76
|
Macluskey M, Durham J, Bell A, Cowpe J, Crean SJ, Dargue A, Dawson L, Freeman C, Jones J, McDouagh A, McHanwell S, Marley J, Myrddin L, Millsopp L, Oliver R, Renton T, Taylor K, Thomson P. A national survey of UK final year students' opinion of undergraduate oral surgery teaching. EUROPEAN JOURNAL OF DENTAL EDUCATION : OFFICIAL JOURNAL OF THE ASSOCIATION FOR DENTAL EDUCATION IN EUROPE 2012; 16:e205-e212. [PMID: 22251348 DOI: 10.1111/j.1600-0579.2011.00717.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND A national survey was undertaken to establish a baseline of our final year students' perception of how their undergraduate oral surgery education has equipped them for key areas of general dental practice. MATERIALS AND METHODS Questionnaires were distributed to the 13 UK schools with final year students, towards the end of the academic year in 2009. The questionnaires were completed anonymously and were optically scanned. RESULTS In total, 632 questionnaires were returned, which represents 66% of the students of the graduating year. The majority (83%) of the respondents perceived that the teaching in oral surgery had given them sufficient knowledge to undertake independent practise. Most respondents (99%) felt confident to perform forceps exodontia, but confidence in the various aspects of surgical exodontia was lower. A majority (83%) had experience of an outreach scheme performing forceps exodontia (75%) and surgical exodontia (16%) in this environment. Twenty per cent indicated a desire to undertake a career in oral surgery, 6% in oral and maxillofacial surgery and 35% in another speciality. CONCLUSION This survey suggests that the majority of the students perceive that the oral surgery education has prepared them well for key areas of general practice. It also suggests that there is, however, a need to provide further improvement in the delivery of surgical skills and knowledge.
Collapse
|
77
|
Vickers M, Samson B, Colwell B, Cripps C, Jalink D, El-Sayed S, Chen E, Porter G, Goel R, Villeneuve J, Sundaresan S, Asselah J, Biagi J, Jonker D, Dawson L, Letourneau R, Rother M, Maroun J, Thirlwell M, Hussein M, Tehfe M, Perrin N, Michaud N, Hammad N, Champion P, Rajan R, Burkes R, Barrette S, Welch S, Yarom N, Asmis T. Eastern Canadian Colorectal Cancer Consensus Conference: setting the limits of resectable disease. ACTA ACUST UNITED AC 2011; 17:70-7. [PMID: 20651901 DOI: 10.3747/co.v17i3.610] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Montreal, Quebec, October 22-24, 2009. Health care professionals involved in the care of patients with colorectal cancer participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management colorectal cancer, such as the management of hepatic and pulmonary metastases, the role of monoclonal antibodies to the epidermal growth factor receptor, and the benefits and safety of chemotherapy in elderly patients. The management of gastrointestinal neuroendocrine tumours and gastric cancer are also discussed.
Collapse
|
78
|
Macluskey M, Durham J, Balmer C, Bell A, Cowpe J, Dawson L, Freeman C, Hanson C, McDonagh A, Jones J, Millsopp L, Oliver R. Dental student suturing skills: a multicentre trial of a checklist-based assessment. EUROPEAN JOURNAL OF DENTAL EDUCATION : OFFICIAL JOURNAL OF THE ASSOCIATION FOR DENTAL EDUCATION IN EUROPE 2011; 15:244-9. [PMID: 21985209 DOI: 10.1111/j.1600-0579.2010.00665.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
BACKGROUND The assessment of clinical skills is essential to determine whether an undergraduate is competent to perform the tasks outlined in the curriculum. Such assessments in dentistry have historically not been subjected to large scale validity and reliability testing due the relatively small student numbers at each institute. The aims of this study were to test the validity and reliability of a standardised, checklist-based, suturing objective structured clinical examination (OSCE) and then to perform a multicentre trial to determine its performance over a large cohort of students. MATERIALS AND METHODS A total of seven UK schools agreed to take part in the trial. To test the validity and reliability of the checklist, the examiner at each institution reviewed and scored video footage of 10 students performing the assessment. Each institution then carried out the assessment providing a checklist score and a global score for each of their own students. RESULTS The assessment was well received by the staff, with acceptable inter-examiner variability. In total, 496 students completed the suturing OSCE with a success rate of 81% with a variation between schools of between 66% and 96%. A significant correlation was found between the checklist score and the global score (r = 0.361, P = 0.000). No one item on the checklist was found to be a determinant factor in the outcome of the OSCE. CONCLUSIONS This checklist-based assessment of suturing skills was found to have face and content validity. Its reliability was promising, but merits further investigation. There may be an argument for the standardisation of the assessment of this core surgical skill throughout several UK-based dental schools.
Collapse
|
79
|
Huang S, Cheng L, Xu W, Waldron J, Bayley A, Kim J, Dawson L, Hope A, Cho J, O'Sullivan B. 8508 POSTER DISCUSSION Outcome of Radiotherapy Alone for Locoregionally Advanced Head and Neck Cancer Patients Unfit for Chemotherapy. Eur J Cancer 2011. [DOI: 10.1016/s0959-8049(11)72150-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
80
|
Tam CS, O'Reilly M, Andresen D, Lingaratnam S, Kelly A, Burbury K, Turnidge J, Slavin MA, Worth LJ, Dawson L, Thursky KA. Use of empiric antimicrobial therapy in neutropenic fever. Australian Consensus Guidelines 2011 Steering Committee. Intern Med J 2011; 41:90-101. [PMID: 21272173 DOI: 10.1111/j.1445-5994.2010.02340.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Administration of empiric antimicrobial therapy is standard practice in the management of neutropenic fever, but there remains considerable debate about the selection of an optimal regimen. In view of emerging evidence regarding efficacy and toxicity differences between empiric treatment regimens, and strong evidence of heterogeneity in clinical practice, the current guidelines were developed to provide Australian clinicians with comprehensive guidance for selecting an appropriate empiric strategy in the setting of neutropenic fever. Beta-lactam monotherapy is presented as the treatment of choice for all clinically stable patients while early treatment with combination antibiotic therapy is considered for patients at higher risk. Due consideration is given to the appropriate use of glycopeptides in this setting. Several clinical caveats, accounting for institution- and patient-specific risk factors, are provided to help guide the judicious use of the agents described. Detailed recommendations are also provided regarding time to first dose, timing of blood cultures, selection of a first-line antibiotic regimen, subsequent modification of antibiotic choice and cessation of therapy.
Collapse
|
81
|
Hoskin P, Chow E, Dawson L, Hahn C, Holt T, Lutz S, Rodrigues G, Tsao M. 520 oral THIRD INTERNATIONAL CONSENSUS ON PALLIATIVE RADIOTHERAPY: A JOINT ASTRO, ESTRO, CARO & TROG INITIATIVE. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)70642-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
82
|
Badcock JC, Dragovic M, Dawson L, Jones R. Normative Data for Rey's Auditory Verbal Learning Test in Individuals with Schizophrenia. Arch Clin Neuropsychol 2011; 26:205-13. [DOI: 10.1093/arclin/acr005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
83
|
Durham J, Balmer C, Bell A, Cowan G, Cowpe J, Crean SJ, Dawson L, Evans A, Freeman C, Jones J, Macluskey M, McDonagh A, McHanwell S, Millsopp L, Myrddin L, Oliver R, Renton T, Sivarajasingam V, Still D, Taylor K, Thomson P. A generic consensus assessment of undergraduate competence in forceps exodontia in the United Kingdom. EUROPEAN JOURNAL OF DENTAL EDUCATION : OFFICIAL JOURNAL OF THE ASSOCIATION FOR DENTAL EDUCATION IN EUROPE 2010; 14:210-214. [PMID: 20946248 DOI: 10.1111/j.1600-0579.2009.00612.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
UNLABELLED The assessment of competence in clinical skills has become more frequent in published healthcare curricula and syllabuses recently. There are agreed mechanisms for the assessment of competence in the post-graduate environment, but no consensus within the undergraduate curriculum. This paper seeks to develop an agreed generic checklist for the assessment of competence in forceps exodontia. MATERIALS AND METHODS A modified Delphi process was undertaken with representatives from all UK dental schools (n = 13) to develop a generic checklist for the assessment of competence in forceps exodontia. A content analysis of the assessments employed by each school was used to help discussion and inform the Delphi process. RESULTS Seven schools currently employ a summative assessment of competence in forceps exodontia, with the majority employing a structured clinical objective test (n = 6). From the seven assessments, there were a total of 29 putative items and 10 putative domains identified for a generic checklist. These were reduced to five domains and 19 items through the content analysis and Delphi process, and a generic overarching checklist was created. CONCLUSION Using this generic checklist, it may now be possible to pool data inter-institution to perform more powerful analyses on how our students obtain, or fail to obtain competence in forceps exodontia.
Collapse
|
84
|
Huang S, O'Sullivan B, Waldron J, Bayley A, Kim J, Cummings B, Dawson L, Hope A, Cho B, Lockwood G, Ringash J. 28 PATTERNS OF CARE IN ELDERLY HEAD AND NECK CANCER PATIENTS: A SINGLE INSTITUTION RECENT EXPERIENCE. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)72415-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
85
|
Han K, Cummings B, Bayley A, Brierley J, Dawson L, Dinniwell R, Ringash J, Wong R, Krzyzanowska M, MacKay H, Moore M, Chen E, Craig T, Kim J. 182 INTENSITY MODULATED RADIOTHERAPY (IMRT) AND CONCURRENT CHEMOTHERAPY (CHT) FOR ANAL AND PERIANAL CANCER: PRELIMINARY REPORT OF ACUTE TOXICITY. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)72569-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
86
|
Nguyen T, Eccles C, Velec M, Moseley J, Dawson L, Jaffray D, Brock K. THE REPRODUCIBILITY OF LIVER RESPIRATION MOTION AND DAILY DEFORMATION USING AN ABDOMINAL COMPRESSION PLATE. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)73070-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
87
|
Delport J, Dawson L, Kramer J, Raedeke M. P104 Prevalence of non-hemolytic and non-typeable group B Streptococcus isolates from screening specimens of pregnant women. Int J Antimicrob Agents 2009. [DOI: 10.1016/s0924-8579(09)70323-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
88
|
Yeung I, Dawson L, Cho Y, Moseley D, Case R, Tang Q. SU-FF-I-43: Iterative Methods of Cone-Beam CT Image Reconstruction for Under-Sampled and Truncated Projection Data. Med Phys 2009. [DOI: 10.1118/1.3181162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
89
|
Nguyen TN, Moseley J, Dawson L, Jaffray D, Brock K. SU-FF-I-96: Motion Adaptation for Registering Daily Online CBCT Images to Planning CT Images. Med Phys 2009. [DOI: 10.1118/1.3181216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
90
|
Broaddus CC, Lamm CG, Kapil S, Dawson L, Holyoak GR. Bovine viral diarrhea virus abortion in goats housed with persistently infected cattle. Vet Pathol 2009; 46:45-53. [PMID: 19112114 DOI: 10.1354/vp.46-1-45] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Twenty-four border disease virus-seronegative, pregnant, mixed breed goats were experimentally comingled with 3 heifers persistently infected with bovine viral diarrhea virus type 2a (BVDV-2a). Twelve of the 24 exposed does aborted. Twenty-nine fetuses and 16 placentas from affected does were submitted to the Oklahoma Animal Disease Diagnostic Laboratory for a necropsy examination. Infection with BVDV was confirmed with a combination of immunohistochemistry, BVDV-2 polymerase chain reaction, and virus isolation in 19 of the 29 fetuses. On gross examination of the 19 fetuses and placentas in which BVDV-2a infection was confirmed, a mild placentitis (3/19), fetal mummification (1/19), and facial deformities (4/19) were noted. Histologically, placentitis (2/19), myocarditis (4/19), thymic depletion (5/19), choroid plexitis (3/19), encephalitis (2/19), and cerebral gliosis (1/19) were noted. Other causes of abortion in goats, including common bacterial and viral infections, were ruled out with histology, virus isolation, polymerase chain reaction, and aerobic bacteriologic cultures. As supported by the findings in this case, BVDV-2a should be included as a differential for abortion in goats. This is the first report of abortion in goats after exposure to persistently infected cattle.
Collapse
|
91
|
Kleijn R, Van Spreuwel-Verheijen M, Kalkman B, Tangkau P, Dawson L, Visser SS, Meynaar I. SmartCare is faster than paper-protocol weaning. Crit Care 2009. [PMCID: PMC4083911 DOI: 10.1186/cc7189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
92
|
Meynaar I, Visser SS, Dawson L, Tangkau P, Van Spreuwel-Verheijen M. Outcome of patients with metastatic cancer or haematological malignancy in intensive care. Crit Care 2009. [PMCID: PMC4084382 DOI: 10.1186/cc7660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
93
|
Leavens C, Pekar V, Vik T, Schulz H, Allaire S, Dawson L, O'Sullivan B, Breen S, Kim J, Jaffray D. TH-D-332-03: Optimization of Landmark Detection for Auto-Contouring in Radiation Treatment Planning for Head and Neck Cancer. Med Phys 2008. [DOI: 10.1118/1.2962932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
94
|
Sturdza AE, Bezjak A, Pond GR, Brrows K, Millar B, Garraway C, Laperriere N, Dawson L, Wong RK. A phase II prospective study of standardized steroid dosing for patients with brain metastases undergoing whole brain radiotherapy. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.2050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
95
|
Lam-Tse WK, van den Berg L, Dawson L, van Ravenswaay Claasen HH, Hart W, Maartense E. [Clinical reasoning and decision-making in practice. A patient with fever and pancytopenia]. NEDERLANDS TIJDSCHRIFT VOOR GENEESKUNDE 2008; 152:606-614. [PMID: 18410020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
An 82-year-old man was admitted with a 1-week history of chilling fever and dry cough. Laboratory tests revealed pancytopenia and elevated levels of C-reactive protein and lactic dehydrogenase (LDH). Screening for infectious diseases was negative. A bone marrow biopsy showed aspecific findings. The combination of pancytopenia, persistent fever, elevated LDH and hepatomegaly (demonstrated by ultrasound examination of the abdomen) was suggestive of the haemophagocytic syndrome. This was confirmed by very high levels of ferritin and soluble interleukin-2 receptor in the blood. In addition, re-examination of the bone marrow showed several haemophagocytic histiocytes. A polymerase chain reaction for Epstein-Barr virus (EBV) revealed a very high viral load. Since the patient had a history of an increased level of anti-EBV immunoglobulin-G, this was explained by a reactivation of the EBV infection. On the sixth day in hospital the patient developed signs of bilateral pneumonia and subsequent multiple organ failure. Despite intensive treatment the patient died. Autopsy revealed no haematological or other malignancies, but did show haemophagocytosis in many organs. It was then concluded that the patient had a virus-associated haemophagocytic syndrome, due to a reactivation of EBV, for which no underlying cause was found.
Collapse
|
96
|
Van Ketel R, Meynaar I, Dawson L, Visser SS, Van Spreuwel-Verheijen M, Tangkau P. High-volume continuous venovenous hemofiltration reduces mortality in critically ill patients with acute renal failure. Crit Care 2008. [PMCID: PMC4088847 DOI: 10.1186/cc6697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
97
|
Huang S, Lockwood G, Irish J, Ringash J, Kim J, Waldron J, Dawson L, Bayley A, Cummings B, O'Sullivan B. The Truths and Myths of Radiotherapy for Verrucous Carcinoma of Larynx. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
98
|
Hwang D, Vakilha M, Breen S, Thomas C, Dawson L, Ringash J, Kim J, Cummings B, O'Sullivan B, Waldron J. Temporo-spatial Changes of Enlarged Cervical Lymph Nodes During Head and Neck Cancer IMRT Imaged With Daily On-Line Cone-Beam CT. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.1565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
99
|
Sadikov E, Bezjak A, Yi QL, Wells W, Dawson L, Millar BA, Laperriere N. Value of whole brain re-irradiation for brain metastases--single centre experience. Clin Oncol (R Coll Radiol) 2007; 19:532-8. [PMID: 17662582 DOI: 10.1016/j.clon.2007.06.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 05/09/2007] [Accepted: 06/05/2007] [Indexed: 11/23/2022]
Abstract
AIMS There is controversy in published studies regarding the role of repeat whole brain radiation (WBRT) for previously irradiated brain metastases. The aim of our retrospective study was to document the practice at Princess Margaret Hospital with respect to the re-irradiation of patients with progressive or recurrent brain metastatic disease after initial WBRT. MATERIALS AND METHODS A comprehensive computerised database was used to identify patients treated for brain metastases with more than one course of WBRT between 1997 and 2003. Seventy-two patients were treated with WBRT for brain metastases and retreated with WBRT at a later date. The records of these patients were reviewed. RESULTS The median age was 56.5 years. The most common primary sites were lung (51 patients) and breast (17 patients). The most frequent dose used for the initial radiotherapy was 20 Gy/5 fractions (62 patients). The most common doses of re-irradiation were 25 Gy/10 fractions (22 patients), 20 Gy/10 fractions (12 patients), 15 Gy/5 fractions (11 patients) and 20 Gy/8 fractions (10 patients). Thirty-one per cent of patients experienced a partial clinical response after re-irradiation, as judged by follow-up clinical notes; 27% remained stable; 32% deteriorated after re-irradiation. Patients who had Eastern Cooperative Oncology Group performance status 0-1 at the time of retreatment lived longer. In responders, the mean duration of response was 5.1 months. The median survival after re-irradiation was 4.1 months. One patient was reported as having memory impairment and pituitary insufficiency after 5 months of progression-free survival. CONCLUSION Repeat radiotherapy may be a useful treatment in carefully selected patients. With increased survival and better systemic options for patients with metastatic disease, more patients may be candidates for consideration of repeat WBRT for recurrent brain metastases, but prospective studies are needed to more clearly document their outcomes.
Collapse
|
100
|
Wysocka BA, Kassam Z, Lockwood G, Brierley J, Dawson L, Ringash J. Assessment of intra and interfractional organ motion during adjuvant radiochemotherapy in gastric cancer. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.15132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
15132 Background: Adjuvant combined chemotherapy and radiotherapy (RT) in gastric cancer improves survival, however acute toxicity is substantial. Toxicity may be improved with three-dimensional (3D) RT, but organ motion must be considered in planning target volume (PTV) delineation. Methods: Participants (n=22) had baseline free breathing planning CT (CT0) with BodyFix immobilization. Abdominal CTs in free breathing (FB), inhale (I) and exhale (E) states were obtained in weeks 1, 3 and 5 of RT. Datasets were fused to CT0 in Pinnacle3 6.2 planning system using bone registration. Volumes of interest (VOIs) [right (R) and left (L) kidney, liver, stomach, pancreas, celiac axis and porta hepatis] were contoured and points of interest (POIs) were placed at each centre of mass. POIs were manually placed at the left dome of diaphragm and splenic hilum. Organ motion was determined by the difference between POI positions in cranial-caudal (CC), anterior-posterior (AP) and right-left (RL) directions. Maximal respiratory motion was determined from the difference between I and E positions. Interfractional displacement in organs relative to bones at weeks 1, 3 and 5 was determined on FB scans as compared to baseline. Results: Interfractional organ motion was maximal in CC direction with median absolute displacements (range) in mm of: splenic hilum 10 (0–52), stomach 8 (0.4–27.2), liver 7.4 (0.5–23.6), diaphragm 6 (0–28), L kidney 5.7 (0–37.3), R kidney 5.3 (0.2–35.3), pancreas 5.7 (0.3–29.1), porta hepatis 4 (0–14) and celiac axis 1.7 (0–9.1). Median interfraction displacement (range) in CC, AP and RL in mm for all organs was: 5.7 (0- 52), 2.1 (0–23.1), 2.3 (0–15.9). Positional difference between I and E state (median for all organs) was: 16 mm CC, 5.9 mm AP, and 1.7 mm RL with maximal individual breathing excursions of 59.9, 30.2 and 21.1 mm, respectively. Conclusions: Interfraction organ displacement relative to bones can be quantified and used in the safe design of 3D conformal radiotherapy. Respiratory motion can be substantial in some individuals. Accounting for organ motion in 3D RT planning is necessary and may reduce the toxicity of treatment. No significant financial relationships to disclose.
Collapse
|