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1.
S. Dressel M.‐C. Gosselin M. H. Capstick E. Carrasco M. S. Weyland S. Scheidegger E. Neufeld N. Kuster S. Bodis C. Rohrer Bley 《Veterinary and comparative oncology》2018,16(2):202-213
Hyperthermia (HT) as an adjuvant to radiation therapy (RT) is a multimodality treatment method to enhance therapeutic efficacy in different tumours. High demands are placed on the hardware and treatment planning software to guarantee adequately planned and applied HT treatments. The aim of this prospective study was to determine the effectiveness and safety of the novel HT system in tumour‐bearing dogs and cats in terms of local response and toxicity as well as to compare planned with actual achieved data during heating. A novel applicator with a flexible number of elements and integrated closed‐loop temperature feedback control system, and a tool for patient‐specific treatment planning were used in a combined thermoradiotherapy protocol. Good agreement between predictions from planning and clinical outcome was found in 7 of 8 cases. Effective HT treatments were planned and verified with the novel system and provided improved quality of life in all but 1 patient. This individualized treatment planning and controlled heat exposure allows adaptive, flexible and safe HT treatments in palliatively treated animal patients. 相似文献
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Donald E. Thrall DVM PHD Deborah A. McLeod DVM Gunilla C. Bentel RTT Mark W. Dewhirst DVM PHD 《Veterinary radiology & ultrasound》1989,30(5):194-221
Because radiation cell killing follows Poisson statistics, radiation dose response curves for tumors and normal tissue response are sigmoidal in shape. This shape implies that small errors in delivery of radiation dose can result in large changes in the probability of normal tissue necrosis or tumor control. Thus it is important for veterinarians involved with radiation oncology to be familiar with the basic aspects of radiation physics and dose calculation as they relate to radiation therapy. In this paper, we present a review of pertinent physics and treatment planning relative to orthovoltage and cobalt irradiation. The usefulness of radiation treatment planning computers is emphasized for improving the radiation oncologist's knowledge of dose distribution and selection of the optimum treatment plan. 相似文献
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Magnetic resonance (MR) images may be useful for radiation planning due to greater contrast resolution. One disadvantage of MR images for radiation planning is the inability to incorporate electron density information into the dose calculation algorithm. To assess the magnitude of this problem, we evaluated radiation dose distribution in canine brain by comparing computed tomography (CT)-based radiotherapy plans with and without electron density correction. Computerized radiotherapy plans were generated for 13 dogs with brain tumors using 6 MV photons. A tissue-contouring program was used to outline the gross tumor volume (GTV) and the planning target volume (PTV) for each patient. Two treatment plans were generated for each dog. First, the plan was optimized without heterogeneity correction. Then the heterogeneity correction was implemented without changing any other plan parameters. Isodose distributions and dose volume histograms (DVHs) were used to compare the two plans. The D95 (dose delivered to 95% of the volume) within the PTV was calculated for each treatment plan and differences in the D95s were compared. The mean D95s without and with heterogeneity correction were 49.1 +/- 0.7 and 48.9 +/- 1.0Gy, respectively. The absolute mean percent dose difference without and with heterogeneity correction was 1.0 - 0.9% (-1.3-3.2%) and was not considered to be clinically significant. We found no clinically significant difference between CT-based radiotherapy plans without and with heterogeneity correction for brain tumors in small animals, which supports the use of MR-based treatment planning for radiotherapy of small animal brain tumors. 相似文献
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Acute radiation‐induced dermatitis (ARID) is a common sequela of radiation therapy in dogs. There is no consensus regarding ARID management in human medicine and the standard of care in veterinary medicine has not been reported. The objective was to report the practice standards for ARID management in dogs in North America. The design used was a questionnaire survey. Fifty‐eight private and university teaching veterinary hospitals were contacted, 54 participated. The topical and oral medications used to treat ARID, prevent or treat bacterial infection, control pain and the indications for and timing of treatment initiation were the outcome measures. A minority of facilities (4/54, 7.5%) use exactly the same protocol regarding all parameters. There was agreement (>75% of facilities) with respect to the general use of oral antibiotics (77.8%), the need for pain control (92.6%) and the use of tramadol for pain control (76%), although the details of their use varied widely. There is a divergence of opinions regarding all details of ARID management in dogs except the general use of oral antibiotics and pain control medications. 相似文献
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M. A. Keyerleber M. C. McEntee J. Farrelly M. S. Thompson P. V. Scrivani C. W. Dewey 《Veterinary and comparative oncology》2015,13(4):385-397
Treatment protocols, treatment planning methods and tumour types in studies evaluating radiotherapy for canine brain tumours have been varied. This case series retrospectively evaluated the outcome of definitive, three‐dimensional conformal radiation therapy (3D‐CRT) as either a sole modality or as an adjuvant to surgery in 31 dogs diagnosed with meningioma by histopathology (n = 10) or cross‐sectional imaging of the head (n = 21, assessed independently by two board certified radiologists). Prescribed dose ranged from 45 to 54 Gy in 2.5 to 3 Gy fractions. Median overall survival was 577 days (interquartile range = 272–829 days; range = 30–1942 days) when all deaths were considered and 906 days (interquartile range = 336–912 days; range = 101–1942 days) when only dogs dying due to meningioma were considered. No significant difference in survival time was detected for the defined clinical or imaging findings or between treatment with radiotherapy alone versus adjuvant radiotherapy, suggesting that 3D‐CRT may be a viable alternative to surgery. 相似文献
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M. A. Keyerleber T. L. Gieger H. N. Erb M. S. Thompson M. C. McEntee 《Veterinary and comparative oncology》2012,10(4):237-245
Differences in dose homogeneity and irradiated volumes of target and surrounding normal tissues between 3D conformal radiation treatment planning and simulated non‐graphic manual treatment planning were evaluated in 18 dogs with apocrine gland adenocarcinoma of the anal sac. Overall, 3D conformal treatment planning resulted in more homogenous dose distribution to target tissues with lower hot spots and dose ranges. Dose homogeneity and guarantee of not under‐dosing target tissues with 3D conformal planning came at the cost, however, of delivering greater mean doses of radiation and of irradiating greater volumes of surrounding normal tissue structures. 相似文献
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H. Gardner J. Fidel G. Haldorson W. Dernell B. Wheeler 《Veterinary and comparative oncology》2015,13(1):40-47
The objective of this retrospective study was to report the outcome of treatment of canine oral fibrosarcomas (FSA) in relation to median survival and progression‐free survival (PFS), and to report whether grade was prognostic in relation to median survival. Sixty‐five dogs with oral FSA presented to the WSU VTH between June 1998 and March 2010. Significant predictors of median survival were location (P = 0.0099), tumour size or oral stage (P = 0.0312), type of surgery (P = 0.0182), margins (P = 0.0329) and grade (P = 0.0251). Significant predictors of PFS were location (P = 0.0177), and radiation protocol (P = 0.0343). A combination of surgery and radiation was the strongest predictor of prolonged median survival (P = 0.0183) and PFS (P = 0.0263) at 505 and 301 days, respectively. Treatment of canine oral FSA with a combination of surgery and radiation therapy provided the longest median survivals. 相似文献
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Hiroto Yoshikawa Donald M. Roback Susan M. Larue Michael W. Nolan 《Veterinary radiology & ultrasound》2015,56(6):687-695
Potential benefits of planning radiation therapy on a contrast‐enhanced computed tomography scan (ceCT) should be weighed against the possibility that this practice may be associated with an inadvertent risk of overdosing nearby normal tissues. This study investigated the influence of ceCT on intensity‐modulated stereotactic body radiotherapy (IM‐SBRT) planning. Dogs with head and neck, pelvic, or appendicular tumors were included in this retrospective cross‐sectional study. All IM‐SBRT plans were constructed on a pre‐ or ceCT. Contours for tumor and organs at risk (OAR) were manually constructed and copied onto both CT's; IM‐SBRT plans were calculated on each CT in a manner that resulted in equal radiation fluence. The maximum and mean doses for OAR, and minimum, maximum, and mean doses for targets were compared. Data were collected from 40 dogs per anatomic site (head and neck, pelvis, and limbs). The average dose difference between minimum, maximum, and mean doses as calculated on pre‐ and ceCT plans for the gross tumor volume was less than 1% for all anatomic sites. Similarly, the differences between mean and maximum doses for OAR were less than 1%. The difference in dose distribution between plans made on CTs with and without contrast enhancement was tolerable at all treatment sites. Therefore, although caution would be recommended when planning IM‐SBRT for tumors near “reservoirs” for contrast media (such as the heart and urinary bladder), findings supported the use of ceCT with this dose calculation algorithm for both target delineation and IM‐SBRT treatment planning. 相似文献
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An 11-year-old male Bearded Collie was brought to the Gifu University Animal Medical Centre with a skin mass on the lateral right thigh. Physical examination revealed a 30 × 65-mm oval mass with an alopecic and ulcerated surface. Histopathology of the surgically excised sample confirmed malignant trichoepithelioma. Five months after the surgery, the dog experienced lumbar pain resulting from metastasis to the lumbar vertebrae. Radiation therapy (RT) was performed and it alleviated the lumbar pain. Nine months after the surgery, multiple skin metastases were identified. RT was performed at each occurrence, which reduced the size of each tumour and resulted in a partial response; however, systemic metastasis occurred and the dog died 17 months after the initial surgery. Canine malignant trichoepithelioma is a rare tumour, so an effective treatment has not been determined. Data from our case study indicate that RT has potential for pain control of primary and metastatic malignant trichoepithelioma. 相似文献
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Nicholas J. Rancilio Michelle R. Custead Jean M. Poulson 《Veterinary radiology & ultrasound》2016,57(5):E46-E50
A 5‐year‐old spayed female Shih Tzu was referred for evaluation of a nasal transitional carcinoma. A total lifetime dose of 117 Gy was delivered to the intranasal mass in three courses over nearly 2 years using fractionated intensity modulated radiation therapy (IMRT) to spare normal tissues. Clinically significant late normal tissue side effects were limited to bilaterally diminished tear production. The patient died of metastatic disease progression 694 days after completion of radiation therapy course 1. This case demonstrates that retreatment with radiation therapy to high lifetime doses for recurrent local disease may be well tolerated with IMRT. 相似文献
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CATHERINE VAUDAUX UWE SCHNEIDER BARBARA KASER-HOTZ 《Veterinary radiology & ultrasound》2007,48(5):475-481
We evaluated the impact of inverse planned intensity-modulated radiation therapy (IMRT) on the dose-volume histograms (DVHs) and on the normal tissue complication probabilities (NTCPs) of brain and eyes in dogs with nasal tumors. Nine dogs with large, caudally located nasal tumors were planned using conventional techniques and inverse planned IMRT for a total prescribed dose of 52.5 Gy in 3.5 Gy fractions. The equivalent uniform dose for brain and eyes was calculated to estimate the normal tissue complication probability (NTCP) of these organs. The NTCP values as well as the DVHs were used to compare the treatment plans. The dose distribution in IMRT plans was more conformal than in conventional plans. The average dose delivered to one-third of the brain was 10 Gy lower with the IMRT plan compared with conventional planning. The mean partial brain volume receiving 43.6 Gy or more was reduced by 25.6% with IMRT. As a consequence, the NTCPs were also significantly lower in the IMRT plans. The mean NTCP of brain was two times lower and at least one eye could be saved in all patients planed with IMRT. Another possibility with IMRT is dose escalation in the target to improve tumor control while keeping the NTCPs at the same level as for conventional planning. Veterinary 相似文献
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Although anisotropic analytical algorithm (AAA) and Acuros XB (AXB) are both radiation dose calculation algorithms that take into account the heterogeneity within the radiation field, Acuros XB is inherently more accurate. The purpose of this retrospective method comparison study was to compare them and evaluate the dose discrepancy within the planning target volume (PTV). Radiation therapy (RT) plans of 11 dogs with intranasal tumors treated by radiation therapy at the University of Georgia were evaluated. All dogs were planned for intensity‐modulated radiation therapy using nine coplanar X‐ray beams that were equally spaced, then dose calculated with anisotropic analytical algorithm. The same plan with the same monitor units was then recalculated using Acuros XB for comparisons. Each dog's planning target volume was separated into air, bone, and tissue and evaluated. The mean dose to the planning target volume estimated by Acuros XB was 1.3% lower. It was 1.4% higher for air, 3.7% lower for bone, and 0.9% lower for tissue. The volume of planning target volume covered by the prescribed dose decreased by 21% when Acuros XB was used due to increased dose heterogeneity within the planning target volume. Anisotropic analytical algorithm relatively underestimates the dose heterogeneity and relatively overestimates the dose to the bone and tissue within the planning target volume for the radiation therapy planning of canine intranasal tumors. This can be clinically significant especially if the tumor cells are present within the bone, because it may result in relative underdosing of the tumor. 相似文献
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Hiroto Yoshikawa Joseph F. Harmon James T. Custis Susan M. LaRue 《Veterinary radiology & ultrasound》2012,53(6):667-672
For canine and feline patients with head tumors, simultaneous irradiation of the primary tumor and mandibular and retropharyngeal lymph nodes (LNs) is often indicated. The purpose of this study was to assess the repeatability of a planning target volume (PTV) expansion protocol for these LNs. Two CT image sets from 44 dogs and 37 cats that underwent radiation therapy for head tumors were compared to determine LN repositioning accuracy and precision; planning‐CT (for radiation therapy planning) and cone‐beam CT (at the time of actual treatment sessions). Eleven percent of dogs and 65% of cats received treatment to their LNs. In dogs, the mandibular LNs were positioned more caudally (P = 0.0002) and the right mandibular and right retropharyngeal LNs were positioned more to the left side of the patient (P = 0.00015 and P = 0.003, respectively). In cats, left mandibular LN was positioned higher (toward roof) than the planning‐CT (P = 0.028). In conclusion, when the patient immobilization devices and bony anatomy matching are used to align the primary head target and these LNs are treated simultaneously, an asymmetrical PTV expansion that ranges 4–9 mm (dogs) and 2–4 mm (cats), depending on the directions of couch movement, should be used to include the LNs within the PTV at least 95% of the time. 相似文献
14.
Margaret C McEntee Michele Steffey Nathan L Dykes 《Veterinary radiology & ultrasound》2008,49(4):395-399
The goal of this prospective study was to determine the effect of hemoclip use on the size of radiation treatment fields based on a 3-cm margin around a surgical incision alone (field setup 1) vs. a 3-cm margin around the surgical incision plus hemoclips (field setup 2). Forty-seven dogs that underwent surgical resection of a total of 55 soft tissue masses had surgical hemoclips placed at the time of surgery and orthogonal radiographs made immediately postoperatively. Radiation treatment field simulation was done and field areas measured. Additional determinations included number of hemoclips outside of the radiation treatment field based on a margin around the incision alone, hemoclip distance from the incision, and association between incision length and greatest distance of hemoclips from the incision. There was a significant difference in radiation treatment field size using information regarding the location of hemoclips in conjunction with the surgical scar compared with the surgical scar alone for truncal (P = 0.0003) vs. extremity tumors (P = 0.087). In simulating radiation treatment fields hemoclips were located outside of field setup 1 for the majority of tumors (79%) resected from the trunk but only in a minority of tumors (10.7%) resected from extremity sites. The findings from this study suggest that surgical hemoclips have potential utility in simulation of radiation treatment fields in the postoperative setting. 相似文献
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Hege Kippenes DVM PHD Patrick R. Gavin DVM PHD Homayon Parsaei PHD Mark H. Phillips PHD Paul S. Cho PHD Charles W. Leathers DVM PHD Ronald D. Sande DVM MS PHD 《Veterinary radiology & ultrasound》2003,44(3):360-366
Intensity modulated radiation therapy (IMRT) theoretically allows detailed tailoring of the dose distribution in tissue. The goal of this study was to determine if a method of dynamic IMRT could be used to deliver a high dose of radiation to a concave shaped target around the cervical spinal cord. Fifteen young adult dogs from our laboratory population were randomly divided into two groups. A radiation dose of 84 Gy in 4 Gy fractions was delivered with a conventional 4 field technique for Group A dogs, and with dynamic IMRT for Group B dogs to a "C-shaped" target close to the cervical spinal cord. Neurologic status, magnetic resonance imaging results and histopathologic changes were compared among dogs in the two groups. Group A dogs developed myelomalacia with a latency period of 65 +/- 9 days. Group B dogs did not have any histologic changes to the cervical spinal cord when euthanasia was performed 12 months after irradiation. The results demonstrate that this IMRT technique can be safely and precisely delivered to a patient in a clinical situation. 相似文献
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Larissa A. Hautekeete DVM Safdar A. Khan DVM MS PhD 《Journal of Veterinary Emergency and Critical Care》1999,9(4):203-207
Pemoline is a central nervous system stimulant commonly used for Attension Deficit Disorder in humans. This study describes the clinical syndrome associated with pemoline ingestion as well as its treatment. Ten years worth (1987–1997) of records from the ASPCa National Animal Poison Control Center involving pemoline ingestion in dogs were reviewed. The data suggests that most dogs ingesting pemoline show signs of central nervous system and cardiovascular stimulation including hyperactivity, tremors, ataxia, seizure, tachycardia, hyperthermia, and mydriasis. Blood chemistry alterations included electrolyte imbalances in some dogs. The minimum dose reported to cause clinical signs was 2.8 mg/kg and the minimum dose reported to have caused death was 10 mg/kg. Dogs generally showed clinical signs within 30 minutes to 24 hours of ingestion. The duration of clinical signs ranged from 15 hours to four days. Ninety-four percent of the dogs recovered with supportive treatment. (Vet. Emerg. & Crit. Care, 9:203–207, 1999) 相似文献
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