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.

Dexamethasone for the prophylaxis of radiation-induced emesis: a National Cancer Institute of Canada Clinical Trials Group phase III study.

PURPOSE: To investigate the efficacy of dexamethasone as a prophylactic antiemetic for patients receiving fractionated radiotherapy to the upper abdomen in a randomized controlled trial. PATIENTS AND METHODS: One hundred fifty-four patients planned to receive fractionated radiotherapy to fields involving the upper abdomen (minimum total dose, 20 Gy; minimum number of fractions, five) were randomized to receive prophylactic dexamethasone (2 mg orally three times a day [tid], starting in the morning of first treatment and continuing until after their fifth treatment) or placebo. The primary end point of the study was the proportion of patients free from emesis during the study period. Secondary end points included a quality-of-life assessment using the core questionnaire of the European Organization for Research and Treatment of Cancer and side effects of dexamethasone therapy in this population of patients. RESULTS: Fifty-four (70%) out of 75 patients receiving dexamethasone had complete protection versus 37 (49%) out of 75 patients on placebo (P = .025). Most emetic episodes occurred during the initial phase of treatment. Although there was no difference in global quality of life between the two sets of patients, patients receiving dexamethasone had less nausea and vomiting and less loss of appetite but more insomnia. CONCLUSION: Dexamethasone 2 mg tid seems to be an effective prophylactic antiemetic in this situation. Side effects were acceptable, but there seemed to be no overall effect on global quality of life.

Concurrent chemoradiation therapy with oral etoposide and cisplatin for locally advanced inoperable non-small-cell lung cancer: radiation therapy oncology group protocol 91-06.

PURPOSE: Patients with locally advanced inoperable non-small-cell lung cancer (NSCLC) have a poor clinical outcome. We conducted a prospective study to evaluate the merit of chemotherapy administered concurrently with hyperfractionated thoracic radiation therapy. PATIENTS AND METHODS: Seventy-nine patients with inoperable NSCLC were enrolled onto a multicenter phase II trial of concurrent chemoradiation therapy. Treatment consisted of two cycles of oral etoposide 100 mg/d (50 mg/d if body-surface area [BSA] < 1.70 m2), intravenous cisplatin 50 mg/m2 on days 1 and 8, and hyperfractionated radiation therapy 5 days per week (1.2 Gy twice daily > 6 hours apart; total 69.6 Gy). RESULTS: Seventy-six assessable patients with a Karnofsky performance status > or = 60 and adequate organ function who had received no prior therapy were evaluated for clinical outcome and toxic effects. After a minimum follow-up duration of 21 months, the 1- and 2-year survival rates and the median survival duration were 67%, 35%, and 18.9 months overall; they were 70%, 42%, and 21.1 months for patients with weight loss of < or = 5%. Toxicity was significant; 57% developed grade 4 hematologic toxicity, 53% grade 3 or 4 esophagitis, and 25% grade 3 or 4 lung toxicity. However, only 6.6% of patients had grade 4 or lethal nonhematologic toxicity, which included three treatment-related deaths (two of pneumonitis and one of renal failure). CONCLUSION: Concurrent chemoradiation therapy with oral etoposide and cisplatin plus hyperfractionated radiation therapy is feasible. The survival outcome from this regimen compares favorably with that of other chemoradiation trials and even of multimodality trials that have included surgery.

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.