Biomedical subjects

S Pohar

Publications and source records attributed to S Pohar.

6 recordsLinked to original sources

PubMed2006

Febuxostat for prevention of gout attacks.

(1) Febuxostat is a selective inhibitor of xanthine oxidase. Its use in the management of hyperuricemia and gout is being studied. (2) In a 52-week, phase III randomized clinical trial, febuxostat was superior to allopurinol for lowering uric acid levels. Its efficacy in preventing gout attacks was similar to that of allopurinol. Despite a similar rate of adverse effects, individuals on febuxostat were more likely to stop treatment than those on allopurinol. (3) The most commonly observed adverse effects with febuxostat include liver function test abnormalities, diarrhea, headache, nausea, vomiting, abdominal pain, and dizziness. (4) Given that renal dysfunction is a risk factor for hyperuricemia and gout, the safety and efficacy of febuxostat in this population should be considered, but only limited data are available. (5) The diffusion of febuxostat may be limited by its price relative to that of allopurinol, regardless of whether febuxostat proves to have advantages in specific populations.

Allopurinol↗

PubMed1995

Effectiveness of brachytherapy in treating carcinoma of the vulva.

PURPOSE: Radical radiotherapeutic management of vulvar cancer often incorporates brachytherapy as a portion of the treatment regimen. However, few studies using this modality alone to manage vulvar cancer have been published. METHODS AND MATERIALS: Thirty four patients were treated with iridium-192 (192Ir) brachytherapy for vulvar cancer between 1975 and 1993 at Centre Alexis Vautrin. Twenty-one patients were treated at first presentation when surgery was contraindicated or declined. Of these patients, 12 had International Federation of Gynecology and Obstetrics Classification Stage III or IV disease, 8 were Stage II, 1 was Stage I, and 1 was Stage 0. Thirteen patients were treated for recurrent disease. Paris system rules for implantation and dose prescription were followed. The median reference dose was 60 Gy (range 53 to 88 Gy). At the time of analysis, 10 of 34 patients were alive. Median follow-up in these 10 patients was 31 months (range: 21 months to 107 months). Fourteen of the 24 deaths were from causes other than vulvar cancer. RESULTS: Kaplan-Meier actuarial 5-year local control was 47% (95% confidence interval (CI) = 23 to 73%) and 5-year actuarial loco-regional control was 45% (95% CI = 21 to 70%). Kaplan-Meier actuarial 5-year disease-specific survival was 56% (95% CI = 33 to 76%) and actuarial 5-year survival was 29% (95% CI = 15 to 49%). Median time to death was 14 months. Subset analysis revealed a higher actuarial 5-year local control in patients treated at first presentation than those treated for recurrence (80 vs. 19%, log rank, p = 0.04). Similarly, actuarial 5-year loco-regional control was higher in patients treated at first presentation (80 vs. 16%, log rank, p = 0.01). The two groups did not differ significantly in disease-specific or overall survival. The actuarial 5-year disease specific survival of 56% is somewhat less than the expected 5-year disease-specific survival after surgery in a group having a similar proportion of early stage, advanced stage, and recurrent vulvar cancer. CONCLUSIONS: Brachytherapy is an effective treatment for patients with carcinoma of the vulva who decline surgery or in whom surgery is contraindicated.

Actuarial Analysis↗

PubMed1995

A method for delivering accurate and uniform radiation dosages to the head and neck with asymmetric collimators and a single isocenter.

PURPOSE: To investigate the use of asymmetric collimators and a single isocenter for delivering a uniform, accurate dose of radiation to the head, neck, and supraclavicular lymph nodes. METHODS AND MATERIALS: A linear accelerator with a pair of asymmetric collimators is required for this technique. An isocenter was placed at the junction of the lateral head and neck fields and the anterior supraclavicular field. The asymmetric collimators were set longitudinally, by collimator rotation if necessary. The collimators split the radiation beam to all portals. Dose uniformity was measured at the junction with films in solid-water phantoms. RESULTS: Film dosimetry showed a uniform dose at the junction without hot or cold regions. A digital display tolerance of +/- 1.0 mm for a field size maintained an acceptable uniform dose (+/- 5% dose variation) at the junction. The single isocenter and asymmetric collimators reduced field setup time by half. No table rotation was required to match fields. CONCLUSION: The asymmetric collimators lead to easy and accurate patient setup. The absence of the trapezoid effect resulted in the complete coverage of the submandibular and cervical nodes without any hot spots.

Head and Neck Neoplasms↗

PubMed1993

Management of epistaxis in Rendu-Osler disease: is brachytherapy effective?

PURPOSE: This paper reviews the results of intranasal brachytherapy for epistaxis in 43 patients with Rendu-Osler disease treated between 1971-1991 at Henri Mondor Hospital. METHODS AND MATERIALS: 2-3 intranasal catheters were afterloaded with 192Ir sources. Computer dosimetry was performed and then the dose was prescribed to an isodose thought to cover the nasal mucosa. The dose rate ranged from 0.16 Gy/h-0.63 Gy/h with a median of 0.34 Gy/h. Dose at one application ranged from 15-35 Gy with a median of 30 Gy. The severity of epistaxis was graded 1 to 5. RESULTS: The time to recurrence of significant epistaxis ranged from 6-178 months with a median of 24 months. The dose prescribed did not correlate with control rate. The only brachytherapy complication was septal perforation in 4 patients; in one this was a result of repeated nasal coagulation. CONCLUSION: We suggest that intranasal brachytherapy is a useful modality in the management of epistaxis in Rendu-Osler disease.

Adult↗

PubMed1993

Chronic lymphocytic leukemia with CNS involvement.

Direct involvement of the brain by chronic lymphocytic leukemia (CLL) is extremely rare. This is the second documented case. A 63 year-old-man presented with motor deficits. Conventional radiographic imaging showed no abnormalities but an MRI scan of the head showed a high signal intensity lesion in the left cerebellum. Biopsy of this area showed a perivascular infiltrate of small B lymphocytes consistent with CLL involvement. The patient was treated with radiotherapy and had some improvement in symptoms. Three years later he remains alive with some neurologic deficit. This case confirms that CLL can be complicated by direct brain involvement.

Brain↗

PubMed1993

Effect of intersource spacing on local control and complications in brachytherapy of mobile tongue and floor of mouth.

From 1971 to 1988, 133 T1 and 141 T2 biopsy-proven squamous cell carcinomas of mobile tongue and floor of mouth were definitively managed by Iridium-192. Implantations were performed using either guide gutters or afterloading plastic catheters. The prescribed dose at the reference isodose (85% of the basal dose rate, Paris system) was 60-70 Gy. Total dose was not adjusted to dose rate or tumor volume. Results of the 274 implants have been analysed to look for a possible influence of intersource spacing on local control and necrosis. Follow up for patients free of local recurrence is 1-180 months with median of 35 months. The 274 tumors were divided into two groups according to intersource spacing: 9-14 mm (n = 204), and 15-20 mm (n = 70). At 5 years, the estimated local control (Kaplan Meier) was 86% and 76%; respectively (p = 0.13); the necrosis rate was 33% and 46%, respectively (p = 0.04). Multivariate analysis shows that dose and activity of wires were significantly related to local control, while only tumor site was predictive of necrosis; there was a non-statistically significant relationship between intersource spacing of wires and local control (p = 0.055). When considering only patients with oral tongue cancers, necrosis was significantly related to activity of wires (p = 0.013), and there was a non-significant trend to a relationship between necrosis and intersource spacing (p = 0.066) and tumor diameter (p = 0.065). For patients with floor of mouth cancer, none of these factors was significantly related to necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗