Response assessment using radiological methods

Radiological response of ceramic and polymeric devices for breast brachytherapy

In the present study, the radiological visibility of ceramic and polymeric devices implanted in breast phantom was investigated for future applications in brachytherapy. The main goal was to determine the radiological viability of ceramic and polymeric devices in vitro by performing simple radiological diagnostic methods such as conventional X-ray analysis and mammography due to its easy access to the population. The radiological response of ceramic and polymeric devices implanted in breast phantom was determined using conventional X-ray, mammography and CT analysis.

Comparison of Outcomes of Phase II Studies and Subsequent Randomized Control Studies Using Identical Chemotherapeutic Regimens

Purpose

To determine whether promising results from phase II studies could be reproduced in phase III studies, and to examine which characteristics of phase II studies might be of predictive value for subsequent phase III studies.

Methods

We searched for all phase III studies of chemotherapy in advanced solid malignancies, published in the English language literature from July 1998 to June 2003. Each phase III study was reviewed to identify preceding phase II studies. Phase II and phase III studies included in this analysis must have used identical regimens. Data were extracted from both phase II and phase III studies.

Results

Of 181 phase III studies identified, 43 used therapeutic regimens identical to those in 49 preceding phase II studies. Twelve phase III studies (28%) were “positive.” The vast majority (81%) of phase III studies have lower response rates than preceding phase II studies, with a mean difference of 12.9% among all studies analyzed. None of the phase II study characteristics evaluated significantly predicted for “positive” phase III studies, but the sample size of phase II studies demonstrated a trend toward being predictive (P = .083).

Conclusion

Promising results from phase II studies frequently do not translate into “positive” phase III studies. Response rates in most phase III studies are lower than those in preceding phase II studies.

Interobserver and intraobserver variability in measurement of non-small-cell carcinoma lung lesions: implications for assessment of tumor response

PURPOSE

Response of solid malignancies to therapy is usually determined by serial measurements of tumor size. The purpose of our study was to assess the consistency of measurements performed by readers evaluating lung tumors.

MATERIALS AND METHODS

The study group was composed of 33 patients with lung tumors more than 1.5 cm. Bidimensional (BD) and unidimensional (UD) measurements were performed on computed tomography (CT) scans according to the World Health Organization (WHO) criteria and the Response Evaluation Criteria in Solid Tumors (RECIST), respectively. Measurements were performed independently by five thoracic radiologists using printed film and were repeated after 5 to 7 days. Inter- and intraobserver measurement variations were estimated through statistical modeling.

RESULTS

There were 40 tumors with an average size of 1.8 to 8.0 cm (mean, 4.1 cm). Analysis of variance showed a significant difference (P <.05) among readers and among the measured nodules for UD and BD measurements. Interobserver misclassification rates were more than intraobserver misclassification rates using either progressive disease or response criteria. The probability of misclassifying a tumor with the WHO criteria or RECIST was greatest with interobserver measurements when criteria for progression (43% BD, 30% UD) were used and lowest with intraobserver measurements when criteria for response (2.5% BD, 3.0% UD) were used. In addition, interobserver misclassification rates were more than intraobserver misclassification rates for both regular and irregular tumors.

CONCLUSION

Measurements of lung tumor size on CT scans are often inconsistent and can lead to an incorrect interpretation of tumor response. Consistency can be improved if the same reader performs serial measurements for any one patient.

Radiologist review versus group peer review of claimed responses in a phase II study on high-dose ifosfamide in advanced soft tissue sarcomas of the adult: a study of the EORTC Soft Tissue and Bone Sarcoma Group

The Soft Tissue and Bone Sarcoma Group (STBSG) of the EORTC ran a phase II study to assess the therapeutic activity of high-dose ifosfamide in patients with advanced soft tissue sarcomas by means of response rate (RR). Investigators claiming a response submitted the relevant chest radiographs (CXR) or scans to two other members of the STBSG for peer review. The reviewers completed a questionnaire indicating overall response or reasons for rejecting the claimed responses. An independent radiologist also reviewed the cases and he was blinded to the results of the peer review until the study was concluded. Twenty-two patients were reviewed by the radiologist and peer review, and the completed questionnaires were retrospectively reviewed. Two differences were noted, one partial responder (PR) was regarded as stable disease by the radiologist and one PR by peer review was determined a complete response by the radiologist. The radiologist found subsequent evidence of progressive disease in three patients who initially showed a PR, whilst the review group noted only one. This study suggests peer review in this tumor type is a satisfactory method of achieving an accurate, objective RR.