0–7–21 Radiation Therapy for the Palliation of Advanced Cancer in Dogs

Abstract

The 0-7-21 radiation therapy protocol was investigated as a palliative treatment in dogs with advanced malignancies. Twenty-four dogs with a variety of tumor types were irradiated using 800 cGy fractions given on days 0, 7, and 2 1 .Twenty-three dogs were evaluated. Palliative response was assessed using a quality of life instrument developed for veterinary use. This pain score was based on owner response to questions regarding analgesic requirement, activity level, appetite, and degree of lameness in the affected dogs. Seventeen (74%) of the 23 dogs experihen cancer patients present with advanced or disseminated disease, the goal of treatment becomes palliative, rather than curative. Palliative therapy is directed at reducing pain and other clinical signs that detract from a patient's quality of life. In many cancers, pain increases in frequency and severity with disease progression.''2 This is a major source of concern for pet owners. In humans, the incidence of pain is greatest in patients with primary bone tumors and cancers of the oral In 1970, Gillette described radiation therapy as an effective means to alleviate pain and extend "meaningful" survival in domestic anirnal~.~ Despite this, the palliative qualities of radiation have received little attention in the veterinary literature. Radiation therapy has generally been approached with curative intent, although the result is often palliative.6 Dose and fractionation have not varied with the intended outcome. Without the possibility of cure, euthanasia has been considered a more humane option than a radical course of radiation therapy.' In humans, close to 50% of radiation therapy is prescribed with palliative intent.' Fractionation patterns have vaned widely and range from single 800 to 1,000 cGy fractions, to 2,000 cGy given over 5 days, to extended courses of 5,000 cGy given over 5 The aim of palliative radiation is to achieve rapid, effective, and lasting symptomatic relief in as short a course as possible, provided the normal tissue reactions can be kept to a minimum.The benefits of palliative therapy are difficult to assess. Traditional end points, such as survival and tumor control are not appropriate measurements of quality of life. Quality of life instruments have not been previously described for animal patients, but should be developed to evaluate palliative protocols.The 0-7-21 radiation therapy protocol is a hypofractionated regime consisting of 800 cGy fractions given on days 0, 7, and 21. This protocol has shown promise in humans for the palliation of mucosal or metastatic melanoma.10-'2 The purposes of this study were to ( 1) determine if the 0-7-2 1 protocol resulted in palliation in a variety of spontaneous canine tumors; and (2) to evaluate the response to therapy using a quality of life instrument. Materials and MethodsFrom June 1989 to July 1991, 24 dogs presented to the Ontario Veterinary College with advanced malignancies received radiation therapy with palliative intent. Dogs were considered eligible if they had ( I ) advanced local...

Owners’ assessments of their dog's quality of life during palliative chemotherapy for lymphoma

“…Quality of life assessments have been reported infrequently in small animal oncology studies (Bateman andothers 1994, Malik andothers 2001). Such assessments will inevitably be subjective in small animals and based mainly on the observations of the veterinarian in charge of the treatment, and the owner.…”

Evaluation of Intravenous Pamidronate Administration in 33 Cancer-Bearing Dogs with Primary or Secondary Bone Involvement

“…Although similar assessments of clinical response have been described previously in studies evaluating palliative therapy for canine OSA, inherent limitations and bias exist with the use of any pain grading scale. [41][42][43][44] Although the apparent improvement in bone pain after IV pamidronate is promising, these results must not be overstated given that all 10 dogs, before study entry, were treated with conventional NSAIDs for at least 21 days and continued to receive NSAIDs throughout the course of pamidronate therapy. Although unlikely, the perceived improvement in bone pain control may result from a delayed effect of long-term NSAID usage.…”

Percutaneous Cementoplasty in the Palliative, Multimodal Treatment of Primary Bone Tumors of the Distal Aspect of the Radius in Four Dogs

“…A significant reduction in lameness after palliative radiation therapy for an OSA lesion affecting the appendicular skeleton may be expected in 74-92% of the dogs treated. [12][13][14][15][16] Because of the early death of Dog 2 at 4 weeks only 3 dogs could be evaluated after completing the palliative radiation protocol 6 weeks after PC. Only Dog 4 had a significant improvement in PVF compared with the level measured 2 weeks after PMMA injection.…”

“…Palliative radiotherapy is effective both in palliation of lameness and, in combination with chemotherapy, in prolonging survival 12–14 . The response rate varies from 74% to 92% and the median duration of response ranges from 53 to 94.5 days 12–16 . This means that up to 25% of the dogs either do not respond or have a short duration of response to radiation therapy.…”

“…[12][13][14] The response rate varies from 74% to 92% and the median duration of response ranges from 53 to 94.5 days. [12][13][14][15][16] This means that up to 25% of the dogs either do not respond or have a short duration of response to radiation therapy. Singleagent pamidronate has recently been identified as another palliative treatment modality for appendicular OSA resulting in a significant pain alleviation for 44 months in 28% of the dogs.…”