Radiological measurement of breast cancer metastases to lung and liver: comparison between WHO (bidimensional) and RECIST (unidimensional) guidelines

Biocompatible astaxanthin as novel contrast agent for biomedical imaging

Photoacoustic imaging (PAI) is a hybrid imaging modality with high resolution and sensitivity that can be beneficial for cancer staging. Due to insufficient endogenous photoacoustic (PA) contrast, the development of exogenous agents is critical in targeting cancerous tumors. The current study demonstrates the feasibility of marine-oriented material, astaxanthin, as a biocompatible PA contrast agent. Both silicon tubing phantoms and ex vivo bladder tissues are tested at various concentrations (up to 5 mg/ml) of astaxanthin to quantitatively explore variations in PA responses. A Q-switched Nd : YAG laser (λ = 532 nm) in conjunction with a 5 MHz ultrasound transducer is employed to generate and acquire PA signals from the samples. The phantom results presented that the PA signal amplitudes increase linearly with the astaxanthin concentrations (threshold detection = 0.31 mg/ml). The tissue injected with astaxanthin yields up to 16-fold higher PA signals, compared with that with saline. Due to distribution of the injected astaxanthin, PAI can image the margin of astaxanthin boles as well as quantify their volume in 3D reconstruction. Further investigations on selective tumor targeting are required to validate astaxanthin as a potential biocompatible contrast agent for PAI-assisted bladder cancer detection.

Response Evaluation of Chemotherapy for Lung Cancer

Assessing response to therapy allows for prospective end point evaluation in clinical trials and serves as a guide to clinicians for making decisions. Recent prospective and randomized trials suggest the development of imaging techniques and introduction of new anti-cancer drugs. However, the revision of methods, or proposal of new methods to evaluate chemotherapeutic response, is not enough. This paper discusses the characteristics of the Response Evaluation Criteria In Solid Tumor (RECIST) version 1.1 suggested in 2009 and used widely by experts. It also contains information about possible dilemmas arising from the application of response assessment by the latest version of the response evaluation method, or recently introduced chemotherapeutic agents. Further data reveals the problems and limitations caused by applying the existing RECIST criteria to anti-cancer immune therapy, and the application of a new technique, immune related response criteria, for the response assessment of immune therapy. Lastly, the paper includes a newly developing response evaluation method and suggests its developmental direction.

Assessment of treatment response using PET

This article reviews the major treatment response evaluation guidelines in the domain of cancer imaging and how the potential of PET imaging, particularly with fluorodeoxyglucose, is increasingly explored in this important aspect of cancer management. Certain disease-specific response criteria (such as in lymphoma) are also reviewed with emphasis on the changes made over time and the main areas of concern in PET interpretation. The major present clinical applications are illustrated and potential new areas are discussed with regard to clinical applications in the future. Finally, the evolving role of newer and novel PET metrics, which hold promise in treatment response evaluation, is illustrated with examples.

Phase II study of temozolomide (TMZ) and everolimus (RAD001) therapy for metastatic melanoma: a North Central Cancer Treatment Group study, N0675

OBJECTIVE

Mammalian target of rapamycin (mTOR) pathway is activated in malignant melanoma and in situ lesions as opposed to benign nevi. Inhibition of PI3K-Akt-mTOR signaling is implicated in sensitization of melanoma cells to alkylating agents (temozolomide [TMZ]) and inhibition of tumor angiogenesis.

METHODS

We conducted a single-arm phase II multi-institution cooperative group study to assess the antitumor activity and safety profile of the combination of TMZ and the rapamycin derivative everolimus in patients with metastatic unresectable malignant melanoma. Patients received 10 mg/d of RAD001 for 5 of 7 days (ie, 50 mg/wk) and 200 mg/m/d of TMZ for 5 days each cycle.

RESULTS

Of the first 39 eligible patients, 17 were PFS-9 successes, for a predetermined threshold of 18/39 patients for a positive trial. Overall, 21 of 48 patients were progression free at 9 weeks, for an event-free survival rate of 44% (95% confidence interval, 29%-59%). The median progression-free survival was 2.4 months and the median overall survival was 8.6 months. Four patients achieved a partial response; the median duration of response was 15.1 months. No complete remissions were observed. Treatment was in general well tolerated with only 1 patient discontinuing therapy due to toxicity (hyperlipidemia).

CONCLUSIONS

The combination of TMZ and RAD001 was well tolerated but failed to meet/exceed our study threshold for promising clinical activity in patients with metastatic melanoma.

Consistent efficacy and safety of gemcitabine-paclitaxel in patients with metastatic breast cancer: a retrospective comparison of East Asian and global studies

AIMS

The incidence of breast cancer in China is increasing at a rate greater than the global average. For treatment of metastatic breast cancer, a phase 3 trial of 529 patients (study JHQG) found that the combination of gemcitabine, a cytotoxic nucleoside analog, and paclitaxel, a taxane, significantly improved both overall and progression-free survival compared with paclitaxel monotherapy. As ethnic differences in the safety and efficacy of some anticancer therapies have been reported, this review provides oncologists treating East Asian patients with an evidence base to extrapolate results of the predominately Caucasian phase 3 JHQG study to their patients.

METHODS

Three phase 2 studies in Chinese or Japanese patients with metastatic breast cancer are reviewed with reference to the global study JHQG. The results of pharmacokinetic, efficacy and safety analyses are descriptively compared between the global and Asian studies.

RESULTS

Peak and total drug exposure values differed by less than 10% across the studies. Response rate, overall and progression-free survival values were similar, although values from the Asian studies for each of these parameters were slightly higher. Asian patients had higher rates of hematologic toxicities but lower rates of other adverse events.

CONCLUSION

Examination of the data from three studies of the gemcitabine-paclitaxel combination reveals no clinically significant ethnic differences in efficacy and safety between East Asian patients and their global counterparts. Given its demonstrated efficacy and safety profile, the gemcitabine-paclitaxel regimen should be one of the standard treatments for East Asian patients with metastatic breast cancer.

Differential microstructure and physiology of brain and bone metastases in a rat breast cancer model by diffusion and dynamic contrast enhanced MRI

Pharmacological approaches to treat breast cancer metastases in the brain have been met with limited success. In part, the impermeability of the blood brain barrier (BBB) has hindered delivery of chemotherapeutic agents to metastatic tumors in the brain. BBB-permeable chemotherapeutic drugs are being developed, and noninvasively assessing the efficacy of these agents will be important in both preclinical and clinical settings. In this regard, dynamic contrast enhanced (DCE) and diffusion weighted imaging (DWI) are magnetic resonance imaging (MRI) techniques to monitor tumor vascular permeability and cellularity, respectively. In a rat model of metastatic breast cancer, we demonstrate that brain and bone metastases develop with distinct physiological characteristics as measured with MRI. Specifically, brain metastases have limited permeability of the BBB as assessed with DCE and an increased apparent diffusion coefficient (ADC) measured with DWI compared to the surrounding brain. Microscopically, brain metastases were highly infiltrative, grew through vessel co-option, and caused extensive edema and injury to the surrounding neurons and their dendrites. By comparison, metastases situated in the leptomenengies or in the bone had high vascular permeability and significantly lower ADC values suggestive of hypercellularity. On histological examination, tumors in the bone and leptomenengies were solid masses with distinct tumor margins. The different characteristics of these tissue sites highlight the influence of the microenvironment on metastatic tumor growth. In light of these results, the suitability of DWI and DCE to evaluate the response of chemotherapeutic and anti-angiogenic agents used to treat co-opted brain metastases, respectively, remains a formidable challenge.

The LoG characteristic scale: a consistent measurement of lung nodule size in CT imaging

Nodule growth as observed in computed tomography (CT) scans acquired at different times is the primary feature to malignancy of indeterminate small lung nodules. In this paper, we propose the estimation of nodule size through a scale-space representation which needs no segmentation and has high intra- and inter-operator reproducibility. Lung nodules usually appear in CT images as blob-like patterns and can be analyzed in the scale-space by Laplacian of Gaussian ( LoG ) kernels. For each nodular pattern the LoG scale-space signature was computed and the related characteristic scale adopted as measurement of nodule size. Both in vitro and in vivo validation of LoG characteristic scale were carried out. In vitro validation was done by 40 nondeformable phantoms and 10 deformable phantoms. A close relationship between the characteristic scale and the equivalent diameter, i.e., the diameter of the sphere having the same volume of nodules, (Pearson correlation coefficient was 0.99) and, for nodules undergoing little deformations (obtained at constant volume), small variability of the characteristic scale was observed. The in vivo validation was performed on low and standard-dose CT scans collected from the ITALUNG screening trial (86 nodules) and from the LIDC public data set (89 solid nodules and 40 part-solid nodules or ground-glass opacities). The Pearson correlation coefficient between characteristic scale and equivalent diameter was 0.83-0.93 for ITALUNG and 0.68-0.83 for LIDC data set. Intra- and inter-operator reproducibility of characteristic scale was excellent: on a set of 40 lung nodules of ITALUNG data, two radiologists produced identical results in repeated measurements. The scan-rescan variability of the characteristic scale was also investigated on 86 two-year-stable solid lung nodules (each one observed, on average, in four CT scans) identified in the ITALUNG screening trial: a coefficient of repeatability of about 0.9 mm was observed. Experimental evidence supports the clinical use of the LoG characteristic scale to measure nodule size in CT imaging.

RECIST revised: implications for the radiologist. A review article on the modified RECIST guideline

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 ≥10 mm but <15 mm and target LN ≥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 ≥20% increase in the sum of the longest diameter (SLD) from the nadir but also a ≥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.

Beyond RECIST: molecular and functional imaging techniques for evaluation of response to targeted therapy

The development of targeted therapies is a major breakthrough in the treatment of cancer. By evoking necrosis and cavitation, evaluation based on tumour size alone, as is done in the RECIST criteria, is no longer an adequate method. New molecular and functional imaging techniques are developed. This review focuses on the use of new imaging modalities for the evaluation of treatment response of pathway based targeted therapies. First, the basic principles of functional and molecular imaging modalities are briefly discussed. Thereafter, their clinical application in targeted therapies is correlated to the underlying biological mechanism. In this way, the best method for response evaluation for a new agent can be identified.

Imaging techniques to evaluate the response to treatment in oncology: current standards and perspectives

Response evaluation in solid tumours currently uses radiological imaging techniques to measure changes under treatment. Imaging requires a well-defined anatomical lesion to be viewed and relies on the measurement of a reduction in tumour size during treatment as the basis for presumed clinical benefit. However, with the development of anti-angiogenesis agents, anatomical imaging has became inappropriate as certain tumours would not reduce in size. Functional studies are therefore necessary and dynamic contrast enhanced magnetic resonance imaging (DCE-MRI), DCE-computed tomography (CT) and DCE-ultrasonography (US) are currently being evaluated for monitoring treatments. Diffusion-weighted MR imaging (DW-MRI) and magnetic resonance spectroscopy (MRS) are also capable of detecting changes in cell density and metabolite content within tumours. In this article, we review anatomical and functional criteria currently used for monitoring therapy. We review the published data on DCE-MRI, DCE-CT, DCE-US, DW-MRI and MRS. This literature review covers the following area: basic principles of the technique, clinical studies, reproducibility and repeatability, limits and perspectives in monitoring therapy. Anatomical criteria such as response evaluation criteria in solid tumours (RECIST) will require adaptation to employ not only new tools but also different complementary techniques such as functional imaging in order to monitor therapeutic effects of conventional and new anti-cancer agents.

Phase 2 trial of talactoferrin in previously treated patients with metastatic renal cell carcinoma

BACKGROUND

Talactoferrin (TLF), a recombinant form of human lactoferrin (hLF), is an immunomodulatory iron-binding glycoprotein first identified in breast milk. Its immunomodulatory functions include activation of natural killer (NK) and lymphokine-activated killer cells and enhancement of polymorphonuclear cells and macrophage cytotoxicity. Studies in animal models have shown promising anticancer activity, and clinical antitumor activity has been observed in nonsmall cell lung cancer and other tumor types. The purpose of the current study was to evaluate the activity and safety of TLF in patients with refractory metastatic renal cell carcinoma (RCC).

METHODS

Forty-four adult patients with progressive advanced or metastatic RCC who had failed prior systemic therapy received oral talactoferrin at a dose of 1.5 g twice daily on a 12-week-on 2-week-off schedule. Patients were evaluated for progression-free survival at 14 weeks, overall response rate, and progression-free and overall survival.

RESULTS

TLF was well tolerated. No significant hematologic, hepatic, or renal toxicities were reported. The study met its predefined target with a 14-week progression-free survival rate of 59%. The response rate was 4.5%. The mMedian progression-free survival was 6.4 months and the median overall survival was 21.1 months.

CONCLUSIONS

TLF is a well-tolerated new agent that has demonstrated preliminary signs of clinical activity. Given the lack of toxicity, the lack of rapid disease progression in this cohort, and the preclinical data on immune activation, a randomized study assessing its effects on disease progression in patients with metastatic RCC is rational.

Validation of radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas: Japanese Orthopaedic Association Committee on Musculoskeletal Tumors Cooperative Study

BACKGROUND

The radiographic evaluation of the response to preoperative chemotherapy for bone and soft tissue sarcomas is based mostly on the change in primary tumor size before and after chemotherapy, as is done for many solid cancers. Its prognostic correlation, however, has hardly been validated.

METHODS

We conducted a retrospective validation study of the Japanese Orthopaedic Association (JOA) radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas as a JOA Committee on Musculoskeletal Tumors cooperative study. A total of 125 consecutive patients with high-grade bone (n = 77) and soft tissue (n = 48) sarcomas treated with neoadjuvant chemotherapy and definitive surgery in 25 tertiary referral hospitals were selected for the study. We investigated the correlation between the tumor size-based radiographic response evaluation criteria of preoperative chemotherapy for bone and soft tissue sarcomas provided by the JOA Committee on Musculoskeletal Tumors (hereafter called the JOA criteria) and the patients' overall survival using the Kaplan-Meier method and the log-rank test.

RESULTS

The JOA criteria correlated relatively well with survival for malignant bone tumors (mostly comprising osteosarcoma and Ewing's sarcoma) but not for soft tissue sarcomas, suggesting that the tumor size-based radiographic evaluation criteria for the response to preoperative chemotherapy in patients with soft tissue sarcomas is invalid.

CONCLUSIONS

The JOA criteria, based on the change in primary tumor size, is valid for malignant bone tumors but invalid for soft tissue sarcomas. Other new evaluation modalities of the response to preoperative chemotherapy using innovative functional imaging techniques are needed for soft tissue sarcomas.

[Comparison of unidimensional and bidimensional measurement to assess therapeutic response in the treatment of solid tumors]

PURPOSE

In this prospective study we applied both the bidimensional WHO method and the unidimensional RECIST method in treatment follow-up of solid tumors.

MATERIAL AND METHODS

Computed tomography was performed in 80 patients before and after one chemotherapy cycle: 20 patients each with lung cancer, lymphoma, and metastases of the lung and the liver. In 207 tumor lesions unidimensional and bidimensional measurements were performed: 36 lesions of lung cancer, 51 lesions of lymphoma, and 60 lesions of metastases of the lung and the liver, respectively. We assigned the results to the corresponding response categories.

RESULTS

For tumor assessment, the kappa statistic produced a high agreement of 0.94 between the two methods for assessment of therapeutic response.

CONCLUSION

The unidimensional RECIST measurement is easier to perform in order to assess tumor size during treatment follow-up in oncologic radiology.

Post-treatment imaging of liver tumours

In the past few years, great improvements have been made to achieve local tumour control of primary liver malignancies and liver metastases. For hepatocellular carcinoma (HCC), transarterial chemoembolisation (TACE) and tumour ablation techniques, including percutaneous ethanol injection (PEI), radiofrequency ablation (RF), and laser-induced interstitial thermotherapy (LITT) have been developed. For colorectal liver metastases, surgery is still the standard technique in localised disease, although percutaneous RF ablation has gained considerable acceptance. In patients with widespread disease, chemotherapy with new drugs offers improved survival. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are the modalities of choice to evaluate treatment response. The present review demonstrates imaging findings of complete and incomplete tumour control after intervention as well as the imaging spectrum of complications. Imaging guidelines according to the World Health Organization and Response Evaluation Criteria In Solid Tumors (RECIST) for assessment of chemotherapy response are presented.

Nasopharyngeal Cancers: Which Method Should be Used to Measure these Irregularly Shaped Tumors on Cross-Sectional Imaging?

PURPOSE

To determine whether the standard techniques of measuring tumor size and change in size after treatment could be applied to the measurement of nasopharyngeal cancers, which are often irregular in shape.

METHODS AND MATERIALS

The standard measurements of bidimensional (BDM) (World Health Organization criteria) and unidimensional (UDM) (Response Evaluation Criteria in Solid Tumors [RECIST] criteria), together with the maximum depth of the tumor perpendicular to the pharyngeal wall (DM), were acquired from axial magnetic resonance images of primary nasopharyngeal carcinoma in 44 patients at diagnosis and in 29 of these patients after treatment. Tumor volume measurements (VM), acquired from the summation of areas from the axial magnetic resonance images, were used as the reference standard.

RESULTS

There was a significant association between VM and BDM with respect to tumor size at diagnosis (p = 0.002), absolute change in tumor size after treatment (p < 0.001), and percentage change in tumor size after treatment (p = 0.044), but not between VM and UDM. There was also a significant association between VM and DM with respect to percentage change in tumor size after treatment (p = <0.0001) but not absolute change (p = 0.222).

CONCLUSION

When using simple measurements to assess irregularly shaped nasopharyngeal cancers, the BDM should be used to measure size at diagnosis and the BDM and percentage change in size with treatment. Unidimensional measurement does not reflect size or change in size, and therefore the RECIST criteria may not be applicable to all tumor shapes. The use of DM requires further evaluation.

Surgical and Nonsurgical Therapy for Lung Metastasis: Indications and Outcomes

The management of pulmonary metastasis is a broad and multifaceted topic. Because of the filtration function and the favorable microenvironment of the lung, most malignancies cause pulmonary metastases. This article focuses on recent experience with secondary lung malignancies and their newer treatment options, indications, and technical aspects.

Operator-Dependent Reproducibility of Size Measurements of Small Phantoms and Lung Nodules Examined With Low-Dose Thin-Section Computed Tomography

OBJECTIVE

We sought to assess the reproducibility of size measurements of small lung nodules examined with low-dose thin-section computed tomography (LDTSCT).

MATERIALS AND METHODS

Three radiologists measured volume with a semiautomatic tool and diameters manually of 20 (equivalent diameter range, 5.3-11 mm) phantom nodules and 37 (mean diameter range, 5-8.5 mm) lung nodules in subjects undergoing LDTSCT.

RESULTS

In phantoms, the worst 95% limits of agreement (95% LA) for volume were -3.0% and 3.0% within operator and -3.1% and 2.8% between operators. The coefficient of repeatability (CR) for diameter ranged between 0.51 and 0.67 mm within operator and the 95% LA were from -0.71 to 0.71 mm between operators. In nodules, the worst intraoperator 95% LA for volume were -14.4% and 17.6% within operator and -13.1% and 14.2% between operators. The CR for diameter ranged between 0.48 and 0.73 mm within operator and the 95% LA were from -1.16 to 1.16 mm between operators.

CONCLUSION

Operator-dependent variability of size measurements of small nodules examined with LDTSCT is not negligible and should be considered in lung cancer-screening studies.

18F-FDG-PET for evaluation of the response to concurrent chemoradiation therapy with intensity-modulated radiation technique for Stage T4 nasopharyngeal carcinoma

PURPOSE

This article evaluates [18F] fluorodeoxyglucose positron emission tomography (18F-FDG-PET) findings as a predictor for local responders (R) vs. nonresponders (NR) in nasopharyngeal carcinoma (NPC) patients with Stage T4 lesions, before and at 3 months after completion of concurrent chemotherapy and radiation therapy (CCRT).

METHODS AND MATERIALS

From January 2002 to November 2003, 39 T4 NPC patients were enrolled. All had magnetic resonance imaging and 18F-FDG-PET, both before and 3 months after CCRT. Any residual/recurrent lesions were confirmed histopathologically.

RESULTS

Of the 39 eligible patients, after a follow-up of 24.2 +/- 9.5 months, 35 became disease-free and 4 had residual or recurrent disease. Marginal differences in standard uptake values (SUV) were observed (10.9 +/- 5.3 vs. 15.6 +/- 3.4, p = 0.058) between R and NR before treatment, and value changes of SUV before and after CCRT were not significantly different. However, highly significantly lower values of SUV were noted for R than for NR 3 months after completion of CCRT (2.1 +/- 0.8 vs. 5.5 +/- 3.2, p = 0.001). One hundred percent positive and negative predictive values were observed for SUV values of 4.0, set 3 months after completion of CCRT.

CONCLUSIONS

Neither the pretreatment SUV nor the changes of SUV between pretreatment and posttreatment were significant predictors for local response. SUV at 3 months after completion of CCRT was a significant determinator for local response. The cutoff of 4.0 for SUV at 3 months after completion of CCRT was useful to be offered as a diagnostic reference for recurrent or residual tumor for NPC treatment.

Measures of response: RECIST, WHO, and new alternatives

RECIST (Response Evaluation Criteria in Solid Tumors) is a widely employed method introduced in 2000 to assess change in tumor size in response to therapy. The simplicity of the technique, however, contrasts sharply with the increasing sophistication of imaging instrumentation. Anatomically based imaging measurement, although supportive of drug development and key to some accelerated drug approvals, is being pressed to improve its methodologic robustness, particularly in the light of more functionally-based imaging that is sensitive to tissue molecular response such as fluorodeoxyglucose positron emission tomography. Nevertheless ready availability of computed tomography and magnetic resonance imaging machines largely assures anatomically based imaging a continuing role in clinical trials for the foreseeable future. Recent advances in image processing enabled by the computational power of modern clinical scanners open a considerable opportunity to characterize tumor response to therapy as a complement to image acquisition. Various alternative quantitative volumetric approaches have been proposed but have yet to gain wide acceptance by clinical and regulatory communities, nor have these more complex techniques shown incontrovertible evidence of greater reproducibility or predictive value of clinical events and outcome. Unless plans are created for clinical trials that incorporate the design needed to prove the added value and unique clinical utility of these novel approaches, any theoretical benefit of these more elaborate methods could remain unfulfilled.

Response to chemotherapy in patients with lung metastases: how many nodules should be measured?

Objective: With the introduction of cross-sectional imaging methods the number of lesions per patient that can be evaluated is frequently large and most oncologists and study protocols use only one lesion or a few ‘representative’ lesions to evaluate chemotherapy response. Intra-patient response variability can therefore affect evaluation reproducibility. This study evaluates intra-individual variation in response to chemotherapy in patients with multiple lung metastases. Methods: We prospectively studied chest CT images of patients with solid tumors and pulmonary metastases under systemic chemotherapy being evaluated for tumor response. The response of 566 pulmonary nodules in 41 evaluations was determined by both WHO and RECIST criteria in order to determine intra-individual tumor response variation. Results: There was almost perfect agreement between the WHO and the RECIST criteria for the evaluation of tumor response. High intra-individual variability of tumor response was observed in a significant proportion of the evaluations. A new nodule was the main criterion for determination of disease progression. A mean of 35% of the total number of nodules of a patient have a response evaluation different from that calculated with all the nodules together. Conclusions: Intra-individual variation in tumor response of pulmonary metastases is elevated in some patients. Selecting any or some nodules for response evaluation could significantly influence therapeutic response perception.

CT of colon cancer metastases to the liver using modified RECIST criteria: determining the ideal number of target lesions to measure

OBJECTIVE

We sought to define the ideal number of target lesions to be measured to assess disease response in patients undergoing chemotherapy for colon cancer metastases to the liver.

MATERIALS AND METHODS

Thirty consecutive patients were recruited for this study. Patients were part of a multisite, randomized, double-arm, phase 3 clinical trial involving chemotherapy with an investigational drug for metastatic colon cancer. Patients were recruited from U.S. and international sites. Institutional review board approval was obtained, and informed consent was obtained from all patients. Our study included CT measurements of hepatic metastases. All patients (n = 30) had a minimum of five target lesions in the liver. Target-lesion size was defined by Response Evaluation Criteria in Solid Tumors (RECIST) criteria. We calculated the patient response at 2 months and at 6 months (complete response, partial response, stable disease, and progressive disease) using RECIST. Patient response was calculated based on the percentage increase or decrease at 2 and 6 months in the greatest diameter of the single largest lesion, two large lesions, three large lesions, four lesions, and five lesions, respectively. The concordance between five-target-lesion measurement and lesser numbers of lesions was analyzed using kappa statistics (StatView, 5.0).

RESULTS

In 93.33% of patients (n = 28/30), there was agreement on patient response irrespective of the number of measurements made on CT. Of these 30 patients, 47% had a partial response (n = 14/30), 43% had stable disease (n = 13/30), and 10% had progressive disease at 2 months (n = 3/30). At 6 months, 43% had a partial response (n = 13/30), 47% had stable disease (n = 14/30), and 10% had progressive disease (n = 3/30). Agreement in response evaluation between lesion groups for multiple measurements was high, with values of 1.0 for multiple-lesion measurements and 0.88 for single-lesion measurements at 2 months. The concordance values were the same at 6 months.

CONCLUSION

In the majority of patients with hepatic metastases of colorectal cancer, measuring the maximal diameter of the single largest lesion yielded the same treatment-response classification as measuring up to five target lesions. This result suggests that it may be possible to reduce the number of lesions measured in clinical trials.

RECIST revisited: a review of validation studies on tumour assessment

The response evaluation criteria in solid tumours (RECIST) was developed in the late 1990s to replace the WHO criteria for response evaluation. The new criteria included important changes such as unidimensional tumour measurement, selection of target lesions with a minimum size, details concerning imaging modalities and a new threshold for assignment of objective progression. RECIST was published in February 2000 and very quickly came into operation first in clinical trials performed under the auspices of EORTC, US NCI or NCI Canada Clinical Trials Group but was adopted quickly thereafter by the entire cancer clinical research community. As several key features of RECIST were based on analysis of retrospective clinical data, it was felt important to carefully monitor the implementation of the guidelines and stimulate prospective validation studies. This paper reviews the literature that has been published on RECIST from 2000 up to November 2005. In total 60 papers and ASCO, abstracts directly refer to research studies or reviews related to RECIST and its implementation. Amongst the 60 references identified for this review, 11 papers refer to validation studies (seven prospective and four retrospective), six papers refer to the comparison of unidimensional measurements versus bi or tri-dimensional measurements, 12 papers address issues raised with the implementation of RECIST in Mesothelioma and Gastro-Intestinal Stromal Tumours and four papers report on an adaptation of RECIST for specific tumour types. In general, RECIST has been well received by the scientific community and most validation studies fully support the implementation of the new criteria. As expected, however, some issues have been identified. In keeping with the mathematical differences in definition of progression, RECIST delays the identification of progression as compared to WHO criteria in some instances. RECIST criteria are not easily applicable in some types of trials such as those in paediatric tumours and in mesothelioma. Furthermore, anatomical changes in the tumour as described by RECIST may be detected later than functional changes in some circumstances, as for example in Gastro-Intestinal Stromal Tumours treated with Imatinib. However, there is no other universal method of tumour assessment as yet and functional imaging methods have not been validated and will not be widely available for some time. The findings of this review, together with experience acquired thus far and the results of some ongoing research projects, have paved the way for RECIST 2.0 to be hopefully announced later this year.

Validation of neuroradiologic response assessment in gliomas: measurement by RECIST, two-dimensional, computer-assisted tumor area, and computer-assisted tumor volume methods

Significant limitations are associated with the use of standard radiographic measurements as indicators of response in glioma therapy trials. The Response Evaluation Criteria in Solid Tumors (RECIST) were recently introduced in an attempt to standardize and simplify assessment of response to treatment in cancer clinical trials. However, their applicability in gliomas has been assessed in only a very small number of patients. Our aim was to validate radiographic response assessment in newly diagnosed glioma patients. Sixty-seven newly diagnosed glioma patients participating in nine North Central Cancer Treatment Group glioma trials were included; 565 MRI scans were analyzed. All scans were performed with the same technique. Kappa statistics were calculated to determine agreement between assessment methods. Cox proportional hazards analyses and time-dependent Cox models were used to assess the association between different measurement methods and overall survival. Results showed agreement between the one-dimensional (1D) and two-dimensional (2D) measurements both for T2 images and for gadolinium-enhanced images. Comparison of duration of response and time to progression as assessed by eight different methods showed similarity in response assessments by 1D, 2D, area, and volume gadolinium measurements. In contrast, time to progression was significantly shorter when assessed by 1D-T2 or 2D-T2 images as compared to area-T2 or volume-T2 images. This set of data indicates that RECIST could be used instead of 2D imaging for response assessment in newly diagnosed glioma trials. Overall, responses as determined by any tumor measurement method did not correlate with patient survival for either enhancing or nonenhancing tumors, although the small number of responders limits definitive conclusions. Time-dependent Cox models demonstrated that, in contrast to the case of nonenhancing tumors, progression as determined by 1D, 2D, area, and volume measurements in gadolinium-enhanced images was predictive of survival of patients with enhancing tumors.

Comparison of WHO and RECIST criteria for response in metastatic colorectal carcinoma

PURPOSE

This study compared the WHO criteria with the response evaluation criteria in solid tumors (RECIST) in the same patients with metastatic colorectal cancer in order to determine the significance of the RECIST. In addition, this study compared the estimations of medical oncologists with those of a radiologist.

MATERIALS AND METHODS

Between 2002 and 2005, a total of 48 patients (male: female ratio, 29:19; median age, 58 years) with measurable lesions receiving chemotherapy for metastatic colorectal carcinoma were enrolled in this study. Two medical oncologists and one radiologist, who were blinded to the patients' condition, independently reviewed all the CT images. The results were compared using a kappa test.

RESULTS

The kappa test for concordance between the WHO and RECIST criteria of the medical oncologists and the radiologist were 0.908 and 0.841, respectively. The level of concordance between the investigators using the WHO and RECIST were 0.722 and 0.753, respectively.

CONCLUSION

The RECIST criteria are comparable to the WHO criteria in evaluating the response of colorectal carcinoma, but have simple and reproducible guidelines. The use of RECIST is recommended for evaluating the treatment efficacy in clinical trials and practice.

131I-Labelled-iodized oil for palliative treatment of hepatocellular carcinoma

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) is growing in western countries. Poor liver status and tumour size make curative options scarce. Palliative treatments such as chemo-embolization are improving survival in selected patients, but side-effects are frequent. There is a need for the validation of alternative treatments. Metabolic radiotherapy using lipiodol labelled with 131I-iodine (I-131-lipiodol) is one of these treatments.

OBJECTIVES

To analyse the effect of I-131-lipiodol in a population of advanced HCC patients and to define the potential prognostic factors in this setting.

METHODS

A retrospective analysis of the effect of I-131-lipiodol on 29 patients bearing multifocal tumours was performed. An analysis of two subgroups, defined by a Cancer of the Liver Italian Program (CLIP) score of 2 or less (n=20) or greater than 2 (n=9) was performed to assess the prognostic significance of the score in this setting.

RESULTS

Overall median survival in the entire study population was 203 days (95% confidence interval 83-322 days). Median survival was significantly better in the group with CLIP scores of 2 or less than in the group with CLIP scores greater than 2 (453 versus 60 days, P< or =0.001). Treatment-related mortality was 6.9% (one interstitial pneumonia and one acute liver failure).

CONCLUSION

The survival of patients treated with I-131-lipiodol in this series compared favourably with published data. Stratification according to the CLIP score was useful to predict survival. In particular, patients with portal vein thrombosis should only be considered for I-131-lipiodol if the CLIP score is lower than 2.

RECIST vs. WHO: prospective comparison of response criteria in an EORTC phase II clinical trial investigating ET-743 in advanced soft tissue sarcoma

The present study was set up just after the publication of the response evaluation criteria in solid tumors (RECIST) as a prospective validation exercise in soft tissue sarcoma. Forty-nine patients were entered into a phase II clinical trial aiming at determining the activity and safety of ET-743 (Ecteinascidin) in second line advanced soft tissue sarcoma. Response to treatment and progression were monitored following the WHO criteria and RECIST. Discordances between WHO and RECIST criteria for the best response were reported for two cases: one no-change (WHO) reported as partial response (RECIST) and one progression (WHO) reported as no-change (RECIST). In terms of date of progression, 3 patients progressed on WHO criteria while they were still stable with RECIST. Overall the results of the study would not have changed if RECIST had been used instead of WHO criteria. In conclusion, response criteria as defined by RECIST are adequate to measure response and progression in non-GIST soft tissue sarcoma and can be used instead of the modified WHO criteria.

Interobserver and intraobserver variability in the assessment of pulmonary nodule size on CT using film and computer display methods

RATIONALE AND OBJECTIVES

A critical element in determining biologic behavior of pulmonary nodules is volume and temporal volume change. We evaluate variability in nodule volume among readers and measuring methods.

MATERIALS AND METHODS

55 small (<2 cm) lung nodules were measured in long- and short-axis dimensions independently by 4 radiologists, using 3 methods: 1) hard copy, 2) GE Advantage Windows workstation (GE Healthcare, Milwaukee, WI), 3) Siemens IMACS workstation (Siemens Medical Systems, Iselan, NJ). Nodule margin was recorded as smooth, lobulated, or spiculated. Volume was calculated from diameter measurements. Variability in nodule volume was evaluated within each reader, between readers, and across measurement tools.

RESULTS

Mean nodule short-axis diameter was 5.3 mm; mean long-axis diameter 7.2 mm. There was statistically significant variation among readers and measurement method for nodule volume. Volume was significantly larger using hard-copy measurements (51.9%-54.1% variation; P < .0001) than either workstation, and not different between workstations. There was greater intraobserver variability in volume using the hard-copy method, and no difference between workstation methods. Volumes based on measurements from one reader were consistently lower than those from other readers (P = < .001, .003, and .02); volume was consistently larger for another reader (P < .0001, .03, and .12). Reader agreement for nodule margin was good to excellent.

CONCLUSION

Considerable interobserver and intraobserver variability in measuring nodules exists using hard-copy and computer tools. Since a small change in diameter indicates a much larger change in volume, this may be significant when using early repeat CT to follow small pulmonary nodules. Computer-aided diagnostic tools that reproducibly measure nodule volume are strongly needed.

MRI measurements of breast tumor volume predict response to neoadjuvant chemotherapy and recurrence-free survival

OBJECTIVE

The purpose of this study was to assess the value of MRI measurements of breast tumor size for predicting recurrence-free survival (RFS) in patients undergoing neoadjuvant (preoperative) chemotherapy and to compare the predictive value of MRI with that of established prognostic indicators.

SUBJECTS AND METHODS

The study included 62 patients undergoing neoadjuvant chemotherapy. The longest diameter and volume of each tumor were measured on MRI before and after one and four cycles of treatment. Change in diameter on clinical examination, tumor size at pathology, and the number of positive nodes were determined. Each measure of tumor extent was assessed for the ability to predict RFS.

RESULTS

Univariate Cox analysis showed initial MRI volume was the strongest predictor of RFS (p = 0.002). Final change in MRI volume (p = 0.015) was more predictive than change in diameter on MRI (p = 0.077) or clinical examination (p = 0.27). Initial diameter on MRI (p = 0.003) and clinical examination (p = 0.033), tumor size at pathology (p = 0.016), and number of positive nodes (p = 0.045) were also significantly predictive of RFS. Early change in MRI volume (p = 0.071) and diameter (p = 0.081) after one chemotherapy cycle showed trends of association with RFS. Multivariate analysis showed initial MRI volume (p = 0.005) and final change in MRI volume (p = 0.003) were significant independent predictors.

CONCLUSION

MRI tumor volume was more predictive of RFS than tumor diameter, suggesting that volumetric changes measured using MRI may provide a more sensitive assessment of treatment efficacy.