Determination Of Tumor Volume Research Articles

The individual internal gross target volume for hepatocellular carcinoma: four-dimensional CT vs three-dimensional CT associated with active breathing control

Objective To research the feasibility of using three-dimensional CT (3DCT) associated with active breathing control (ABC) in determination of the individual internal tumor volume (ITV) for hepatocellular carcinoma (HCC) comparing the four-dimensional CT (4DCT).Methods After 4DCT scans of 15 HCC patients who had accepted TACE,completed the 3DCT scans associated with ABC in three ways of breathing:free breathing ( FB),end inspiration hold ( EIH),end expiration hold (EEH).4DCT images were sorted into 10 phases and the maximum intensity projection (MIP) images were constructed.The GTVs were manually contoured on 4DCT and 3DCT images (labeled as GTV0,GTV10.….GTV90,GTVMIP,,GTVFB,GTVEIH and GTVEEH).GTV0…GTV90,GTV0 and GTV50,GTV0,GTV20 and GTV50,GTVEIH and GTVEEH were respectively merged into IGTV1,IGTV2,IGTV3,IGTV4.The volume and geometry displacement of GTVs and IGTVs were compared.Results All patients were compatible with the ABC technique and completed the CT scans in two ways.The motion of diaphragm measured between 4DCT and 3DCT images was not significantly different ( 1.39 cm and 1.39 cm,t =-0.02,P =0.983 ),it was similar to the volume difference among GTV0,GTV20,GTV50,GTVEIH,GTVEEH and GTVFB (56.4,54.6,55.5,55.6,55.2,59.7 cm3,F =0.01,P =1.000 ).The comparison result of volume difference among IGTV1,IGTV2,IGTV3,IGTV4 and GTVMIP (77.9,71.4,73.4,72.3 and 66.3 cm3,F =0.02,P =1.000)were similar to the differences of geometry displacement in x,y and z axial among them (F =0.48,0.04,0.02,P =0.750,0.997,0.999,respectively).Conclusion The application of 3DCT associated with ABC in determination of the individual IGTV for HCC is feasible and safe comparing to 4DCT. Key words: Tomography, X-ray computed, three-dimensional; Tomography, X-ray computed,four-dimensional; Active breathing control; Liver neoplasm/radiotherapy

Chemoradionuclide Therapy with186Re-labeled Liposomal Doxorubicin in Combination with Radiofrequency Ablation for Effective Treatment of Head and Neck Cancer in a Nude Rat Tumor Xenograft Model

To determine the therapeutic efficacy of rhenium 186 ((186)Re)-labeled PEGylated liposomal doxorubicin ((186)Re-liposomal doxorubicin) in combination with radiofrequency (RF) ablation of human head and neck squamous cell carcinoma (HNSCC) xenograft in nude rats. This investigation was approved by the animal care committee. Sixty nude rats with subcutaneously implanted HNSCC xenografts (six per group) were treated with (a) RF ablation (70 °C for 5 minutes), (b) PEGylated liposomes, (c) liposomal doxorubicin, (d) (186)Re-PEGylated liposomes (1295 MBq/kg), (e) (186)Re-liposomal doxorubicin (555 MBq/kg), (f) PEGylated liposomes plus RF ablation, (g) liposomal doxorubicin plus RF ablation, (h) (186)Re-PEGylated liposomes plus RF ablation, or (i) (186)Re-liposomal doxorubicin plus RF ablation. Six rats did not receive any treatment (control group). Tumor uptake in (186)Re therapy groups was monitored with small-animal single photon emission computed tomography for 5 days. Therapeutic efficacy was monitored for 6 weeks with measurement of tumor volume, calculation of the percentage injected dose of fluorine 18 fluorodeoxyglucose (FDG) in tumor from small-animal positron emission tomography (PET) images, and determination of viable tumor volume at histopathologic examination. Significant differences between groups were determined with analysis of variance. The average tumor volume (± standard deviation) on the day of therapy was 1.32 cm(3) ± 0.17. At 6 weeks after therapy, control of tumor growth was better with (186)Re-liposomal doxorubicin than with liposomal doxorubicin alone (tumor volume, 2.26 cm(3) ± 0.89 vs 5.43 cm(3) ± 0.93, respectively; P < .01). The use of RF ablation with liposomal doxorubicin and (186)Re-liposomal doxorubicin further improved tumor control (tumor volume, 2.05 cm(3) ± 1.36 and 1.49 cm(3) ± 1.47, respectively). The tumor growth trend correlated with change in percentage of injected dose of FDG in tumor for all groups (R(2) = 0.85, P < .001). Viable tumor volume was significantly decreased in the group treated with (186)Re-liposomal doxorubicin plus RF ablation (0.54 cm(3) ± 0.38; P < .001 vs all groups except (186)Re-liposomal doxorubicin alone). Triple and dual therapies had an observable trend ((186)Re-liposomal doxorubicin plus RF ablation > (186)Re-liposomal doxorubicin > liposomal doxorubicin plus RF ablation > liposomal doxorubicin) of improved tumor growth control and decreased viable tumor compared with other therapies. FDG PET could be used as a noninvasive surrogate marker for tumor growth and viability in this tumor model.

Suitability of PSA-detected localised prostate cancers for focal therapy: experience from the ProtecT study

Background:Contemporary screening for prostate cancer frequently identifies small volume, low-grade lesions. Some clinicians have advocated focal prostatic ablation as an alternative to more aggressive interventions to manage these lesions. To identify which patients might benefit from focal ablative techniques, we analysed the surgical specimens of a large sample of population-detected men undergoing radical prostatectomy as part of a randomised clinical trial.Methods:Surgical specimens from 525 men who underwent prostatectomy within the ProtecT study were analysed to determine tumour volume, location and grade. These findings were compared with information available in the biopsy specimen to examine whether focal therapy could be provided appropriately.Results:Solitary cancers were found in prostatectomy specimens from 19% (100 out of 525) of men. In addition, 73 out of 425 (17%) men had multiple cancers with a solitary significant tumour focus. Thus, 173 out of 525 (33%) men had tumours potentially suitable for focal therapy. The majority of these were small, well-differentiated lesions that appeared to be pathologically insignificant (38–66%). Criteria used to select patients for focal prostatic ablation underestimated the cancer's significance in 26% (34 out of 130) of men and resulted in overtreatment in more than half. Only 18% (24 out of 130) of men presumed eligible for focal therapy, actually had significant solitary lesions.Conclusion:Focal therapy appears inappropriate for the majority of men presenting with prostate-specific antigen-detected localised prostate cancer. Unifocal prostate cancers suitable for focal ablation are difficult to identify pre-operatively using biopsy alone. Most lesions meeting criteria for focal ablation were either more aggressive than expected or posed little threat of progression.

3D Volumetric Conformal Analysis of Vestibular Schwannomas

Objective: Compare 3D conformal volumetric analysis (3DCVA) versus traditional linear measurements on serial MRI imaging of vestibular schwannomas (VS) for determination and assessment of accurate tumor volume and growth rates. Method: Retrospectively identified VS patients followed with serial 0.7-3.0 Tesla MRI were included. Maximal linear dimensions were obtained from gadolinium-contrasted T1 sequences from 3 serial MRI scans per RECIST guidelines. Volumetric analysis was performed with semiautomated 3DCVA. Annual tumor growth rate and percentage change were compared for linear and volumetric measurements. Results: The average time span during which the serial MRI scans were obtained was 2.86 years in this initial retrospective analysis of 11 patients. The linear growth measurements averaged 0.5 mm/y, corresponding to a 6.4% average change per year. With 3DCVA the average tumor growth rate was 5mm3/y, corresponding to 3.7 mm/y growth in each dimension. There was an average increase in tumor volume of 29% per year with 3DCVA, compared with 6.4% with linear measurements. The difference in percentage change per year between methods was significant when compared with paired 2-tailed t-test ( P = .036). Conclusion: VS assume complex configurations. In this initial retrospective study, linear measurements may underestimate true tumor growth compared to 3D conformal volumetric analysis. 3DCVA may provide a more robust tool in assessing tumor volume, growth rate, and volume change for a more accurate reflection of tumor progression compared to linear measurements.

Monitoring neoadjuvant chemotherapy in breast cancer patients: Improved MR assessment at 3 T?

To investigate possible improvements in predicting the response to neoadjuvant chemotherapy (NAC) at 3 T for locally advanced breast cancer (LABC). Dynamic contrast-enhanced magnetic resonance (DCE-MR) images acquired before and during NAC were retrospectively analyzed in 85 patients. Tumor volume and diameter, three volumes based on the shape of the enhancement curve, relative signal intensity, area under the curve, and the signal-to-noise ratio were extracted. Differences between responders and nonresponders at the same and between MR timepoints during treatment were evaluated. A higher signal-to-noise ratio was observed on 3 T images compared to 1.5 T, and 3 T revealed more significant findings related to response compared to 1.5 T. The DCE-MRI-derived volume parameters were the earliest predictors of response at both 1.5 and 3 T. Our results show that 3 T provides an improved assessment of the response to NAC in LABC patients, where the MR determined tumor volume reduction before the second cycle of NAC was the strongest and earliest predictor of a response.

Tumor volume measurement errors of RECIST studied with ellipsoids

The authors investigate the extent to which Response Evaluation Criteria in Solid Tumors (RECIST) can predict tumor volumes in ideal geometric settings and using clinical data. The authors consider a hierarchy of models including uniaxial ellipsoids, general ellipsoids, and composites of ellipsoids, using both analytical and numerical techniques to show how well RECIST can predict tumor volumes in each case. The models have certain features that are compared to clinical data. The principal conclusion is that a change in the reported RECIST value needs to be a factor of at least 1.2 to achieve a 95% confidence that one ellipsoid is larger than another assuming the ratio of maximum to minimum diameters is no more than 2, an assumption that is reasonable for some classes of tumors. There is a significant probability that RECIST will select a tumor other than the largest due to orientation effects of nonspherical tumors: in previously reported malignoma data, RECIST would have selected a tumor other than the largest in 9% of the cases. Also, the widely used spherical model connecting RECIST values for a single tumor to volumes overestimates these volumes. RECIST imposes a limit on the ability to determine tumor volumes, which is greater than the limit imposed by modem medical computed tomography machines. It is also likely the RECIST limit is above natural biological variability of stable lesions. The authors recommend the study of such natural variability as a fruitful avenue for further study.

Abstract 4575: Novel monoclonal antibody targeting EMMPRIN for pancreatic cancer therapy

Abstract Purpose: To evaluate a novel monoclonal antibody targeting extracelluar matrix metalloproteinase (EMMPRIN) in orthotopic pancreatic-cancer murine models. Methods: In vitro cytotoxic assay of anti-EMMPRIN mAb was conducted with MIA PaCA-2 and PANC-1 human pancreatic-cancer cell lines. Binding assay of Tc-99m labeled anti-EMMPRIN mAb was repeated three times independently for MIA PaCa-2 cells or MIA PaCa-2 cells silenced for EMMPRIN gene expression by siRNA. For the in vivo animal study, MIA PaCa-2 cells were implanted in groups 1-6, while EMMPRIN silenced cells were implanted in group 7. For groups 1-4 (solid tumor model, n=5-7/group), dosing started at 21 days after cell implantation, while dosing started immediately after cell implantation for groups 5-7 (residual tumor model, n=10-12/group); groups 1 and 2 were injected with PBS and anti-EMMPRIN mAB (0.2mg) twice weekly for 3 weeks respectively; ultrasound imaging (USI) was applied at days 21, 28, 35, and 42 to determine tumor volume. Groups 3 and 4 were injected with PBS and anti-EMMPRIN mAb (1mg) twice weekly for 2 weeks, respectively; USI and diffusion-weighted MRI were applied at days 21, 28, and 35. Groups 5 and 6 were injected with PBS and anti-EMMPRIN mAB (0.2mg) twice weekly for 3 weeks respectively; group 7 was injected with PBS during the same time. For groups 5-7, USI was applied at 15 and 21 days post cell injection. Ki-67 and TUNEL staining were conducted on tumor sections from groups 1 and 2 at the study end. Results: In vitro treatment with antibody alone did not demonstrate significant cytotoxic effect in either cell line. The Kd in MIA PaCa-2 cells was 4.31±0.59 (mean ± SE) nM, which was not statistically different from that in EMMPRIN silenced cells. The average number of EMMPRIN per MIA PaCa-2 cell was 582,000±56,000, significantly higher than that per EMMPRIN silenced cells at 220,000±89,000 (p=0.03). Tumor-volume increases of group 1 relative to day 21 were 282±33, 495±107, and 725±166% at days 28, 35, and 42, while those of group 2 were 191±7, 263±27, and 429±39%; groups 1 and 2 were statistically different at day 28 (p=0.03), not at the other days. Group 3 showed an increase in tumor-volume of 317±55 and 505±96% at days 28 and 35 respectively, while those in group 4 were 189±27 and 244±41%; groups 3 and 4 were statistically different at day 35 (p=0.04), but not at day 28. Mean intra-tumoral ADC change of group 4 was not statistically significant from that of group 3. Tumor volumes of groups 5-7 were 66±17, 21±5, and 4±2mm3 at day 15, while those at day 21 were 240±41, 80±15, and 15±4mm3, which represent statistical differences among groups at each day (p&amp;lt;0.05). Proliferating cell density of group 2 was significantly lower than that of group 1 (p=0.01), while apoptotic cell densities were not. Conclusion: Tumor growth was successfully arrested following treatment with anti-EMMPRIN antibody for both solid- and residual-tumor models, consistent with reduced proliferating cell density. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4575. doi:10.1158/1538-7445.AM2011-4575

Apport de l’imagerie structurale par micro scanner X dans l’évaluation pré-clinique de chimiothérapies du carcinome hépatocellulaire sur greffe orthotopique chez le rat ACI

Animal experimentation is a prerequisite for preclinical evaluation of treatments such as chemotherapy. It's strictly regulated with the purpose of reducing the number of experimental animal as well as their pain. Small animal imaging should provide a painless longitudinal follow up of tumor progression on a single animal. The aim of the study is to validate small animal imaging by microscanner (μscan) in longitudinal follow up of a hepatocellular carcinoma (HCC) and to demonstrate its interest for in vivo evaluation of tumor response to different therapeutics. An HCC model achieved by orthotopic graft of the MH3924A cell line in ACI rats was followed using a Imtek/Siemens microscanner (μscan) with contrast agents (Fenestra® LC/VC). The procedures giving the optimal enhancement of the liver as well as a reliable determination of tumor volumes by μscan were validated. Three protocols for therapeutic assessment through μscan longitudinal follow up were performed. Each consisted in three groups testing a chemotherapy (gemcitabine, gemcitabine-oxaliplatine or sorafenib) versus two control groups (placebo and doxorubicine). Comparison was done on tumor volumes, median and actual survivals. There was a significant correlation between tumor volumes measured by μscan and autopsy. Treatment by sorafenib, at the contrary of gemcitabine alone or with oxaliplatine, resulted in a significant reduction in tumor volumes and prolongation of actuarial survival. These results are consistent with available clinical data for these diverse therapeutics. In conclusion, small animal imaging with μscan is a non-invasive, reliable, and reproducible method for preclinical evaluation of antitumor agents.

MicroRNA-100 Expression is Independently Related to Biochemical Recurrence of Prostate Cancer

Abnormal miRNA expression has emerged as crucial factors in carcinogenesis and is important in the comprehension of prostate cancer behavior. We determined the correlation of miRNA expression profiles with prostate cancer progression. We studied frozen specimens from 49 patients treated for prostate cancer with radical prostatectomy. We intentionally chose 28 men without and 21 with biochemical recurrence, defined as prostate specific antigen greater than 0.2 ng/ml. The expression of 14 miRNAs was determined by quantitative reverse transcriptase-polymerase chain reaction. All radical prostatectomy specimens were studied in toto to determine tumor volume, Gleason score and 2002 TNM pathological stage. Benign prostate tissue from benign prostatic hyperplasia served as a control. Four miRNAs were related to tumor recurrence. Using the Cox regression test the risk of recurrence was 3.0, 3.3, 2.7 and 3.4 for high levels of miR-100, miR-145, miR-191 and miR-let7c, respectively. When considering statistically significant clinical variables on univariate analysis of biochemical-free survival, prostate specific antigen and tumor volume, results revealed that miR-100 and tumor volume were independently related to tumor recurrence. A high level of miR-100 is related to biochemical recurrence of localized prostate cancer in patients treated with radical prostatectomy. The role of miR-100 during carcinogenesis must be resolved in future studies to better understand the molecular pathways in which miR-100 is involved. This may open the possibility of using it as a prognostic marker and inspire the development of a target drug.

Artifacts in Conventional Computed Tomography (CT) and Free Breathing Four-Dimensional CT Induce Uncertainty in Gross Tumor Volume Determination

Artifacts impacting the imaged tumor volume can be seen in conventional three-dimensional CT (3DCT) scans for planning of lung cancer radiotherapy but can be reduced with the use of respiration-correlated imaging, i.e., 4DCT or breathhold CT (BHCT) scans. The aim of this study was to compare delineated gross tumor volume (GTV) sizes in 3DCT, 4DCT, and BHCT scans of patients with lung tumors. A total of 36 patients with 46 tumors referred for stereotactic radiotherapy of lung tumors were included. All patients underwent positron emission tomography (PET)/CT, 4DCT, and BHCT scans. GTVs in all CT scans of individual patients were delineated during one session by a single physician to minimize systematic delineation uncertainty. The GTV size from the BHCT was considered the closest to true tumor volume and was chosen as the reference. The reference GTV size was compared to GTV sizes in 3DCT, at midventilation (MidV), at end-inspiration (Insp), and at end-expiration (Exp) bins from the 4DCT scan. The median BHCT GTV size was 4.9 cm(3) (0.1-53.3 cm(3)). Median deviation between 3DCT and BHCT GTV size was 0.3 cm(3) (-3.3 to 30.0 cm(3)), between MidV and BHCT size was 0.2 cm(3) (-5.7 to 19.7 cm(3)), between Insp and BHCT size was 0.3 cm(3) (-4.7 to 24.8 cm(3)), and between Exp and BHCT size was 0.3 cm(3) (-4.8 to 25.5 cm(3)). The 3DCT, MidV, Insp, and Exp median GTV sizes were all significantly larger than the BHCT median GTV size. In the present study, the choice of CT method significantly influenced the delineated GTV size, on average, leading to an increase in GTV size compared to the reference BHCT. The uncertainty caused by artifacts is estimated to be in the same magnitude as delineation uncertainty and should be considered in the design of margins for radiotherapy.

SU‐GG‐J‐04: Determination of Tumor Volume Using a Joint Motion‐PVE Correction Technique in PET/CT Imaging

Objective: 4D‐CT has been used to determine the tumor volume (TV) for lung/thoracic radiation therapy treatment planning primarily due to its ability to detect the tumor motion extent and trajectory. However, 4‐D CT is usually characterized by high patient radiation exposure. The objective of this abstract is to propose and evaluate an approach that relies on a single static PET/CT scan than can determine the TV by simultaneously correcting for respiratory motion artifact and partial volume effect (PVE) thereby eliminating the need for 4D‐CT and reducing patient exposure.Materials and Methods: The proposed joint correction approach incorporates a model of motion blurring, PVE and object size/shape. A motion blurring kernel (MBK) is then estimated from the deconvolution of the joint model while the TV is derived from convolving the MBK by the object size/shape obtained from the CT image. To test this technique, two studies were performed using 2 spheres of different sizes moving in a 2cm 1D‐sinusoidal and 2D‐circular waveforms respectively. In both cases, a 4D‐CT and a PET/CT of the 2 spheres were acquired. For both studies, the TV from the proposed technique was compared to the maximum‐intensity projection (MIP) volume of the 4D‐CT. Also a Dice coefficient of the two volumes was calculated. Results: The TV of the proposed technique was on average 3% different from the MIP volume. The average Dice coefficient was 0.87. The motion trajectory derived from the proposed technique is continuous while that of the 4D‐CT is discrete. Conclusion: Using this approach, a single static PET/CT can replace a 4D‐CT to determine the TV. This approach also has the ability to determine the tumor motion extent and trajectory and has the added advantage of reducing patient radiation exposure and determining the tumor locale probability (or MBK) compared to 4D‐CT.

Les méthodes de seuillage en TEP : un état de l’art

This work deals with positron emission tomography segmentation methods for tumor volume determination. We propose a state of art techniques based on fixed or adaptive threshold. Methods found in literature are analysed with an objective point of view on their methodology, advantages and limitations. Finally, a comparative study is presented.

Comparison of prostate cancer tumor volume and percent cancer in prediction of biochemical recurrence and cancer specific survival

Objectives Tumor volume and percent cancer (ratio of tumor volume/prostate volume) have been proposed as predictors of biochemical recurrence and cancer specific survival after radical prostatectomy. However, their relative merits as prognosticators have not been tested. We therefore evaluated and compared tumor volume and percent cancer as independent predictors of biochemical recurrence and prostate cancer specific death after radical prostatectomy. Methods and Materials A retrospective review of 739 patients who underwent radical prostatectomy for prostate cancer between 1984 and 2004 was conducted. Median follow-up was 91.7 months, and 22 patients died of prostate cancer. Univariate and multivariate analysis evaluated the following factors in predicting biochemical recurrence and prostate cancer specific death: tumor volume, prostate volume, percent cancer, Gleason score, percentage of Gleason grade 4/5, margin status, capsular invasion status, seminal vesicle invasion status, preoperative PSA, and lymph node status. Results In univariate analysis, both tumor volume ( P < 0.001) and percent cancer ( P < 0.001) significantly correlated with biochemical recurrence. Since they are highly correlated, they did not predict outcome independently when included in the same model; however, both were highly predictive for biochemical recurrence in separate multivariate models ( P = 0.01 for both). Both also correlated with cancer specific survival as single variables; however, in separate multivariate models, only tumor volume ( P = 0.03) predicted death, while percent cancer did not ( P = 0.09). Conclusions Tumor volume and percent cancer are independent predictors of recurrence after radical prostatectomy. However, in our series, tumor volume predicted cancer specific death better than percent cancer. Therefore, accurate determination of tumor volume, along with other accepted pathologic indices, is sufficient and preferred over percent cancer for prognostication after radical prostatectomy.

TH‐B‐211A‐02: Clinical Implementation of Respiration Motion Correlated Imaging, Treatment Planning and Delivery

Respiratory motion is a significant factor in determining a suitable planning target volume (PTV) that surrounds the demonstrable gross tumor volume (GTV) in the radiotherapy of mobile lesions. Historically, a “one‐size‐fits‐all” margin derived from population statistics has been employed to account for such motion. The advent of respiratory phase correlation (4D) and multi‐slice CT technology has enabled patient‐specific determination of both demonstrable tumor volume and its motion from a single imaging study. Management of such additional information during treatment planning and delivery however presents several challenges. Furthermore, guidelines for establishing clinical treatment planning and delivery protocols based on respiratory correlated imaging data differ from one institution to the other. The purpose of this presentation is to educate the community on the different respiratory correlated radiotherapy approaches currently available and compare the benefits and pitfalls in each case. Special focus will be on treatment planning, dose calculation and treatment delivery related issues.After the course, the attendees should be able to:1. Understand the different respiratory correlated treatment planning and delivery approaches2. Compare the benefits and pitfalls of each of the above approaches3. Develop and establish respiratory correlated imaging, treatment planning and4. delivery appropriate to the available equipment

Establishment of reproducible osteosarcoma rat model using orthotopic implantation technique

In experimental musculoskeletal oncology, there remains a need for animal models that can be used to assess the efficacy of new and innovative treatment methodologies for bone tumors. Rat plays a very important role in the bone field especially in the evaluation of metabolic bone diseases. The objective of this study was to develop a rat osteosarcoma model for evaluation of new surgical and molecular methods of treatment for extremity sarcoma. One hundred male SD rats weighing 125.45+/-8.19 g were divided into 5 groups and anesthetized intraperitoneally with 10% chloral hydrate. Orthotopic implantation models of rat osteosarcoma were performed by injecting directly into the SD rat femur with a needle for inoculation with SD tumor cells. In the first step of the experiment, 2x10(5) to 1x10(6) UMR106 cells in 50 microl were injected intraosseously into median or distal part of the femoral shaft and the tumor take rate was determined. The second stage consisted of determining tumor volume, correlating findings from ultrasound with findings from necropsia and determining time of survival. In the third stage, the orthotopically implanted tumors and lung nodules were resected entirely, sectioned, and then counter stained with hematoxylin and eosin for histopathologic evaluation. The tumor take rate was 100% for implants with 8x10(5) tumor cells or more, which was much less than the amount required for subcutaneous implantation, with a high lung metastasis rate of 93.0%. Ultrasound and necropsia findings matched closely (r=0.942; p<0.01), which demonstrated that Doppler ultrasonography is a convenient and reliable technique for measuring cancer at any stage. Tumor growth curve showed that orthotopically implanted tumors expanded vigorously with time-lapse, especially in the first 3 weeks. The median time of survival was 38 days and surgical mortality was 0%. The UMR106 cell line has strong carcinogenic capability and high lung metastasis frequency. The present rat osteosarcoma model was shown to be feasible: the take rate was high, surgical mortality was negligible and the procedure was simple to perform and easily reproduced. It may be a useful tool in the investigation of antiangiogenic and anticancer therapeutics. Ultrasound was found to be a highly accurate tool for tumor diagnosis, localization and measurement and may be recommended for monitoring tumor growth in this model.

Determination of patient-specific internal gross tumor volumes for lung cancer using four-dimensional computed tomography

BackgroundTo determine the optimal approach to delineating patient-specific internal gross target volumes (IGTV) from four-dimensional (4-D) computed tomography (CT) image data sets used in the planning of radiation treatment for lung cancers.MethodsWe analyzed 4D-CT image data sets of 27 consecutive patients with non-small-cell lung cancer (stage I: 17, stage III: 10). The IGTV, defined to be the envelope of respiratory motion of the gross tumor volume in each 4D-CT data set was delineated manually using four techniques: (1) combining the gross tumor volume (GTV) contours from ten respiratory phases (IGTVAllPhases); (2) combining the GTV contours from two extreme respiratory phases (0% and 50%) (IGTV2Phases); (3) defining the GTV contour using the maximum intensity projection (MIP) (IGTVMIP); and (4) defining the GTV contour using the MIP with modification based on visual verification of contours in individual respiratory phase (IGTVMIP-Modified). Using the IGTVAllPhases as the optimum IGTV, we compared volumes, matching indices, and extent of target missing using the IGTVs based on the other three approaches.ResultsThe IGTVMIP and IGTV2Phases were significantly smaller than the IGTVAllPhases (p < 0.006 for stage I and p < 0.002 for stage III). However, the values of the IGTVMIP-Modified were close to those determined from IGTVAllPhases (p = 0.08). IGTVMIP-Modified also matched the best with IGTVAllPhases.ConclusionIGTVMIP and IGTV2Phases underestimate IGTVs. IGTVMIP-Modified is recommended to improve IGTV delineation in lung cancer.

Dynamic Contrast-Enhanced Magnetic Resonance Imaging in the Evaluation of the Prostate

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a novel MR technique that allows to interrogate pharmacokinetic processes in the tissues at a voxel level and to generate parametric maps that can be displayed for clinical interpretation. Dynamic contrast-enhanced MRI is an important imaging technique for the imaging of angiogenesis and vasculogenesis because it probes the microvascular networks at a microscopic level by being sensitive to the compartmentalization of tissue into the vascular and extravascular-extracellular space and to the diffusion of contrast molecules across the vascular endothelium and capillary boundaries. Dynamic contrast-enhanced MRI has already shown to improve detection and localization of prostate cancer, to improve prediction of extracapsular extension, determination of tumor volume, and after treatment follow-up. In this article, we outline the fundamental principles of DCE-MRI and describe the application of DCE methods in the imaging of the prostate.

The role of magnetic resonance imaging (MRI) in prostate cancer imaging and staging at 1.5 and 3 Tesla: The Beth Israel Deaconess Medical Center (BIDMC) approach

Management decisions for patients with prostate cancer present a dilemma for both patients and their clinicians because prostate cancers demonstrate a wide range in biologic activity, with the majority of cases not leading to a prostate cancer related death. Furthermore, the current treatment options have significant side effects, such as incontinence, rectal injury and impotence. Key elements for guiding appropriate treatment include: distinction of organ-confined disease from extracapsular extension (ECE); and determination of tumor volume and tumor grade, none of which have been satisfactorily accomplished in today's pre-treatment paradigm. Magnetic resonance imaging (MRI) has the capability to assess prostate tissue, both functionally and morphologically. MRI as a staging tool has not shown enough consistency or sufficient accuracy for widespread adoption in clinical practice; yet, recent technical developments in MRI have yielded improved results. At our institution we have combined the use of new endorectal 3 Tesla MRI technology, T2-weighted, and high spatial resolution dynamic-contrast enhanced (DCE) MRI to non-invasively assess the prostate with higher signal-to-noise ratio and spatial resolution than previously achieved. This approach allows assessment of prostate-tissue morphology and kinetics, thus providing a non-invasive tool for tumor detection and staging and, consequently, directing biopsy and treatment specifically to diseased areas for a pre-treatment evaluation that can assist in the rational selection of patients for appropriate prostate cancer therapy.

Volume Determination of Oral Cavity Tumors by 3-Dimensional Ultrasonography

With the help of 3-dimensional (3D) ultrasound, the ultrasonographic determination of tumor volumes offers a new view of tumors in the oral cavity. These are classified according to their maximal diameter in TNM classification whereby the possibility exists in the high T category of overestimating small tumors that have spread into surrounding structures, and in the low T of underestimating large volume tumors that do not extend into surrounding structures. We analyzed a group of 49 patients with tumors of the oral cavity, all of whom underwent surgery. Tumor volumes were determined before surgery with 3D ultrasound aided by 3D View program software. After excision, the tumors were classified in pT categories based on pathologic findings. N stage was determined after neck dissection and correlation to tumor volume were performed. The average volume of T1 tumors was 1.74 cm(3); T2 was 5.21 cm(3); T3 was 23.36 cm(3), and T4 was 13.53 cm(3). There were significant differences in tumor volumes between all T categories except T3 and T4. Tumor volumes in our patients did not correlate with N stage. Volume determination of tumors with the help of 3D View software may categorize small tumors better and perhaps become a new refinement in TNM tumor classification. Results show that although T category in oral cavity tumors is determined by diameter in T1 to T3, the volumes match with T category. By using this method, a successful follow-up can be performed and the effects of radiotherapy or chemotherapy can be evaluated.

MO‐A‐AUD C‐02: Clinical Implementation of Respiration Motion Correlated Imaging, Treatment Planning and Delivery

Respiratory motion is a significant factor in determining a suitable planning target volume (PTV) that surrounds the demonstrable gross tumor volume (GTV) in the radiotherapy of mobile lesions. The advent of respiratory phase correlation (4D) and multi‐slice CT technology has enabled patient‐specific determination of both demonstrable tumor volume and its motion from a single acquisition. Management of such additional information during treatment planning and delivery however presents several challenges. Furthermore, guidelines for establishing clinical treatment planning and delivery protocols based on respiratory correlated imaging data differ from one institution to the other. The purpose of this presentation is to educate the community on the different respiratory correlated radiotherapy approaches currently available and compare the benefits and pitfalls in each case. Special focus will be on treatment planning, dose calculation and treatment delivery related issues.Educational Objectives:1. Understand the different respiratory correlated treatment planning and delivery approaches.2. Compare the benefits and pitfalls of each of the above approaches.3. Develop and establish respiratory correlated imaging, treatment planning and delivery appropriate to the available equipment.