-
Rebecca K S Wong,
Daniel Letourneau,
Anita Varma,
Jean Pierre Bissonnette,
David Fitzpatrick,
Daniel Grabarz,
Christine Elder,
Melanie Martin,
Andrea Bezjak, Tony Panzarella,
Mary Gospodarowicz,
David A Jaffray
[show abstract]
[hide abstract]
ABSTRACT: To develop a cone-beam computed tomography (CT)-enabled one-step simulation-to-treatment process for the treatment of bone metastases.
A three-phase prospective study was conducted. Patients requiring palliative radiotherapy to the spine, mediastinum, or abdomen/pelvis suitable for treatment with simple beam geometry (≤2 beams) were accrued. Phase A established the accuracy of cone-beam CT images for the purpose of gross tumor target volume (GTV) definition. Phase B evaluated the feasibility of implementing the cone-beam CT-enabled planning process at the treatment unit. Phase C evaluated the online cone-beam CT-enabled process for the planning and treatment of patients requiring radiotherapy for bone metastases.
Eighty-four patients participated in this study. Phase A (n = 9) established the adequacy of cone-beam CT images for target definition. Phase B (n = 45) established the quality of treatment plans to be adequate for clinical implementation for bone metastases. When the process was applied clinically in bone metastases (Phase C), the degree of overlap between planning computed tomography (PCT) and cone-beam CT for GTV and between PCT and cone-beam CT for treatment field was 82% ± 11% and 97% ± 4%, respectively. The oncologist's decision to accept the plan under a time-pressured environment remained of high quality, with the cone-beam CT-generated treatment plan delivering at least 90% of the prescribed dose to 100% ± 0% of the cone-beam CT planning target volume (PTV). With the assumption that the PCT PTV is the gold-standard target, the cone-beam CT-generated treatment plan delivered at least 90% and at least 95% of dose to 98% ± 2% and 97% ± 5% of the PCT PTV, respectively. The mean time for the online planning and treatment process was 32.7 ± 4.0 minutes. Patient satisfaction was high, with a trend for superior satisfaction with the cone-beam CT-enabled process.
The cone-beam CT-enabled palliative treatment process is feasible and is ready for clinical implementation for the treatment of bone metastases using simple beam geometry, providing a streamlined one-step process toward palliative radiotherapy.
International journal of radiation oncology, biology, physics 05/2012; 84(3):834-40. · 4.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: PurposeTo compare the image quality and acceptability of a low dose with those of standard dose abdominal/pelvic multidetector CT
in patients with stage 1 testicular cancer managed by surveillance.
MethodsOne hundred patients (median age 31years; range 19–83years), 79 with seminoma and 21 with non-seminoma, underwent abdominal/pelvic
imaging with low and standard dose protocols on 64-slice multidetector CT. Three reviewers independently evaluated images
for noise and diagnostic quality on a 5-point scale and for diagnostic acceptability.
ResultsOn average, each reader scored noise and diagnostic quality of standard dose images significantly better than corresponding
low dose images (p < 0.0001). One reader found all CT examinations acceptable; two readers each found 1/100 (1%) low dose examinations unacceptable.
Median and mean dose–length product for low and standard dose protocols were 416.0 and 452.2 (range 122.9–913.4) and 931.9
and 999.8 (range 283.8–1,987.7)mGycm, respectively.
ConclusionsThe low dose protocol provided diagnostically acceptable images for at least 99% of patients and achieved mean dose reduction
of 55% compared with the standard dose protocol.
KeywordsCT-Testicular cancer-Radiation-Dose-Image quality
European Radiology 04/2012; 20(7):1624-1630. · 3.22 Impact Factor
-
Danny Vesprini,
Peter Chung,
Shaun Tolan,
Mary Gospodarowicz,
Michael Jewett,
Martin O'Malley,
Joan Sweet,
Malcolm Moore, Tony Panzarella,
Jeremy Sturgeon,
Linda Sugar,
Lynn Anson-Cartwright,
Padraig Warde
[show abstract]
[hide abstract]
ABSTRACT: The serum tumor markers α-fetoprotein (AFP), β-human chorionic gonadotropin (HCG), and lactate dehydrogenase (LDH) are often measured as part of surveillance protocols in patients with stage I seminoma. In this study, the authors evaluated the utility of routine measurement of these markers in the detection of disease relapse.
Data were gathered from a prospectively maintained database of patients who underwent surveillance for stage I testicular seminoma diagnosed between 1982 and 2005 at Princess Margaret Hospital. Patients were followed on a predefined schedule with physical examination (PE), serum tumor markers, abdominopelvic computed tomography, and chest x-rays. The records of patients who relapsed were examined for details of imaging and serum tumor markers throughout the period of follow-up until the time of relapse.
Of the 527 patients who were managed by surveillance, 75 patients (14%) relapsed at a median follow-up of 72 months. Of these, 65 patients relapsed within the first 3 years and had routine serum tumor markers measured. In total, 11 patients had abnormal tumor markers at the time of relapse (AFP, 0 patients; HCG, 6 patients; LDH, 4 patients; and HCG and LDH, 1 patient). Only 1 patient had an elevated tumor marker (LDH) before relapse, as defined by an abnormal imaging study (n = 64) or physical examination (n = 1), for which the treatment and outcome were not affected.
Serum tumor marker levels did not aid in the early diagnosis of disease relapse in patients with stage I seminoma who were managed with surveillance. The current results indicated that routine measurement of serum tumor markers can be discontinued safely in seminoma surveillance schedules. Cancer 2012. © 2012 American Cancer Society.
Cancer 04/2012; 118(21):5245-50. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To assess the relative effectiveness of five image-guidance (IG) frequencies on reducing patient positioning inaccuracies and setup margins for locally advanced lung cancer patients.
Daily cone-beam computed tomography data for 100 patients (4,237 scans) were analyzed. Subsequently, four less-than-daily IG protocols were simulated using these data (no IG, first 5-day IG, weekly IG, and alternate-day IG). The frequency and magnitude of residual setup error were determined. The less-than-daily IG protocols were compared against the daily IG, the assumed reference standard. Finally, the population-based setup margins were calculated.
With the less-than-daily IG protocols, 20-43% of fractions incurred residual setup errors ≥ 5 mm; daily IG reduced this to 6%. With the exception of the first 5-day IG, reductions in systematic error (∑) occurred as the imaging frequency increased and only daily IG provided notable random error (σ) reductions (∑ = 1.5-2.2 mm, σ = 2.5-3.7 mm; ∑ = 1.8-2.6 mm, σ = 2.5-3.7 mm; and ∑ = 0.7-1.0 mm, σ = 1.7-2.0 mm for no IG, first 5-day IG, and daily IG, respectively. An overall significant difference in the mean setup error was present between the first 5-day IG and daily IG (p < .0001). The derived setup margins were 5-9 mm for less-than-daily IG and were 3-4 mm with daily IG.
Daily cone-beam computed tomography substantially reduced the setup error and could permit setup margin reduction and lead to a reduction in normal tissue toxicity for patients undergoing conventionally fractionated lung radiotherapy. Using first 5-day cone-beam computed tomography was suboptimal for lung patients, given the inability to reduce the random error and the potential for the systematic error to increase throughout the treatment course.
International journal of radiation oncology, biology, physics 08/2011; 80(5):1330-7. · 4.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To describe the degree of interobserver and intraobserver variability in target and field definition when using three-dimensional (3D) volume- vs. two-dimensional (2D) field-based planning.
Standardized case scenario and diagnostic imaging for 9 palliative cases (3 bone metastases, 3 palliative lung cancer, and 3 abdominal pelvis soft-tissue disease) were presented to 5 study radiation oncologists. After a decision on what the intended anatomic target should be, observers created two sets of treatment fields, first using a 2D field-based and then a 3D volume-based planning approach. Percent overlap, under-coverage, and over-coverage were used to describe interobserver and intraobserver variations in target definition.
The degree of interobserver variation for 2D and 3D planning was similar with a degree of overlap of 76% (range, 56%-85%) and 74% (range, 55%-88%), respectively. When comparing the treatment fields defined by the same observer using the two different planning methods, the mean degree of overlap was 78%; over-coverage, 22%; and under-coverage, 41%. There was statistically significantly more under-coverage when field-based planning was used for bone metastases (33%) vs. other anatomic sites (16%) (p = 0.02). In other words, 2D planning is more likely to result in geographic misses in bone metastases compared with other areas.
In palliative radiotherapy clinically significant interobserver and intraobserver variation existed when using both field- and volume-based planning approaches. Strategies that would reduce this variability deserve further investigation.
International journal of radiation oncology, biology, physics 08/2011; 80(5):1498-504. · 4.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We compared the outcomes including health-related quality of life (HRQOL) in adult patients undergoing allogeneic transplantation using myeloablative conditioning (MAC) or reduced-intensity conditioning (RIC). This outcome study was a nonrandomized, prospective, observational noninferiority study, and primarily designed to determine whether RIC was as effective as MAC for myeloid malignancies. Comprehensive longitudinal assessment of HRQOL was done at baseline, day 30, day 100, day 180, and day 365 using validated instruments. A total of 115 patients (MAC, 51; RIC, 64) participated in this study. Of these 115 patients, 105 (91%) participated for HRQOL assessments. The main indication for HCT was acute myeloid leukemia (72%). Except age (median 41 vs 59 years, P < .0001), baseline characteristics were similar in patients undergoing MAC and RIC, respectively. Progression-free survival (PFS) at 1 year was 59% (SE = 7%) and 53% (SE = 6%) for the patients undergoing MAC and RIC, respectively (90% confidence interval [CI] -9% to +21%, P = .53). No significant difference in overall survival (OS), cumulative incidents of acute and chronic graft-versus-host disease (aGVHD, cGVHD), nonrelapse mortality (NRM) or relapse was observed in the 2 cohorts. The trajectory of decline and recovery of HRQOL was similar between the 2 cohorts. We conclude that clinical outcomes and HRQOL in patients with myeloid malignancies undergoing RIC are not inferior to MAC at 1 year.
Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 06/2011; 18(1):113-24. · 3.15 Impact Factor
-
Kim Edelstein,
Brenda J Spiegler,
Sharon Fung, Tony Panzarella,
Donald J Mabbott,
Natalie Jewitt,
Norma Mammone D'Agostino,
Warren P Mason,
Eric Bouffet,
Uri Tabori,
Normand Laperriere,
David C Hodgson
[show abstract]
[hide abstract]
ABSTRACT: Treatment for medulloblastoma during childhood impairs neurocognitive function in survivors. While those diagnosed at younger ages are most vulnerable, little is known about the long-term neurocognitive, functional, and physical outcomes in survivors as they approach middle age. In this retrospective cohort study, we assessed 20 adults who were treated with surgery and radiotherapy for medulloblastoma during childhood (median age at assessment, 21.9 years [range, 18-47 years]; median time since diagnosis, 15.5 years [range, 6.5-42.2 years]). Nine patients also underwent chemotherapy. Cross-sectional analyses of current neurocognitive, functional, and physical status were conducted. Data from prior neuropsychological assessments were available for 18 subjects; longitudinal analyses were used to model individual change over time for those subjects. The group was well below average across multiple neurocognitive domains, and 90% had required accommodations at school for learning disorders. Longer time since diagnosis, but not age at diagnosis, was associated with continued decline in working memory, a common sign of aging. Younger age at diagnosis was associated with lower intelligence quotient and academic achievement scores, even many years after treatment had been completed. The most common health complications in survivors were hearing impairment, second cancers, diabetes, hypertension, and endocrine deficiencies. Adult survivors of childhood medulloblastoma exhibit signs of early aging regardless of how young they were at diagnosis. As survival rates for brain tumors continue to improve, these neurocognitive and physical sequelae may become evident in survivors diagnosed at different ages across the lifespan. It will become increasingly important to identify factors that contribute to risk and resilience in this growing population.
Neuro-Oncology 03/2011; 13(5):536-45. · 5.72 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To compare the image quality and acceptability of a low dose with those of standard dose abdominal/pelvic multidetector CT in patients with stage 1 testicular cancer managed by surveillance.
One hundred patients (median age 31 years; range 19-83 years), 79 with seminoma and 21 with non-seminoma, underwent abdominal/pelvic imaging with low and standard dose protocols on 64-slice multidetector CT. Three reviewers independently evaluated images for noise and diagnostic quality on a 5-point scale and for diagnostic acceptability.
On average, each reader scored noise and diagnostic quality of standard dose images significantly better than corresponding low dose images (p < 0.0001). One reader found all CT examinations acceptable; two readers each found 1/100 (1%) low dose examinations unacceptable. Median and mean dose-length product for low and standard dose protocols were 416.0 and 452.2 (range 122.9-913.4) and 931.9 and 999.8 (range 283.8-1,987.7) mGy cm, respectively.
The low dose protocol provided diagnostically acceptable images for at least 99% of patients and achieved mean dose reduction of 55% compared with the standard dose protocol.
European Radiology 07/2010; 20(7):1624-30. · 3.22 Impact Factor
-
Colleen I Dickie,
Amy L Parent,
Peter W M Chung,
Charles N Catton,
Tim Craig,
Anthony M Griffin, Tony Panzarella,
Peter C Ferguson,
Jay S Wunder,
Robert S Bell,
Michael B Sharpe,
Brian O'Sullivan
[show abstract]
[hide abstract]
ABSTRACT: To evaluate inter- and intrafractional motion and rotational error for lower extremity soft tissue sarcoma patients by using cone beam computed tomography (CBCT) and an optical localization system.
Thirty-one immobilized patients received CBCT image-guided intensity-modulated radiation therapy. Setup deviations of >3 mm from the planned isocenter were corrected. A second CBCT acquired before treatment delivery was registered to the planning CT to estimate interfractional setup error retrospectively. Interfractional error and rotational error were calculated in the left-right (LR), superoinferior (SI), and anteroposterior (AP) dimensions. Intrafractional motion was assessed by calculating the maximum relative displacement of optical localization system reflective markers placed on the patient's surface, combined with pre- and postfraction CBCT performed for 17 of the 31 patients once per week. The overall systematic error (SE) and random error (RE) were calculated for the interfractional and intrafractional motion for planning target volume margin calculation.
The standard deviation (SD) of the interfractional RE was 1.9 mm LR, 2.1 mm SI, and 1.8 mm AP, and the SE SD was 0.6 mm, 1.2 mm, and 0.7 mm in each dimension, respectively. The overall rotation (inter- and intrafractional) had an RE SD of 0.8° LR, 1.7° SI, and 0.7° AP and an SE SD of 1.1° LR, 1.3° SI, and 0.3° AP. The SD of the overall intrafractional RE was 1.6 mm LR, 1.6 mm SI, and 1.4 mm AP, and the SE SD was 0.7 mm AP, 0.6 mm SI, and 0.6 mm AP.
A uniform 5-mm planning target volume margin was quantified for lower extremity soft tissue sarcoma patients and has been implemented clinically for image-guided intensity-modulated radiation therapy.
International journal of radiation oncology, biology, physics 03/2010; 78(5):1437-44. · 4.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A study was performed to identify variables that affected cause-specific survival (CSS) and local relapse-free rate (LRFR) in patients with differentiated thyroid cancer (DTC) and extrathyroid extension (ETE) and to examine the role of external beam radiotherapy (XRT). Prognostic factors were similar to those found in studies of all patients with DTC. In patients with postoperative gross residual disease treated with radiotherapy, 10-year CSS and LRFR were 48% and 90%. For patients with no residual or microscopic disease, 10-year CSS and LRFR were 92% and 93%. In patients older than 60 years with T3 ETE but no gross residual disease postoperatively there was an improved LRFR at 5 years of 96%, compared to 87.5% without XRT (P = .02). Patients with gross ETE benefit from XRT and there may be a potential benefit in reducing locoregional failure in patients over 60 years with minimal extrathyroidal extension (T3).
Journal of thyroid research. 01/2010; 2010:183461.
-
[show abstract]
[hide abstract]
ABSTRACT: Teaching delivery of bad news is part of the standard medical school curriculum. Lung cancer is a common disease with poor outcomes; therefore, "poor prognosis" discussions occur frequently. Trainee preparedness to conduct these has not been studied well to date. We surveyed residents treating lung cancer in Ontario, assessing preparedness to discuss a poor prognosis.
A 17-question survey was distributed to residents in medical oncology, palliative care, radiation oncology, respirology, and thoracic surgery. The survey questioned demographics, prior communication skills training, lung cancer knowledge, comfort in discussing a poor prognosis, and preferred approach to these consultations.
Of 153 surveys distributed, 46% were completed. Most residents (68%) were Canadian trained and 70% were in the second-half of training. Lung cancer knowledge scores appear to be related to specialty (p = 0.016); medical oncology residents scored higher (mean score 2.7/4) than other specialties (range 0-1.9). Comfort in discussing prognosis increased with years of training (p < 0.0001). Observation of attending physicians was the preferred learning method (58%, p < 0.0001). Similar numbers of residents preferred an optimistic or realistic approach in a poor prognosis consultation (49% versus 45%). Lung cancer knowledge, training location, specialty, age, gender, and level of comfort or preparedness in discussing bad news did not influence the approach taken by residents in a scenario of discussing a poor prognosis.
Comfort in discussing bad news improves with time. Residents rate observation the most useful tool in learning this skill. Efforts to enhance preparedness should include resident attendance and involvement in these consultations.
Supportive Care in Cancer 08/2009; 18(4):491-7. · 2.09 Impact Factor
-
Shaun Tolan,
Danny Vesprini,
Michael A S Jewett,
Padraig R Warde,
Martin O'Malley, Tony Panzarella,
Jeremy F G Sturgeon,
Malcolm Moore,
Betty Tew-George,
Mary K Gospodarowicz,
Peter W M Chung
[show abstract]
[hide abstract]
ABSTRACT: After orchidectomy, the standard management options available for stage I seminoma are surveillance, adjuvant radiotherapy, or adjuvant chemotherapy. The optimal follow-up protocol for surveillance is yet to be determined but includes frequent chest radiography (CXR) and computed tomography (CT) scan of the abdomen and pelvis (CT-AP).
The purpose of this study was to identify the modality that first detected relapse and to assess the value of the CXR in this setting.
Five hundred twenty-seven patients with histologically confirmed stage I testicular seminoma were managed with surveillance at our institution between 1982 and 2005. Routine CXRs were performed with each CT-AP and were done every 4-6 mo for 7 yr and annually thereafter. The median follow-up was 72 mo (range: 1-193).
Measurements included the 5-yr relapse rate, overall survival, and disease-free survival to determine the modality that first detected relapse disease.
The 5-yr actuarial relapse rate for the 527 patients was 14%. The 5-yr disease-free survival and overall survival were 85.7% and 98.6%, respectively. Seventy-three patients (97.3%) had an abnormal CT-AP and a normal CXR at relapse. One patient (1.3%) had an abnormal CT-AP with pulmonary metastasis on CXR and CT chest scan, and one patient (1.3%) had a biopsy-proven inguinal node metastasis with a normal CXR. No patient had a normal CT-AP or physical examination with an abnormal CXR at relapse. This is a single-center retrospective study based on a relatively small number of relapses and may be subject to bias. Confirmation of these results from other studies would be useful for wider clinical applicability.
All except one relapse were detected by CT-AP with no relapses detected on CXR alone; therefore, CXR may be omitted as routine imaging in surveillance protocols.
European urology 07/2009; 57(3):474-9. · 7.67 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The number of individuals receiving genetic counseling for hereditary breast and ovarian cancer syndrome has steadily risen. To triage patients for genetic counseling and to help reduce the amount of time needed by a genetic counselor in direct patient contact, many clinics have implemented the use of family history questionnaires. Although such questionnaires are widely used, scant literature exists evaluating their effectiveness. This article explores the extent to which family history questionnaires are being used in Ontario and addresses the utility of such questionnaires in one familial cancer clinic. By comparing the pedigrees created from questionnaires to those updated during genetic counseling, the accuracy and effectiveness of the questionnaires was explored. Of 121 families recruited into the study, 12% acquired changes to their pedigree that led to a revised probability estimate for having a BRCA1 or BRCA2 mutation and 5% acquired changes that altered their eligibility for genetic testing. No statistically significant difference existed between the eligibility for genetic testing prior to and post counseling. This suggests that family history questionnaires can be effective at obtaining a family history and accurately assessing eligibility for genetic testing. Based on the variables that were significantly associated with a change in probability estimate, we further present recommendations for improving the clarity of such questionnaires and therefore the ease of use by patients.
Journal of Genetic Counseling 06/2009; 18(4):366-78. · 1.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine if the pathology of small (< or = 4 cm) solid renal tumors can be predicted from findings on multidetector CT.
This retrospective study included 46 patients (median age, 60 years; range, 32-91 years; 27 males, 19 females) with 47 tumors who underwent triphasic renal CT with pathology correlation. Two radiologists reviewed CT studies blinded to pathology results and recorded the morphologic and enhancement features of the tumors.
The 47 tumors (median diameter, 2.5 cm; range, 0.6-4.0 cm) included: 26 (55%) clear cell renal cell carcinomas; 9 (19%) oncocytomas; 7 (15%) papillary renal cell carcinomas; 2 (4%) chromophobe renal cell carcinomas; 2 (4%) inflammatory pseudotumors; and 1 (2%) angiomyolipoma with minimal fat. Amongst the three commonest tumors, heterogeneity was seen in 23/26 (88%) clear cell renal cell carcinomas, 6/9 (67%) oncocytomas, and 2/7 (29%) papillary renal cell cancer. Median (minimum-maximum) absolute nephrographic phase enhancement (nephrographic minus unenhanced phase) was: clear cell renal cell carcinomas 65 HU (34-120), oncocytomas 80 HU (51-111), and papillary renal cell carcinomas 16 HU (7-32).
Absolute nephrographic phase enhancement of < or = 32 HU distinguished papillary renal cell carcinomas from clear cell renal cell carcinomas and oncocytomas.
Abdominal Imaging 06/2009; 35(4):488-93. · 1.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The purpose of this study was to determine the accuracy and efficiency of a custom-designed immobilization device for patients with extremity soft-tissue sarcoma. The custom device consisted of a thermoplastic shell, vacuum pillow, and adaptable baseplate. The study included patients treated from January 2005 to March 2007, with 92 patients immobilized with the custom device and 98 with an established standard. Setup times for these cohorts were analyzed retrospectively for conformal and intensity modulated radiotherapy techniques (IMRT). Thigh tumor setup times were analyzed independently. A subset of patients treated with IMRT was analyzed for setup error using the radiographically verified isocenter position measured daily with electronic portal imaging and cone-beam computed tomography. Mean setup time was reduced by 2.2 minutes when using the custom device for conformal treatment (p = 0.03) and by 5.8 min for IMRT of thigh tumors (p = 0.009). All other setup time comparisons were not significant. A significant systematic error reduction was seen in all directions using the custom device. Random error standard deviations favored the custom device. The custom device offers immobilization advantages. Patient setup time was reduced for conformal techniques and IMRT of thigh tumors. Positioning uncertainty was improved, permitting a reduction of the planning target volume margin by 2 to 4 mm.
Medical dosimetry: official journal of the American Association of Medical Dosimetrists 02/2009; 34(3):243-9. · 1.26 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Cancer care professionals work in a stressful environment, but it is not clear what factors contribute to this stress. We surveyed 60 oncology personnel on an inpatient unit and a palliative care unit regarding levels of perceived work stress and its potential contributors. Logistic regression analyses were performed to determine predictors of staff stress. A total of 63% of staff reported experiencing ;;a great deal'' of stress at work, which was predicted by greater perceived workload (odds ratio = 32.2; P < .0001), insufficient time to grieve patients' death (odds ratio = 9.75; P = .0007), lack of institutional support (odds ratio = 0.16; P = .009), perceived lack of resources (odds ratio = 0.06; P = .007), and lack of control over the choice of workplace (odds ratio = 0.10; P = .03). Measures to address work-related stress should be included in the planning of cancer programs.
The American journal of hospice & palliative care 01/2009; 26(2):105-11.
-
[show abstract]
[hide abstract]
ABSTRACT: To derive and validate a simple predictive model for survival of patients with metastatic cancer attending a palliative radiotherapy clinic.
We described previously a model predicting survival of patients referred for palliative radiotherapy using six prognostic factors: primary cancer site, site of metastases, Karnofsky performance score (KPS), and the fatigue, appetite, and shortness of breath subscales from the Edmonton Symptom Assessment Scale. Here we simplified the model to include only three factors: primary cancer site, site of metastases, and KPS. Each factor was assigned a value proportional to its prognostic weight, and the weighted scores for each patient were summed to obtain a survival prediction score (SPS). Patients were also grouped according to their number of risk factors (NRF): nonbreast cancer, metastases other than bone, and KPS < or = 60. The three- and six- variable models were evaluated for their ability to predict survival in patients referred during a different time period and of those referred to a different cancer center.
A training set of 395 patients, a temporal validation set of 445 patients, and an external validation set of 467 patients were used. The ability of the three- and six-variable models to separate patients into three prognostic groups and to predict their survival was similar using both SPS and NRF methods in the training, temporal, and external validation data sets. There was no statistically significant difference in the performance of the models.
The three-variable NRF model is preferred because of its relative simplicity.
Journal of Clinical Oncology 11/2008; 26(36):5863-9. · 18.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To construct a predictive model for survival of patients referred to the Rapid Response Radiotherapy Program using recursive partitioning (RP).
We analyzed 16 factors characterizing patients with metastases at first referral to the Rapid Response Radiotherapy Program for palliative radiotherapy in 1999 for their effect on survival. They included age, primary cancer site, site of metastases, weight loss (>or=10% during the past 6 months), Karnofsky performance status (KPS), interval from the first diagnosis of cancer to the first consultation at the Rapid Response Radiotherapy Program, analgesic consumption within the previous 24 h, and the nine symptom scores from the Edmonton Symptom Assessment Scale. We used RP to develop a predictive model of survival for patients referred in 1999, followed by temporal validation using patients referred in 2000, and external validation using patients referred in 2002 to another institution.
The model was able to separate patients into three groups with different durations of survival that were defined by (1) KPS >60; (2) KPS <or=60 with bone metastases only; and (3) KPS <or=60 with other metastases. The model performed moderately well when applied to the validation sets, but a major limitation was that it led to an unequal distribution of patients, with a small proportion of patients in the intermediate group.
We have demonstrated that RP can be used to predict the survival of patients with advanced cancer. However, this model has no advantages compared with our published prognostic models that use the survival prediction scores and number of risk factors.
International journal of radiation oncology, biology, physics 10/2008; 73(4):1169-76. · 4.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To validate a predictive model for survival of patients attending a palliative radiotherapy clinic.
We described previously a model that had good predictive value for survival of patients referred during 1999 (1). The six prognostic factors (primary cancer site, site of metastases, Karnofsky performance score, and the fatigue, appetite and shortness-of-breath items from the Edmonton Symptom Assessment Scale) identified in this training set were extracted from the prospective database for the year 2000. We generated a partial score whereby each prognostic factor was assigned a value proportional to its prognostic weight. The sum of the partial scores for each patient was used to construct a survival prediction score (SPS). Patients were also grouped according to the number of these risk factors (NRF) that they possessed. The probability of survival at 3, 6, and 12 months was generated. The models were evaluated for their ability to predict survival in this validation set with appropriate statistical tests.
The median survival and survival probabilities of the training and validation sets were similar when separated into three groups using both SPS and NRF methods. There was no statistical difference in the performance of the SPS and NRF methods in survival prediction.
Both the SPS and NRF models for predicting survival in patients referred for palliative radiotherapy have been validated. The NRF model is preferred because it is simpler and avoids the need to remember the weightings among the prognostic factors.
International journal of radiation oncology, biology, physics 09/2008; 73(1):280-7. · 4.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This study compared our experience with completion thyroidectomy (CT) and total thyroidectomy (TT) in the management of well-differentiated thyroid cancer (WDTC). We compared complication rates and analyzed the implications of the intraoperative management of the parathyroid glands.
We performed a retrospective cohort study comparing outcomes between patients undergoing CT and TT between January 1994 and December 2004. All patients had surgery for either suspected or confirmed WDTC on fine-needle aspiration.
There were 201 CTs and 149 TTs. Mean hospital stays were 4.5 and 3.5 days for the CT and TT groups, respectively (p=0.001). Temporary recurrent laryngeal nerve paresis occurred in 2.0% (4 of 201) and 3.3% (5 of 149) of patients in the CT and TT groups, respectively. There was one (0.5%) case of permanent recurrent laryngeal nerve paralysis in the CT group. Permanent hypoparathyroidism rates were 2.5% and 3.3% in the CT and TT groups, respectively. There was no difference between the two groups in terms of total numbers of parathyroid glands autotransplanted (p=0.63) or present in the specimen (p=0.26).
Completion thyroidectomy is a safe and appropriate option in the management of select cases of WDTC in which a definitive preoperative or intraoperative diagnosis is not available. But it requires a longer hospitalization, so it has implications for both hospital resources and the patients involved.
Journal of the American College of Surgeons 11/2007; 205(4):602-7. · 4.55 Impact Factor
