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Biomedical subjects

A W Yasko

Publications and source records attributed to A W Yasko.

32 records · Page 2Linked to original sources
PubMed1997

Anterior approaches to the thoracic spine in patients with cancer: indications and results.

BACKGROUND: Multidisciplinary surgical teams enable an aggressive approach to tumors involving the thoracic spine. METHODS: From February 1994 to July 1996, 61 patients underwent anterior resections of thoracic spine tumors. Their median age was 56 years. The indications for operation were curative in intent in 7 of 61 and palliative in 54 of 61 (to relieve intractable metastatic bone pain with neurologic compromise [n = 38] and pain alone [n = 16]). Sixteen patients came to our institution unable to ambulate with impending paraplegia. RESULTS: Anterior approaches included combined left side of the neck and median sternotomy for lesions involving vertebrae T-1 through T-3 (n = 9), posterolateral thoracotomy for T-3 through T-10 (n = 39), and thoracoabdominal approach at T-11 and T-12 (n = 13). Median hospital stay was 9.0 days (range, 4 to 57 days). Complications occurred in 18 of 61 (29.5%). In 55 of 61 (90%), pain was significantly improved after the operation. Twelve of the 16 patients who initially presented in wheelchairs regained ambulatory function. There were five perioperative deaths (8.2%). The 1-year cumulative survival for the entire group was 60%. CONCLUSIONS: An aggressive surgical approach in cancer patients with locally advanced or metastatic disease in the thoracic spine was associated with acceptable morbidity and mortality. There was significant improvement in their quality of life by control of intractable pain in 90% and recovery of ambulatory function in 75% of patients who presented with critical spinal cord compromise.

Humans↗
PubMed1996

Conventional and dedifferentiated parosteal osteosarcoma. Diagnosis, treatment, and outcome.

BACKGROUND: Dedifferentiated parosteal osteosarcoma (dd-POS) designates high grade transformation, of conventional low grade parosteal osteosarcoma (c-POS). The paradigm of preoperative diagnosis, neoadjuvant chemotherapy, and wide local excision has not been adequately evaluated for dd-POS, as it has been for conventional high grade intramedullary osteosarcoma. METHODS: A retrospective review was conducted of 28 patients treated at the authors' institution between January 1980 and December 1992 for an osteosarcoma arising on the surface of the bone diagnosed as either c-POS or dd-POS. The clinicopathologic features, diagnosis, treatment, and patient outcome were analyzed. RESULTS: A dedifferentiated component was identified in 12 of 28 tumors (43%). Neither the presence of radiolucencies (77% in c-POS and 100% in dd-POS, P = 0.06) nor medullary invasion (42% in c-POS and 50% in dd-POS, P = 0.28) distinguished dd-POS from c-POS. However, all patients who presented with focal hypervascularity on an arteriogram defined the high grade component of dd-POS that was confirmed by selective needle biopsy. This differed significantly (P = 0.00003) from c-POS. None of the patients with c-POS died of the disease (median survival duration, 77 months; range, 16-152 months). Six patients (35%) developed a local recurrence, but five were treated successfully with further surgery. In the dd-POS group, 7 of the 12 patients died of the disease. Ten patients with dd-POS received preoperative chemotherapy (IA cis-diamminedichloroplatinum, IV doxorubicin), and a good response (> 90% necrosis of high grade component) was observed in four. Among patients whose disease was localized, continuous disease free survival was prolonged significantly (P = 0.03) in patients with a good response (median, 75 months) compared with those who responded poorly (median, 13 months). Five patients remained continuously disease free (median, 66 months, range, 29-95 months). CONCLUSIONS: Wide surgical excision alone is adequate treatment for patients with c-POS. Recognition of dedifferentiated areas with angiography and percutaneous biopsy of hypervascular areas should prompt the administration of chemotherapy and wide local excision to optimize patient outcome.

Adolescent↗
PubMed1996

Chondrosarcoma of the pelvis. Prognostic factors for 67 patients treated with definitive surgery.

BACKGROUND: Chondrosarcoma (CS) most commonly involves the pelvis. Local and systemic failures often result in poor outcome. Prognostic factors that determine patient outcome remain ill-defined. METHODS: We retrospectively analyzed 67 patients with CS of the pelvis treated by definitive surgery from January 1970 to December 1992. All patients had localized disease including Grade 1 (19 patients), Grade 2 (18 patients), Grade 3 (17 patients), and dedifferentiated (13 patients) tumors. Thirty-two patients underwent a limb-sparing surgical resection and 35 patients underwent hemipelvectomy. Follow-up was available for all patients. The median duration of follow-up for the survivors was 115 months (range, 24-288 months). RESULTS: At last follow-up, 52% of the patients were disease free, 8% were alive with disease, 36% died of disease, and 4% died of other causes. Nineteen patients (28%) had developed a local recurrence (LR). The median time to LR was 23 months (range, 1-111 months). Independent variables in a multivariate analysis associated with increased risk of LR included inadequate surgical margin, tumor epicenter in the pubis, and high grade histology. LR did not influence overall patient survival. Twenty-three patients (36%) developed distant metastases at a median time of 9 months (range, 1-111 months) postoperatively. Metastases developed in 0% of the patients with Grade 1, 20% of the patients with Grade 2 60% of the patients with Grade 3 and 75% of patients with dedifferentiated CS. On multivariate analysis, histologic high grade was the only significant predictive variable for distant relapse (P = 0.005). CONCLUSIONS: The critical issue for a favorable outcome in low grade CS of the pelvis is adequate surgical excision (i.e., negative surgical margin). The high rate of systemic failure in high grade and dedifferentiated CS, despite adequate surgery, emphasizes the need for more effective systemic therapy.

Adult↗
PubMed1996

Avulsion fracture of the anterior inferior iliac spine with abundant reactive ossification in the soft tissue.

Patients who have sustained an avulsion fracture and present clinically during the healing phase of the injury may manifest a mass that clinically and radiographically mimics a malignant neoplasm. A 15-year-old male soccer goalkeeper presented with a large ossified mass in the soft tissues overlying the right hip 6 months after experiencing a popping sensation in his hip joint during a game. Although an osteosarcoma was suspected clinically and radiographically, a Tru-Cut needle biopsy of the lesion revealed reactive bone formation. Correlation of the clinical, radiographic, and pathologic findings indicated an avulsion fracture of the anterior inferior iliac spine with abundant reactive ossification in the soft tissues. The healing phase of an avulsion fracture may clinically and radiographically be mistaken for neoplasia. In such cases, a Tru-Cut needle biopsy may reveal the reactive nature of the process.

Adolescent↗
PubMed1995

Surgical management of primary bone sarcomas.

Effective chemotherapy regimens have changed the nature and scope of surgical management of primary sarcomas of bone. Limb-salvage surgical procedures are performed in the majority of patients without a significantly increased risk of local tumor relapse. Advances in technology have expanded the options available for skeletal reconstruction. End-result analyses have helped refine the application of this technology to maximize function. Further advances are necessary to maintain function in the long term.

Adolescent↗
PubMed1995

Core needle biopsy and fine-needle aspiration in the diagnosis of bone and soft-tissue lesions.

Although core needle biopsy (CNB) and fine needle aspiration (FNA) procedures are widely used for the diagnosis of epithelial neoplasms, these procedures have not gained popularity on patients suspected of having bone or soft-tissue neoplasms. This article describes the University of Texas, M.D. Anderson Cancer Center experience with CNB and FNA procedures in bone and soft tissue performed in over 800 patients.

Biopsy, Needle↗
PubMed1994

Comparison of charges related to radiotherapy for soft-tissue sarcomas treated by preoperative external-beam irradiation versus interstitial implantation.

BACKGROUND: We compared treatment-related charges associated with external beam irradiation and interstitial implantation for soft-tissue sarcoma of the extremity. METHODS: Charges related to radiotherapy in 35 patients with soft-tissue sarcoma of the extremity were reviewed. Preoperative external beam irradiation (EB) delivering 50 Gy in 25 fractions with 6 MV photons was administered to 12 of the patients evaluated. The remaining 23 patients were treated with interstitial implantation (IR) as the only radiotherapeutic intervention. The anatomic distribution of the sarcomas treated by IR included 14 lower-extremity (LE) and nine upper-extremity (UE) lesions. The average length of iridium wire used for IR was 78 cm. Because LE lesions tend to be larger, the average length equaled 109.5 cm as compared with the 47 cm for UE implants. RESULTS: The radiotherapeutic approach represented the only difference in treatment-related charges because the operative procedure of wide local excision was performed in each group. No difference in perioperative complications was observed between the two treatment approaches. Charges were stratified according to hospital-based and professional services. Radiotherapy-based hospital charges for the administration of EB averaged $6,515 compared with $4,050 for IR (p < 0.0001). Professional services also were significantly different, totaling $4,390 for EB and $3,240 for IR (p < 0.0001). The total of these charges for radiotherapy procedures and professional fees equaled $10,905 for EB compared with $7,290 for IR (p < 0.0001). Incorporating the necessary operating-room time for implant placement ($750) and five additional hospital days ($1,800), the costs associated with IR totaled $9,840; using chi-square analysis, the cost for IR remained significantly (p < 0.0001) less expensive than the $10,905 associated with EB. Because a large component of the radiotherapy cost for IR is related to the length of iridium 192 wire required, charges were stratified according to the location of the tumor. The total charge for IR of the UE equaled $9,345 compared with $10,335 for LE implants. Chi-square comparison for both UE and LE implants continued to show significant differences (p < 0.0001) when related to EB therapy. CONCLUSION: Cost-analysis comparison of brachytherapy versus external beam irradiation found lower charges for patients undergoing adjuvant irradiation with brachytherapy for soft-tissue sarcoma. To optimize the cost-benefit ratio, prospective studies are necessary to define the application of these radiotherapeutic approaches based on clinical criteria.

Arm↗
PubMed1992

The healing of segmental bone defects, induced by recombinant human bone morphogenetic protein (rhBMP-2). A radiographic, histological, and biomechanical study in rats.

Subcutaneous implants of a recombinant human form of the bone-inducing protein rhBMP-2 (recombinant human bone morphogenetic protein-2) in rats have resulted in the local induction of endochondral bone formation. To test the osteoinductive activity of rhBMP-2 in an osseous location, we created five-millimeter segmental defects in the femora of forty-five adult male Sprague-Dawley rats. Two doses of lyophilized rhBMP-2 (1.4 or 11.0 micrograms) were implanted in each defect, together with guanidine-hydrochloride extracted demineralized rat-bone matrix as a carrier, and the results were compared with those in rats that had implantation of guanidine-hydrochloride extracted demineralized rat-bone matrix only. The formation and healing of bone were determined by radiographic, histological, and mechanical analysis. Both doses of rhBMP-2 induced formation of endochondral bone in the osseous defects in a dose-related manner. Implantation of 11.0 micrograms of rhBMP-2 yielded significant (p less than 0.05) bone formation, resulting in radiographic, histological, and mechanical evidence of union. Despite new-bone formation in the defects that had received 1.4 micrograms of rhBMP-2, no instances of union were observed.

Animals↗
PubMedDate not supplied

A revisit of MRI analysis for synovial sarcoma.

We evaluated magnetic resonance imaging (MRI) findings of synovial sarcomas in 22 patients, and the most common MRI findings were oval and well-defined nodular masses with heterogeneous intermediate signal intensity (SI) on T1 weighted images (WI), high SI on T2-WI and heterogeneous contrast enhancement. A cystic component was seen in 77%, intratumoral hemorrhage in 73%, and calcification in three monophasic sarcomas. Metastases were noted in lung (mostly biphasic type), lymph node, and bone. Posttreatment changes revealed diffusely increased S1 on T2-W1 and slightly diffuse contrast enhancement with feathery appearance. Morphology and MR signal characteristics assist in synovial sarcoma management.

Adolescent↗
PubMedDate not supplied

Giant-cell tumor of the tendon sheath arising from the posterior cruciate ligament of the knee: a case report and review of the literature.

The localized form of a giant-cell tumor of the tendon sheath is uncommon and rarely intraarticular. While the sonographic findings are nonspecific, the magnetic resonance (MR) findings can be diagnostic. Relatively homogeneous iso- or marginal hyperintensity on T2-weighted sequences, lack of susceptibility effects due to hemosiderin, the demonstration of a fibrous capsule and the absence of adjacent joint involvement may help to differentiate localized and diffuse forms of giant-cell tumors of tendon sheaths and pigmented villonodular synovitis.

Female↗
PubMedDate not supplied

Re-resection with brachytherapy for locally recurrent soft tissue sarcoma arising in a previously radiated field.

PURPOSE: The use of further radiotherapy among patients with soft tissue sarcoma that recurs in a previously irradiated area is controversial. Presented is a review of our 7-year experience with brachytherapy for recurrent soft tissue sarcoma. METHODS: A retrospective review was performed of 26 patients who underwent perioperative brachytherapy between 1990 and 1997 for recurrent soft tissue sarcoma. In all cases, the sarcoma recurred within a previously irradiated field. After-loading brachytherapy catheters were placed at the time of surgical extirpation of the sarcoma within a single-plane implant by use of 1-cm intercatheter spacing. Insertion of the radioactive 192Ir wire was delayed until the fifth to seventh postoperative day to allow initial wound healing. The prescribed dose rate for the 192Ir wire ranged between 50 and 80 cGy an hour, and the dose was specified at 0.5 cm from the plane of the implant. The anatomic locations treated included lower extremity (N = 10), upper extremity (N = 7), trunk (N = 7), and head and neck (N = 2). RESULTS: Total tumor extirpation, confirmed by negative frozen section margins, was accomplished in all cases. The mean dose of external-beam irradiation received before brachytherapy was 55.6 Gy +/- 1.8 Gy (range, 30.0 to 70.3 Gy). The mean dose of radiation prescribed at the implant procedure was 47.2 Gy +/- 1.6 Gy (range, 11.0 to 50.0 Gy). A tissue transfer flap was placed over the bed of resection in 13 cases. Complications occurred in five patients including, three with wound breakdown, one with osteonecrosis, and with neuralgia. Operative intervention was required in four of the five patients with complications; each of the patients requiring operative intervention for wound-related complications had undergone primary wound closure without tissue transfer. Recurrence of disease occurred in 13 patients: nine local and four distant metastases. The median follow-up was 16 months (range, 2 to 73 months). The 5-year local recurrence-free, distant recurrence-free, disease-free, and overall survival rates after brachytherapy were 52%, 75%, 33%, and 52%, respectively. CONCLUSION: Re-irradiation of recurrent soft tissue sarcoma by brachytherapy in conjunction with resection can be performed with acceptable complication rates. Local control can be achieved for the majority of patients who would otherwise require more radical surgical procedures.

Adult↗