Valerie J Poirier

University of Zurich, Zürich, Zurich, Switzerland

Are you Valerie J Poirier?

Claim your profile

Publications (11)16.95 Total impact

  • Valérie J Poirier · Barbara Kaser-Hotz · David M Vail · Rodney C Straw
    [Show abstract] [Hide abstract]
    ABSTRACT: Squamous cell carcinoma (SCC) is the most common feline oral tumor. Standard radiation protocols have been reported to achieve tumor control durations of 1.5-5.5 months (45-165 days). The purpose of this study was to describe the efficacy and toxicity of an accelerated hypofractionated radiation therapy protocol in cats with oral SCC. Twenty-one cats with histologically confirmed oral SCC and T1-3N0M0 were treated with 10 once-daily fractions (Monday-Friday) of 4.8 Gy. Seventeen cats had macroscopic disease and four were microscopic after incomplete excision. Acute toxicity consisted of grade 2 mucositis in all cats and this was effectively managed using esophageal or gastric tube feeding, pain medication, and antibiotics. Late toxicity effects for cats with available follow-up data included alopecia (4 cats), leukotricia (6), tongue ulceration (1), and oronasal fistula (1). Response could be assessed in 17 cats (seven complete response and five partial response). Four cats (19%) developed metastatic disease without evidence of local progression. The median progression-free survival (PFS) was 105 days (1 year PFS of 23%), median local progression-free survival (LPFS) was 219 days (1 year LPFS of 41%), and median overall survival (OS) was 174 days (1 year OS of 29%). Only tumor stage was prognostic, with T1 having a median PFS of 590 days. Findings indicated that this accelerated hypofractionated radiation therapy protocol was well tolerated in cats with oral SCC, with manageable adverse events. Tumor response was observed in most cats and long tumor control durations were achieved in some cats.
    Veterinary Radiology &amp Ultrasound 10/2012; 54(1). DOI:10.1111/j.1740-8261.2012.01970.x · 1.26 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although B-mode ultrasound is very sensitive for the detection of splenic lesions, its specificity is low. Contrast harmonic imaging is used successfully to differentiate benign from malignant liver lesions in humans and dogs. Contrast harmonic imaging could be useful to differentiate benign and malignant splenic lesions in dogs. Sixty dogs (clinical patients) with splenic abnormalities detected during abdominal ultrasonography. A prospective study was performed with a Philips ATL 5000 unit for contrast pulse inversion harmonic imaging (mechanical index: 0.08, contrast medium: SonoVue). Perfusion was assessed subjectively and quantitatively. Cytology or histology identified 27 benign (hyperplasia, extramedullary hematopoiesis, hematoma) and 29 malignant (hemangiosarcoma, malignant lymphoma, malignant histiocytosis, mesenchymal tumors without classification, mast cell tumors, and others) lesions and 4 normal spleens. Except for 1 benign nodule, extensive to moderate hypoechogenicity was only seen in malignant lesions during wash-in, at peak enhancement, and during wash-out (P= .0001, odds ratios: 37.9 [95% CI 4.5-316.5], 66.4 [95% CI 8.0-551.1], and 36.9 [95% CI 4.4-308.4]). Although all but 1 benign lesion enhanced well and were mildly hypo-, iso-, or hyperechoic in comparison with the normal spleen during all blood pool phases, marked enhancement occurred both in benign as well as in malignant splenic lesions. Quantitative perfusion values did not differ significantly between benign and malignant lesions. Moderate to extensive hypoechogenicity clearly identifies canine splenic malignant lesions. In nodules with marked enhancement, contrast harmonic ultrasound is of limited value and histology is needed.
    Journal of Veterinary Internal Medicine 09/2008; 22(5):1095-102. DOI:10.1111/j.1939-1676.2008.0154.x · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this randomized, multicenter study was to evaluate the toxicity and efficacy of liposome-encapsulated doxorubicin (LED) and doxorubicin (DOX) in the treatment of feline vaccine-associated sarcoma (VAS). Cats were divided according to their disease status into a microscopic arm (no evidence of gross disease) and a macroscopic arm (evidence of gross disease). Each arm was randomized to receive either LED (1–1.5 mg/kg IV q3 weeks) or DOX (1 mg/kg IV q3 weeks). Thirty-three cats were entered in the macroscopic arm of the study with an overall response rate of 39% (5 complete response and 8 partial response) and a median time to progression of 84 days. Response rates were not different between LED and DOX. Seventy-five cats were entered into the microscopic arm. When compared to a similar historical control population treated with surgery alone, the cats receiving chemotherapy had a prolonged median disease-free interval (388 days versus 93 days). No difference in efficacy was detected between LED and DOX. LED at 1.5 mg/kg induced delayed nephrotoxicosis in 23%, necessitating a decrease in the recommended dosage to 1 mg/kg, and cutaneous toxicosis in 21.7% of treated cats. This study showed that both DOX and LED are efficacious in the treatment of VAS and should be considered in the treatment of this tumor.
    Journal of Veterinary Internal Medicine 06/2008; 16(6):726 - 731. DOI:10.1111/j.1939-1676.2002.tb02415.x · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To assess the effects of repeated episodes of propofol-associated anesthesia on quality of recovery from anesthesia, clinical status, and erythrocyte physiology in cats. Original study. 37 cats undergoing short-duration anesthesia for radiotherapy. Twice daily on 5 consecutive days, 13 cats with squamous cell carcinoma of the nasal planum (group 1) underwent anesthesia: first via administration of propofol or a midazolam (0.2 mg/kg [0.09 mg/lb])-propofol combination and then via administration of ketamine and midazolam each day (latter data were not analyzed). During a 19-day period, 24 cats with vaccine associated sarcoma (group 2) were anesthetized 12 times with propofol or a midazolam-propofol combination. Anesthesia was maintained with propofol in both groups. Hematologic analysis was performed before, during, and on completion of radiotherapy; changes in Hct and hemoglobin concentration between groups were compared. Mean duration of anesthesia was 8.1 minutes (range, 5 to 20 minutes); no adverse events were detected during recovery. Total dose of propofol administered did not differ between groups 1 (6.34 mg/kg [2.88 mg/lb]) and 2 (4.71 mg/kg [2.14 mg/lb]). Midazolam administration decreased the propofol dose by 26%. Overall decreases from baseline in Hct and hemoglobin concentration were not significantly different between the 2 groups, nor clinically important; however, compared with baseline, values in group 2 were significantly lower after 6 and 12 anesthetic episodes for both protocols. Heinz bodies were identified in low numbers in both groups during radiotherapy. Results indicated that repeated propofol-associated short-duration anesthesia does not lead to clinically relevant hematologic changes in cats undergoing short-duration radiotherapy.
    Journal of the American Veterinary Medical Association 12/2007; 231(9):1347-53. DOI:10.2460/javma.231.9.1347 · 1.67 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to assess the perfusion pattern and perfusion dynamics in the normal canine spleen using contrast harmonic imaging. Twenty-five dogs without clinical or ultrasonographic evidence of splenic disease were studied. Twenty-three dogs were scanned with only manual restraint; two dogs were sedated with buprenorphin. All dogs received an intravenous bolus of a microbubble contrast medium (SonoVue). The perfusion pattern during the blood pool phase represented a skewed bell-shaped curve. A tissue-specific late phase, similar to humans, was not observed. Time/intensity curves were generated for a selected region. Mean average-derived peak intensity (PI) was 6.6dB, mean time to peak intensity calculated from the initial rise (TTP) was 25.6 s and mean area under the curve (AUC) was 523.6 dBs. If dogs were divided into two body weight groups (< or =15 and >15 kg body weight), average derived peak intensity area, time to peak intensity, and area under the curve were lower for the smaller dogs than for the larger animals. However, differences were not statistically significant (P = 0.2, 0.05, and 0.08, respectively). No significant association was found between hematocrit, hemoglobin concentration, red blood cell count, blood pressure, heart rate, age, gender, and the perfusion variables. In conclusion, these baseline data may prove useful in the evaluation of dogs with diffuse or focal splenic disease.
    Veterinary Radiology &amp Ultrasound 09/2007; 48(5):451-6. DOI:10.1111/j.1740-8261.2007.00277.x · 1.26 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Forty-five dogs with incompletely excised grade II mast cell tumors were treated with radiation using a cobalt 60 teletherapy unit (15 fractions of 3.2 Gy for a total of 48 Gy). Twenty-four of the dogs underwent prophylactic regional lymph node irradiation. Three (6.7%) dogs had tumor recurrence, two (4.4%) dogs developed metastasis, and 14 (31%) dogs developed a second cutaneous mast cell tumor. No difference in overall survival rate was observed between the dogs receiving and not receiving prophylactic irradiation of the regional lymph node.
    Journal of the American Animal Hospital Association 11/2006; 42(6):430-4. DOI:10.5326/0420430 · 0.78 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This retrospective study evaluated the efficacy of radiotherapy used alone in macroscopic oral soft tissue sarcoma. Thirty-one dogs qualified for the study. Twenty dogs received curative radiotherapy (median total dose: 52.5 Gy) and eleven dogs were treated palliatively (3 x 8 Gy or 5 x 6 Gy). The time-to-progression for the curatively-treated dogs was 333 days versus 180 days for the palliatively-treated dogs (p=0.134). The overall survival was 331 days for the curative group and 310 days for the palliative group (p =0.2292). The results of this study suggest that radiation therapy is useful in the treatment of oral soft tissue sarcoma.
    In vivo (Athens, Greece) 01/2006; 20(3):415-9. · 1.15 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Radiotherapy is effective for the palliation of pain associated with primary and metastatic bony neoplasia in dogs and humans, but no standard treatment protocol has been established. The goal of this study was to evaluate a 3 x 8 Gy and a 4 x 6 Gy protocol using electrons with a betatron or linear accelerator for the treatment of appendicular osteosarcoma in 54 dogs. Thirty-three dogs received chemotherapy consisting of carboplatin IV concurrently with radiotherapy. Eighty-three % (n = 45) of the dogs experienced pain relief during or following treatment. The median duration of pain relief from treatment start was 53 days. In conclusion, both protocols are effective for palliation of clinical signs of canine appendicular osteosarcoma. The outcome reported here is similar to the results of other studies using Co photons. The use of chemotherapy did not improve the response to radiotherapy.
    In vivo (Athens, Greece) 07/2005; 19(4):713-6. DOI:10.5167/uzh-18944 · 1.15 Impact Factor
  • Valerie J Poirier · Kristine E Burgess · William M Adams · David M Vail
    [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to evaluate short-term adverse effects and determine a safe dosage for vinorelbine (Navelbine)--a new semisynthetic vinca alkaloid--in dogs with malignant tumors. Nineteen dogs were treated with vinorelbine as a 5-minute IV infusion every 7 days at starting dosages ranging from 10 to 20 mg/m2. The median number of treatments per dog was 7 (range, 1-11). The maximum tolerated dosage varied between 15 and 18 mg/m2, and a starting dosage of 15 mg/m2 is recommended. Neutropenia was the dose-limiting toxicity. Although efficacy was a secondary endpoint of this dosage-finding study, 2 dogs with metastatic bronchoalveolar carcinoma experienced a partial response for an overall response rate of 12.5% in 16 dogs with gross measurable disease. Three dogs with microscopic disease were treated (incompletely excised bronchoalveolar carcinoma or lymph node metastatic disease). Two died of pulmonary metastatic disease 113 and 196 days posttreatment, and 1 is still alive after at least 730 days. The well-tolerated toxicity profile and clinical activity observed in dogs with bronchoalveolar carcinoma warrants further investigation.
    Journal of Veterinary Internal Medicine 07/2004; 18(4):536-9. DOI:10.1111/j.1939-1676.2004.tb02581.x · 2.22 Impact Factor
  • Valerie J Poirier · Lisa J Forrest · William M Adams · David M Vail
    [Show abstract] [Hide abstract]
    ABSTRACT: Ten dogs with transitional cell carcinoma (TCC) of the bladder were treated with a combination of once-weekly coarse fraction radiation therapy (six weekly fractions of 5.75 Gray [Gy]), mitoxantrone chemotherapy, and piroxicam. All dogs completed the radiation therapy protocol, and only minimal side effects were observed. Only two (22%) dogs achieved a measurable partial response; however, 90% of the dogs had amelioration of their urinary clinical signs. The median survival time for all dogs was 326 days. While this treatment protocol was well tolerated, the response rate and overall survival duration was not superior to reports using mitoxantrone and piroxicam without radiation therapy in dogs with TCC.
    Journal of the American Animal Hospital Association 03/2004; 40(2):131-6. DOI:10.5326/0400131 · 0.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this randomized, multicenter study was to evaluate the toxicity and efficacy of liposome-encapsulated doxorubicin (LED) and doxorubicin (DOX) in the treatment of feline vaccine-associated sarcoma (VAS). Cats were divided according to their disease status into a microscopic arm (no evidence of gross disease) and a macroscopic arm (evidence of gross disease). Each arm was randomized to receive either LED (1-1.5 mg/kg i.v. q3 weeks) or DOX (1 mg/kg i.v. q3 weeks). Thirty-three cats were entered in the macroscopic arm of the study with an overall response rate of 39% (5 complete response and 8 partial response) and a median time to progression of 84 days. Response rates were not different between LED and DOX. Seventy-five cats were entered into the microscopic arm. When compared to a similar historical control population treated with surgery alone, the cats receiving chemotherapy had a prolonged median disease-free interval (388 days versus 93 days). No difference in efficacy was detected between LED and DOX. LED at 1.5 mg/kg induced delayed nephrotoxicosis in 23%, necessitating a decrease in the recommended dosage to 1 mg/kg, and cutaneous toxicosis in 21.7% of treated cats. This study showed that both DOX and LED are efficacious in the treatment of VAS and should be considered in the treatment of this tumor.
    Journal of Veterinary Internal Medicine 11/2002; 16(6):726-31. DOI:10.1892/0891-6640(2002)016<0726:LDDADI>2.3.CO;2 · 2.22 Impact Factor