of these patients also later died of AIDS. In the remaining 12 patients, local recurrences developed 5-29 months (median, 14 months) after the initial response was achieved. The patients also developed pulmonary metastases 11-60 months after the initial response. In eight patients the local recurrences were extirpated and metastasectomy was performed; however, these patients later died of recurrent pulmonary metastases. The remaining four patients refused to undergo extirpation of the local recurrence. The pulmonary metastases were not resected. They failed to respond to alternate therapy. Thus, the tumor-free survival rate was 23% (7 of 31 patients): 3 patients who were treated with chemotherapy only and 4 patients who were treated with chemotherapy plus surgery. The overall survival rate (patients who remained free of disease and those who underwent resection for local recurrence and metastasectomy) was 48% (15 of 31 patients). Prior to the deaths from AIDS and varicella septicemia, the overall survival was 58% (18 of 31 patients).
Utilizing the regimen employed in the current study, only 3 of 31 patients with osteosarcoma (10%) were cured exclusively with chemotherapy. Four additional patients who underwent extirpation of the primary tumor without disease recurrence and in whom no viable tumor was found in the resected specimens possibly could increase the number of patients who potentially were cured with chemotherapy to 7 (23%). With an overall expected cure rate of 50-65% with "conventional" sin whom no viable tumor was found in the resected specimens possibly could increase the number of patients who potentially were cured with chemotherapy to 7 (23%). With an overall expected cure rate of 50-65% with "conventional" strategies, the results of the current study do not justify the adoption of current forms of chemotherapy as exclusive treatments for osteosarcoma.
Cancer 12/2002; 95(10):2202-10. · 4.77 Impact Factor
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ABSTRACT: BACKGROUND
Contemporary therapy for osteosarcoma is comprised of initial treatment with chemotherapy and surgical extirpation of the primary tumor in the affected bone. In view of the major advances forged by chemotherapy in the treatment of the primary tumor, an attempt was made to destroy the tumor exclusively with this therapeutic modality and abrogate surgery.METHODS
Thirty-one consecutive patients were treated. All had localized disease (absence of metastases) at the time of diagnosis. Initial treatment with chemotherapy was comprised of high-dose methotrexate and leucovorin rescue (MTX-LF) in 3 patients and intraarterial cisplatin in 28 patients. Clinical, radiologic, angiographic, radionuclide, and histologic investigations were utilized to assess the efficacy of treatment. After a response at 3 months, entry into the study was permitted and treatment was maintained for a total of 18–21 months with a combination of agents comprised of MTX-LF, intraarterial cisplatin, and doxorubicin. Patients were monitored closely for disease recurrence with the investigations outlined earlier. Two informed consents were required: one at the time of diagnosis and another at 3 months after the initial response had been attained.RESULTSOnly 3 of 31 patients were cured with the administration of chemotherapy alone. Local recurrence and pulmonary metastases were not reported to develop in these 3 patients during a follow-up period of 204+ to 225+ months. Four other patients also possibly were cured with chemotherapy alone. At their request, several months after the cessation of chemotherapy, they underwent surgical extirpation of the tumor. No evidence of viable tumor was found. These patients remained free of disease for 192+ to 216+ months. Thus, only seven patients did not develop local recurrence and/or pulmonary metastases. Among the remaining 24 patients, 9 developed local recurrences without pulmonary metastases 14–74 months (median, 30 months) after the initial response. Eight of the nine patients were rendered tumor free by extirpation of the local recurrence. Two of these eight patients subsequently died, one of the acquired immunodeficiency syndrome (AIDS) and the other of varicella septicemia. The ninth patient refused amputation and died of metabolic complications. Three other patients developed local recurrences 20–69 months and pulmonary metastases 10–98 months after achievement of the initial response. These patients were rendered tumor free by extirpation of the local recurrence and metastasectomy. One of these patients also later died of AIDS. In the remaining 12 patients, local recurrences developed 5–29 months (median, 14 months) after the initial response was achieved. The patients also developed pulmonary metastases 11–60 months after the initial response. In eight patients the local recurrences were extirpated and metastasectomy was performed; however, these patients later died of recurrent pulmonary metastases. The remaining four patients refused to undergo extirpation of the local recurrence. The pulmonary metastases were not resected. They failed to respond to alternate therapy. Thus, the tumor-free survival rate was 23% (7 of 31 patients): 3 patients who were treated with chemotherapy only and 4 patients who were treated with chemotherapy plus surgery. The overall survival rate (patients who remained free of disease and those who underwent resection for local recurrence and metastasectomy) was 48% (15 of 31 patients). Prior to the deaths from AIDS and varicella septicemia, the overall survival was 58% (18 of 31 patients).CONCLUSIONS
Utilizing the regimen employed in the current study, only 3 of 31 patients with osteosarcoma (10%) were cured exclusively with chemotherapy. Four additional patients who underwent extirpation of the primary tumor without disease recurrence and in whom no viable tumor was found in the resected specimens possibly could increase the number of patients who potentially were cured with chemotherapy to 7 (23%). With an overall expected cure rate of 50–65% with “conventional” strategies, the results of the current study do not justify the adoption of current forms of chemotherapy as exclusive treatments for osteosarcoma. Cancer 2002;95:2202–10. © 2002 American Cancer Society.DOI 10.1002/cncr.10944
Cancer 11/2002; 95(10):2202 - 2210. · 4.77 Impact Factor
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ABSTRACT: Two preteenage girls developed painful swelling of the left clavicle. This was followed by painful swelling of the femur, 7 months later in one girl and 8 years later in the other. Radiographic studies showed a predominantly sclerotic process in one patient and destruction associated with cortical thickening in the other. The patients received analgesic medications only, followed by gradual healing with cortical and medullary sclerosis. Long-term follow-up suggests that the condition is self-limited and that, with or without treatment, the bones eventually return to normal. Although the etiology of the lesions remains unknown, the radiographic features suggest an inflammatory reaction.
Skeletal Radiology 02/1989; 18(1):9-14. · 1.54 Impact Factor
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ABSTRACT: At imaging, the thymus appears in a variety of shapes and sizes, even in the same individual. It gradually involutes with age and may acutely shrink during periods of bodily stress. During the recovery period, it grows back to its original size or even larger, a phenomenon known as thymic rebound hyperplasia. These anatomic variations and dynamic changes appear to be the main source of confusion with pathologic conditions. In turn, these misinterpretations may lead to prolongation or alteration of the chemotherapy regimen or to unnecessary radiation therapy, biopsy, or thymectomy. Familiarity with the embryology, anatomy, and dynamic physiology of the thymus is essential to avoid unnecessary imaging or invasive procedures. Radiologists play a major role in differentiating normal thymic variants, ectopic thymic tissue, and nonneoplastic thymic conditions such as rebound hyperplasia from neoplastic conditions. Knowledge of the imaging findings of thymic tumors and their mimics may help radiologists arrive at the correct diagnosis.
Radiographics 30(2):413-28. · 2.85 Impact Factor
