Charles N Catton

The Princess Margaret Hospital, Toronto, Ontario, Canada

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Publications (115)494.48 Total impact

  • A. Hosni · T. Rosewall · T. Craig · V.C. Kong · A. Bayley · C.N. Catton · P. Chung ·

    International journal of radiation oncology, biology, physics 11/2015; 93(3):E212-E213. DOI:10.1016/j.ijrobp.2015.07.1086 · 4.26 Impact Factor
  • Y. Alayed · T. Craig · C.N. Catton · P.R. Warde · P. Chung · A. Bayley · T. Panzarella · C. Menard ·

    International journal of radiation oncology, biology, physics 11/2015; 93(3):E249. DOI:10.1016/j.ijrobp.2015.07.1173 · 4.26 Impact Factor
  • A.J. McPartlin · A. Hosni · H. Alasti · C.N. Catton · Y.B. Cho · C. Menard ·

    International journal of radiation oncology, biology, physics 11/2015; 93(3):E242. DOI:10.1016/j.ijrobp.2015.07.1157 · 4.26 Impact Factor
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    ABSTRACT: Evidence for external beam radiation therapy (RT) as part of treatment for retroperitoneal sarcoma (RPS) is limited. Preoperative RT is the subject of a current randomized trial, but the results will not be available for many years. In the meantime, many practitioners use preoperative RT for RPS, and although this approach is used in practice, there are no radiation treatment guidelines. An international expert panel was convened to develop consensus treatment guidelines for preoperative RT for RPS. An expert panel of 15 academic radiation oncologists who specialize in the treatment of sarcoma was assembled. A systematic review of reports related to RT for RPS, RT for extremity sarcoma, and RT-related toxicities for organs at risk was performed. Due to the paucity of high-quality published data on the subject of RT for RPS, consensus recommendations were based largely on expert opinion derived from clinical experience and extrapolation of relevant published reports. It is intended that these clinical practice guidelines be updated as pertinent data become available. Treatment guidelines for preoperative RT for RPS are presented. An international panel of radiation oncologists who specialize in sarcoma reached consensus guidelines for preoperative RT for RPS. Many of the recommendations are based on expert opinion because of the absence of higher level evidence and, thus, are best regarded as preliminary. We emphasize that the role of preoperative RT for RPS has not been proven, and we await data from the European Organization for Research and Treatment of Cancer (EORTC) study of preoperative radiotherapy plus surgery versus surgery alone for patients with RPS. Further data are also anticipated pertaining to normal tissue dose constraints, particularly for bowel tolerance. Nonetheless, as we await these data, the guidelines herein can be used to establish treatment uniformity to aid future assessments of efficacy and toxicity. Copyright © 2015 Elsevier Inc. All rights reserved.
    International journal of radiation oncology, biology, physics 07/2015; 92(3):602-612. DOI:10.1016/j.ijrobp.2015.02.013 · 4.26 Impact Factor
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    ABSTRACT: The aim of this study was to determine the relationship of the time interval between completion of preoperative radiation therapy (RT) and surgical resection on wound complications (WCs) in extremity soft tissue sarcoma (STS). Overall, 798 extremity STS patients were managed with preoperative RT and surgery from 1989 to 2013. WCs were defined as requiring secondary operations/invasive procedures for wound care, use of vacuum-assisted closure, prolonged dressing changes, or infection within 120 days of surgery. Mean tumor size was 8.8 cm. A total of 743 (93 %) tumors were primary presentations, 565 (71 %) patients had lower extremity tumors, and 238 patients (30 %) had a prior unplanned excision. Of 242 patients (30 %) who developed a WC, 206 (37 %) had lower extremity tumors and 36 (15 %) had upper extremity tumors. Mean time from RT completion to surgery was 41.3 (range 4-470) days; 42.0 (range 4-470) days for upper extremity cases, and 41.1 (range 4-109) days for lower extremity cases. Similarly, mean time interval for patients who developed a WC was 40.9 (range 4-100) days, and 41.5 (range 4-470) days for those who did not develop a WC (p = 0.69). Thirty-nine cases (5 %) had surgery within 3 weeks of RT; 15 (38 %) patients developed WCs versus 227 (30 %) patients who had their tumors excised after 3 weeks (p = 0.28). One hundred and twenty-nine (16 %) patients had surgery within 4 weeks, and 39 (30 %) patients developed WCs versus 203 (30 %) patients who had their tumors excised after 4 weeks (p = 1.0). A trend towards a higher rate of WCs was seen for those patients who had surgery after 6 weeks (28 % prior vs. 34 % after; p = 0.08). There was no difference in WCs with intensity-modulated RT (IMRT) versus non-IMRT cases (p = 0.6). The time interval between preoperative RT and surgical excision in extremity STS had minimal influence on the development of WCs. Four- or 5-week intervals showed equivalent complication rates between the two groups, suggesting an optimal interval to reduce potential WCs.
    Annals of Surgical Oncology 05/2015; 22(9). DOI:10.1245/s10434-015-4631-z · 3.93 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the variability in target volume and organ at risk (OAR) contour delineation for retroperitoneal sarcoma (RPS) among 12 sarcoma radiation oncologists. Radiation planning computed tomography (CT) scans for 2 cases of RPS were distributed among 12 sarcoma radiation oncologists with instructions for contouring gross tumor volume (GTV), clinical target volume (CTV), high-risk CTV (HR CTV: area judged to be at high risk of resulting in positive margins after resection), and OARs: bowel bag, small bowel, colon, stomach, and duodenum. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Ten radiation oncologists contoured both RPS cases, 1 contoured only RPS1, and 1 contoured only RPS2 such that each case was contoured by 11 radiation oncologists. The first case (RPS 1) was a patient with a de-differentiated (DD) liposarcoma (LPS) with a predominant well-differentiated (WD) component, and the second case (RPS 2) was a patient with DD LPS made up almost entirely of a DD component. Contouring agreement for GTV and CTV contours was high. However, the agreement for HR CTVs was only moderate. For OARs, agreement for stomach, bowel bag, small bowel, and colon was high, but agreement for duodenum (distorted by tumor in one of these cases) was fair to moderate. For preoperative treatment of RPS, sarcoma radiation oncologists contoured GTV, CTV, and most OARs with a high level of agreement. HR CTV contours were more variable. Further clarification of this volume with the help of sarcoma surgical oncologists is necessary to reach consensus. More attention to delineation of the duodenum is also needed. Copyright © 2015 Elsevier Inc. All rights reserved.
    International journal of radiation oncology, biology, physics 05/2015; 92(5). DOI:10.1016/j.ijrobp.2015.04.039 · 4.26 Impact Factor
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    ABSTRACT: Background: The objectives of this study were to evaluate the risk of local recurrence and survival after soft tissue sarcoma (STS) resection with positive margins and to evaluate the safety of sparing adjacent critical structures. Methods: One hundred sixty-nine patients with localized STS who had positive resection margins were identified from a prospective database. Patients who had positive margins were stratified into 3 groups, each representing a specific clinical scenario: critical structure positive margin (eg major nerve, vessel, or bone), tumor bed resection positive margin, and unexpected positive margin. The rates of local recurrence-free survival (LRFS) and cause-specific survival (CSS) were calculated and compared with relevant control patients who had negative margins after STS resection. Results: After planned close dissection to preserve critical structures, the 5-year LRFS and CSS rates both depended on the quality of the surgical margins (97% and 80.3%, respectively, for those with negative margins vs 85.4% and 59.4%, respectively, for those with positive margins; P = .015 and P = .05, respectively). Negative margins achieved through resection of critical structures because of tumor invasion or encasement only slightly improved the 5-year rates of LRFS (91.2%) and CSS (63.6%; P = .8 and P = .9, respectively). The lowest 5-year LRFS and CSS rates were 63.4% and 59.2%, respectively, after an unexpected positive margin during primary surgery. Conclusions: After patients undergo resection of STS with positive margins, oncologic outcomes can be predicted based on the clinical context. Sparing adjacent critical structures in this setting is safe and contributes to improved functional outcomes.
    Cancer 09/2014; 120(18). DOI:10.1002/cncr.28793 · 4.89 Impact Factor

  • International journal of radiation oncology, biology, physics 09/2014; 90(1):S116-S117. DOI:10.1016/j.ijrobp.2014.05.546 · 4.26 Impact Factor
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    ABSTRACT: Late failure is a challenging problem following resection of retroperitoneal sarcoma (RPS). We investigated the effects of preoperative XRT plus dose escalation with early postoperative brachytherapy (BT) on long-term survival and recurrence in RPS. From June 1996 to October 2000, eligible patients with resectable RPS were entered onto a phase II trial of preoperative XRT (45-50Gray) plus postoperative BT (20-25Gray). Kaplan Meier survival curves were constructed and compared by log rank analysis (SPSS 21.0). All 40 patients had preoperative XRT and total gross resection as part of the prospective trial, nineteen received BT (48%). Median follow-up was 106months. For the entire cohort, OS at 5 and 10years was 70% and 64%, respectively; RFS at 5 and 10years was 69% and 63%. RFS was significantly reduced in high versus low grade RPS at 5years (53% vs. 88%, p=0.016), but not at 10years (53% vs. 75%, p=0.079). RFS and OS at 10years were reduced in patients who presented with recurrent compared to primary disease (RFS 30% vs. 74%, p=0.015; OS 36% vs. 76%, p=0.036). At 10years, neither RFS nor OS was improved in patients who received BT compared to those who did not (RFS 56% vs. 69%, p=0.54; OS 52% vs.76%, p=0.23). In this prospective trial with mature follow-up, long-term OS and RFS in patients who underwent combined preoperative XRT plus resection of RPS compare favourably with those reported in retrospective institutional and population-based series. Postoperative BT was associated with unacceptable toxicity and did not contribute to disease control. In a prospective trial with mature follow-up, preoperative radiation combined with complete resection of retroperitoneal sarcoma resulted in favourable long-term RFS and OS compared to historical controls. Dose escalation with postoperative brachytherapy was not associated with better disease control.
    Radiotherapy and Oncology 01/2014; 110(1). DOI:10.1016/j.radonc.2013.10.041 · 4.36 Impact Factor
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    ABSTRACT: Background: This study sought to determine if preoperative image-guided intensity-modulated radiotherapy (IG-IMRT) can reduce morbidity, including wound complications, by minimizing dose to uninvolved tissues in adults with lower extremity soft tissue sarcoma. Methods: The primary endpoint was the development of an acute wound complication (WC). IG-IMRT was used to conform volumes to avoid normal tissues (skin flaps for wound closure, bone, or other uninvolved soft tissues). From July 2005 to June 2009, 70 adults were enrolled; 59 were evaluable for the primary endpoint. Median tumor size was 9.5 cm; 55 tumors (93%) were high-grade and 58 (98%) were deep to fascia. Results: Eighteen (30.5%) patients developed WCs. This was not statistically significantly different from the result of the National Cancer Institute of Canada SR2 trial (P = .2); however, primary closure technique was possible more often (55 of 59 patients [93.2%] versus 50 of 70 patients [71.4%]; P = .002), and secondary operations for WCs were somewhat reduced (6 of 18 patients [33%] versus 13 of 30 patients [43%]; P = .55). Moderate edema, skin, subcutaneous, and joint toxicity was present in 6 (11.1%), 1 (1.9%), 5 (9.3%), and 3 (5.6%) patients, respectively, but there were no bone fractures. Four local recurrences (6.8%, none near the flaps) occurred with median follow-up of 49 months. Conclusions: The 30.5% incidence of WCs was numerically lower than the 43% risk derived from the National Cancer Institute of Canada SR2 trial, but did not reach statistical significance. Preoperative IG-IMRT significantly diminished the need for tissue transfer. RT chronic morbidities and the need for subsequent secondary operations for WCs were lowered, although not significantly, whereas good limb function was maintained.
    Cancer 05/2013; 119(10). DOI:10.1002/cncr.27951 · 4.89 Impact Factor
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    ABSTRACT: The treatment of diffuse tenosynovial giant cell tumor (TGCT) requires extensive surgical resection of the hypertrophic synovium and multiple soft tissue masses yet still may result in high rates of local failure. The authors of this report examined their experience in treating patients with advanced/multiply recurrent TGCT with a combination of surgery and external-beam radiotherapy. Fifty patients who were treated for TGCT with radiotherapy and surgery from 1972 to 2006 were identified. Patient demographics, radiotherapy treatment parameters, surgical treatment, and oncologic and functional outcomes were evaluated. All patients had pathologic review at presentation and required at least 1 year follow-up. Forty-nine patients had diffuse TGCT with both intra-articular and extra-articular disease (1 had malignant TGCT). Twenty-eight patients (56%) were referred after at least 1 local recurrence. Thirty patients (60%) underwent at least 2 operations before radiotherapy. The mean dose of radiation delivered was 39.8 gray. At a mean follow-up of 94 months (range, 19-330 months), 47 patients (94%) had not developed a recurrence or had stable disease/signal characteristics on serial cross-sectional imaging (for those patients who had gross residual disease at the time of radiotherapy). Two patients required subsequent total hip arthroplasty because of progressive osteoarthritis, and there were 4 cases of avascular necrosis (only 1 post-treatment). Forty-one patients had good/excellent function. For patients with extensive or multiple local relapses or when surgery alone would result in a large burden of residual disease or major functional loss, the addition of moderate-dose adjuvant radiotherapy provided excellent local control while maintaining good function with low treatment-related morbidity. Cancer 2012. © 2012 American Cancer Society.
    Cancer 10/2012; 118(19):4901-9. DOI:10.1002/cncr.26529 · 4.89 Impact Factor
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    ABSTRACT: The objective of this study was to examine the effect of known predictors of local recurrence of soft tissue sarcoma in a competing risk setting. The outcome of interest was the cumulative probability of local recurrence per category of relevant predictors, with death as a competing event. In total, 1668 patients with a localized soft tissue sarcoma of the extremity or trunk were included. Tumor size (hazard ratio, 3.3), depth (hazard ratio, 3.2), and histologic grade (hazard ratio, 4.5) were the variables that had the most effect on the risk of metastasis and, accordingly, were the most likely to induce competition. Surgical margins (hazard ratio, 3.3), histologic grade (hazard ratio, 2.1), presentation status (hazard ratio, 2.4), and tumor depth (hazard ratio, 1.5) were the variables that had the most effect on the risk of local recurrence. The 10-year cumulative probabilities of local recurrence were markedly different within categories for presentation status (P < .001) and surgical margin status (P < .001). However, because of the competing effect of death, there was little difference in the 10-year cumulative probabilities of local recurrence with regard to tumor depth (12% and 11.4% for deep and superficial tumors, respectively; P = .2), tumor size (10.6% and 13.3% for large and small tumors, respectively; P = .99), or histologic tumor grade (12.6%, 10.7%, and 11.1% for high, intermediate, and low-grade tumors, respectively; P = .17). Because of the competition between local recurrence and death, histologic tumor grade, tumor size, and tumor depth had little influence on the cumulative probability of local recurrence. The authors concluded that local management should be based on presentation status and surgical margins rather than other, previously acknowledged factors. Cancer 2012.
    Cancer 05/2012; 118(23). DOI:10.1002/cncr.27639 · 4.89 Impact Factor
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    Carol J Swallow · Charles N Catton ·
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    ABSTRACT: This article presents the current understanding of prognostic factors and outcomes for retroperitoneal sarcoma. The discussion focuses on the literature published since 2000, including studies with cohorts of at least 30 patients. An interpretation of factors that have contributed to an improvement in outcomes has been performed. With demonstration of the potential for good long-term outcomes and a better appreciation for the importance of minimizing treatment-related morbidity, the international sarcoma community has increasingly recognized and emphasized the importance of expert multidisciplinary assessment and care for this rare malignancy.
    Surgical Oncology Clinics of North America 04/2012; 21(2):317-31. DOI:10.1016/j.soc.2012.01.002 · 1.81 Impact Factor

  • Fuel and Energy Abstracts 10/2011; 81(2). DOI:10.1016/j.ijrobp.2011.06.648

  • Fuel and Energy Abstracts 10/2011; 81(2). DOI:10.1016/j.ijrobp.2011.06.327
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    ABSTRACT: To examine the effect of age on the recurrence of soft tissue sarcoma in the extremities and trunk. This was a multicenter study that included 2,385 patients with median age at surgery of 57 years. The end points considered were local recurrence and metastasis. Cox proportional hazards models were used to estimate hazard ratios across the age ranges with and without adjustment for known confounding factors. Older patients presented with tumors that were larger (P < .001) and of higher grade (P < .001). The proportion of positive margins increased significantly as patients age (P < .001), but radiation therapy was relatively underused in patients older than age 60 years. The 5-year cumulative incidences of local recurrence were 7.2% (95% CI, 4% to 11.7%) for patients age 30 years or younger and 12.9% (95% CI, 9.1% to 17.5%) for patients age 75 years or older. The corresponding 5-year cumulative incidences of metastasis were 17.5% (95% CI, 12.1% to 23.7%) and 33.9% (95% CI, 28.1% to 39.8%) for the same groups. Regression models showed that age was significantly associated with local recurrence (P < .001) and metastasis (P < .001) in nonadjusted models. After adjusting for imbalance in presentation and treatment variables, age remained significantly associated with local recurrence (P = .031) and metastasis (P = .019). Older patients have worse outcomes because they tend to present with worse tumors and are treated less aggressively. However, there remained a significant increase in the risk of both local and systemic recurrence associated with increasing age that could not be explained by tumor or treatment characteristics.
    Journal of Clinical Oncology 09/2011; 29(30):4029-35. DOI:10.1200/JCO.2010.34.0711 · 18.43 Impact Factor
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    ABSTRACT: To quantify the effect of delineation method on bladder DVH, observer variability (OV) and contouring time for prostate IMRT plans. Planning CT scans and IMRT plans of 30 prostate cancer patients were anonymized. For 20 patients, 1 observer delineated the bladder using 9 methods. The effect of delineation method on the DVH curve, discrete dose levels and delineation time was quantified. For the 10 remaining CTs, 6 observers delineated bladder wall using 4 methods. Observer-based volume variation and intraclass correlation coefficient (ICC) were used to describe the dosimetric effects of OV. Manual delineation of the bladder wall (BW_m) was significantly slower than any other method (mean: 20 min vs. ≤ 13 min) and the dosimetric effect of OV was significantly larger (V70 Gy ICC: 0.78 vs. 0.98). Only volumes created using a 2.5mm contraction from the outer surface, and a method providing a consistent wall volume, showed no notable dosimetric differences from BW_m in both absolute and relative volume. Automatic contractions from the outer surface provide quicker, more reproducible and reasonably accurate substitutes for BW_m. The widespread use of automatic contractions to create a bladder wall volume would assist in the consistent application of IMRT dose constraints and the interpretation of reported dose.
    Radiotherapy and Oncology 08/2011; 101(3):479-85. DOI:10.1016/j.radonc.2011.06.039 · 4.36 Impact Factor

  • International journal of radiation oncology, biology, physics 07/2011; 80(3):959-60. DOI:10.1016/j.ijrobp.2011.02.029 · 4.26 Impact Factor
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    ABSTRACT: A study was undertaken to evaluate results of surgery and radiotherapy (RT) for high-risk extracranial chondrosarcomas. Between 1986 and 2006, 60 patients underwent surgery and RT for extracranial high-risk chondrosarcoma. Preoperative RT (median, 50 gray [Gy]) and postoperative RT (median, 60 Gy) were used in 40% and 60% patients, respectively. Sites included pelvis/lower extremity (48%), chest wall (22%), spine/paraspinal (17%), and head and neck (13%). Overall, median tumor size was 7 cm (range, 1-22 cm), and tumor grade was I, II, and III in 22%, 64%, and 14% of cases, respectively. Pathologically clear surgical margins (R0) were present in 50%, microscopic positive margins (R1) in 28%, and gross positive margins (R2) in 13%, half of whom had clinically detectable residual disease; surgical margin was unknown in 8%. Median follow-up was 75 months (range, 5-230 months). The crude local control rate was 90%. Patients with R0, R1, and R2 resections had local control of 100%, 94%, and 42%, respectively. Of the 8 cases that had R2 resection, 3 experienced uncontrolled progression, but 5 patients had stable disease with long-term follow-up. The 10-year overall survival, progression-free survival, and cause-specific survival were 86%, 80.5%, and 89.4%, respectively. Younger age and grade III tumors were associated with worse progression-free survival (P = .03 and .0003, respectively). Although surgery with complete resection is paramount in management of chondrosarcoma, RT is a useful adjuvant treatment and appears to offer excellent and durable local control where wide surgical resection is difficult to accomplish. Cancer 2011.
    Cancer 06/2011; 117(11). DOI:10.1002/cncr.25806 · 4.89 Impact Factor
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    ABSTRACT: To examine the geometric relationship between local recurrence (LR) and external beam radiotherapy (RT) volumes for soft-tissue sarcoma (STS) patients treated with function-preserving surgery and RT. Sixty of 768 (7.8%) STS patients treated with combined therapy within our institution from 1990 through 2006 developed an LR. Thirty-two received preoperative RT, 16 postoperative RT, and 12 preoperative RT plus a postoperative boost. Treatment records, RT simulation images, and diagnostic MRI/CT data sets of the original and LR disease were retrospectively compared. For LR location analysis, three RT target volumes were defined according to the International Commission on Radiation Units and Measurements 29 as follows: (1) the gross tumor or operative bed; (2) the treatment volume (TV) extending 5 cm longitudinally beyond the tumor or operative bed unless protected by intact barriers to spread and at least 1-2 cm axially (the TV was enclosed by the isodose curve representing the prescribed target absorbed dose [TAD] and accounted for target/patient setup uncertainty and beam characteristics), and (3) the irradiated volume (IRV) that received at least 50% of the TAD, including the TV. LRs were categorized as developing in field within the TV, marginal (on the edge of the IRV), and out of field (occurring outside of the IRV). Forty-nine tumors relapsed in field (6.4% overall). Nine were out of field (1.1% overall), and 2 were marginal (0.3% overall). The majority of STS tumors recur in field, indicating that the incidence of LR may be affected more by differences in biologic and molecular characteristics rather than aberrations in RT dose or target volume coverage. In contrast, only two patients relapsed at the IRV boundary, suggesting that the risk of a marginal relapse is low when the TV is appropriately defined. These data support the accurate delivery of optimal RT volumes in the most precise way using advanced technology and image guidance.
    International journal of radiation oncology, biology, physics 06/2011; 82(4):1528-34. DOI:10.1016/j.ijrobp.2011.03.061 · 4.26 Impact Factor

Publication Stats

4k Citations
494.48 Total Impact Points


  • 1991-2015
    • The Princess Margaret Hospital
      Toronto, Ontario, Canada
  • 1998-2014
    • Mount Sinai Hospital, Toronto
      • • Department of Pathology and Laboratory Medicine
      • • Department of Medical Imaging
      Toronto, Ontario, Canada
  • 1997-2014
    • University of Toronto
      • • Department of Radiation Oncology
      • • Department of Laboratory Medicine and Pathobiology
      Toronto, Ontario, Canada
  • 2007
    • Oregon Health and Science University
      Portland, Oregon, United States
  • 2004
    • Toronto Rehabilitation Institute
      Toronto, Ontario, Canada