George Dundas

Exercise preferences of endometrial cancer survivors: a population-based study.

Exercise has gained recognition as an effective supportive care intervention for cancer survivors, yet participation rates are low. Knowledge of the specific exercise counseling and programming preferences of cancer survivors may be useful for designing effective interventions. In this study, we examined the exercise preferences of 386 endometrial cancer survivors. Participants completed a questionnaire that included measures of past exercise behavior, exercise preferences, and medical and demographic information. Some key findings were as follows: (a) 76.9% of participants said they were interested or might be interested in doing an exercise program and (b) 81.7% felt they were able or likely able to actually do an exercise program. Participants also indicated that walking was their preferred activity (68.6%) and moderate exercise was their preferred intensity (61.1%). Logistic regression analyses showed that meeting public health guidelines for exercise, being overweight or obese, receiving adjuvant treatment, months since diagnosis, income, marital status, and level of education all influenced exercise preferences. These results suggest that endometrial cancer survivors have unique exercise preferences that are moderated by a number of demographic and medical variables. These findings may have implications for the design and implementation of clinical and population-based exercise interventions for endometrial cancer survivors.

Significant Reduction of Late Toxicities in Patients With Extremity Sarcoma Treated With Image-Guided Radiation Therapy to a Reduced Target Volume: Results of Radiation Therapy Oncology Group RTOG-0630 Trial

PURPOSE We performed a multi-institutional prospective phase II trial to assess late toxicities in patients with extremity soft tissue sarcoma (STS) treated with preoperative image-guided radiation therapy (IGRT) to a reduced target volume. PATIENTS AND METHODS Patients with extremity STS received IGRT with (cohort A) or without (cohort B) chemotherapy followed by limb-sparing resection. Daily pretreatment images were coregistered with digitally reconstructed radiographs so that the patient position could be adjusted before each treatment. All patients received IGRT to reduced tumor volumes according to strict protocol guidelines. Late toxicities were assessed at 2 years. RESULTS In all, 98 patients were accrued (cohort A, 12; cohort B, 86). Cohort A was closed prematurely because of poor accrual and is not reported. Seventy-nine eligible patients from cohort B form the basis of this report. At a median follow-up of 3.6 years, five patients did not have surgery because of disease progression. There were five local treatment failures, all of which were in field. Of the 57 patients assessed for late toxicities at 2 years, 10.5% experienced at least one grade ≥ 2 toxicity as compared with 37% of patients in the National Cancer Institute of Canada SR2 (CAN-NCIC-SR2: Phase III Randomized Study of Pre- vs Postoperative Radiotherapy in Curable Extremity Soft Tissue Sarcoma) trial receiving preoperative radiation therapy without IGRT (P < .001). CONCLUSION The significant reduction of late toxicities in patients with extremity STS who were treated with preoperative IGRT and absence of marginal-field recurrences suggest that the target volumes used in the Radiation Therapy Oncology Group RTOG-0630 (A Phase II Trial of Image-Guided Preoperative Radiotherapy for Primary Soft Tissue Sarcomas of the Extremity) study are appropriate for preoperative IGRT for extremity STS.

Assessment of Extended-Field Radiotherapy for Stage IIIC Endometrial Cancer Using Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, and Helical Tomotherapy

PURPOSE To perform a dosimetric comparison of three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and helical tomotherapy (HT) plans for pelvic and para-aortic RT in postoperative endometrial cancer patients; and to evaluate the integral dose (ID) received by critical structures within the radiation fields. METHODS AND MATERIALS We selected 10 patients with Stage IIIC endometrial cancer. For each patient, three plans were created with 3D-CRT, IMRT, and HT. The IMRT and HT plans were both optimized to keep the mean dose to the planning target volume (PTV) the same as that with 3D-CRT. The dosimetry and ID for the critical structures were compared. A paired two-tailed Student t test was used for data analysis. RESULTS Compared with the 3D-CRT plans, the IMRT plans resulted in lower IDs in the organs at risk (OARs), ranging from -3.49% to -17.59%. The HT plans showed a similar result except that the ID for the bowel increased 0.27%. The IMRT and HT plans both increased the IDs to normal tissue (see Table 1 and text for definition), pelvic bone, and spine (range, 3.31-19.7%). The IMRT and HT dosimetry showed superior PTV coverage and better OAR sparing than the 3D-CRT dosimetry. Compared directly with IMRT, HT showed similar PTV coverage, lower Ids, and a decreased dose to most OARs. CONCLUSION Intensity-modulated RT and HT appear to achieve excellent PTV coverage and better sparing of OARs, but at the expense of increased IDs to normal tissue and skeleton. HT allows for additional improvement in dosimetry and sparing of most OARs.

Twenty-year review of radiotherapy for vaginal cancer: An institutional experience

OBJECTIVE To evaluate clinical outcome, prognostic factors and chronic morbidity with radiotherapy for vaginal cancer treatment. MATERIALS AND METHODS 68 patients with vaginal cancer treated by radical or adjuvant radiotherapy (RT) were selected. Five with rare subtypes of histopathology and 8 with adenocarcinoma were excluded from this study. 76.4% of the remainder had early-stage diseases (stage I: 14, II: 28, III: 9, and IV: 4). The patients in the years from which they were treated were almost evenly distributed (1st 5 years: 13, 2nd: 14, 3rd: 16, and 4th: 12). There were four treatment groups: external beam radiotherapy (EBRT) alone (n=18), brachytherapy (BT) alone (n=4), EBRT and BT (n=30), and surgery plus RT (n=3). RESULTS Median follow-up was 50.3 months ranging from 3 to 213 months. 5-year overall survival (OS) was 55.6%, disease-specific survival (DSS) was 77.3%, disease-free survival was 74.2%, and local control was 87.7%. Independent prognostic factors for DSS and OS were tumor stage, site and size (p<0.05). Late radiation toxicity was minimal in the bladder (4.6%) and bowel (4.6%). Vaginal morbidity was observed in 35 patients (63.6%). It was lowest in the BT alone (0%), and highest in the EBRT and BT group (82.1%), especially for those received more than 70 Gy (p=0.05, Odds ratio=4.64, 95% confidence interval: 1.01-21.65). CONCLUSION This retrospective review suggested that tumor stage, site, and size were important prognostic factors in patients with vaginal cancer. Higher radiation dose was associated with more frequent vaginal toxicity.

Prostate-specific antigen: Monitoring the response of carcinoma of the prostate to radiotherapy with a new tumor marker

The role of prostate‐specific antigen (PSA), a sensitive tumor marker for cancer of the prostate, has yet to be defined in patients treated with radiotherapy. To evaluate this, PSA and acid phosphatase (AP) were measured prospectively in 110 sequential patients who presented with locoregional carcinoma of the prostate and in whom radiotherapy was to be definitive treatment. Therapy was divided into the following treatment groups: external‐beam radiotherapy alone (EBRT), EBRT with brachytherapy (EBRT + B), and hormone therapy either pre‐EBRT or post‐EBRT (EBRT + H). All patients have been followed for 1 to 17 months and a total of 521 posttreatment PSA determinations have been made. in 91 of 110 patients (83%) PSA was elevated pretreatment and correlated with clinical stage and subsequent relapse. There was no association with Gleason grade, assigned treatment group, or lymph node involvement. Acid phosphatase was elevated in only 31% of the patients initially and had no predictive value in subsequent failure. Nine patients have developed local and/or distant recurrence. None of the patients who failed had their PSA return to normal whereas 74 of 101 (73%) of the remainder have done so. Levels of PSA that do not return to normal during follow‐up probably indicate active disease, often without evidence of clinical relapse. The authors conclude that PSA is a useful tumor marker for monitoring response to radiotherapy and may be a predictor of eventual failure thus identifying patients eligible for early intervention therapy as and when it becomes available.

The management of inoperable Stage I endometrial cancer using intracavitary brachytherapy alone: A 20-year institutional review

OBJECTIVE To review our institutions results with primary low dose rate (LDR) intracavitary brachytherapy using Heymans capsules for medically inoperable cancer of the endometrium. METHODS The study was a retrospective review of inoperable early-stage endometrial cancer patients at the Cross Cancer Institute in Edmonton, Canada, treated with primary radiotherapy from January 10, 1986 to July 17, 2006. Forty-four patients with International Federation of Gynaecology and Obstetrics (FIGO) clinical Stage I disease were included in the study. Kaplan-Meier survival analysis was performed to obtain estimates of overall survival (OS), disease-free survival, and disease-specific survival (DSS). Tumor grade was assessed as a potential predictor of OS by comparing survival curves using a log-rank test. RESULTS The median OS time was 75.5 months (95% confidence interval 55.6-95.3 months). For the entire group, the 5- and 10-year OS was 60.5% and 24.0%, respectively. The 5- and 10-year DSS was 87.7% and 79.7%, respectively. For a subset treated as planned, the 5- and 10-year OS was 54.5% and 34.5%, respectively. The 5- and 10-year DSS was 83.0% and 76.4%, respectively. When stratified by grade, trends in survival analysis are inversely related to grade. Both the trend analysis and the log-rank test were statistically significant at a p<0.05 level. CONCLUSIONS Our experience with LDR brachytherapy for the treatment of Stage I endometrial cancer is comparable to surgical treatment and to results reported in the literature for high dose rate brachytherapy. Further study that would help define the indications for a primary radiotherapeutic approach in early-stage endometrial cancer may lower current thresholds for recommending primary radiotherapy versus surgery.

2009 Canadian radiation oncology resident survey.

PURPOSE Statistics from the Canadian post-MD education registry show that numbers of Canadian radiation oncology (RO) trainees have risen from 62 in 1999 to approximately 150 per year between 2003 and 2009, contributing to the current perceived downturn in employment opportunities for radiation oncologists in Canada. When last surveyed in 2003, Canadian RO residents identified job availability as their main concern. Our objective was to survey current Canadian RO residents on their training and career plans. METHODS AND MATERIALS Trainees from the 13 Canadian residency programs using the national matching service were sought. Potential respondents were identified through individual program directors or chief resident and were e-mailed a secure link to an online survey. Descriptive statistics were used to report responses. RESULTS The eligible response rate was 53% (83/156). Similar to the 2003 survey, respondents generally expressed high satisfaction with their programs and specialty. The most frequently expressed perceived weakness in their training differed from 2003, with 46.5% of current respondents feeling unprepared to enter the job market. 72% plan on pursuing a postresidency fellowship. Most respondents intend to practice in Canada. Fewer than 20% of respondents believe that there is a strong demand for radiation oncologists in Canada. CONCLUSIONS Respondents to the current survey expressed significant satisfaction with their career choice and training program. However, differences exist compared with the 2003 survey, including the current perceived lack of demand for radiation oncologists in Canada.

Margin reduction from image guided radiation therapy for soft tissue sarcoma: Secondary analysis of Radiation Therapy Oncology Group 0630 results.

PURPOSE Six imaging modalities were used in Radiation Therapy Oncology Group (RTOG) 0630, a study of image guided radiation therapy (IGRT) for primary soft tissue sarcomas of the extremity. We analyzed all daily patient-repositioning data collected in this trial to determine the impact of daily IGRT on clinical target volume-to-planning target volume (CTV-to-PTV) margin. METHODS AND MATERIALS Daily repositioning data, including shifts in right-left (RL), superior-inferior (SI), and anterior-posterior (AP) directions and rotations for 98 patients enrolled in RTOG 0630 from 18 institutions were analyzed. Patients were repositioned daily on the basis of bone anatomy by using pretreatment images, including kilovoltage orthogonal images (KVorth), megavoltage orthogonal images (MVorth), KV fan-beam computed tomography (KVCT), KV cone beam CT (KVCB), MV fan-beam CT (MVCT), and MV cone beam CT (MVCB). Means and standard deviations (SDs) for each shift and rotation were calculated for each patient and for each IGRT modality. The Students t tests and F-tests were performed to analyze the differences in the means and SDs. Necessary CTV-to-PTV margins were estimated. RESULTS The repositioning shifts and day-to-day variations were large and generally similar for the 6 imaging modalities. Of the 2 most commonly used modalities, MVCT and KVorth, there were no statistically significant differences in the shifts and rotations (P = .15 and .59 for the RL and SI shifts, respectively; and P = .22 for rotation), except for shifts in AP direction (P = .002). The estimated CTV-to-PTV margins in the RL, SI, and AP directions would be 13.0, 10.4, and 11.7 mm from MVCT data, respectively, and 13.1, 8.6, and 10.8 mm from KVorth data, respectively, indicating that margins substantially larger than 5 mm used with daily IGRT would be required in the absence of IGRT. CONCLUSIONS The observed large daily repositioning errors and the large variations among institutions imply that daily IGRT is necessary for this tumor site, particularly in multi-institutional trials. Otherwise, a CTV-to-PTV margin of 1.5 cm is required to account for daily setup variations.

Positron-emission tomography for locally advanced cervical cancer: a survey assessing Canadian practice patterns and access

PURPOSE Imaging by fluorodeoxyglucose positron-emission tomography (pet) has emerged as a valuable tool in the management of locally advanced cervical cancer (lacc), both for assessment of lymph node status and determination of response to chemoradiotherapy. The aim of the present study was to survey Canadian radiation oncologists to determine access to pet imaging for lacc patients and to assess current patterns of practice. METHODS Radiation oncology centres across Canada were contacted to identify radiation oncologists who treat patients with lacc. The focus of the survey was patients treated with radical chemoradiotherapy with curative intent. An anonymous online tool was used to distribute a 23-item questionnaire asking about access to pet imaging, opinions on indications for pet imaging, and practice patterns relating to the use of pet in this patient population. Questionnaire responses were tabulated and analyzed. RESULTS The response rate was 65% (35 of 54 questionnaire recipients). Most respondents (80%) have access to pet for lacc patients, usually restricted to study protocols. Of the respondents,48% considered that access to pet was timely. Frequency of routine orders for pet before and after treatment (to assess response) was 63% and 15% respectively. With better access, 91% of respondents would routinely order pet before treatment, and 61% would routinely order it for posttreatment assessment. For initial staging, 85% of respondents considered pet to be a standard of care, and nearly half (45%) believed it should be a standard of care to assess treatment response. Because of access limitations, nearly 70% of respondents (23 of 34) do not order pet as often as they feel it is clinically indicated, and 74% agree that better access to pet would lead to improved care for lacc patients in Canada. CONCLUSIONS Canadian radiation oncologists support the routine use of pet imaging in the initial workup of patients with lacc. Access to pet imaging limits routine use for these patients in clinically indicated situations. There is strong support for developing guidelines for pet use in this patient population.

Sci—Sat AM: Brachy — 08: MRI‐guided planning and maximum achievable HR‐CTV doses in cervix brachytherapy

PURPOSE To present an institutional experience with MRI-based intracavitary brachytherapy planning for cervix cancer treatments using the EMBRACE protocol and to evaluate maximum HR-CTV doses that can be achieved when OAR (bladder, rectum, and sigmoid) doses are allowed to equal GECESTRO recommended thresholds. METHOD Dose metrics from treatment plans for 20 patients created using MR images (for contouring HR-CTV and OARs) fused with CT images (for applicator reconstruction) are presented. Starting with a standard Manchester loading, plans were manually optimized (MO) by adjusting dwell positions and times to obtain the desired HR-CTV D90 target coverage of 35 Gy while limiting OAR doses to below recommended tolerances. In addition, retrospective planning was done using: (i) volume optimization (VO) to compare differences with MO in obtaining the desired target coverage; and (ii) MO and VO techniques to get the highest possible HR-CTV coverage by allowing OAR doses to equal tolerance values. The latter plans are referred to as MAX plans. RESULTS AND CONCLUSIONS 3D MRI-guided treatment planning for cervix brachytherapy was shown to improve dose-volume coverage of the target and OARs. MO could conform HR-CTV D90 to the prescribed dose similar to the VO technique. Sigmoid was often the dose limiting structure. With respect to the prescribed HR-CTV D90 dose of 35 Gy, MAX plans could increase the prescribed dose by about 22% and 30% for MO and VO plans, respectively, without exceeding OAR thresholds. Consequently, dose escalation for MRI-guided cervix brachytherapy appears feasible should clinical circumstances warrant.