Eye Tracking for Deep Learning Segmentation Using Convolutional Neural Networks

Deep learning with convolutional neural networks (CNNs) has experienced tremendous growth in multiple healthcare applications and has been shown to have high accuracy in semantic segmentation of medical (e.g., radiology and pathology) images. However, a key barrier in the required training of CNNs is obtaining large-scale and precisely annotated imaging data. We sought to address the lack of annotated data with eye tracking technology. As a proof of principle, our hypothesis was that segmentation masks generated with the help of eye tracking (ET) would be very similar to those rendered by hand annotation (HA). Additionally, our goal was to show that a CNN trained on ET masks would be equivalent to one trained on HA masks, the latter being the current standard approach. Step 1: Screen captures of 19 publicly available radiologic images of assorted structures within various modalities were analyzed. ET and HA masks for all regions of interest (ROIs) were generated from these image datasets. Step 2: Utilizing a similar approach, ET and HA masks for 356 publicly available T1-weighted postcontrast meningioma images were generated. Three hundred six of these image + mask pairs were used to train a CNN with U-net-based architecture. The remaining 50 images were used as the independent test set. Step 1: ET and HA masks for the nonneurological images had an average Dice similarity coefficient (DSC) of 0.86 between each other. Step 2: Meningioma ET and HA masks had an average DSC of 0.85 between each other. After separate training using both approaches, the ET approach performed virtually identically to HA on the test set of 50 images. The former had an area under the curve (AUC) of 0.88, while the latter had AUC of 0.87. ET and HA predictions had trimmed mean DSCs compared to the original HA maps of 0.73 and 0.74, respectively. These trimmed DSCs between ET and HA were found to be statistically equivalent with a p value of 0.015. We have demonstrated that ET can create segmentation masks suitable for deep learning semantic segmentation. Future work will integrate ET to produce masks in a faster, more natural manner that distracts less from typical radiology clinical workflow.

Validation of RECIST 1.1 for use with cytotoxic agents and targeted cancer agents (TCA): Results of a RECIST Working Group analysis of a 50 clinical trials pooled individual patient database

2534

Background: The Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 were derived from an international collaborative effort supported by data from clinical trials (16 studies, 9147 patients) on cytotoxic chemotherapy (CT), providing a standard tool for response assessment. RECIST’s role has been questioned for TCA. Using a pooled individual patient database (IPD) from clinical trials performed by industry and cooperative groups, we assessed whether modifications to RECIST are required to evaluate antitumor activity of TCA. Methods: Data were collected from phase 2 and 3 clinical trials testing TCA in solid tumors. To study the occurrence of mixed responses, the variability of response of lesions within patients was studied. Furthermore, response was correlated with survival through landmark analyses and time dependent Cox models. Results: Clinical data were obtained from 23,259 patients, mainly with lung (36%), colorectal (28%) or breast cancer (11%). 15,620 patients (67%) received a TCA, mainly transduction or angiogenesis inhibitors, either as single agent (37%) or combined with other TCAs (7%) or CT (56%); 28% received CT only and 5% best supportive care or placebo. Within-patient variability reduced as the number of lesions used for response assessment increased, and did so similarly for TCAs (+/- CT) and CT. Mixed responses seemed to occur similarly across these treatment categories as well. Landmark analyses showed improving overall survival by % tumor shrinkage and a clear distinction between the effect of tumor shrinkage and progressive disease (PD) according to RECIST 1.1. This was confirmed by time dependent analysis. In addition target lesion growth showed no marked improvement in overall survival prediction over and above the other components of RECIST 1.1 PD (new lesions, non-target PD), regardless of treatment (TCA, CT or both) received. Similar results were seen focusing on major tumor types and classes of TCA. Conclusions: Using a large IPD dataset we demonstrated that RECIST 1.1 performs equally well for response assessment of TCA as for CT. No modifications are required.

A Multiparametric Model for Mapping Cellularity in Glioblastoma Using Radiographically Localized Biopsies

BACKGROUND AND PURPOSE

The complex MR imaging appearance of glioblastoma is a function of underlying histopathologic heterogeneity. A better understanding of these correlations, particularly the influence of infiltrating glioma cells and vasogenic edema on T2 and diffusivity signal in nonenhancing areas, has important implications in the management of these patients. With localized biopsies, the objective of this study was to generate a model capable of predicting cellularity at each voxel within an entire tumor volume as a function of signal intensity, thus providing a means of quantifying tumor infiltration into surrounding brain tissue.

MATERIALS AND METHODS

Ninety-one localized biopsies were obtained from 36 patients with glioblastoma. Signal intensities corresponding to these samples were derived from T1-postcontrast subtraction, T2-FLAIR, and ADC sequences by using an automated coregistration algorithm. Cell density was calculated for each specimen by using an automated cell-counting algorithm. Signal intensity was plotted against cell density for each MR image.

RESULTS

T2-FLAIR (r = -0.61) and ADC (r = -0.63) sequences were inversely correlated with cell density. T1-postcontrast (r = 0.69) subtraction was directly correlated with cell density. Combining these relationships yielded a multiparametric model with improved correlation (r = 0.74), suggesting that each sequence offers different and complementary information.

CONCLUSIONS

Using localized biopsies, we have generated a model that illustrates a quantitative and significant relationship between MR signal and cell density. Projecting this relationship over the entire tumor volume allows mapping of the intratumoral heterogeneity in both the contrast-enhancing tumor core and nonenhancing margins of glioblastoma and may be used to guide extended surgical resection, localized biopsies, and radiation field mapping.

Phase III randomized study of sorafenib plus doxorubicin versus sorafenib in patients with advanced hepatocellular carcinoma (HCC): CALGB 80802 (Alliance)

192

Background: An exploratory analysis of a randomized phase II study in HCC comparing doxorubicin (D) alone to doxorubicin plus sorafenib (D+S) showed a significant improvement in overall survival favoring D+S (JAMA, 2011). The results appeared promising compared to the historic outcomes seen in the pivotal sorafenib (S) trials. CALGB 80802 was designed to determine if D+S improved survival compared to S alone. Methods: Patients with histologically proven advanced HCC, no prior systemic therapy and Child-Pugh A were randomized to receive D 60 mg/m2 every 21 days plus S 400 mg PO twice daily (D+S) or S alone. For bilirubin ≥ 1.3x normal, D and S doses were halved. D was maxed out at 360 mg/m2. The study was stratified by extent of disease (locally advanced; metastatic), the primary endpoint was overall survival (OS); and secondary endpoint progression-free survival (PFS). The final analysis was to occur when 364 events were observed among 480 total patients, with 90% power to detect a 37% increase in median OS (10.7 to 14.7 months; 1-sided α = 0.05). Results: The Alliance DSMB halted the study after accrual of 346 patients (173 on each of D+S and S) when a futility boundary was crossed at a planned interim analysis. With 107 events in each arm, median OS was 9.3 months (95%CI 7.1-12.9) for D+S, and 10.5 months (95% CI 7.4-14.3) for S with a hazard ratio (HR) 1.06 (95% CI 0.8-1.4) for D+S vs. S. Median PFS was 3.6 (95% CI 2.8-4.6) and 3.2 months (95% CI 2.3-4.1), respectively (HR = 0.90, 95% CI 0.72-1.2). There were 38 deaths on treatment: 18 on D+S and 20 on S. Among these 8 [sepsis (1), dysphagia (1), pneumonia (1), cardiac (2), hepatic failure (2), and not otherwise specified (1)] on D+S, and 3 [fatigue (1), hepatic failure (1), and a secondary malignancy (1)] on S, were at least possibly related to treatment. A maximum grade 3 or 4 only hematologic adverse events (AE) occurred in 37.8% of patients on D+S and 8.1% of patients on S. Non-hematologic AEs were comparable, in 63.6% and 61.5% of patients, respectively. Conclusions: The addition of D to S resulted in higher toxicity and did not improve OS or PFS. The S median OS of about 10 months is consistent with previous reports. NCI Grant U10CA180821 Clinical trial information: NCT01015833.

Comparative Effects of CT Imaging Measurement on RECIST End Points and Tumor Growth Kinetics Modeling

Quantitative assessments of tumor burden and modeling of longitudinal growth could improve phase II oncology trials. To identify obstacles to wider use of quantitative measures we obtained recorded linear tumor measurements from three published lung cancer trials. Model-based parameters of tumor burden change were estimated and compared with similarly sized samples from separate trials. Time-to-tumor growth (TTG) was computed from measurements recorded on case report forms and a second radiologist blinded to the form data. Response Evaluation Criteria in Solid Tumors (RECIST)-based progression-free survival (PFS) measures were perfectly concordant between the original forms data and the blinded radiologist re-evaluation (intraclass correlation coefficient = 1), but these routine interrater differences in the identification and measurement of target lesions were associated with an average 18-week delay (range, -20 to 55 weeks) in TTG (intraclass correlation coefficient = 0.32). To exploit computational metrics for improving statistical power in small clinical trials will require increased precision of tumor burden assessments.

Semiautomated volumetric measurement on postcontrast MR imaging for analysis of recurrent and residual disease in glioblastoma multiforme

BACKGROUND AND PURPOSE

A limitation in postoperative monitoring of patients with glioblastoma is the lack of objective measures to quantify residual and recurrent disease. Automated computer-assisted volumetric analysis of contrast-enhancing tissue represents a potential tool to aid the radiologist in following these patients. In this study, we hypothesize that computer-assisted volumetry will show increased precision and speed over conventional 1D and 2D techniques in assessing residual and/or recurrent tumor.

MATERIALS AND METHODS

This retrospective study included patients with native glioblastomas with MR imaging performed at 24-48 hours following resection and 2-4 months postoperatively. 1D and 2D measurements were performed by 2 neuroradiologists with Certificates of Added Qualification. Volumetry was performed by using manual segmentation and computer-assisted volumetry, which combines region-based active contours and a level set approach. Tumor response was assessed by using established 1D, 2D, and volumetric standards. Manual and computer-assisted volumetry segmentation times were compared. Interobserver correlation was determined among 1D, 2D, and volumetric techniques.

RESULTS

Twenty-nine patients were analyzed. Discrepancy in disease status between 1D and 2D compared with computer-assisted volumetry was 10.3% (3/29) and 17.2% (5/29), respectively. The mean time for segmentation between manual and computer-assisted volumetry techniques was 9.7 minutes and <1 minute, respectively (P < .01). Interobserver correlation was highest for volumetric measurements (0.995; 95% CI, 0.990-0.997) compared with 1D (0.826; 95% CI, 0.695-0.904) and 2D (0.905; 95% CI, 0.828-0.948) measurements.

CONCLUSIONS

Computer-assisted volumetry provides a reproducible and faster volumetric assessment of enhancing tumor burden, which has implications for monitoring disease progression and quantification of tumor burden in treatment trials.

Contrast-enhanced ultrasound monitoring of perfusion changes in hepatic neuroendocrine metastases after systemic versus selective arterial 177Lu/90Y-DOTATOC and 213Bi-DOTATOC radiopeptide therapy

AIM

Radiopeptide therapy with beta emitter labeled (177)Lu/(90)Y- DOTA(0)-Phe(1)-Tyr(3)-octreotide (DOTATOC) and more recently also alpha emitting (213)Bi-DOTATOC are promising new treatments for neuroendocrine tumors. No early predictors for treatment response have been recognized and tumor-shrinkage after radiation therapy appears slowly. In some solid tumors a decline in tumor perfusion was found predictive of final treatment response but the gold standard multiphase computed tomography (CT) has a high radiation burden. Therefore we evaluated the ability of contrast-enhanced ultrasound (CEUS) to evaluate tumor perfusion as a response criteria.

MATERIALS AND METHODS

14 patients with hepatic neuroendocrine tumor (NET) metastases were enrolled in the retrospective study. Eleven patients were treated with beta-emitting (177)Lu/(90)Y-DOTATOC, either intravenous (i.v.) (n = 5) or intra-arterial (i.a.) (n = 6) and three patients received alpha-emitting (213)Bi-DOTATOC (i.a.). CEUS and contrast-enhanced CT (CE-CT) were performed before and 3 months after treatment.

RESULTS

CE-CT and CEUS presented comparable results in the baseline study and in the assessment of perfusion changes due to the different treatment regimes. A therapy related decrease in tumor perfusion is an early predictor of longterm morphologic response.

CONCLUSION

CEUS is available and radiation free technique which showed comparable results for perfusion and diameter of liver metastases compared to CE-CT. Intensity reduction in an arterial phase CEUS can be seen as a positive sign indicating long term tumor response to treatment. Therefore CEUS may be considered as an imaging modality for monitoring early treatment after focal alpha and beta targeted therapy.

Impact of peptide receptor radionuclide therapy on the 68Ga-DOTATOC-PET/CT uptake in normal tissue

AIM

Positron-emission tomography/computed tomography (PET/CT) with [68Ga]DOTA0-Phe1-Tyr3-octreotide (68Ga-DOTA-TOC) became a standard for somatostatin receptor imaging. We investigated the potential changes of normal tissue uptake in patients with neuroendocrine tumor undergoing peptide receptor radionuclide therapy (PRRT).

METHODS

Sixteen patients underwent [68Ga]-DOTA-TOC-PET/CT prior and after 4-6 cycles of PRRT (mean administered activity: 13.8 GBq 90Y+ 9.6 177Lu). The maximum standardized uptake values (SUVmax) of pituitary, thyroid, spleen, liver parenchyma, pancreas, kidneys and adrenals were determined, respectively.

RESULTS

SUVmax values prior and after PRRT were in pituitary (5, 56±2,91/ 4,47±2,53), thyroid (2.05±1.11/ 2.49±2.47), spleen (24.95±14.20/20.06±8.53), liver (7.13±3.96/6.62±2.63), pancreas (6.96±1.99/6.83±2.00), kidneys (13.0±3.85/11.31±3.31) and adrenals (9.65± 4.20/7.10±2.86). A comparison of pre- and post treatment values revealed no significant differences (P>0.05) in any of these organs.

CONCLUSION

The uptake of [68Ga] DOTA-TOC in normal tissue is not significantly affected by PRRT. This is relevant with regards to therapeutic monitoring were tumor-to-non-tumor ratio seems to be the most robust biomarker.

Assessment of neurovascular involvement by malignant musculoskeletal tumors

Determining the presence or absence of neurovascular involvement by a malignant musculoskeletal neoplasm is an important aspect of local tumor staging. This article discusses issues concerning such assessments made by diagnostic imaging techniques, including factors inherent to the patient and those related to imaging technology. The distinction between tumor contact and tumor encasement is emphasized and illustrated.

MR Imaging of Bone Marrow in Patients with Musculoskeletal Tumors

Knowledge of the appearances of normal bone marrow, metastases involving marrow, and therapy-related marrow changes shown by MR imaging is necessary in order to avoid misdiagnosis. This article reviews MR imaging techniques and the findings that allow distinction of normal yellow (fatty) marrow and red marrow from tumor in marrow, as well as the identification of marrow changes resulting from radiation therapy or treatment with marrow-stimulating drugs in patients with musculoskeletal tumors.

Soft tissue edema around musculoskeletal sarcomas at magnetic resonance imaging

The presence of soft tissue edema around a malignant musculoskeletal neoplasm can interfere with accurate local tumor staging at magnetic resonance imaging. This article discusses and illustrates such edema, emphasizing means for avoiding misinterpretation of edema and subsequent overstaging.

Prognostic significance of adrenal gland morphology at CT in patients with three common malignancies

OBJECTIVES

To determine whether minor alterations in adrenal gland morphology at baseline CT in three common cancers indicate early metastasis.

METHODS

689 patients (237 with lung cancer, 228 with breast cancer, 224 with melanoma) underwent baseline and follow-up CTs that included the adrenals. Two readers independently scored each adrenal at baseline CT as normal, smoothly enlarged, nodular or mass-containing. Adrenals containing a mass >10 mm were excluded. The appearance of each adrenal on the latest available CT was assessed for change since baseline. Cox models were used to assess the association between adrenal morphology at initial CT and subsequent development of adrenal metastasis (defined as new mass >10 mm, corroborated by follow-up imaging). κ statistics were calculated to assess inter-reader agreement.

RESULTS

Initial and follow-up CT evaluations were recorded for 1317 adrenals (median follow-up, 18.6 months). At initial CT, Readers 1 and 2 interpreted 1242 and 1230 adrenals as normal, 40 and 57 as smoothly enlarged, 29 and 25 as nodular, and 6 and 5 as containing masses ≤ 10 mm, respectively. κ-values were 0.52 (moderate) at initial CT and 0.70 (substantial) at follow-up. The hazard ratio for developing a metastasis at follow-up CT given an abnormal adrenal assessment at baseline was 0.7 [95% confidence interval (CI) 0.2-2.1; p = 0.47] for Reader 1, and 2.0 (95% CI 0.8-4.7; p = 0.12) for Reader 2.

CONCLUSION

Minor morphological abnormalities of adrenals at initial CT did not represent early adrenal metastasis in most patients in this population.

Data sets for the qualification of volumetric CT as a quantitative imaging biomarker in lung cancer

The drug development industry is faced with increasing costs and decreasing success rates. New ways to understand biology as well as the increasing interest in personalized treatments for smaller patient segments requires new capabilities for the rapid assessment of treatment responses. Deployment of qualified imaging biomarkers lags apparent technology capabilities. The lack of consensus methods and qualification evidence needed for large-scale multi-center trials, as well as the standardization that allows them, are widely acknowledged to be the limiting factors. The current fragmentation in imaging vendor offerings, coupled with the independent activities of individual biopharmaceutical companies and their contract research organizations (CROs), may stand in the way of the greater opportunity were these efforts to be drawn together. A preliminary report, "Volumetric CT: a potential biomarker of response," of the Quantitative Imaging Biomarkers Alliance (QIBA) activity was presented at the Medical Imaging Continuum: Path Forward for Advancing the Uses of Medical Imaging in the Development of New Biopharmaceutical Products meeting of the Extended Pharmaceutical Research and Manufacturers of America (PhRMA) Imaging Group sponsored by the Drug Information Agency (DIA) in October 2008. The clinical context in Lung Cancer and a methodology for approaching the qualification of volumetric CT as a biomarker has since been reported [Acad. Radiol. 17, 100-106, 107-115 (2010)]. This report reviews the effort to collect and utilize publicly available data sets to provide a transparent environment in which to pursue the qualification activities in such a way as to allow independent peer review and verification of results. This article focuses specifically on our role as stewards of image sets for developing new tools.

Regional chemotherapy for unresectable primary liver cancer: results of a phase II clinical trial and assessment of DCE-MRI as a biomarker of survival

BACKGROUND

This study reports the results of hepatic arterial infusion (HAI) with floxuridine (FUDR) and dexamethasone (dex) in patients with unresectable intrahepatic cholangiocarcinoma (ICC) or hepatocellular carcinoma (HCC) and investigates dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) assessment of tumor vascularity as a biomarker of outcome.

PATIENTS AND METHODS

Thirty-four unresectable patients (26 ICC and eight HCC) were treated with HAI FUDR/dex. Radiologic dynamic and pharmacokinetic parameters related to tumor perfusion were analyzed and correlated with response and survival.

RESULTS

Partial responses were seen in 16 patients (47.1%); time to progression and response duration were 7.4 and 11.9 months, respectively. Median follow-up and median survival were 35 and 29.5 months, respectively; 2-year survival was 67%. DCE-MRI data showed that patients with pretreatment integrated area under the concentration curve of gadolinium contrast over 180 s (AUC 180) >34.2 mM.s had a longer median survival than those with AUC 180 <34 mM.s (35.1 versus 19.1 months, P = 0.002). Decreased volume transfer exchange between the vascular space and extracellular extravascular space (-DeltaK(trans)) and the corresponding rate constant (-Deltak(ep)) on the first post-treatment scan both predicted survival.

CONCLUSIONS

In patients with unresectable primary liver cancer, HAI therapy can be effective and safe. Pretreatment and early post-treatment changes in tumor perfusion characteristics may predict treatment outcome.

New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1)

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.

Evaluation of lymph nodes with RECIST 1.1

Lymph nodes are common sites of metastatic disease in many solid tumours. Unlike most metastases, lymph nodes are normal anatomic structures and as such, normal lymph nodes will have a measurable size. Additionally, the imaging literature recommends that lymph nodes be measured in the short axis, since the short axis measurement is a more reproducible measurement and predictive of malignancy. Therefore, the RECIST committee recommends that lymph nodes be measured in their short axis and proposes measurement values and rules for categorising lymph nodes as normal or pathologic; either target or non-target lesions. Data for the RECIST warehouse are presented to demonstrate the potential change in response assessment following these rules. These standardised lymph node guidelines are designed to be easy to implement, focus target lesion measurements on lesions that are likely to be metastatic and prevent false progressions due to minimal change in size.

Imaging response assessment in oncology

The role of imaging in the clinical setting as well as in the drug development process is expanding rapidly. Imaging technology now exists that is capable of detecting tumor response within hours. In parallel with this advance, a new array of more targeted and specific therapies are being developed. This paradigm shift in turn demands a more sophisticated way of quantifying response. There is a need to update and modify the current response evaluation criteria in solid tumors (RECIST), which rely solely on anatomic size measurement of tumors. In addition, response assessment guidelines will need to be increasingly disease-specific. Response assessment by imaging is now intimately involved with all stages of the drug development process, from exploratory drug discovery through clinical trials, as well as in clinical use. Imaging biomarkers and surrogate endpoints have the potential to speed drug approval significantly. The major funding institutions and the pharmaceutical industry are working more and more with researchers to help maintain progress in this multidisciplinary area involving oncologists, radiologists, molecular imaging specialists, medical physicists, and computer scientists.

Measuring tumor response and shape change on CT: esophageal cancer as a paradigm

BACKGROUND

Accurate response assessment is essential for evaluating new cancer treatments. We evaluated the impact of Response Evaluation Criteria in Solid Tumors (RECIST), World Health Organization (WHO) criteria and tumor shape on response assessment in patients with metastatic esophageal cancer.

PATIENTS AND METHODS

In 19 patients with metastatic esophageal cancer in a phase II trial of bryostatin-1 and paclitaxel, response was retrospectively assessed for 89 lesions with RECIST and WHO criteria on baseline and serial follow-up CT scans. The eccentricity factor (EF) was introduced for measuring the degree to which tumor shape diverges from a perfect sphere [EF = radical1-(LPD/MD)(2), where LPD is the largest perpendicular diameter and MD is the maximal diameter].

RESULTS

The disagreement rate in best overall response categorization between RECIST (unidimensional) and WHO (bidimensional) criteria was 26.3%. Change in eccentricity was significantly greater (P < 0.01) for patients with disagreement (mean 0.31, range 0-0.91). When the short axis was used for unidimensional lymph node measurement, disagreement between WHO and RECIST lessened.

CONCLUSIONS

Response assessment by WHO and RECIST differs substantially. Greater change in eccentricity is associated with greater discordance between WHO and RECIST. The discordance between WHO and RECIST may impact on how effective a therapy is judged to be.

Evaluation of the response to treatment of solid tumours - a consensus statement of the International Cancer Imaging Society

New guidelines to evaluate the response to treatment in solid tumors using imaging techniques have major limitations and important implications for radiological workload. This consensus statement from the International Cancer Imaging Society (ICIS) reviews the RECIST criteria and addresses several challenges regarding tumour measurement. Recommendations are made regarding tumour measurement and other issues are raised. The growing need to introduce a multimodality approach to monitoring response is recognized. ICIS welcomes a dialogue with the authors of RECIST to address issues raised in this review.

Imaging of hepatocellular carcinoma: a practical approach

Imaging of hepatocellular carcinoma (HCC) is complicated because the tumor has a varied radiologic appearance and frequently coexists with cirrhotic regenerative and dysplastic nodules. In cirrhotic patients, any dominant solid nodule that is not clearly a hemangioma should be considered a HCC until proven otherwise, especially if the lesion is hypervascular, of high T2 signal intensity, or demonstrates venous invasion. Biopsy of HCC in cirrhosis is risky and surveillance is often preferable. The doubling time of HCC is 1 to 12 months, and a nodule that is stable over 4 months is very unlikely to be a HCC. However, stable nodules cannot be dismissed, since livers containing dysplastic nodules are at high risk to develop HCC. In noncirrhotic patients, any solid mass that is not clearly a hemangioma or focal nodular hyperplasia is potentially a HCC, and biopsy may be required. Venous invasion by tumor should be distinguished from bland thrombus. Imaging detection of nodal metastases is limited by the frequent finding of benign reactive lymphadenopathy in cirrhosis. Resection is the preferred treatment for HCC, but is contraindicated in the presence of tumors in both lobes, major venous invasion, invasion of adjacent organs other than the gallbladder, tumor rupture, nodal metastases, or distant metastases.

Breast Cancer

OBJECTIVE

The purpose of this study was to determine the benefit of routine pelvic CT in the evaluation of patients with primary breast cancer and to assess the frequency with which equivocal or abnormal findings on pelvic CT prompted the performance of additional studies or procedures that yielded results relevant to patient care.

MATERIALS AND METHODS

The reports of 6628 body CT scans that included images of at least the pelvis in 2426 patients with breast cancer during a 9-year period were reviewed. The presence and sites of reported definite or probable metastases or pelvic tumors were recorded for each scan. Also, the types and results of diagnostic examinations and procedures prompted by equivocal or abnormal findings on pelvic CT were recorded.

RESULTS

Pelvic metastases shown on CT were the only known site of metastasis in 13 (0.5%) of 2426 patients, and four other patients (0.2%) had new or enlarging pelvic metastases despite the presence of stable extrapelvic metastases. The pelvic metastases in these 17 patients were located in bone only in 11 patients, in adnexa only in five patients, and in adnexa, endometrium, and bone in one patient. In addition, pelvic CT led to the performance of 204 additional radiologic examinations, including 186 pelvic sonographic examinations, and 50 surgical procedures; 215 (84.6%) of these 254 additional examinations and procedures yielded normal, benign, or indeterminate results.

CONCLUSION

The routine use of pelvic CT in the evaluation of patients with breast cancer has an extremely low yield and often prompts performance of pelvic sonographic or surgical procedures, the results of which were rarely relevant to cancer therapy.

Management of 155 patients with benign liver tumours

BACKGROUND

Benign hepatic tumours continue to represent a diagnostic and therapeutic challenge. This study evaluates the indications and results of resection compared with observation in patients with benign hepatic tumours.

METHODS

Patients with a primary diagnosis of benign liver tumour were identified from a prospective database and evaluated retrospectively.

RESULTS

From January 1992 to June 1999, 155 patients with benign hepatic tumours were evaluated. The diagnoses included haemangioma (n = 97), focal nodular hyperplasia (FNH) (n = 42), hepatic adenoma (n = 12) and cystadenoma (n = 4). Sixty-eight patients (44 per cent) underwent resection because of symptoms (n = 36), inability to exclude a malignancy (n = 31) or enlargement on serial imaging (n = 11). The operative morbidity and mortality rates were 21 per cent and zero respectively. Thirty patients had a preoperative percutaneous needle biopsy, 19 of which were either incorrect or indeterminate. Overall, 39 of 42 patients with symptoms attributed to the tumour were asymptomatic after resection and 18 of 21 patients with symptoms considered unrelated to the tumour were asymptomatic after a period of observation and/or treatment of unrelated conditions (median follow-up 16 months).

CONCLUSION

When indicated, resection of benign liver tumours can be performed safely. Symptomatic patients with a small FNH or haemangioma can be observed because their symptoms are unlikely to be related to the liver tumour. Percutaneous needle biopsy rarely changes management.

Randomized Multicenter Phase II Trial of Subcutaneous Recombinant Human Interleukin-12 Versus Interferon-α2a for Patients with Advanced Renal Cell Carcinoma

Recombinant human interleukin-12 (rHuIL-12) is a pleiotropic cytokine with anticancer activity against renal cell carcinoma (RCC) in preclinical models and in a phase I trial. A randomized phase II study of rHuIL-12 compared with interferon-alpha (IFN-alpha) evaluated clinical response for patients with previously untreated, advanced RCC. Patients were randomly assigned 2:1 to receive either rHuIL-12 or IFN-alpha2a. rHuIL-12 was administered by subcutaneous (s.c.) injection on days 1, 8, and 15 of each 28-day cycle. The dose of IL-12 was escalated during cycle 1 to a maintenance dose of 1.25 microg/kg. IFN was administered at 9 million units by s.c. injection three times per week. Serum concentrations of IL-12, IFN-gamma, IL-10, and neopterin were obtained in 10 patients treated with rHuIL-12 after the first full dose of 1.25 microg/kg given on day 15 (dose 3) of cycle 1 and again after multiple doses on day 15 (dose 6) of cycle 2. Thirty patients were treated with rHuIL-12, and 16 patients were treated with IFN-alpha. Two (7%) of 30 patients treated with rHuIL-12 achieved a partial response, and the trial was closed to accrual based on the low response proportion. IL-12 was absorbed rapidly after s.c. drug administration, with the peak serum concentration appearing at approximately 12 h in both cycles. Serum IL-12 concentrations remained stable on multiple dosing. Levels of IFN-gamma, IL-10, and neopterin increased with rHuIL-12 and were maintained in cycle 2. rHuIL-12 is a novel cytokine with unique pharmacologic and pharmacodynamic features under study for the treatment of malignancy and other medical conditions. The low response proportion associated with rHuIL-12 single-agent therapy against metastatic RCC was disappointing, given the preclinical data. Further study of rHuIL-12 for other medical conditions is underway. For RCC, the study of new cytokines is of the highest priority.

Bone marrow segmentation in leukemia using diffusion and T (2) weighted echo planar magnetic resonance imaging

Magnetic resonance images of leukemic bone marrow were acquired over large regions of the pelvis and lower abdomen with minimal interference from overlying tissues using diffusion and T(2) weighted echo planar imaging. Data acquisition times were on the order of 1 min for scanning volumes of up to 25 l at a spatial resolution of 31 microl. A survey of 21 patients with leukemia and eight healthy adult volunteers was undertaken to determine the magnitude of the observed effect and its dependence upon specific pathologies. The acquisition methods yielded high-quality segmentation of leukemic bone marrow prior to therapy in seven of seven patients with acute lymphocytic leukemia, chronic lymphocytic leukemia or chronic myelogenous leukemia, and who had hypercellular (>95%) bone marrow at the time of the study. The quality of the segmentation was sufficient to allow the use of maximum intensity projection images which afforded a convenient evaluation of both intra- and extramedullary disease. The measured signal-to-noise ratios agreed with a theoretical estimate that accounted for the percentage cellularity, T(2) relaxation time of water, and self-diffusion coefficient of water in iliac bone marrow. In addition, the mean signal-to-noise ratios from iliac marrow were strongly dependent upon the time after the initiation of chemotherapeutic regimens, implying that the methods may be useful for therapeutic monitoring.

Phase III trial of interferon alfa-2a with or without 13-cis-retinoic acid for patients with advanced renal cell carcinoma

PURPOSE

A randomized phase III trial was conducted to determine whether combination therapy with 13-cis-retinoic acid (13-CRA) plus interferon alfa-2a (IFNalpha2a) is superior to IFNalpha2a alone in patients with advanced renal cell carcinoma (RCC).

PATIENTS AND METHODS

Two hundred eighty-four patients were randomized to treatment with IFNalpha2a plus 13-CRA or treatment with IFNalpha2a alone. IFNalpha2a was given daily subcutaneously, starting at a dose of 3 million units (MU). The dose was escalated every 7 days from 3 to 9 MU (by increments of 3 MU), unless >/= grade 2 toxicity occurred, in which case dose escalation was stopped. Patients randomized to combination therapy were given oral 13-CRA 1 mg/kg/d plus IFNalpha2a. Quality of life (QOL) was assessed.

RESULTS

Complete or partial responses were achieved by 12% of patients treated with IFNalpha2a plus 13-CRA and 6% of patients treated with IFNalpha2a (P =.14). Median duration of response (complete and partial combined) in the group treated with the combination was 33 months (range, 9 to 50 months), versus 22 months (range, 5 to 38 months) for the second group (P =.03). Nineteen percent of patients treated with IFNalpha2a plus 13-CRA were progression-free at 24 months, compared with 10% of patients treated with IFNalpha2a alone (P =.05). Median survival time for all patients was 15 months, with no difference in survival between the two treatment arms (P =.26). QOL decreased during the first 8 weeks of treatment, and a partial recovery followed. Lower scores were associated with the combination therapy.

CONCLUSION

Response proportion and survival did not improve significantly with the addition of 13-CRA to IFNalpha2a therapy in patients with advanced RCC. 13-CRA may lengthen response to IFNalpha2a therapy in patients with IFNalpha2a-sensitive tumors. Treatment, particularly the combination therapy, was associated with a decrease in QOL.

Evaluation of tumor measurements in oncology: use of film-based and electronic techniques

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Evaluation of pectoralis major muscle in patients with posterior breast tumors on breast MR images: early experience

PURPOSE

To evaluate the ability to use breast magnetic resonance (MR) imaging to assess disease extent in patients with posterior breast masses who are suspected to have tumor invasion into underlying muscle.

MATERIALS AND METHODS

Nineteen patients with posterior breast masses underwent three-dimensional, gradient-echo, 1.5-T MR imaging before and after the administration of gadopentetate dimeglumine. Thirteen had deep palpable masses that were clinically determined to be fixed to the underlying chest wall. Twelve had mammographic findings that caused muscle involvement to be suspected, and seven had normal mammograms. All patients underwent surgery. MR images were reviewed and were correlated with histologic findings.

RESULTS

Enhancing masses were identified on MR images in all 19 patients. Five (26%) of the 19 patients had masses that abutted the muscles, with obliteration of the fat plane and muscle enhancement. All five had muscle involvement at surgery. In the remaining 14 (74%) patients, no enhancement of muscle was seen; none of these had invasion of the muscle at surgery.

CONCLUSION

Extension of adjacent tumor into underlying musculature was indicated by abnormal enhancement within these structures. Violation of the fat plane between tumor and muscle, without other findings, did not indicate tumor involvement of these deep structures.

Deep inspiration breath-hold technique for lung tumors: the potential value of target immobilization and reduced lung density in dose escalation

PURPOSE/OBJECTIVE

This study evaluates the dosimetric benefits and feasibility of a deep inspiration breath-hold (DIBH) technique in the treatment of lung tumors. The technique has two distinct features--deep inspiration, which reduces lung density, and breath-hold, which immobilizes lung tumors, thereby allowing for reduced margins. Both of these properties can potentially reduce the amount of normal lung tissue in the high-dose region, thus reducing morbidity and improving the possibility of dose escalation.

METHODS AND MATERIALS

Five patients treated for non-small cell lung carcinoma (Stage IIA-IIIB) received computed tomography (CT) scans under 4 respiration conditions: free-breathing, DIBH, shallow inspiration breath-hold, and shallow expiration breath-hold. The free-breathing and DIBH scans were used to generate 3-dimensional conformal treatment plans for comparison, while the shallow inspiration and expiration scans determined the extent of tumor motion under free-breathing conditions. To acquire the breath-hold scans, the patients are brought to reproducible respiration levels using spirometry, and for DIBH, modified slow vital capacity maneuvers. Planning target volumes (PTVs) for free-breathing plans included a margin for setup error (0.75 cm) plus a margin equal to the extent of tumor motion due to respiration (1-2 cm). Planning target volumes for DIBH plans included the same margin for setup error, with a reduced margin for residual uncertainty in tumor position (0.2-0.5 cm) as determined from repeat fluoroscopic movies. To simulate the effects of respiration-gated treatments and estimate the role of target immobilization alone (i.e., without the benefit of reduced lung density), a third plan is generated from the free-breathing scan using a PTV with the same margins as for DIBH plans.

RESULTS

The treatment plan comparison suggests that, on average, the DIBH technique can reduce the volume of lung receiving more than 25 Gy by 30% compared to free-breathing plans, while respiration gating can reduce the volume by 18%. The DIBH maneuver was found to be highly reproducible, with intra breath-hold reproducibility of 1.0 (+/- 0.9) mm and inter breath-hold reproducibility of 2.5 (+/- 1.6) mm, as determined from diaphragm position. Patients were able to perform 10-13 breath-holds in one session, with a comfortable breath-hold duration of 12-16 s.

CONCLUSION

Patients tolerate DIBH maneuvers well and can perform them in a highly reproducible fashion. Compared to conventional free-breathing treatment, the DIBH technique benefits from reduced margins, as a result of the suppressed target motion, as well as a decreased lung density; both contribute to moving normal lung tissue out of the high-dose region. Because less normal lung tissue is irradiated to high dose, the possibility for dose escalation is significantly improved.

Advances in cross-sectional imaging of colorectal cancer

Imaging of colorectal cancer is primarily accomplished with computed tomography (CT) and magnetic resonance imaging (MRI). These two modalities have been used for more than a decade in imaging both primary and metastatic colorectal cancer. Recent advances in the CT and MRI technologies are redefining the precise role of these imaging modalities in the work-up and evaluation of patients with colorectal cancer.

Pulmonary nodules resected at video-assisted thoracoscopic surgery: etiology in 426 patients

PURPOSE

To determine the etiology of pulmonary nodules resected at video-assisted thoracoscopic surgery (VATS) and establish the probabilities that single or multiple nodules resected at VATS represent malignancy in patients with or patients without known cancer.

MATERIALS AND METHODS

Pathology reports from VATS performed between January 1995 and July 1997 were searched for data on gross specimens revealing pulmonary nodules 3 cm or smaller. Findings were correlated with clinical and histologic data.

RESULTS

In 254 patients with one nodule resected at VATS, the nodules were malignant in 108 patients with and in 32 patients without known cancer (P < .03). Among 172 patients with multiple nodules resected, at least one nodule was malignant in 85 patients with and in 20 patients without known cancer (P > .05). Nodules larger than 1 cm were more likely to be malignant than were smaller nodules (P < .002). In patients with known malignancy, nodules smaller than 0.5 cm were more likely to be benign, whereas nodules larger than 0.5 cm but smaller than 1 cm were more likely to be malignant (P < .001).

CONCLUSION

A single pulmonary nodule resected at VATS was more likely to be malignant in patients with known cancer. Nodules larger than 1 cm but smaller than 3 cm resected at VATS were more likely to be malignant. Nodules smaller than 0.5 cm were more likely to be benign.

Comparison of magnetic resonance and endoscopic retrograde cholangiopancreatography in malignant pancreaticobiliary obstruction

HYPOTHESIS

We hypothesize that magnetic resonance cholangiopancreatography (MRCP) is comparable to endoscopic retrograde cholangiopancreatographic (ERCP) as a diagnostic tool in patients with malignant biliary obstruction.

DESIGN

Eighteen patients with suspected pancreaticobiliary malignancy were evaluated by ERCP and MRCP in 8 months (March 1, 1996, to October 31, 1996). Magnetic resonance cholangiopancreatography was performed with a 1.5-T scanner using 4-mm slices. Images were obtained in a 14- to 28-second breath-hold. Images from MRCP were retrospectively evaluated by a radiologist for image quality, ductal dilation, level of obstruction, and overall diagnostic impression. Images from ERCP were retrospectively evaluated by a biliary endoscopist (L.H.S.) and served as the standard for calculating sensitivity, specificity, and positive predictive values. In addition, intraoperative findings were compared with MRCP results in all patients explored.

RESULTS

Diagnostic-quality MR images were obtained in 18 patients (100%). Diagnostic-quality endoscopic images were obtained in 16 (89%) of 18 attempted biliary cannulations and 11 (78%) of 14 attempted pancreatic cannulations. Magnetic resonance CP accurately delineated the level of extrahepatic biliary ductal obstruction in 13 (87%) of 15 patients. More important, MRCP provided valuable staging information in most patients. Findings from MRCP correlated with operative findings (size and location of tumor and mesenteric vascular involvement) in 8 (80%) of 10 patients who underwent surgery, while failing in 2 patients (20%) with carcinomatosis.

CONCLUSIONS

Magnetic resonance CP is a sensitive study for detecting the presence and level of biliary ductal obstruction in patients with cancer. The results are comparable to those of ERCP; however, MRCP provides additional data regarding extent of disease that is not available from ERCP alone.

Recurrent gallbladder carcinoma along laparoscopic cholecystectomy port tracks: CT demonstration

PURPOSE

To describe the computed tomographic (CT) appearance of recurrent gallbladder carcinoma along port tracks after laparoscopic cholecystectomy and to assess the effect of recurrence on patient care.

MATERIALS AND METHODS

Seventeen abdominal CT scans in 16 of 19 consecutive patients who underwent hepatic resection for gallbladder carcinoma diagnosed at laparoscopic cholecystectomy were reviewed retrospectively. Medical records were reviewed to determine the clinical effect of tumor recurrence along a port track.

RESULTS

CT revealed 12 tumor recurrences along laparoscopic port tracks in six (32%) patients (mean, two recurrences per patient; range, one to four per patient). Eight (67%) CT-depicted recurrences appeared homogeneous, and nine (75%) directly involved subjacent omental fat. The mass was the only site of recurrence at CT in two (33%) patients. The presence of an abdominal wall tumor recurrence affected patient care in four (67%) of six patients. Histopathologic examination results confirmed recurrent tumor in all five (100%) patients who underwent biopsy.

CONCLUSION

Tumor recurrence along port tracks is a potential complication of laparoscopic cholecystectomy when gallbladder carcinoma is present, even after subsequent hepatic resection is performed for attempted cure. Recurrences appear as a new or enlarging abdominal wall mass, often involving subjacent omental fat, and may be the only site of recurrent disease at CT. Demonstration of abdominal wall tumor recurrence affects patient care.

A phase II study of pyrazoloacridine in patients with advanced renal cell carcinoma

The aim of this study was to determine the antitumor activity of pyrazoloacridine in patients with renal cell carcinoma. Eligible patients had advanced renal cell carcinoma with bidimensionally measurable disease, a Karnofsky performance status of at least 70, life expectancy of greater than three months, no prior treatment with chemotherapy, and no evidence of brain metastases. Patients were treated intravenously with 750 mg/m2 every three weeks. Twelve patients were enrolled in this study and all were evaluable for response and toxicity. Of the twelve patients, no major responses were achieved. Toxicity was mild, with three patients requiring a 20% dose reduction. At the dose and schedule used in this trial, pyrazoloacridine is inactive in renal cell carcinoma.

Magnetic resonance cholangiopancreatography

Magnetic resonance cholangiopancreatography (MRCP) uses MR imaging to visualize fluid in the biliary and pancreatic ducts as high signal intensity on T2-weighted sequences; it is the newest modality for biliary and pancreatic duct imaging. MRCP is of proven utility in a variety of biliary and pancreatic diseases, including choledocholithiasis, congenital anatomic variants, chronic pancreatitis, post-cholecystectomy disorders, and neoplastic duct obstruction. MRCP is an evolving technique, but it has reached the stage of development where it is clinically useful and of comparable accuracy to conventional cholangiography. With further progress, it is likely that by the start of the new millennium MRCP will replace diagnostic endoscopic retrograde cholangiopancreatography as the modality of choice for imaging the biliary and pancreatic ducts.

Magnetic resonance cholangiopancreatography

Magnetic resonance cholangiopancreatography (MRCP) uses MR imaging to visualize fluid in the biliary and pancreatic ducts as high signal intensity on T2-weighted sequences; it is the newest modality for biliary and pancreatic duct imaging. MRCP is of proven utility in a variety of biliary and pancreatic diseases, including choledocholithiasis, congenital anatomic variants, chronic pancreatitis, post-cholecystectomy disorders, and neoplastic duct obstruction. MRCP is an evolving technique, but it has reached the stage of development where it is clinically useful and of comparable accuracy to conventional cholangiography. With further progress, it is likely that by the start of the new millennium MRCP will replace diagnostic endoscopic retrograde cholangiopancreatography as the modality of choice for imaging the biliary and pancreatic ducts.

Prevalence and importance of small hepatic lesions found at CT in patients with cancer

PURPOSE

To assess the prevalence of small hepatic lesions discovered at computed tomography (CT) in patients with cancer and to determine the frequency with which they represent clinically important findings.

MATERIALS AND METHODS

The authors reviewed the CT reports obtained in 2,978 patients with cancer during a 24-month period. Small hepatic lesions (lesions 1 cm or less in diameter or deemed too small to characterize by the interpreting radiologist) noted on the initial scan were assessed at follow-up CT. The number and type of any other intrahepatic lesion, the histologic type of the primary tumor, and the presence of extrahepatic metastatic disease were also recorded.

RESULTS

Small hepatic lesions were reported in 378 (12.7%) patients; 15 (4.0%) of these patients also reportedly had other larger hepatic lesions that were interpreted as metastases. Small hepatic lesions demonstrated interval growth in 44 (11.6%) patients and were therefore considered metastatic. Small hepatic lesions in 303 (80.2%) patients demonstrated no interval growth (mean follow-up, 25.6 months; range, 6-56 months) and were therefore presumed benign. Small hepatic lesions in 31 (8.2%) patients were stable at follow-up of less than 6 months and were considered indeterminate. Among the three most common tumors (lymphoma and colorectal and breast cancers), small hepatic lesions were metastatic in 4%, 14%, and 22%, respectively.

CONCLUSION

Although small hepatic lesions in patients with cancer more frequently are benign than malignant, these lesions represent metastases in 11.6% of patients.

Hepatocellular carcinoma: MR imaging findings in cirrhotic livers and noncirrhotic livers

PURPOSE

To compare the magnetic resonance (MR) imaging findings of primary hepatocellular carcinoma (HCC) in cirrhotic versus noncirrhotic livers.

MATERIALS AND METHODS

MR images in 36 patients with HCC (30 men and she women aged 42-84 years [mean age, 65 years]) were retrospectively reviewed. The number and size of hepatic lesions were assessed. Lesion margins were categorized as well circumscribed or ill defined. The presence of a capsule, intratumoral high signal intensity on T1-weighted MR images, and a stellate scar were determined.

RESULTS

Eleven (31%) patients had MR imaging evidence of cirrhosis, and 25 (69%) did not: Lesions in cirrhotic livers differed significantly from those in noncirrhotic livers in terms of size (22 cm2 vs 99 cm2, P < .05), frequency of a solitary lesion (27% vs 72%, P < .05), and frequency of a central scar (6% vs 50%, P < .05). There was no difference between the cirrhotic and noncirrhotic livers with regard to tumor margin, intratumoral high signal intensity on T1-weighted images, or tumor capsule.

CONCLUSION

Differences exist in the MR imaging appearance of HCC between patients with and those without cirrhosis, although there is overlap of imaging findings.

Randomized phase III trial comparing the new potent and selective third-generation aromatase inhibitor vorozole with megestrol acetate in postmenopausal advanced breast cancer patients. North American Vorozole Study Group

PURPOSE

To compare the efficacy and safety of vorozole (VOR) 2.5 mg once daily with that of megestrol acetate (MA) 40 mg four times per day as second-line therapy in postmenopausal women with advanced breast cancer whose disease progressed after tamoxifen treatment.

PATIENTS AND METHODS

A total of 452 patients were enrolled onto an open, multicenter, randomized phase III trial comparing VOR to MA for tumor response, safety, and quality of life (as indicated by the Functional Living Index-Cancer score).

RESULTS

Vorozole produced a response rate of 9.7%, compared with 6.8% for MA (P = .24). Clinical benefit (complete response + partial response + no change in > 6 months) was demonstrated in 23.5% and 27.2% of patients treated with VOR and MA, respectively (P = .42). Median duration of response was 18.2 months for VOR versus 12.5 months for MA (P = .074). There was no significant difference in time to progression or survival between the treatment groups. Discontinuation of treatment because of adverse events occurred less frequently in the VOR-treated group (3.1% v 6.2%; P = .18). Patients on the VOR arm reported significantly more nausea, hot flushes, arthralgia, upper respiratory tract infection, anorexia, and paresthesia, whereas those treated with MA had significantly more dyspnea, increased appetite, and weight increase. There was no difference between the two treatment groups in Functional Living Index-Cancer scores (total or subscales). However, when analyzed by objective response, patients with complete or partial responses (P = .032) or no change (P = .033) who were receiving VOR had significant improvement in the psychologic well-being subscale, compared with patients given MA.

CONCLUSION

Vorozole is well tolerated and as effective as MA in the treatment of postmenopausal advanced breast cancer patients with disease progression after tamoxifen treatment.

Liver resection for metastatic colorectal cancer: assessing the risk of occult irresectable disease

BACKGROUND

Liver resection is standard therapy for selected patients with metastatic colorectal cancer. Extrahepatic metastases and inability to remove all hepatic disease usually preclude curative resection and are the most common contraindications. This study analyzes irresectability in patients considered to have resectable disease taken to operation for potentially curative hepatic resection. We describe preoperative factors associated with irresectability and propose a preoperative scoring system that identifies patients at particularly high risk for occult irresectable disease.

STUDY DESIGN

Patients considered to have resectable hepatic colorectal metastases were identified from a prospective database. Intraoperative findings that precluded liver resection were recorded. Demographic data, characteristics of the primary tumor, and characteristics of the hepatic metastases were recorded and analyzed.

RESULTS

From April 1992 through July 1997, 416 patients were explored with the intention of performing a potentially curative liver resection; 329 (79%) were resected. Eighty-seven patients (21%) had apparently resectable tumors on preoperative imaging but irresectable disease at laparotomy. Forty-four patients (51%) had irresectable disease limited to the liver; 32 had extensive bilobar disease not appreciated before surgery, and 12 were not resected for technical or other reasons unrelated to disease extent. Forty-three patients (49%) had extrahepatic disease, 31 of whom had resectable hepatic tumors. Of the several preoperative factors analyzed, only the estimated number of hepatic tumors was an independent predictor of irresectable findings at operation. This held true for patients with extrahepatic metastases and those with extensive hepatic disease. From these data, we devised a preoperative scoring system that estimates the probability of finding occult irresectable disease. Resectability ranged from 95% in patients with a score of 0 (solitary, unilobar) to 62% in those with a score of 3 (multiple, bilobar; p = 0.0001). The predictive value of this scoring system was then validated by applying it prospectively to an additional group of 118 patients taken to surgery for resection; the results were similar.

CONCLUSIONS

Standard preoperative investigations predicted resectability in 79% of patients with hepatic colorectal metastases. Unresectable disease limited to the liver and extrahepatic disease were seen with nearly equal frequency. The majority of patients with extrahepatic metastases had resectable hepatic disease (31 of 43, 72%). A preoperative scoring system is proposed that identifies patients at high risk for unrecognized irresectable disease and may help focus the use of additional diagnostic modalities such as laparoscopy and positron emission tomography (PET).

Complex postcholecystectomy biliary disorders: preliminary experience with evaluation by means of breath-hold MR cholangiography

PURPOSE

To assess preliminary experience with breath-hold single-shot fast spin-echo magnetic resonance (MR) cholangiography in complex postcholecystectomy biliary disorders.

MATERIALS AND METHODS

MR cholangiography was performed in 17 consecutive patients referred for specialist surgical evaluation of suspected complex postcholecystectomy biliary disorders. Two readers, unaware of surgical, histopathologic, or other imaging findings, independently reviewed the MR cholangiographic images to assess the presence of biliary occlusion, peribiliary lesions, nonspecific biliary dilatation (biliary dilatation without an abrupt transition in caliber and without a visible underlying cause), bile duct stones, or biliary fistulas. Final diagnoses were established with surgery (n = 9), imaging other than MR (n = 6), and histopathologic review of the initial surgical specimen (n = 2).

RESULTS

Final diagnoses were biliary occlusion (n = 8), peribiliary lesions (n = 3), nonspecific biliary dilatation (n = 3), bile duct stones (n = 2), and biliary-colonic fistula (n = 1). The two readers correctly categorized these diagnoses in 15 (88%) and 13 (76%) of the 17 cases, with excellent interobserver agreement (kappa = 0.82).

CONCLUSION

Single-shot fast spin-echo MR cholangiography is an accurate, noninvasive modality for the assessment of complex postcholecystectomy biliary disorders.

Small cell and anaplastic prostate cancer: correlation between CT findings and prostate-specific antigen level

PURPOSE

To evaluate the computed tomographic (CT) findings in patients with the anaplastic clinical variant of prostate cancer and to correlate these with prostate-specific antigen (PSA) levels.

MATERIALS AND METHODS

Twenty-seven men with the anaplastic clinical variant of prostate cancer, including 12 patients with small cell cancer of the prostate, underwent CT before platinum-based chemotherapy. CT findings were retrospectively reviewed for the extent of disease in the abdominal and pelvic lymph nodes, liver, bone, and prostate. CT findings were correlated with baseline PSA levels.

RESULTS

The overall mean PSA level was 59.9 ng/ml +/- 23.3 (range, 0-583 ng/ml; median, 4 ng/ml), with a mean PSA level in the small cell cancer subgroup of 12.3 ng/ml +/- 9.0 (range, 0-110 ng/mL; median, 1.7 ng/mL). Twenty-six patients (96%) had metastatic disease evident at CT, but only nine (33%) had PSA levels greater than 10 ng/mL. The mean PSA level in patients with pelvic lymphadenopathy was 12.8 ng/mL +/- 7.9 (median, 1.6 ng/mL); that in the small cell cancer subgroup was only 2.8 ng/ml +/- 1.4 (median, 1.6 ng/ml). Whereas 19 (70%) of all patients had osseous metastases and an average PSA level of 73 ng/ml +/- 32(median, 9.1 ng/mL), the seven (58%) with small cell cancer and bone metastases had an average PSA level of 18 ng/mL +/- 13 (median, 4 ng/mL).

CONCLUSION

Unlike patients with advanced typical adenocarcinoma of the prostate, patients with the anaplastic clinical variant of prostate cancer often have extensive metastatic disease at CT despite relatively low PSA levels.

Neoplastic pancreaticobiliary duct obstruction: evaluation with breath-hold MR cholangiopancreatography

OBJECTIVE

The purpose of this study was to investigate the use of breath-hold single-shot fast spin-echo MR cholangiopancreatography in neoplastic pancreaticobiliary duct obstruction.

MATERIALS AND METHODS

Breath-hold MR cholangiopancreatography was performed for preoperative examination of 32 consecutive patients with pathologically confirmed neoplastic obstruction of the biliary tract or pancreatic duct using a single-shot fast spin-echo sequence. Two observers, unaware of clinical or pathologic findings, independently reviewed the MR cholangiopancreatograms to assess level of obstruction and site of underlying tumor. Pathologic diagnoses, based on surgical or CT-guided biopsy specimens, were pancreatic tumor (n = 12), gallbladder cancer (n = 9), intrahepatic cancer (n = 9), and ampullary cancer (n = 2).

RESULTS

On the basis of conventional cholangiography, CT, and surgical findings, 20 patients had isolated bile duct obstruction, 11 patients had combined pancreatic and bile duct obstruction, and one patient had isolated pancreatic duct obstruction. Isolated bile duct obstruction was classified as lobar (n = 5), hilar (n = 12), or distal (n = 3). These levels of obstruction were correctly identified in 27 (84%) and 28 (88%) of the 32 cases by the two observers. The site of the underlying tumor was identified in 27 (84%) and 29 (91%) cases by the two observers. Good interobserver agreement was reached for both level of obstruction (kappa = .70) and identification of tumor site (kappa = .75).

CONCLUSION

Breath-hold single-shot fast spin-echo MR cholangiopancreatography is accurate in identifying the level of obstruction and the site of underlying tumor in neoplastic pancreaticobiliary duct obstruction, with good interobserver agreement.

Distal lower extremity arteries: evaluation with two-dimensional MR digital subtraction angiography

PURPOSE

To test the hypothesis that magnetic resonance (MR) digital subtraction angiography is superior to two-dimensional time-of-flight (TOF) MR angiography for demonstration of patent arteries in the distal lower extremity.

MATERIALS AND METHODS

Thirty-seven lower extremities in 23 consecutive patients were imaged with two-dimensional TOF MR angiography and two-dimensional MR digital subtraction angiography. Images were interpreted in a randomized and blinded manner. Each lower extremity was subdivided into seven potential arterial segments. The number of digital arteries visualized was also determined. Overall image quality of MR digital subtraction and TOF angiograms was compared. The relative ability of MR digital subtraction angiography and TOF MR angiography to demonstrate patent arterial segments was assessed.

RESULTS

MR digital subtraction angiography was significantly superior to TOF MR angiography for demonstration of patent arterial segments and digital arteries (P < .001). MR digital subtraction angiographic images were qualitatively superior to TOF images (P < .001).

CONCLUSION

Two-dimensional MR digital subtraction angiography is superior to two-dimensional TOF MR angiography for help in identifying patent segments in the distal lower extremity.

Phase I trial of subcutaneous recombinant human interleukin-12 in patients with advanced renal cell carcinoma

Patients with advanced renal cell carcinoma were treated in a Phase I trial with escalating doses of recombinant human interleukin-12 (rHuIL-12) given on days 1, 8, and 15 of each 28-day cycle. Treatment in the initial dose scheme consisted of a fixed dose with dose levels of 0.1, 0.5, and 1.0 microg/kg given to cohorts composed of three or six patients. On the basis of the toxicity profile, a second scheme (up-titration) was undertaken wherein rHuIL-12 was escalated for each patient from week 1 to week 2, to a target dose given week 3 and thereafter; cohort target dose levels were 0.5, 0.75, 1.0, 1.25, and 1.5 microg/kg. Fifty-one patients were treated: 32 (63%) had prior cytokine therapy and 19 (37%) had received no prior systemic therapy. The maximum tolerated dose for the fixed dose scheme was 1.0 microg/kg. Dose-limiting toxicities included increase in transaminase concentration, pulmonary toxicity, and leukopenia. The most severe toxicities occurred with the first injection and were milder upon further treatment. With the up-titration dose scheme, the maximum tolerated dose was reached at 1.5 microg/kg, and dose-limiting toxicity consisted of an increase in serum transaminase levels. At the maximum tolerated dose of 1.5 microg/kg, serum IL-12 levels increased to a mean peak level of 706 pg/ml. Serum levels of IFN-gamma increased to a mean peak level of about 200 pg/ml at 24 h after the first maintenance dose of 1.5 microg/kg. The best responses were as follows: one patient had complete response, 34 patients were stable, 14 patients showed progression, and 1 patient was inevaluable. In conclusion, rHuIL-12 was relatively well tolerated when administered by s.c. injection. The recommended dose according to the up-titration schedule of rHuIL-12 (microg/kg) for Phase II trials was as follows: cycle 1, 0.1 (day 1), 0.5 (day 8), 1.25 (day 15); cycle 2 onwards, 1.25. Phase II trials of rHuIL-12 were initiated in previously untreated patients with renal cell carcinoma and in patients with melanoma.

A phase II study of 13-cis-retinoic acid in patients with advanced renal cell carcinoma

The aim of this study was to determine the antitumor activity of 13-cis-retinoic acid as a single agent in patients with advanced renal cell carcinoma. Eligible patients had advanced renal cell carcinoma with bi-dimensionally measurable disease, a Karnofsky performance status of at least 70, life expectancy of greater than three months, no evidence of brain metastases, and treatment with no more than one chemotherapy regimen. Patients were treated with one mg/kg/day of 13-cis-retinoic acid orally. Twenty-six patients were enrolled in this study and 25 were evaluable for response and toxicity. Of the twenty-five evaluable patients, no major responses were achieved. Toxicity was mild, with no patient requiring a dose reduction. At the dose administered in this trial, 13-cis-retinoic acid is inactive as a single agent in renal cell carcinoma.