Low-Dose CT Protocol Performs Well in Lung Nodule Assessment
http://www.medscape.com/viewarticle/749243
Am J Roentgenol. 2011;197:1-8.
Abstract
September 7, 2011 — For monitoring lung nodules with computed tomography
(CT), radiation dose can be reduced to approximately 3% of the current standard dose without compromising efficacy, according to a recent study by investigators from Stanford University in California and the University of Bern in Switzerland.
The study,
which appears in the September issue of the
American Journal of Roentgenology, found that tube current-time settings could be set as low as 10 milliampere-seconds (mAs), compared with the standard 100 to 300 mAs, without affecting diagnostic image quality.
>...........
The study found that the use of a computer to measure nodule size decreased the variability that is observed with manual measurements. The mean nodule volume
measurement error between 5 and 300 mAs was 2.2% with the computer, which is much lower than the interobserver volume measurement error rate of 38%.
>...........
Other investigators have evaluated outcomes with lower doses of radiation, but the current study takes this approach a step farther,
Kavita Garg, MD, professor of radiology at the University of Colorado, Denver explained to
Medscape Medical News. "What is unique is that they used a wide range of dosages, as low as 5 mAs. The other unique feature is that they addressed small nodules," she said.
Eur Radiol. 2010 Jun;20(6):1456-67. Epub 2009 Dec 22.
RECIST revised: implications for the radiologist. A review article on the modified RECIST guideline.
van Persijn van Meerten EL,
Gelderblom H,
Bloem JL.
Source
Department of Radiology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
epersijn@lumc.nl
Free PMC Article
Abstract
The purpose of this review article is to familiarize radiologists with the recently revised Response Evaluation Criteria in Solid Tumours (RECIST), used in many anticancer drug trials to assess response and progression rate. The most important modifications are: a reduction in the maximum number of target lesions from ten to five, with a maximum of two per organ, with a longest diameter of at least 10 mm; in lymph nodes (LNs) the short axis rather than the long axis should be measured, with normal LN measuring <10 mm, non-target LN >or=10 mm but <15 mm and target LN >or=15 mm; osteolytic lesions with a soft tissue component and cystic tumours may serve as target lesions; an additional requirement for progressive disease (PD) of target lesions is not only a >or=20% increase in the sum of the longest diameter (SLD) from the nadir but also a >or=5 mm absolute increase in the SLD (the other response categories of target lesion are unchanged); PD of non-target lesions can only be applied if the increase in non-target lesions is representative of change in overall tumour burden; detailed imaging guidelines. Alternative response criteria in patients with hepatocellular carcinoma and gastrointestinal stromal tumours are discussed.
- PMID:
- 20033179
- [PubMed - indexed for MEDLINE]
- PMCID: PMC2872013
Eur J Cancer. 2009 Jan;45(2):228-47.
New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1).
Eisenhauer EA,
Therasse P,
Bogaerts J,
Schwartz LH,
Sargent D,
Ford R,
Dancey J,
Arbuck S,
Gwyther S,
Mooney M,
Rubinstein L,
Shankar L,
Dodd L,
Kaplan R,
Lacombe D,
Verweij J.
FREE TEXT
Source
National Cancer Institute of Canada-Clinical Trials Group, 10 Stuart Street, Queen's University, Kingston, Ontario, Canada.
eeisenhauer@ctg.queensu.ca
Abstract
BACKGROUND: Assessment of the change in tumour burden is an important feature of the clinical evaluation of cancer therapeutics: both tumour shrinkage (objective response) and disease progression are useful endpoints in clinical trials. Since RECIST was published in 2000, many investigators, cooperative groups, industry and government authorities have adopted these criteria in the assessment of treatment outcomes. However, a number of questions and issues have arisen which have led to the development of a revised RECIST guideline (version 1.1). Evidence for changes, summarised in separate papers in this special issue, has come from assessment of a large data warehouse (>6500 patients), simulation studies and literature reviews. HIGHLIGHTS OF REVISED RECIST 1.1: Major changes include: Number of lesions to be assessed: based on evidence from numerous trial databases merged into a data warehouse for analysis purposes, the number of lesions required to assess tumour burden for response determination has been reduced from a maximum of 10 to a maximum of five total (and from five to two per organ, maximum). Assessment of pathological lymph nodes is now incorporated: nodes with a short axis of 15 mm are considered measurable and assessable as target lesions. The short axis measurement should be included in the sum of lesions in calculation of tumour response. Nodes that shrink to <10mm short axis are considered normal. Confirmation of response is required for trials with response primary endpoint but is no longer required in randomised studies since the control arm serves as appropriate means of interpretation of data.
Disease progression is clarified in several aspects: in addition to the previous definition of progression in target disease of 20% increase in sum, a 5mm absolute increase is now required as well to guard against over calling PD when the total sum is very small. Furthermore, there is guidance offered on what constitutes 'unequivocal progression' of non-measurable/non-target disease, a source of confusion in the original RECIST guideline. Finally, a section on detection of new lesions, including the interpretation of FDG-PET scan assessment is included. Imaging guidance: the revised RECIST includes a new imaging appendix with updated recommendations on the optimal anatomical assessment of lesions. FUTURE WORK: A key question considered by the RECIST Working Group in developing RECIST 1.1 was whether it was appropriate to move from anatomic unidimensional assessment of tumour burden to either volumetric anatomical assessment or to functional assessment with PET or MRI. It was concluded that, at present, there is not sufficient standardisation or evidence to abandon anatomical assessment of tumour burden. The only exception to this is in the use of FDG-PET imaging as an adjunct to determination of progression. As is detailed in the final paper in this special issue, the use of these promising newer approaches requires appropriate clinical validation studies.
- PMID:
- 19097774
- [PubMed - indexed for MEDLINE]
Radiographics. 2008 Mar-Apr;28(2):329-44.
Radiologic measurements of tumor response to treatment: practical approaches and limitations.
Suzuki C,
Jacobsson H,
Hatschek T,
Torkzad MR,
Bodén K,
Eriksson-Alm Y,
Berg E,
Fujii H,
Kubo A,
Blomqvist L.
FREE TEXT
Source
Department of Diagnostic Radiology, Institution for Molecular Medicine and Surgery, Karolinska University Hospital Solna and Karolinska Institute, Stockholm S-171 76, Sweden.
Chikako.Tanaka@ki.se
Abstract
Objective response assessment is important to describe the treatment effect of anticancer drugs. Standardization by using a "common language" is also important for comparison of results from different trials. In contrast to clinical results, which can be subjective, diagnostic imaging provides a greater opportunity for objectivity and standardization. It was generally accepted that a decrease in tumor size correlated with treatment effect; as a result, imaging was adopted for lesion measurement in the World Health Organization (WHO) criteria in 1979. However, because of some limitations of the WHO criteria,
the Response Evaluation Criteria in Solid Tumors (RECIST) were introduced in 2000. In RECIST, imaging was recognized as indispensable for response evaluation of solid tumors. Nevertheless, the widespread use of multidetector computed tomography and other imaging innovations have made RECIST outdated, with a concomitant need for modifications. Meanwhile, newer anticancer agents with targeted mechanisms of action have demonstrated an inherent limitation and unsuitability of anatomic tumor evaluation that assesses only lesion size. In addition, the effect of these new drugs changes the paradigm according to which tumor response or response rate is measured. Complete and partial responses cannot be the end points in all clinical trials; in some cases, disease control or progression-free survival may be the more relevant end point.
(c) RSNA, 2008
- PMID:
- 18349443
- [PubMed - indexed for MEDLINE]
Sometimes Size Doesn't Matter: Reevaluating RECIST and Tumor Response Rate Endpoints
FULL TEXT
- Rabiya S. Tuma
If you give a cancer patient a drug and then the tumor's growth screeches to a halt or a hole appears in its middle, most people would say the drug was working. But on the basis of the response criteria most widely used for solid tumors, these changes mean nothing.
Standardized response criteria are critical for directing individual patient care, evaluating new therapies, and communicating risk to family and patients. Yet just what those criteria should be for solid tumors is up for debate. Although some groups are looking for new ways to physically measure success, others are moving away from tumor measurements altogether and strictly examining survival.
“I think standardizing response assessment is generally a good thing because people speak the same language when they are reporting studies,” said Primo N. Lara, M.D., associate professor of medicine at the University of California at Davis in Sacramento, who presented on the topic at the American Society of Clinical Oncology annual meeting. “Some people misinterpret a tumor response as being an end-all or be-all for a particular study, but our study showed that even if you don't have a [measurable] response, having stable disease or nonprogression at a certain time point is a good predictor of outcome. You may not need to have a nice 30% reduction in tumor size to benefit from a treatment.”
<<<<
A more recently developed standard, called the Choi criteria, appears to better predict survival in a small series of patients than RECIST, said Robert S. Benjamin, M.D., chair of sarcoma medical oncology at the University of Texas M. D. Anderson Cancer Center in Houston, at the ASCO meeting.
A good response by the Choi criteria is defined as a 10% decrease in tumor size or a 15% decrease in tumor density on contrast-enhanced computed tomography (CT) scan.
J Clin Oncol. 2007 May 1;25(13):1760-4.
We should desist using RECIST, at least in GIST.
Benjamin RS,
Choi H,
Macapinlac HA,
Burgess MA,
Patel SR,
Chen LL,
Podoloff DA,
Charnsangavej C.
LINK
Source
Department of Sarcoma Medical Oncology and the Division of Diagnostic Imaging, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
rbenjami@mdanderson.org
Abstract
PURPOSE:
Response Evaluation Criteria in Solid Tumors (RECIST) are insensitive in evaluating imatinib-treated gastrointestinal stromal tumors (GISTs).
Response by Choi criteria, a 10% decrease in size or a 15% decrease in density on contrast-enhanced CT, correlated well in a small training set of patients who showed response as measured by positron emission tomography, and was more predictive of time to tumor progression (TTP) than response by RECIST. This study was designed to validate these observations in an independent data set.
PATIENTS AND METHODS:
Fifty-eight patients with imatinib-treated GISTs were evaluated by RECIST and Choi criteria. TTP was compared with TTP in the training set. Patients were analyzed initially with follow-up to 28 months, extended to 60 months for survival analysis.
RESULTS:
Patients who met Choi response criteria on CT at 2 months had significantly better TTP than those who did not (P = .0002), whereas response group by RECIST was not significantly correlated with TTP. Even when the 98 patients from both sets were analyzed together, the
response group by RECIST did not correlate significantly with TTP, whereas response group by Choi criteria did correlate significantly with TTP. Disease-specific survival (DSS) was also significantly correlated with response group by Choi criteria (P = .04), but not with response group by RECIST.
CONCLUSION:
Choi response criteria are reproducible, more sensitive, and more precise than RECIST in assessing the response of GISTs to imatinib mesylate. Response by Choi criteria, unlike response by RECIST, correlates significantly with TTP and DSS. Response by Choi criteria should be incorporated routinely into future studies of GIST therapy. We should desist using RECIST, at least in GIST.
Comment in
Clin Cancer Res. 2011 Jul 1;17(13):4504-12. Epub 2011 Apr 29.
Changes in tumor density in patients with advanced hepatocellular carcinoma treated with sunitinib.
Faivre S,
Zappa M,
Vilgrain V,
Boucher E,
Douillard JY,
Lim HY,
Kim JS,
Im SA,
Kang YK,
Bouattour M,
Dokmak S,
Dreyer C,
Sablin MP,
Serrate C,
Cheng AL,
Lanzalone S,
Lin X,
Lechuga MJ,
Raymond E.
LINK
Source
Beaujon University Hospital, Clichy, France.
Abstract
PURPOSE:
Response Evaluation Criteria in Solid Tumors (RECIST) may underestimate the efficacy of targeted therapies. In hepatocellular carcinoma (HCC) studies with sunitinib, RECIST-defined response rates are low, although hypodensity on computed tomography (CT) scans occurs more frequently. This exploratory analysis investigated tumor density as a surrogate endpoint of sunitinib activity in a phase II HCC study.
EXPERIMENTAL DESIGN:
Patients received sunitinib 50 mg/d (4 weeks on/2 weeks off). Tumor size and density were assessed on CT scans by using RECIST and Choi criteria, the latter of which classify a partial response as a 15% or more reduction in tumor density or a 10% or more reduction in tumor size. The overall percentage volume of tumor necrosis was calculated with volumetric reconstruction. Tumor perfusion parameters were assessed by using perfusion CT scans with specific acquisition.
RESULTS:
Among the 26 evaluable patients, 1 achieved a partial response and 22 had tumor stabilization by RECIST. In analysis of tumor density, 17 of 26 patients (65.4%) were responders by Choi criteria. Volumetric assessment showed major tumor necrosis (≥30% of tumor volume) in 10 of 21 patients (47.6%). Among four patients evaluated, tumor blood flow was reduced by 58.8% and blood volume by 68.4% after 4 weeks of treatment. The median time to progression (TTP) was 6.4 months. Patients with responses by Choi criteria had a significantly longer TTP (7.5 months) compared with nonresponders (4.8 months; HR = 0.33, two-sided P = 0.0182).
CONCLUSIONS:
Tumor density assessment suggested that radiologic endpoints in addition to RECIST may be considered to capture sunitinib activity in HCC.
- PMID:
- 21531821
- [PubMed - indexed for MEDLINE]
Cancer Biol Ther. 2010 Jan;9(1):15-9. Epub 2010 Jan 17.
CT response assessment combining reduction in both size and arterial phase density correlates with time to progression in metastatic renal cancer patients treated with targeted therapies.
Nathan PD,
Vinayan A,
Stott D,
Juttla J,
Goh V.
LINK
Source
Mount Vernon Cancer Centre, Northwood, Middlesex, UK.
nathan.pd@gmail.com
Abstract
BACKGROUND:
Response assessment is critical in evaluating effectiveness of anticancer treatment. Tyrosine kinase inhibitors (TKIs) in renal cell carcinoma (RCC) are associated with significant clinical benefit but may not result in significant tumor size reduction. Thus standard size-based response assessment with RECIST is insensitive, resulting in low response rates which do not reflect disease control measured by time to progression. We compared the use of combined size and density response criteria with standard size based criteria in metastatic RCC patients treated with TKI's.
RESULTS:
Partial response (PR) and stable disease (SD) defined by modified criteria successfully identified patients with a long TTP (448 days) or short TTP (89 days) respectively (p = 0.002). Neither RECIST nor standard Choi criteria successfully discriminated between patients having a short or long clinical benefit.
PATIENTS AND METHODS:
CT scans from 32 patients with metastatic RCC treated with either sunitinib (18) or cediranib (14) were assessed. Twelve patients were excluded from the analysis as ten had non-contrast enhanced scans due to renal impairment and two stopped treatment due to toxicity. Scans from 20 evaluable patients at baseline and 12 w on treatment were assessed using RECIST, Choi and modified criteria in which both a 10% decrease in size and 15% decrease in density were required to define a partial response (PR). Response assessment performed using each of the three methods was compared with time to disease progression (TTP) defined by RECIST using Kaplan-Meier statistics and Log-rank test with significance at 5%.
CONCLUSION:
A combined reduction in both size and arterial phase density of RCC metastases treated with TKIs correlates with TTP. RECIST and standard Choi criteria appear inferior.
Comment in
AJR Am J Roentgenol. 2010 Jun;194(6):1470-8.
Morphology, Attenuation, Size, and Structure (MASS) criteria: assessing response and predicting clinical outcome in metastatic renal cell carcinoma on antiangiogenic targeted therapy.
Smith AD,
Shah SN,
Rini BI,
Lieber ML,
Remer EM.
FREE TEXT
Source
Imaging Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
smithmdphd@yahoo.com
Abstract
OBJECTIVE:
The objective of our study was to evaluate response assessment and predict clinical outcome in patients with metastatic renal cell carcinoma (RCC) receiving antiangiogenic targeted therapy. Target lesions were assessed on routine contrast-enhanced CT (CECT) images obtained during the portal venous phase using new response criteria.
MATERIALS AND METHODS:
Standard CECT examinations of patients with metastatic clear cell RCC on first-line sunitinib or sorafenib therapy (n = 84) were retrospectively evaluated using
Mass, Attenuation, Size, and Structure (MASS) Criteria; Response Evaluation Criteria in Solid Tumors (RECIST); Size and Attenuation CT (SACT) Criteria; and modified Choi Criteria. The objective response to therapy was compared with clinical outcomes including time to progression (TTP) and disease-specific survival. The Kaplan-Meier method was used to estimate survival functions.
RESULTS:
A favorable response according to MASS Criteria had a sensitivity of 86% and specificity of 100% in identifying patients with a good clinical outcome (i.e., progression-free survival of > 250 days) versus 17% and 100%, respectively, for RECIST partial response. The objective categories of response used by MASS Criteria-favorable response, indeterminate response, and unfavorable response-differed significantly from one another with respect to TTP (p < 0.0001, log-rank test) and disease-specific survival (p < 0.0001, log-rank test).
CONCLUSION:
Assessment of metastatic RCC target lesions on CECT for changes in morphology, attenuation, size, and structure by MASS Criteria is more accurate than response assessment by SACT Criteria, RECIST, or modified Choi Criteria. Furthermore, the use of MASS Criteria for imaging response assessment showed high interobserver agreement and may predict disease outcome in patients with metastatic RCC on targeted therapy.
Comment in
Analyzing the pivotal trial that compared sunitinib and interferon alfa in renal cell carcinoma, using a method that assesses tumor regression and growth
*
Corresponding Author:Susan E Bates, Molecular Therapeutics Section, Medical Oncology Branch, National Cancer Institute (NCI), Building 10, Room 12N226, 900 Rockville Pike, Bethesda, MD, 20892, United States
sebates@helix.nih.gov
Abstract
Purpose:
We applied a method that analyzes tumor response, quantifying the rates of tumor growth (g) and regression (d), using tumor measurements obtained while patients receive therapy. We used data from the phase III trial comparing sunitinib and interferon-alfa (IFN-alpha) in metastatic renal cell carcinoma (mRCC) patients. Methods: The analysis used an equation that extracts d and g. Results: For sunitinib, overall survival (OS) was strongly correlated with log g (Rsq=0.44, p<0.0001); much less with log d (Rsq=0.04; p=0.0002). The median g of tumors in these patients (0.00082 per days; log g=-3.09) was about half that (p<0.001) of tumors in patients receiving IFN-alpha (0.0015 per day; log g=-2.81). With IFN-α, the OS/log g correlation (Rsq=0.14) was weaker.
Values of g from measurements obtained by study investigators or central review were highly correlated (Rsq=0.80). No advantage resulted in including data from central review in regressions. Further, g can be estimated accurately four months before treatment discontinuation. Extrapolating g in a model that incorporates survival generates the hypothesis that g increased after discontinuation of sunitinib but did not accelerate. Conclusions: In patients with mRCC, sunitinib reduced tumor growth rate, g, more than did IFN-alpha. Correlating g with OS confirms earlier analyses suggesting g may be an important clinical trial endpoint, to be explored prospectively and in individual patients.
- Received September 2, 2011.
- Revision received January 8, 2012.
- Accepted January 27, 2012.
- Copyright © 2012, American Association for Cancer Research.
- PMID:
- 20489085
- [PubMed - indexed for MEDLINE]
-
Free full text
J Nucl Med. 2009 May;50 Suppl 1:122S-50S.
From RECIST to PERCIST: Evolving Considerations for PET response criteria in solid tumors.
Wahl RL,
Jacene H,
Kasamon Y,
Lodge MA.
Free PMC Article
Source
Division of Nuclear Medicine, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-0817, USA.
rwahl@jhmi.edu
Abstract
The purpose of this article is to review the status and limitations of anatomic tumor response metrics including the World Health Organization (WHO) criteria, the Response Evaluation Criteria in Solid Tumors (RECIST), and RECIST 1.1. This article also reviews qualitative and quantitative approaches to metabolic tumor response assessment with (18)F-FDG PET and proposes a draft framework for PET Response Criteria in Solid Tumors (PERCIST), version 1.0.
METHODS:
PubMed searches, including searches for the terms RECIST, positron, WHO, FDG, cancer (including specific types), treatment response, region of interest, and derivative references, were performed. Abstracts and articles judged most relevant to the goals of this report were reviewed with emphasis on limitations and strengths of the anatomic and PET approaches to treatment response assessment. On the basis of these data and the authors' experience, draft criteria were formulated for PET tumor response to treatment.
RESULTS:
Approximately 3,000 potentially relevant references were screened. Anatomic imaging alone using standard WHO, RECIST, and RECIST 1.1 criteria is widely applied but still has limitations in response assessments. For example, despite effective treatment, changes in tumor size can be minimal in tumors such as lymphomas, sarcoma, hepatomas, mesothelioma, and gastrointestinal stromal tumor. CT tumor density, contrast enhancement, or MRI characteristics appear more informative than size but are not yet routinely applied. RECIST criteria may show progression of tumor more slowly than WHO criteria. RECIST 1.1 criteria (assessing a maximum of 5 tumor foci, vs. 10 in RECIST) result in a higher complete response rate than the original RECIST criteria, at least in lymph nodes. Variability appears greater in assessing progression than in assessing response. Qualitative and quantitative approaches to (18)F-FDG PET response assessment have been applied and require a consistent PET methodology to allow quantitative assessments. Statistically significant changes in tumor standardized uptake value (SUV) occur in careful test-retest studies of high-SUV tumors, with a change of 20% in SUV of a region 1 cm or larger in diameter; however, medically relevant beneficial changes are often associated with a 30% or greater decline. The more extensive the therapy, the greater the decline in SUV with most effective treatments. Important components of the proposed PERCIST criteria include assessing normal reference tissue values in a 3-cm-diameter region of interest in the liver, using a consistent PET protocol, using a fixed small region of interest about 1 cm(3) in volume (1.2-cm diameter) in the most active region of metabolically active tumors to minimize statistical variability, assessing tumor size, treating SUV lean measurements in the 1 (up to 5 optional) most metabolically active tumor focus as a continuous variable, requiring a 30% decline in SUV for "response," and deferring to RECIST 1.1 in cases that do not have (18)F-FDG avidity or are technically unsuitable. Criteria to define progression of tumor-absent new lesions are uncertain but are proposed.
CONCLUSION:
Anatomic imaging alone using standard WHO, RECIST, and RECIST 1.1 criteria have limitations, particularly in assessing the activity of newer cancer therapies that stabilize disease, whereas (18)F-FDG PET appears particularly valuable in such cases. The proposed PERCIST 1.0 criteria should serve as a starting point for use in clinical trials and in structured quantitative clinical reporting. Undoubtedly, subsequent revisions and enhancements will be required as validation studies are undertaken in varying diseases and treatments.
- PMID:
- 19403881
- [PubMed - indexed for MEDLINE]
- PMCID: PMC2755245
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