3 research outputs found
First results of triple-modality treatment combining radiotherapy, chemotherapy, and hyperthermia for the treatment of patients with stage IIB, III, and IVA cervical carcinoma
BACKGROUND. Patients with advanced cervical carcinoma are treated routinely with radiotherapy and cisplatin-containing chemotherapy. It has been shown that hyperthermia can improve the results of both radiotherapy and cisplatin. In the current study, the feasibility and efficacy of the combination of all three modalities was studied in previously untreated patients with cervical carcinoma. METHODS. Patients with advanced cervical carcinoma were registered prospectively in the U.S., Norway, and the Netherlands. External-beam radiotherapy and brachytherapy were administered for a biologically effective dose >= 86.7 gray. At least 4 courses of weekly cisplatin (40 mg/m(2)) and 4 sessions of weekly locoregional hyperthermia were added to radiotherapy. RESULTS. Sixty-eight patients with a median age of 45 years were enrolled. Full-dose radiotherapy was delivered to all patients according to plan. At least 4 courses of chemotherapy were received by 97% of patients, and at least 4 courses of hyperthermia treatment were received by 93% of patients. Toxicity was fully comparable to that described for chemoradiotherapy alone, and the median total treatment time was 45 days. Complete remission was achieved by 61 patients (90%). After a median follow-up of 538 days, 74% of patients remained alive without signs of recurrence, and the overall Survival rate was 84%. CONCLUSIONS. The combination of full-dose radiotherapy, chemotherapy, and hyperthermia was feasible and effective in a multicenter international setting among patients with advanced cervical carcinoma. A Phase III study comparing this novel triplet with standard chemoradiation, designed to show at least a 15% improvement in overall survival, has been launche
Potential for release of pulmonary toxic ketene from vaping pyrolysis of vitamin E acetate.
PURPOSE: Target delineation using only CT information introduces large geometric uncertainties in radiotherapy for lung cancer. Therefore, a reduction of the delineation variability is needed. The impact of including a matched CT scan with 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) and adaptation of the delineation protocol and software on target delineation in lung cancer was evaluated in an extensive multi-institutional setting and compared with the delineations using CT only. METHODS AND MATERIALS: The study was separated into two phases. For the first phase, 11 radiation oncologists (observers) delineated the gross tumor volume (GTV), including the pathologic lymph nodes of 22 lung cancer patients (Stages I-IIIB) on CT only. For the second phase (1 year later), the same radiation oncologists delineated the GTV of the same 22 patients on a matched CT-FDG-PET scan using an adapted delineation protocol and software (according to the results of the first phase). All delineated volumes were analyzed in detail. The observer variation was computed in three dimensions by measuring the distance between the median GTV surface and each individual GTV. The variation in distance of all radiation oncologists was expressed as a standard deviation. The observer variation was evaluated for anatomic regions (lung, mediastinum, chest wall, atelectasis, and lymph nodes) and interpretation regions (agreement and disagreement; i.e., >80% vs. 0. For all anatomic regions, the interpretation differences among the radiation oncologists were reduced. The amount of disagreement was 45% and 18% for the first and second phase, respectively. Furthermore, the mean delineation time (12 vs. 16 min, p <0.001) and mean number of corrections (25 vs. 39, p <0.001) were reduced in the second phase compared with the first phase. CONCLUSION: For high-precision radiotherapy, the delineation of lung target volumes using only CT introduces too great a variability among radiation oncologists. Implementing matched CT-FDG-PET and adapted delineation protocol and software reduced observer variation in lung cancer delineation significantly with respect to CT only. However, the remaining observer variation was still large compared with other geometric uncertainties (setup variation and organ motion
Observer variation in target volume delineation of lung cancer related to radiation oncologist-computer interaction: a 'Big Brother' evaluation.
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49013.pdf (publisher's version ) (Closed access)BACKGROUND AND PURPOSE: To evaluate the process of target volume delineation in lung cancer for optimization of imaging, delineation protocol and delineation software. PATIENTS AND METHODS: Eleven radiation oncologists (observers) from five different institutions delineated the Gross Tumor Volume (GTV) including positive lymph nodes of 22 lung cancer patients (stages I-IIIB) on CT only. All radiation oncologist-computer interactions were recorded with a tool called 'Big Brother'. For each radiation oncologist and patient the following issues were analyzed: delineation time, number of delineated points and corrections, zoom levels, level and window (L/W) settings, CT slice changes, use of side windows (coronal and sagittal) and software button use. RESULTS: The mean delineation time per GTV was 16 min (SD 10 min). The mean delineation time for lymph node positive patients was on average 3 min larger (P = 0.02) than for lymph node negative patients. Many corrections (55%) were due to L/W change (e.g. delineating in mediastinum L/W and then correcting in lung L/W). For the lymph node region, a relatively large number of corrections was found (3.7 corr/cm2), indicating that it was difficult to delineate lymph nodes. For the tumor-atelectasis region, a relative small number of corrections was found (1.0 corr/cm2), indicating that including or excluding atelectasis into the GTV was a clinical decision. Inappropriate use of L/W settings was frequently found (e.g. 46% of all delineated points in the tumor-lung region were delineated in mediastinum L/W settings). Despite a large observer variation in cranial and caudal direction of 0.72 cm (1 SD), the coronal and sagittal side windows were not used in 45 and 60% of the cases, respectively. For the more difficult cases, observer variation was smaller when the coronal and sagittal side windows were used. CONCLUSIONS: With the 'Big Brother' tool a method was developed to trace the delineation process. The differences between observers concerning the delineation style were large. This study led to recommendations on how to improve delineation accuracy by adapting the delineation protocol (guidelines for L/W use) and delineation software (double window with lung and mediastinum L/W settings at the same time, enforced use of coronal and sagittal views) and including FDG-PET information (lymph nodes and atelectasis)