Sequential Low‐Dose Rate Half‐Body Irradiation and Chemotherapy for the Treatment of Canine Multicentric Lymphoma

Sixty-three dogs with newly diagnosed lymphoma underwent complete staging and received the same chemotherapy. Diffuse large B-cell lymphoma was the leading histotype (44.4%), followed by peripheral T-cell lymphoma (20.6%). Indolent lymphomas accounted for 30.2% of cases. Most dogs with aggressive B-cell lymphoma had stage IV disease. Dogs with indolent and aggressive T-cell lymphoma had more often stage V disease and were symptomatic. Liver and bone marrow were predominantly involved in B-cell and T-cell lymphoma, respectively. The clinical stage was significantly related to substage, sex and total lactic dehydrogenase (LDH) levels. Aggressive B-cell lymphomas were more likely to achieve remission. Median survival was 55 days for aggressive and indolent T-cell lymphoma, 200 and 256 days for indolent and aggressive B-cell lymphoma, respectively. The prognosis of advanced indolent lymphoma does not appear to be appreciably different from that of aggressive disease. Familiarity with the various histotypes is critical to make the correct diagnosis and drive therapy.

Section: Discussioncontrasting

confidence: 48%

Canine indolent and aggressive lymphoma: clinical spectrum with histologic correlation

Aresu

Martini

Rossi

et al. 2013

“…Two of these were treated with radiation during their initial CHOP‐based chemotherapy protocol. One received a dose of cranial half body radiation and the other received both cranial and caudal half body low‐dose rate irradiation after the first cycle of CHOP as described by Lurie et al The patient that was treated with cranial and caudal half body RT did not have a documented relapse and died at day 1779 of an unknown cause. The dog treated with cranial half body radiation experienced a PFS of 281 days and OS of 352 days.…”

Section: Resultsmentioning

confidence: 99%

Patient characteristics, prognostic factors and outcome of dogs with high‐grade primary mediastinal lymphoma

Moore

Vernau

Rebhun

et al. 2017

The goals of this retrospective study were to determine the patient characteristics of dogs with high-grade primary mediastinal lymphoma and to determine outcome and associated prognostic factors. A total of 42 dogs were identified, in which 36 received treatment and had follow-up information available. The most common clinical signs included lethargy, anorexia and polyuria/polydipsia. Hypercalcemia and pleural effusion were common findings at diagnosis. The phenotype was almost exclusively T-cell, most often in association with lymphoblastic cytomorphology as defined by the World Health Organization (WHO) lymphoma classification scheme. The overall progression-free survival (PFS) and overall survival (OS) were 133 and 183 days, respectively. Treatment with a CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) protocol was associated with an improved PFS (144 days) and OS (194 days) when compared with dogs that received other medical therapies (P = .005 and P = .002, respectively); the absence of pleural effusion at diagnosis was associated with an increased OS but not PFS. These results suggest that while the prognosis for dogs with mediastinal lymphoma is poor, survival may be improved with treatment using a CHOP-based protocol.

“…In adult dogs, the large flat bones (ribs, pelvis and skull) support the majority of active haematopoiesis 20 . Mild to moderate haematologic toxicity associated with half‐body radiation therapy protocols for treatment of lymphoma in dogs is reported, but the true impact of radiation is difficult to ascertain in these cases with multidrug induction chemotherapy used immediately before the delivery of radiation 21–24 . Factors such as patient age, concurrent illness, tumour type and concurrent medications may also influence normal tissue toxicity 25 .…”

Section: Discussionmentioning

confidence: 99%

Radiotherapy‐induced myelosuppression in dogs: 103 cases (2002–2006)

Clermont

LeBlanc

Adams

et al. 2011

Definitive radiotherapy refers to delivery of large doses, typically 48-62 Gray, of ionizing radiation over several weeks using a daily or alternate-day fractionation schedule. The impact of definitive radiotherapy alone on haematopoiesis in tumour-bearing dogs is unknown. Medical records from 103 dogs receiving definitive 60 Cobalt teletherapy for cancer over a 5-year period were reviewed for signalment, tumour type and location, total radiotherapy dose and fractionation scheme. Complete blood count data were collected before, halfway through, and at the end of radiation treatment, and analysed for changes associated with patient variables. The results demonstrate significant reductions in haematocrit, total white blood cell count, neutrophils, eosinophils, monocytes, lymphocytes and platelets occurred during definitive radiotherapy but remained within laboratory reference intervals. These data are important for anticipation of toxicity associated with combinations of radiotherapy and chemotherapy in dogs but do not support the routine monitoring of haematology parameters during definitive radiotherapy. Keywords cancer, dogs, myelosuppression, radiotherapyDefinitive therapeutic radiotherapy where large doses of radiation, typically 48-62 Gray, are delivered over several weeks using a daily or alternate-day fractionation schedule, is an effective means of gaining long-term local control for common veterinary tumours with a relatively low metastatic rate.