Long-term remission and survival in dogs with high-grade, B cell lymphoma treated with chemotherapy with or without sequential low-dose rate half-body irradiation.

BACKGROUND: Standard of care for dogs with high-grade lymphoma, multiagent chemotherapy, achieves good initial responses but long-term remissions are infrequent; previous studies using half-body irradiation suggest improved long-term outcomes. HYPOTHESIS: The addition of low-dose rate half-body irradiation would improve outcomes in dogs with B-cell lymphoma. ANIMALS: Client-owned dogs with stage III or higher, substage a, B-cell lymphoma that achieved complete remission after 4 doses of multiagent chemotherapy. METHODS: A case-controlled design comparing 2-year remission and survival rates between dogs treated with CHOP-based chemotherapy and those treated with chemotherapy and sequential low-dose rate half-body irradiation. RESULTS: Thirty-eight dogs were enrolled with 18 included in final analysis, 9 prospectively-enrolled dogs and 9 case-matched historical controls. The irradiation cohort's 2-year disease-free rate was 56% whereas median duration exceeded the 730-day study period compared with 0% and 261 days in the chemotherapy only group. Remission duration significantly differed between cohorts (P < .01), hazard ratio 0.218 (95% CI: 0.06-0.77). The irradiation cohort's 2-year survival rate was 78% with median overall survival duration exceeding the 730 day study period compared with 11% and 286 days in the chemotherapy only group. Overall survival time significantly differed between cohorts (P < .02), hazard ratio 0.173 (95% CI: 0.03-0.839). CONCLUSIONS AND CLINICAL IMPORTANCE: The improved long-term outcome achieved by dogs administered sequential low-dose rate half-body irradiation in this study is similar to previous observational studies. Where long-term remission is sought in dogs with B-cell lymphoma low-dose rate half-body irradiation could be considered in addition to standard chemotherapy.

Hard palate defect repair by using haired angularis oris axial pattern flaps in dogs.

OBJECTIVE: To describe the repair of large hard palate defects with a haired angularis oris axial pattern flap (HAOF) and to report the postoperative outcome. STUDY DESIGN: Anatomical cadaver study and short case series. ANIMALS: One cadaver and three dogs with neoplasia of the caudal hard palate. METHODS: Large caudal and central hard palate defects were reconstructed by using the HAOF. The flap, composed of full-thickness skin and buccal mucosa, was rotated at the base of the angularis oris artery. The haired surface of the skin flap was placed facing into the oral cavity. RESULTS: Reconstruction of defects extending as far rostral as the maxillary canine tooth were feasible on the cadaver. The flap in dog 1 healed without complication and was intact at day 649 after surgery. Two minor areas of dehiscence were noted in dog 2, without further evidence of complications at 1331 days after surgery. Dog 3 had upper respiratory obstructive noise due to swelling immediately after surgery. These signs resolved, but local recurrence of the tumor prompted euthanasia at day 86. CONCLUSION: Anatomical studies provide evidence that the HAOF can be used to reconstruct caudal and central hard palate defects extending to the maxillary canine teeth. Its clinical use led to successful closure of such defects in three dogs. CLINICAL SIGNIFICANCE: HAOF provides an alternative for reconstruction of large defects of the caudal and central hard palate.

Outcomes of Limb-Sparing Surgery Using Two Generations of Metal Endoprosthesis in 45 Dogs With Distal Radial Osteosarcoma. A Veterinary Society of Surgical Oncology Retrospective Study.

OBJECTIVE: To report outcomes in dogs with distal radial osteosarcoma (OSA) treated with metal endoprosthesis limb-sparing surgery and compare outcomes between 2 generations of endoprosthesis. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Forty-five dogs with distal radial OSA treated with endoprosthesis and chemotherapy. METHODS: Data of dogs treated with either first-generation endoprosthesis (GEN1) or second-generation endoprosthesis (GEN2) were sourced from medical records and radiographs. Surgical outcomes included postoperative lameness assessment and the presence, severity, and time to onset of complications. Oncologic outcomes included presence of local recurrence or metastasis, time to onset of local recurrence, metastasis-free interval (MFI), and survival time. Results for surgical and oncologic outcomes were compared between GEN1 and GEN2. RESULTS: Twenty-eight dogs received GEN1 and 17 dogs received GEN2. There were 39 complications (96%, 14 minor, 29 major) including infection (78%), implant-related complication (36%), and local recurrence (24%). Metastatic frequency was 67% and median MFI was 188 days (95% confidence interval [CI]: 126-250 days). Survival time ranged from 34 days to 6.1 years with a median of 289 days (95% CI: 207-371 days). There was no significant difference in complication severity, frequency, time to complication, MFI, or survival time between dogs receiving GEN1 and GEN2. CONCLUSION: There was no significant difference in outcomes between dogs receiving GEN1 and GEN2 for limb-sparing surgery of the radius. Metastatic frequency and survival time for metal endoprosthesis were similar to that of amputation with curative intent chemotherapy.

Lateral caudal axial pattern flap in 13 dogs.

OBJECTIVE: To describe the frequency and extent of complications associated with lateral caudal axial pattern flaps used to cover large traumatic or excision skin defects on the dorsum, gluteal, and perineal region in 13 dogs. STUDY DESIGN: Case series. ANIMALS: Thirteen client-owned dogs. METHODS: Medical records from 8 institutions were reviewed for dogs treated with a lateral caudal axial pattern flap, including cases in which the procedure was combined with other reconstructive techniques. The flap length relative to the tail length, location of tail skin incision, size and cause of the defect, and short- and long-term complications were recorded. RESULTS: Thirteen dogs were included, 11 with tumors and 2 with traumatic skin loss. The mean estimated length of the flap relative to tail length was 51% (range 33-70%). Four dogs had wound complications. This included 2 dogs with minor postoperative wound complications (mild distal dehiscence) that did not require surgical revision and 2 dogs with major complications that required surgical revision. Two of these 4 dogs had distal flap necrosis, one was revised surgically and one was managed conservatively. In these 2 dogs, the flap length was estimated as 80% and 65% of the tail length, respectively. At 30 days, flaps in all dogs were completely healed. No long-term complications were recorded in any dog. For some dogs, the reconstruction was not obvious, with only the change in hair direction and color noticeable. CONCLUSION: Lateral caudal axial pattern flap is a reconstructive option for gluteal, dorsal, and perineal skin defects in dogs. Distal flap necrosis and dehiscence due to wound infection occurred in 4 dogs that required additional wound care but not always surgical revision.

Clinical outcome of 42 dogs with scapular tumors treated by scapulectomy: a Veterinary Society of Surgical Oncology (VSSO) retrospective study (1995-2010).

OBJECTIVE: To report signalment, clinical signs, preoperative staging tests, histologic diagnosis, surgical, and oncologic outcomes including postoperative limb use, in dogs with scapular tumors treated by scapulectomy. STUDY DESIGN: Retrospective case series ANIMALS: Dogs (n = 42) with scapular tumors. METHODS: Medical records (1995-2010) from 6 hospitals were searched for dogs with scapular tumors treated by scapulectomy. Data retrieved were: signalment, weight, percentage of scapula removed, histologic diagnosis, postoperative limb use, adjunctive therapy, disease free interval (DFI), and survival time (ST). Individual variables were modeled with a Cox proportional hazard model accounting for censoring to determine risk factors for decreased DFI and ST. For categorical variables, Kaplan-Meier survival plots as well as mean and median survival times (MSTs) were calculated. RESULTS: Subtotal scapulectomy was performed in 18 dogs (42.9%). Osteosarcoma (OSA) was diagnosed in 27 dogs (64.3%). Limb use was evaluated immediately after surgery in 41 dogs. Information on limb use at other times (1, 2, 3, and >3 months) postoperatively was also available for some dogs and was good to excellent overall. Only adjunctive chemotherapy had a positive significant effect on DFI (P = .00011) and ST (P = .0003). CONCLUSION: Canine scapular tumors can be treated effectively by scapulectomy and limb use is fair to excellent for most dogs. OSA was the most common scapular tumor. Overall prognosis for scapular OSA is similar to appendicular OSA at other sites and use of adjunctive chemotherapy prolonged the overall DFI and MST.

Biologic behavior and clinical outcome of 25 dogs with canine appendicular chondrosarcoma treated by amputation: a Veterinary Society of Surgical Oncology retrospective study.

OBJECTIVE: To characterize biologic behavior, clinical outcome, and effect of histologic grade on prognosis for dogs with appendicular chondrosarcoma treated by amputation alone. STUDY DESIGN: Case series. ANIMALS: Dogs (n=25) with appendicular chondrosarcoma. METHODS: Medical records were searched to identify dogs with appendicular chondrosarcoma treated by limb amputation alone. Information recorded included signalment, anatomic location, radiographic appearance, and development of metastasis. Histopathologic diagnosis was confirmed and graded (1, 2, or 3). Survival curves were generated by the Kaplan-Meier method and the association between covariates (gender, age, weight, and tumor grade) and survival were evaluated using the univariate proportional hazards model. RESULTS: Histopathology slides were available for 25 dogs. Rates of pulmonary metastasis were as follows: grade 1-0%, grade 2-31%, and grade 3-50%. Overall median survival time (MST) was 979 days. Age, weight, and sex were not significantly associated with survival (P=.16; .33; and .31, respectively). Survival was significantly associated with tumor grade (P=.008), with dogs with tumor grade of 1, 2, and 3 having MSTs of 6, 2.7, and 0.9 years, respectively. CONCLUSION: Canine appendicular chondrosarcoma can be treated effectively with amputation alone. Low to intermediate grade chondrosarcoma has a good prognosis, whereas high-grade tumors appear to behave aggressively. CLINICAL RELEVANCE: The overall prognosis for appendicular chondrosarcoma is better than that of appendicular osteosarcoma treated by amputation alone or in combination with chemotherapy.

Use of single-agent carboplatin as adjuvant or neoadjuvant therapy in conjunction with amputation for appendicular osteosarcoma in dogs.

Survival following amputation and administration of single-agent carboplatin for treatment of appendicular osteosarcoma (OSA) in dogs was retrospectively examined. Records of 155 dogs with appendicular OSA treated with amputation and single-agent carboplatin were included from 14 centers. Any carboplatin dosage, number of doses, and protocol schedule were eligible for inclusion. The median disease-free interval (DFI) was 256 days. The median overall survival time was 307 days. Similar prognostic survival factors were identified in this study as reported in prior studies of canine appendicular OSA. Median DFI and survival were comparable to those reported in the original Bergman et al publication. Carboplatin treatment improves the survival probability in dogs with appendicular OSA compared to amputation alone and remains an acceptable alternative to adjuvant treatment with cisplatin.

Combined dorsolateral and intraoral approach for the resection of tumors of the maxilla in the dog.

This paper describes in detail a combined dorsal and intraoral approach for maxillectomy for tumors involving tissues more caudal to the third premolar. The only intraoperative complication was that of blood loss, with six out of 20 dogs requiring a single unit of blood. Histopathologically clean margins were obtained in 14 of the 20 cases, with a recurrence rate of 50% in these dogs and a median time to recurrence of 24 months. This represents an improvement in outcome over previously reported studies, and the authors postulate this is due to the better exposure and access to the area afforded by the combined approach over the standard intraoral approach.