Evaluation of tumor measurements in oncology: Use of film-based and electronic techniques
ABSTRACT To evaluate the variability in bidimensional computed tomography (CT) measurements obtained of actual tumors and of tumor phantoms by use of three measurement techniques: hand-held calipers on film, electronic calipers on a workstation, and an autocontour technique on a workstation.
Three radiologists measured 45 actual tumors (in the lung, liver, and lymph nodes) on CT images, using each of the three techniques. Bidimensional measurements were recorded, and their cross-products calculated. The coefficient of variation was calculated to assess interobserver variability. CT images of 48 phantoms were measured by three radiologists with each of the techniques. In addition to the coefficient of variation, the differences between the cross-product measurements of tumor phantoms themselves and the measurements obtained with each of the techniques were calculated.
The differences between the coefficients of variation were statistically significantly different for the autocontour technique, compared with the other techniques, both for actual tumors and for tumor phantoms. There was no statistically significant difference in the coefficient of variation between measurements obtained with hand-held calipers and electronic calipers. The cross-products for tumor phantoms were 12% less than the actual cross-product when calipers on film were used, 11% less using electronic calipers, and 1% greater using the autocontour technique.
Tumor size is obtained more accurately and consistently between readers using an automated autocontour technique than between those using hand-held or electronic calipers. This finding has substantial implications for monitoring tumor therapy in an individual patient, as well as for evaluating the effectiveness of new therapies under development.
- SourceAvailable from: Octavian C Ioachimescu
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ABSTRACT: BACKGROUND Bidimensional tumor measurements are used routinely as surrogates for tumor volume. The purpose this study was to determine whether there is any added benefit in bidimensional or tridimensional measurements over a unidimensional measurement.METHODS Sixty-nine colorectal hepatic metastases on 19 computed tomography scans (1–8 lesions per scan) from 9 patients were analyzed. Five patients contributed 2–4 scans each (mean, 3 scans). The standard volume of these lesions was determined by the “summation of areas” technique. The maximum axial dimension, the product of the greatest axial dimensions, and several volume estimates (based on the volumes of a sphere, an ellipsoid, and a cube) each were correlated with the standard volume.RESULTSThe maximum axial dimension and the product of the greatest axial dimensions correlated equally with tumor volume (correlation coefficient = 0.93). Surrogate measures based on the equations for a sphere and an ellipsoid underestimated tumor volume, whereas the equation for a cube overestimated volume.CONCLUSIONS When reporting tumor size, there is no significant added benefit in reporting bidimensional or tridimensional measurements over the maximum axial dimension. Cancer 2001;91:555–60. © 2001 American Cancer Society.Cancer 01/2001; 91(3):555 - 560. DOI:10.1002/1097-0142(20010201)91:3<555::AID-CNCR1034>3.0.CO;2-F · 4.90 Impact Factor
Article: Alveolar soft part sarcoma[Show abstract] [Hide abstract]
ABSTRACT: BACKGROUND Alveolar soft part sarcoma (ASPS) is a rare form of soft tissue sarcoma. Brain metastases have been reported to be a common feature of Stage IV ASPS, and recent practice guidelines recommend routine intracranial imaging as part of the staging evaluation in all patients who present with ASPS.METHODS The authors performed a comprehensive retrospective review of the clinical presentation, treatment, outcome, and patterns of failure in a consecutive series of patients with localized (American Joint Committee on Cancer [AJCC] Stages II/III) or metastatic (AJCC Stage IV) ASPS who presented to a tertiary care cancer center between 1959 and 1998.RESULTSSeventy-four patients were identified from the database searches. The anatomic distribution of their primary tumors included: extremities, 44 patients (60%); trunk, 15 patients (20%); head and neck, 9 patients (12%); and retroperitoneum, 6 patients (8%). The median tumor size was 6.5 cm (range, 1.2–24 cm). The AJCC stage at presentation was Stage II or III in 35% of the patients and Stage IV in 65% of the patients. The 5-year actuarial local recurrence free, distant recurrence free, disease free, and overall survival rates among the 22 patients with localized ASPS were 88%, 84%, 71%%, and 87%, respectively. At a median follow-up of 9 years, 2 of 22 patients with localized disease had developed local recurrences and 3 had developed metastatic disease (all to the lung only). Brain metastases were noted in 9 of 48 patients who presented with Stage IV (M1) disease (19%) and always were noted in association with metastasis to other sites. The median survival of patients with M1 disease was 40 months, with a 5-year survival rate of 20%.CONCLUSIONS Long term follow-up of patients with localized ASPS reveals a relatively indolent clinical course with relatively low rates of local and distant recurrence. In patients with Stage IV ASPS, brain metastases were observed only as part of more disseminated disease. The observations of the current study do not support current practice guidelines for the staging of patients with ASPS and suggest that selective rather than routine intracranial imaging should be used in patients presenting with ASPS. Cancer 2001;91:585–91. © 2001 American Cancer Society.Cancer 02/2001; 91(3):585 - 591. DOI:10.1002/1097-0142(20010201)91:3<585::AID-CNCR1038>3.0.CO;2-0 · 4.90 Impact Factor