Imaging In Breast Cancer Patients Research Articles

PET-CT Imaging in Breast Cancer Patients: New Tracers, Future Directions

Positron Emission Tomography using 18F-fluoro-deoxi-glucose (FDG-PET) is giving a new perspective in disease staging and therapeutic response evaluation in daily oncological practice. To understand better the biological behavior and therapeutic response of breast cancer, new tracers and targets of molecular imaging are under investigation.These tracers may lead to non-invasive evaluation of the main, leading therapeutic decision-maker properties of metastatic breast cancer such as receptor status, proliferation activity and therapy resistance, and could also become predictive markers in the early measurement of therapeutic response in the neoadjuvant treatment of locally advanced breast cancer. However, these new agents are currently not available in the daily practice; the preliminary results are promising.

Abstract BS3-2: Molecular Imaging of Breast Cancer: Visualizing In Vivo Breast Cancer Biology

Abstract The ability to measure biochemical and molecular processes underlies progress in breast cancer biology and treatment. These assays have traditionally been performed by analysis of cell culture or tissue samples. More recently, functional and molecular imaging allows in vivo assay of biochemistry and molecular biology that is highly complementary to tissue-based assay. Molecular imaging can serve and number of roles, from characterization of pre-clinical models, to testing the ability of novel drugs to interact with their intended targets, to characterizing entire burden of disease for patients with breast cancer, to helping direct therapeutic choices and assign their efficacy. This talk will review basic principals of molecular imaging, with an emphasis on those methods of greatest translational potential. The session will discuss the use of pre-clinical models of breast disease to help test and validate new molecular imaging methods, and in turn, the use of molecular imaging to characterize the disease process in the animal models. The session will then review the current state of molecular imaging in breast cancer patients, including methods in routine clinical use, those undergoing advanced clinical trials, and those in early-phase testing. The session is designed for a broad audience, ranging from breast cancer translational scientists to practicing physicians caring for breast cancer patients.

The Neuropeptide Y Y1 Receptor: A Diagnostic Marker? Expression in MCF-7 Breast Cancer Cells Is Down-Regulated by Antiestrogens In Vitro and in Xenografts

The neuropeptide Y (NPY) Y1 receptor (Y1R) has been suggested as a tumor marker for in vivo imaging and as a therapeutic target. In view of the assumed link between estrogen receptor (ER) and Y1R in mammary carcinoma and with respect to the development of new diagnostic tools, we investigated the Y1R protein expression in human MCF-7 cell variants differing in ER content and sensitivity against antiestrogens. ER and Y1R expression were quantified by radioligand binding using [3H]-17β-estradiol and the Y1R selective antagonist [3H]-UR-MK114, respectively. The latter was used for cellular binding studies and for autoradiography of MCF-7 xenografts. The fluorescent ligands Cy5-pNPY (universal Y1R, Y2R and Y5R agonist) and UR-MK22 (selective Y1R antagonist), as well as the selective antagonists BIBP3226 (Y1R), BIIE0246 (Y2R) and CGP71683 (Y5R) were used to identify the NPY receptor subtype(s) by confocal microscopy. Y1R functionality was determined by mobilization of intracellular Ca2+. Sensitivity of MCF-7 cells against antiestrogen 4-hydroxytamoxifen correlated directly with the ER content. The exclusive expression of Y1Rs was confirmed by confocal microscopy. The Y1R protein was up-regulated (100%) by 17β-estradiol (EC50 20 pM) and the predominant role of ERα was demonstrated by using the ERα-selective agonist “propylpyrazole triol”. 17β-Estradiol-induced over-expression of functional Y1R protein was reverted by the antiestrogen fulvestrant (IC50 5 nM) in vitro. Furthermore, tamoxifen treatment of nude mice resulted in an almost total loss of Y1Rs in MCF-7 xenografts. In conclusion, the value of the Y1R as a target for therapy and imaging in breast cancer patients may be compromised due to Y1R down-regulation induced by hormonal (antiestrogen) treatment.

Clinical Outcome of Magnetic Resonance Imaging-Detected Additional Lesions in Breast Cancer Patients

PurposeThe aim of this study was to investigate the clinical outcome of additional breast lesions identified with breast magnetic resonance imaging (MRI) in breast cancer patients.MethodsA total of 153 patients who underwent breast MRI between July 2006 and March 2008 were retrospectively reviewed. Thirty-three patients (21.6&) were recommended for second-look ultrasound (US) for further characterization of additional lesions detected on breast MRI and these patients constituted our study population.ResultsAssessment for lesions detected on breast MRI consisted of the following: 25 benign lesions (73.5&), two indeterminate (5.9%), and seven malignant (20.6%) in 33 patients. Second-look US identified 12 additional lesions in 34 lesions (35.3%) and these lesions were confirmed by histological examination. Of the 12 lesions found in the 11 patients, six (50.0%) including one contralateral breast cancer were malignant. The surgical plan was altered in 18.2% (six of 33) of the patients. The use of breast MRI justified a change in treatment for four patients (66.7%) and caused two patients (33.3&) to undergo unwarranted additional surgical procedures.ConclusionBreast MRI identified additional multifocal or contralateral cancer which was not detected initially on conventional imaging in breast cancer patients. Breast MRI has become an indispensable modality in conjunction with conventional modalities for preoperative evaluation of patients with operable breast cancer.

MR and US imaging for breast cancer patients who underwent conservation surgery after neoadjuvant chemotherapy: comparison of triple negative breast cancer and other intrinsic subtypes

Neoadjuvant chemotherapy (NAC) is commonly utilized to treat operable breast cancer. The purpose of this study was to review the findings of ultrasonography (US) and magnetic resonance (MR) imaging in patients treated with breast conservation surgery (BCS) after NAC with a focus on intrinsic subtypes. Eighty-six patients underwent BCS after NAC. The tumors were classified into four subgroups by receptor status. US and MR were performed before and after NAC. The tumor diameters in US and MR after NAC were examined for correlations with pathological tumor distances in the specimens from BCS after NAC. The correlation coefficient (r) of US to pathological tumor size was 0.3 in all tumors, 0.6 in HER2-type tumors, and 0.7 in triple negative breast cancers (TNBC). The correlation coefficient of tumor size in MR to pathological tumor size was 0.9 in TNBC, and other correlations were not statistically significant. The correlation between tumor size in MR and pathological tumor size in triple negative breast cancers corresponded best. This information is one of the clues to selecting patients for BCS after NAC.

Valor añadido de la técnica en decúbito prono para el estudio con tomografía por emisión de positrones-tomografía computarizada en las pacientes con cáncer de mama

Aim This study has aimed to assess if the prone position shows significant differences in regards to the supine position in PET/CT studies in breast cancer patients and to determine which modality offers better evaluation of the images. Method A total of 30 patients were included from October 2009 to February 2010 prior to beginning neoadjuvant chemotherapy. An intravenous 18F-FDG dose ranging from 180 to 240 MBq was administered. Image acquisition was begun 60±10 min after injection. First of all, a thorax scan was performed with the patient in prone position, followed by a whole body study with the patient in supine position. Results Uptake in tumor lesions was observed in all of the patients. Twenty-four patients (80%) had the same number of lesions with both techniques. Five patients (17%) had a different amount of axillary lymph nodes. One patient (3.3%) had a different number of lesions. The prone position lesions had a mean SUVmax 8.89±4.18 compared to 7.67±4.34 in supine position. The areas of the primary breast lesions were higher in the prone position (8.59±7.80 compared with 7.81±7.39). Mean SUVmax of axillary nodes was 5.97±4.02 in prone and 4.41±3.10 in supine. Conclusion The hanging breast technique can achieve higher lesion visualization as well as higher semiquantitative values in comparison with standard procedure. This supports its inclusion in acquisition guidelines of PET/CT imaging in breast cancer patients.

Prognostic value of pretreatment dynamic contrast-enhanced MR imaging in breast cancer patients receiving neoadjuvant chemotherapy: Overall survival predicted from combined time course and volume analysis

The prognostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in breast cancer has been explored, and the results are promising. To investigate the possible correlation between pretreatment DCE-MRI and overall survival 5 years after diagnosis in breast cancer patients receiving neoadjuvant chemotherapy (NAC) using combined time course analysis and volume measurement from DCE-MRI data acquired with 1 min temporal resolution. Pretreatment DCE-MR images of 32 female patients were examined. The total enhancing volume was calculated by including the voxels with >60% signal enhancing 1 min postcontrast. The signal intensity time course data were automatically classified on a voxel-by-voxel basis according to the enhancing characteristics: persistent (type I), plateau (type II) or washout (type III), and the resulting volumes of each enhancement type were calculated. A significant correlation between total enhancing volume and 5-year survival was found, P=0.05 (log-rank). The survival was 51 +/-15 months (mean +/-95% confidence intervals (CI)) and 73+/-12 months in patients with a total enhancing volume >41 cm(3) and < or =41 cm(3), respectively. A two-dimensional discriminator, taking both total enhancing volume and type III enhancing volume into account, improved the prediction of survival, resulting in a P value (log-rank) between survivors and non-survivors of <0.001. The survival was 44+/-16 months (mean +/-95% CI) and 74+/-11 months in patients with a total enhancing volume >58 cm(3) and/or a type III volume >8 cm(3), and < or =58 cm(3) and < or =8 cm(3), respectively. Pretreatment DCE-MRI might help in predicting prognosis in breast cancer patients receiving NAC.

Acute Radiation Effects on Cardiac Function Detected by Strain Rate Imaging in Breast Cancer Patients

To investigate the occurrence of early radiation-induced changes in regional cardiac function using strain rate imaging (SRI) by tissue Doppler echocardiography. We included 20 left-sided and 10 right-sided breast cancer patients receiving radiotherapy (RT) to the breast or chest wall. Standard echocardiography and SRI were performed before RT (baseline), immediately after RT (post-RT), and at 2 months follow-up (FUP) after RT. Regional strain (S) and strain rate (SR) values were obtained from all 18 left ventricular (LV) segments. Data were compared to the regional radiation dose. A reduction in S was observed post-RT and at FUP in left-sided patients (S(post-RT): -17.6 ± 1.5%, and S(FUP): -17.4 ± 2.3%, vs. S(baseline): -19.5 ± 2.1%, p < 0.001) but not in right-sided patients. Within the left-sided patient group, S and SR were significantly reduced after RT in apical LV segments (S(post-RT): -15.3 ± 2.5%, and S(FUP): -14.3 ± 3.7%, vs. S(baseline): -19.3 ± 3.0%, p < 0.01; and SR(post-RT): -1.06 ± 0.15 s(-1), and SR(FUP): -1.16 ± 0.28 s(-1), vs. SR(baseline): -1.29 ± 0.27 s(-1), p = 0.01), but not in mid- or basal segments. Furthermore, we observed that segments exposed to more than 3 Gy showed a significant decrease in S after RT (S(post-RT): -16.1 ± 1.6%, and S(FUP): -15.8 ± 3.4%, vs. S(baseline): -18.9 ± 2.6%, p < 0.001). This could not be observed in segments receiving less than 3 Gy. SRI shows a dose-related regional decrease in myocardial function after RT. It might be a useful tool in the evaluation of modern RT techniques, with respect to cardiac toxicity.

Added value of prone position technique for PET-TAC in breast cancer patients

Aim This study has aimed to assess if the prone position shows significant differences in regards to the supine position in PET/CT studies in breast cancer patients and to determine which modality offers better evaluation of the images. Method A total of 30 patients were included from October 2009 to February 2010 prior to beginning neoadjuvant chemotherapy. An intravenous 18F-FDG dose ranging from 180 to 240 MBq was administered. Image acquisition was begun 60±10 min after injection. First of all, a thorax scan was performed with the patient in prone position, followed by a whole body study with the patient in supine position. Results Uptake in tumor lesions was observed in all of the patients. Twenty-four patients (80%) had the same number of lesions with both techniques. Five patients (17%) had a different amount of axillary lymph nodes. One patient (3.3%) had a different number of lesions. The prone position lesions had a mean SUVmax 8.89±4.18 compared to 7.67±4.34 in supine position. The areas of the primary breast lesions were higher in the prone position (8.59±7.80 compared with 7.81±7.39). Mean SUVmax of axillary nodes was 5.97±4.02 in prone and 4.41±3.10 in supine. Conclusion The hanging breast technique can achieve higher lesion visualization as well as higher semiquantitative values in comparison with standard procedure. This supports its inclusion in acquisition guidelines of PET/CT imaging in breast cancer patients.

Optimal gantry angles and field sizes in kilovoltage cone-beam tomosynthesis for set-up of women with breast cancer undergoing radiotherapy treatment

Optimal beam geometry for kilovoltage cone-beam tomosynthesis (CB-TS) imaging for the set-up of 20 patients with breast cancer was analyzed and presented for prone and supine scenarios. Gantry angles and field sizes that allow maximum clearance and minimum dose to normal organs from kilovoltage imaging were determined for medial and lateral arcs. Optimal CB-TS arc span may vary depending on patient geometry, particularly on the separation between the cavity and the chest wall. CB-TS arc angles ⩾40° were found to be optimal for the cavity to chest wall separation d > 3 cm for supine set-up and d > 7 cm for prone set-up. Maximum required jaw openings were 20 × 14 cm 2. Recommendations are provided for clinical implementation of CB-TS imaging for breast cancer patients.

Breast-conserving surgery using supine magnetic resonance imaging in breast cancer patients receiving neoadjuvant chemotherapy

Background: Success of breast-conserving surgery (BCS) following neoadjuvant chemotherapy (NAC) depends on accurate assessment of the initial lesion. We developed a new procedure (NIPR) in which initial naked magnetic resonance images are projected onto the skin before BCS. Methods: Thirty-five breast cancer patients underwent supine oblique MRI of the operative area. In 20 DCIS patients, the metallic clips were reproduced by projection on the skin using NIPR, and discrepancies between the projection site and clip were measured on X-rays. Fifteen patients (T1;3,T2;8,T3;4 cases) treated with NIPR were compared to 20 (T1;5 , T2;15 cases) treated using the conventional method with regard to excision area and additional excision rate of BCS after NAC. Results: The median discrepancy (linear distance) was 2.6 mm. NIPR significantly reduced the excision area and additional excision rate in T1 and T2 compared to the conventional method ( P < 0.05 ). Conclusions: NIPR is a reliable technique for BCS following NAC with significant reductions in excision area and additional excision rate and superior cosmetic results.

Intraoperative identification of sentinel lymph node guided by near-infrared fluorescence imaging for breast cancer patients

615 Background: Recently, radioactive tracer, a vital dye, or a combination of both has been applied intraoperatively to detect sentinel lymph nodes (SLN) for patients with early breast cancers. We present a novel method of SLN identification using near-infrared fluorescence imaging that provides with high detection and low false-negative rates. Materials and Methods: This study enrolled 52 patients with a tumor less than 3 cm in diameter. Their mean age was 54.7 years. Preoperative TNM stage was I in 35 cases, IIa in 12, and IIb in 5, respectively. Initially the combination dye of indocyanine green and indigocarmine was injected subdermally in the areola. Fluorescence imaging (photodynamic eye: Hamamatsu Photonics Co.) was obtained using a charge coupled device camera with a cut filter as the detector, and light emitting diodes at 760 nm as the light source. Subcutaneous lymphatic channels draining from the areola to the axilla or other directions were visible by fluorescence imagings immediately. After incising the axillary skin 1 cm cranial side from the disappeared point of fluorescence image, SLN was then dissected under the guidance of fluorescence. Results: In all but one patient, lymphatic channels and SLN were successfully visualized (identification rate: 98.1%). SLN was observed before skin incision in two patients. The number of fluorescence SLN ranged from 0 to 11 (mean: 4.7) and blue dyed SLN ranged from o to 6 (mean: 2.0). SLN was not identified in one patient in the former and 7 patients in the latter. Twelve patients had lymph node metastases pathologically. All of them were recognized by fluorescence imaging, however, three patients with metastatic LN were not identified by a vital dye. Conclusions: This method is feasible and safe to detect SLN intraoperatively with less invasive, real-time observation and no requirement of training. We are convinced that this method will provide with high detection and low false-negative rates in SLN navigation surgery. No significant financial relationships to disclose.

SU-FF-J-105: Predicting Late Skin Effects Using Digital Infrared Imaging for Breast Cancer Patients Treated with Radiation

Purpose: Establish a methodology based on digital infrared imaging (DII) to predict skin reaction after breast irradiation using the Skin Radiosensitivity Index (SRI) derived from early skin temperature changes. Method and Materials: Five breast cancer patients treated with accelerated partial breast irradiation to a total dose of 3850cGy over 10 fractions were imaged using a digital infrared camera, including DII images obtained before and after radiation treatment, and a baseline image.Images obtained at scheduled follow‐ups were also included in the analysis of the late skin effect. DII derived temperatures were averaged over regions of interest (ROIs) in the irradiated and normal breast, the latter used as control. The SRI was calculated based on the early pattern of change in skin temperature relative to the normal breast. SRI = Δ T/N avg, Base = ( T avg, FX 1 − N avg, Base )/ N avg, Base where Tavg, FX1 is the average temperature in the ROI of the irradiated breast after the 1st fraction (i.e. after 385 cGy), and Navg, Base is the average temperature in the normal breast ROI at baseline. Results: In all patients, higher temperature was observed in the irradiated breast than in the normal breast. However, only patients with higher temperature differences at follow up between the normal and irradiated breast reported skin problems early after treatment. For these patients, ΔTs were greater than 3°C and corresponded to SRI values greater than 0.1, values that might be considered as threshold for mild skin reaction. None of the five patients imaged had severe skin reaction. A threshold SRI value to determine severe skin reaction was therefore not established. Conclusion: Although the small number of patients in this study make the results anecdotal, the evidence supports the potential use of DII derived SRI in predicting late skin effects in patients treated with radiation.

Targeted Ultrasound for MR-Detected Lesions in Breast Cancer Patients

ObjectiveTo investigate the usefulness of targeted ultrasound (US) in the identification of additional suspicious lesions found by magnetic resonance (MR) imaging in breast cancer patients and the changes in treatment based on the identification of the lesions by the use of targeted US.Materials and MethodsOne-hundred forty nine patients who underwent breast MR imaging for a preoperative evaluation of breast cancer between January 2002 and July 2004 were included in the study. We searched all cases for any additional lesions that were found initially by MR imaging and investigated the performance of targeted US in identifying the lesions. We also investigated their pathological outcomes and changes in treatment as a result of lesion identification.ResultsOf the 149 patients with breast cancer, additional suspicious lesions were detected with MR imaging in 62 patients (42%). Of the 69 additional lesions found in those 62 patients, 26 (38%) were confirmed as cancers by histology. Thirty-eight lesions in 31 patients were examined with targeted US and were histologically revealed as cancers in 18 (47%), high risk lesions in two (5%), benign lesions in 15 (39%), and unidentified lesions in three (8%). The cancer rate was statistically higher in lesions with a US correlate than in lesions without a US correlate (p = 0.028). Of 31 patients, the surgical plan was altered in 27 (87%). The use of targeted US justified a change in treatment for 22 patients (81%) and misled five patients (19%) into having an unnecessary surgical excision.ConclusionTargeted US can play a useful role in the evaluation of additional suspicious lesions detected by MR imaging in breast cancer patients, but is limited in lesions without a US correlate.

Preoperative evaluation of residual tumor extent by three-dimensional magnetic resonance imaging in breast cancer patients treated with neoadjuvant chemotherapy

The purpose of this study is to evaluate the usefulness of three-dimensional magnetic resonance imaging (3D MRI) for the preoperative assessment of residual tumor extent in breast cancer patients treated with neoadjuvant chemotherapy (NAC). Thirty-eight breast cancer patients treated with NAC containing taxane and/or anthracycline for 3 to 6 months were enrolled in this study. Tumor size was measured by means of calipers, ultrasonography, and dynamic MRI before and after NAC. Three-dimensional maximum intensity projection MRIs to measure the tumor size were created for every case. The tumor size determined by calipers, ultrasonography, and 3D MRI after NAC was compared with that determined by pathologic examination. The tumor size determined by 3D MRI showed a strong correlation with that determined by pathologic examination (r=.896). Moderate but significant correlations were found between measurements obtained with calipers and pathology (r=.554), and between ultrasonography and pathology (r=.484). The response rates to NAC were estimated at 84.2% with calipers, 58.0% with ultrasonography, and 44.7% with 3D MRI. Calipers and ultrasonography thus tended to overestimate the response to NAC compared to 3D MRI (P<.001 and .240, respectively). Three-dimensional MRI can visualize residual tumor extent after NAC more accurately than calipers and ultrasonography, and seems to be more reliable than other modalities for estimating response to NAC. It should also help surgeons with decision making for breast-conserving surgery after NAC.

Preoperative Evaluation of Residual Tumor Extent by Three-Dimensional Magnetic Resonance Imaging in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy

The purpose of this study was to evaluate the usefulness of three-dimensional magnetic resonance imaging (3D MRI) for the preoperative assessment of residual tumor extent in breast cancer patients treated with neoadjuvant chemotherapy (NAC). Thirty-eight breast cancer patients treated with NAC containing taxane and/or anthracycline for 3-6 months were enrolled in this study. Tumor size was measured by means of calipers, ultrasonography, and dynamic MRI before and after NAC. Three-dimensional maximum intensity projection MRIs to measure the tumor size were created for every case. The tumor size determined by calipers, ultrasonography, and 3D MRI after NAC was compared with that determined by pathologic examination. The tumor size determined by 3D MRI showed a strong correlation with that determined by pathologic examination (r = 0.896). Moderate, but significant correlations were found between measurements obtained with calipers and pathology (r = 0.554), and between ultrasonography and pathology (r = 0.484). The response rates to NAC were estimated at 84.2% with calipers, 58.0% with ultrasonography, and 44.7% with 3D MRI. Calipers and ultrasonography thus tended to overestimate the response to NAC compared to 3D MRI (p < 0.001 and 0.240, respectively). Three-dimensional MRI can visualize residual tumor extent after NAC more accurately than calipers and ultrasonography, and seems to be more reliable than other modalities for estimating response to NAC. It should also help surgeons with decision making for breast-conserving surgery after NAC.

Effect Of Granulocyte Colony-Stimulating Factor (G-Csf)-Supported Chemotherapy on Mr Imaging of Normal Red Bone Marrow in Breast Cancer Patients With Focal Bone Metastases

To investigate the effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on normal red bone marrow MR imaging in breast cancer patients with focal bone metastases. Fifteen breast cancer patients who were examined before and after chemotherapy with T1-weighted-SE and long echo-time inversion-recovery turbo-spin-echo (long TE IR-TSE) sequences in the thoracolumbar spine and pelvis were retrospectively studied. Nine of them received G-CSF therapy after the administration of each chemotherapy course. Of these 9 patients, the MR follow-ups were performed during G-CSF in 4 patients and after G-CSF therapy in 5 patients. Six patients did not receive G-CSF. Signal intensity (SI) changes in normal bone marrow were evaluated visually in all patients and quantitatively in 13 patients. In all 4 patients investigated during G-CSF therapy a diffuse, homogeneous SI increase on long TE IR-TSE was observed visually and quantitatively in initially normal bone marrow. This change obscured some focal lesions in 2 patients. No such SI change was visible after G-CSF therapy (p = 0.008) or in patients not receiving G-CSF. On T1-weighted images an SI decrease was found both during and after G-CSF therapy, but an increase occurred in patients not receiving G-CSF. G-CSF-supported chemotherapy can induce diffuse SI changes in normal red bone marrow on MR imaging. On long TE IR-TSE, the changes are visible during G-CSF treatment and can lead to misinterpretations in the response evaluation of bone metastases to therapy.

Myocardial perfusion imaging in breast cancer patients treated with or without post-mastectomy radiotherapy

Purpose: To assess the occurrence and location of myocardial perfusion defects in left-sided mastectomized breast cancer patients, treated with or without postoperative radiotherapy according to the guidelines from the Danish Breast Cancer Cooperative Group (DBCG).Patients and methods: Seventeen left-sided breast cancer patients, with a median age of 59 years (range, 47–75 years), randomized to post-mastectomy irradiation plus systemic treatment, or systemic treatment alone, were examined after a median follow-up of 7.9 years (range, 6.0–12.2 years). The chest wall and the ipsilateral internal mammary nodes had been treated through two anterior-shaped electron fields, and the electron energy was chosen according to chest wall thickness, measured individually by ultrasound. The median absorbed dose was 50 Gy in 25 fractions, with 5 fractions/week. Information on clinical history was obtained and symptoms of ischemic heart disease (IHD), as well as major risk factors, were recorded. All patients had a physical examination, blood chemistry, electrocardiogram (ECG), chest X-ray and myocardial perfusion imaging by sestamibi-single photon emission computerized tomography (SPECT). SPECT-scanning was performed as a rest/dipyridamole 2-day protocol. The evaluation of regional myocardial perfusion was based on scintigrams using a 20-segment model.Results: There was no significant difference between the scintigraphic findings in the two groups. Four of ten irradiated patients and four of seven non-irradiated patients showed scintigraphic defects. An anterior defect was found in one non-irradiated patient.Conclusions: This study does not indicate that the described radiotherapy technique induces detectable coronary artery disease. However, the small number of patients does not allow strong conclusions to be drawn.

Variability of the location of internal mammary vessels and glandular breast tissue in breast cancer patients undergoing routine CT-based treatment planning

Purpose: To determine the variability of position of internal mammary vessels (IMV) and glandular breast tissue (GBT) in patients undergoing breast-conserving radiation therapy. To assess the frequency and magnitude of tangential field border shifts based on preradiation therapy (RT) computed tomography (CT) imaging in breast cancer patients. Methods and Materials: Five hundred and ninety breast cancer patients irradiated between 9/94 and 3/98 underwent routine CT-based treatment planning. Two analyses were performed. First, the position of IMV and GBT, outlined on the central axis CT image, was determined relative to the midsternum in 111 patients irradiated during a 12-month period. In the second analysis, the difference between anticipated (pre-CT) and actual (CT-based) tangential field borders was assessed in 254 patients irradiated during a 2-year period. Results: In the first analysis, the depth of the IMVs varied from 1 to 6 cm (median 2.4 cm). The lateral distance from the midsternum also varied widely (range 1.7 to 3.7 cm, median 2.5 cm). Similar variability was found in the position of the GBT. In the second analysis, CT information led to changes of anticipated field borders in 65% of patients. The lateral border was shifted in 56% of patients (anteriorly 18%, posteriorly 38%). When the patients were segregated based on internal mammary node (IMN) treatment, the medial border was shifted in 49% of patients when the IMNs were treated in the tangential fields and in 24% when the GBT only was treated. The frequency of lateral field border shifts was similar in both groups. Conclusions: The position of IMVs and GBT varies widely in breast cancer patients. Tangential field borders based on surface anatomy may not be ideal. Among 254 breast cancer patients, the field borders were shifted in 65% of patients when CT information was available. Thus, in most breast cancer patients, field borders are shifted when CT-based treatment planning is used.