Breast Lymphoscintigraphy Research Articles

A Practical Technique to Improve Visualization of Sentinel Nodes in Axillary Region on Breast Lymphoscintigraphy: Medial Breast Traction by Patient.

A standard method of performing breast lymphoscintigraphy is anterior and lateral views after periareolar intradermal injection of a radiotracer. However, a sentinel lymph node may be obscured by the activity at injection site, especially on anterior view. Also, breast tissue may cause attenuation to prevent sentinel node visualization. Repeat images during medial traction of breast by patient is an effective technique to improve visualization of sentinel lymph nodes in axillary region.

The Use of Periareolar Topical Lidocaine Jelly After Needle Localization May Reduce Pain of Subsequent Lymphoscintigraphy.

PurposeTechnetium Tc-99m sulfur colloid (99mTc-SC) breast lymphoscintigraphy is commonly performed to identify the sentinel lymph node (SLN) in patients diagnosed with breast carcinoma undergoing lumpectomy. The purpose of this report is to describe how the use of 2% topical lidocaine jelly immediately after the completion of needle localization and prior to scintigraphy may substantially reduce pain associated with the injection of 99mTc-SC.Materials and methodsThis was a quality improvement project. Patients were asked to score the severity of pain associated with the periareolar 99mTc-SC injections for sentinel node lymphoscintigraphy. In order to decrease the discomfort, topical lidocaine was applied to the periareolar skin after the completion of the needle localization, but prior to transferring the patient from the mammography room to the nuclear medicine department for the 99mTc-SC injections. At the time of 99mTc-SC injection, patients were asked to score the pain of injection from 0 (none) to 10 (worst).ResultsThe average pain score of the women who did not receive topical lidocaine jelly was 8 (range: 5-9). In the 10 women who received topical lidocaine jelly after needle localization, the average pain score was 2.5 (range: 1-5). Interestingly, the pain score for women who discussed the possible use of lidocaine jelly with the radiologists but still did not receive topical lidocaine jelly was also low at 6.5. For patients who received the lidocaine jelly only five minutes prior to injection, the average pain score was 6.ConclusionThe application of lidocaine jelly after the conclusion of needle localization, with a 15-40-minute delay prior to periareolar injections with 99mTc-SC for sentinel node lymphoscintigraphy, appears to substantially reduce the pain associated with the injection of 99mTc-SC.

Unexpected breast lymphoscintigraphy findings after surgical removal of accessory mammary gland.

Unexpected breast lymphoscintigraphy findings after surgical removal of accessory mammary gland.

Buffering the Suffering of Breast Lymphoscintigraphy.

Breast lymphoscintigraphy with 99mTc-sulfur colloid is frequently performed before breast-conserving surgery to delineate drainage to a sentinel node. Tracer injection for lymphoscintigraphy can be painful. Our aims were to determine whether administering a solution of buffered lidocaine immediately before lymphoscintigraphy injection could both reduce the patients' pain and increase nuclear medicine technologists' satisfaction with performing the procedure. Methods: A pain scale survey was obtained from patients undergoing breast lymphoscintigraphy with or without buffered lidocaine. Our nuclear medicine technologists were also surveyed for their satisfaction with the procedure, both with and without the addition of buffered lidocaine. Results: The patients' reported pain decreased by 86% with the addition of buffered lidocaine. Technologist satisfaction with performing the procedure increased by 36%. Conclusion: Lidocaine buffered with sodium bicarbonate injected before lymphoscintigraphy significantly reduces pain experienced by the patient and improves nuclear medicine technologist satisfaction in performing the procedure.

Triple-site radiotracer application in breast lymphoscintigraphy and sentinel node discordance.

Sentinel lymph node (SLN) biopsy (SLNB) has demonstrated accuracy in the axillary staging of breast cancer patients. Despite variability in selection criteria and technique, an SLN is consistently identified in approximately 96% of cases and in most series predicts the status of remaining axillary LNs in >95% of cases. The false-negative rate of sentinel lymph node biopsy (SLNB) was originally reported as 5%–10% (sensitivity 90%–95%), but improved rates are attainable by experienced surgeons. Radiolocalization with lymphoscintigraphy (LSG) increases SLN identification rates. LSG is a useful tool to establish the abnormal lymphatic drainage patterns and to detect the extra-axillary nodes, particularly internal mammary nodes. Despite controversy regarding the optimal injection method, studies have generally suggested high concordance between the various radiotracer application sites and axillary SLN identification. Discordant SLN identification would have implications for nodal staging as the true SLN might not be identified with individual injection techniques. In the current study, imaging from consecutive patients presenting for breast LSG over a-19 month period was retrospectively reviewed. Radiotracer application was performed with simultaneous injection of peritumoral, subcutaneous, and subareolar regions. This application method provided a mechanism to assess the LSG drainage patterns with a view to assessing injection site concordance and SLN identification rates. Data from 123 breast LSG patients were reviewed. Using our radiotracer technique, the axillary SLN identification rate was 98%. A single axillary node was detected in 110, two axillary nodes were detected in 10, and no axillary node was detected in three patients. Among those 10 patients in whom two axillary nodes were seen, at least two cases of discordant drainage occurred from different injection sites. This study demonstrates that different LSG injection sites can result in the identification of different axillary sentinel nodes although this appears to be a rare event. This finding may be of clinical importance if the true SLN is sought. In addition, the multisite injection technique appears to be an optimal method of axillary SLN identification, with high SLN detection rates.

Is Sentinel Node Biopsy of the Internal Mammary Lymph Nodes Relevant in the Management of Breast Cancer?

The aim of this study was to review the outcomes of a series of breast cancer patients who underwent sentinel node biopsy inclusive of lymphoscintigraphy, and to assess the incidence of internal mammary node (IMN) metastatic positivity at exploration and whether these findings influenced treatment. Between April 2001 and December 2012, 581 breast cancer patients at Princess Alexandra Hospital underwent preoperative lymphoscintigraphy in the course of the performance of sentinel node biopsy. Analysis was performed of those patients who demonstrated radio-isotope uptake to the IMN chain, and who had sentinel node biopsy of the IMN's and were found to have metastatic involvement. Assessment was made to determine whether the finding of IMN metastases changed the adjuvant systemic management of these patients, and to review complication rates. 95 of 581 (16.4%) patients with preoperative breast lymphoscintigraphy had lymphatic mapping to the IMN chain. 51 (54%) of these patients had IMN chain surgically explored and IMN nodes were found in 35 of these patients (success rate of 69%). Of these, three patients (3/35 = 8.6%) had metastatic involvement of the IMN sentinel node group. All three IMN positive patients received adjuvant breast radiotherapy, chemotherapy, and hormonal therapy. In four patients (7.8%) IMN surgical exploration was complicated by pneumothorax. Only a small proportion of breast cancer patients were found to have metastasic involvement of the IMN chain and which did not significantly change their adjuvant therapy management. These findings suggest that the benefits of exploration of the IMN chain in breast cancer patients are limited and may be outweighed by the risk of complications.

Transmission Imaging in Lymphoscintigraphy with a 153Gd Flood Source.

Lymphoscintigraphy uses intradermal or interstitial injections of (99m)Tc-labeled tracers to produce images of focal lymph nodes. Because there is little or no anatomic information in the (99m)Tc images, a (57)Co flood source is sometimes used to provide transmission data along with the emission data. The anatomic shadow from the transmission scan generally improves interpretation and surgical planning. However, the (57)Co transmission photons contribute to background on the (99m)Tc images, reducing contrast and signal-to-noise ratio (SNR). SNR is related to lesion detection, and some lymph nodes that would be detected in an emission-only scan might not be detected if acquired with a (57)Co flood source. An alternative to a (57)Co flood source is a (153)Gd flood source, which has primary photon emissions well below the (99m)Tc emission window, allowing the shadow to be acquired in a separate transmission window. Significantly smaller crosstalk from (153)Gd should improve SNR and therefore would be expected to improve lymph node detection. We hypothesized that the use of a (153)Gd flood source would reduce background and improve SNR for these studies. Phantom studies simulating lymphoscintigraphy were performed to compare performance with a (153)Gd flood source, a (57)Co flood source, and no flood source. SNR in the (99m)Tc emission images was measured using a water phantom to simulate patient body and point sources of various activities to simulate nodes and injection site. The encouraging phantom studies prompted use of the (153)Gd flood source in routine clinical breast lymphoscintigraphy, melanoma lymphoscintigraphy, and lymphedema studies. Because emission and transmission data were acquired in separate energy windows, fused planar images of emission and transmission data were available to the physician. SNR was highest with no flood source and was lowest with the (57)Co flood source by a significant margin. SNR with the (153)Gd flood source was similar to that with no flood source on the anterior (transmission) view. SNR was reduced somewhat in the posterior (nontransmission) view because of attenuation of signal by the flood source itself. Minor crosstalk in the (99m)Tc window was observed with the (153)Gd flood source, attributed to simultaneous detection of x-ray photons and gamma-photons. This crosstalk was reduced by introducing thin metal filters to absorb most x-ray photons, at the expense of more attenuation in the posterior view. Unlike with the (57)Co flood source, a usable posterior view (with anatomic shadow derived from the anterior view) was generated with the (153)Gd flood source. Clinical lymphoscintigraphy images with the (153)Gd flood source were of high quality. Interpretation was aided by the ability to control image mixing and brightness and contrast of separate color scales. By producing fused images with reduced crosstalk and improved image quality, a (153)Gd flood source offers advantages over a conventional (57)Co flood source for anatomic shadowing in lymphoscintigraphy. Lymph nodes in emission images have higher SNR, indicating a likely improvement in clinical lesion detection. Separate emission and transmission images provide additional flexibility in image display during interpretation.

Lymphoscintigraphy in Differentiated Thyroid Cancer.

There is considerable variability in the surgical approach to differentiated thyroid cancer regarding the decision to explore and remove central or central and lateral compartment lymph nodes. Much as sentinel lymph node sampling has improved the decision to remove axillary nodes for breast cancer, vital dye and lymphoscintigraphy with lymph node sampling may direct the surgical approach to differentiated thyroid cancer.

The Role of the Plastic Surgeon in Sentinel Lymph Node Biopsy of Internal Mammary Nodes.

The Role of the Plastic Surgeon in Sentinel Lymph Node Biopsy of Internal Mammary Nodes.

Administration of subcutaneous buffered lidocaine prior to breast lymphoscintigraphy reduces pain without decreasing lymph node visualization.

Breast lymphoscintigraphy using (99m)Tc-sulfur colloid ((99m)Tc-SC) is well established in clinical practice for staging patients with breast carcinoma. Nearly all patients report having pain during the procedure. However, techniques used to minimize pain during breast lymphoscintigraphy are highly variable across institutions. Our study was to determine whether anesthetizing the skin with sodium bicarbonatehether-buffered lidocaine before performing breast lymphoscintigraphy reduced the pain experienced by the patients. The second objective of this study was to evaluate whether anesthetizing the skin with buffered lidocaine changed visualization of lymph nodes. This prospective, patient-masked and randomized study involved performing breast lymphoscintigraphy in a control group and experimental group of female breast cancer patients. The control group did not receive skin anesthetic before (99m)Tc-SC injections, whereas the experimental group first underwent skin anesthesia with an injection of 2% sodium bicarbonate-buffered lidocaine. All patients were asked to rate their pain levels, using the National Institutes of Health pain scale, before the procedure and immediately after the injections. The change in pain from baseline was compared between the 2 groups. After the injections, scintigraphic imaging of the axilla was performed, and the number of axillary lymph nodes visualized was recorded. No significant difference was found in preprocedural baseline pain from the control group, compared with the experimental group. There was a statistically significant difference in the increase in pain experienced during the procedure between the control group and the experimental group (P = 0.009). There was no significant difference in the detection of lymph nodes between the control and experimental groups (P = 0.56). The results from our study indicate that injecting subcutaneous buffered lidocaine before intradermal injection of (99m)Tc-SC for breast lymphoscintigraphy significantly decreases patient pain without interfering with lymph node visualization.

Corrigendum to “High discordance rates between sub-areolar and peri-tumoural breast lymphoscintigraphy” [Eur J Surg Oncol 39 (2013) 1053–1060

Corrigendum to “High discordance rates between sub-areolar and peri-tumoural breast lymphoscintigraphy” [Eur J Surg Oncol 39 (2013) 1053–1060

High discordance rates between sub-areolar and peri-tumoural breast lymphoscintigraphy

To test the hypothesis that sub-areolar (SA) lymphoscintigraphy (LSG) identifies the same sentinel node as peri-tumoural (PT) injections. It is commonly believed that all LSG techniques will identify the same sentinel lymph nodes (SLN) draining the breast. Hybrid imaging technology (SPECT/CT) allows accurate identification of the exact location of SLNs. Using SPECT/CT SA and PT LSG techniques were compared. In a multi-centre trial 39 patients sequentially underwent LSG (SA followed by PT) separated by 2-7 days. Patients were referred by 4 surgeons to 3 LSG centres, with standardization of isotope (99mTc-antimony sulfide colloid), LSG and SPECT/CT evaluation techniques. LSG were evaluated for SLN concordance and degree of discordance in the axilla and internal mammary nodes (IMN). 39 eligible patients, median age 62 years, were recruited. Successful axillary SLN mapping for SA and PT injection techniques was 87% and 95% respectively. Successful internal mammary SLN mapping occurred with SA and PT LSG in 5% and 36% respectively. Discordance was identified in the IMN (39%) and axilla (21%), with an overall rate of discordance between SA and PT LSG of 56%. There is a high level of discordance in the localization of SLN by these commonly used LSG injection techniques. This discordance has implications for accuracy of axillary and extra-axillary staging and could impact on patient outcome.

Does the Preparation and Utilization of 99mTc-Sulfur Colloid Affect the Outcomes of Breast Lymphoscintigraphy?

The purpose of this study was to determine whether certain factors in the preparation and use of (99m)Tc-sulfur colloid affected the number of sentinel lymph nodes (SLNs) detected during SLN mapping and during intraoperative SLN identification. The factors that were investigated included the use of a dry heat block versus a hot water bath to heat the (99m)Tc-sulfur colloid bulk vial, amount of (99m)TcOH4(-) added to form the sulfur colloid particles, time between the unit dose calibration and the injection of the dose, and breast quadrant in which the injection occurred. Data were collected retrospectively and quantitatively analyzed from images and reports of 488 patients with breast cancer who had undergone SLN mapping and intraoperative SLN identification from January 1, 2008, to June 30, 2011, inclusive. The dependent variables assessed were the number of SLNs visualized during lymphoscintigraphy, number of radioactive SLNs removed during surgery, and total number of lymph nodes removed intraoperatively. There was no significant difference in outcomes when comparing the amount of (99m)TcOH4(-) added during the preparation process to form the sulfur colloid particles, time between the unit dose calibration time and the time that the unit doses were injected, or location in the breast tissue in which the unit dose was administered. Initially, there were observed significant differences in outcomes when the heating methods used to prepare the (99m)Tc-sulfur colloid were compared. When the increased number of patients who were administered a calibrated unit dose activity of 74 MBq in the group using a dry heat block preparation method was taken into account, however, the findings were not significant. The use of a dry heat block versus a hot water bath to heat the (99m)Tc-sulfur colloid bulk vial, amount of (99m)TcOH4(-) added to form sulfur colloid particles, time between the unit dose calibration and the injection of the dose, and breast quadrant in which the injection occurred do not affect the number of SLNs detected during SLN mapping and during intraoperative SLN identification.

The Value of Imaging in Standing Position in Preoperative Breast Lymphoscintigraphy

Breast lymphoscintigraphy is an accurate technique, but in a minority of cases the sentinel node (SN) visualization cannot be achieved or can be very difficult. We evaluated the potential clinical advantages and limitations of performing imaging in the standing position. The aim was to establish if this examination modality is quicker and helpful in the presence of "hidden" SN, checking also for any influence of SN skin landmarking in the upright position on the correct intraoperative SN identification. The overall objective was to verify if the standing position can be routinely used in breast lymphoscintigraphy. A total of 144 patients underwent lymphoscintigraphy in both standing and supine positions. In both modalities, a skin landmark was set coincident with the SN orthogonal projections. The acquisition times of 2 groups (each consisting of 45 patients) examined with the standing or supine acquisition modality, were compared. In 6 cases with hidden SN and in 34 cases with difficult or partial visualization in one of the supine views, the standing protocol was effective and led to better and quicker visualization of lymph nodes (median examination time: 25.5 minutes standing, 35.5 minutes supine). Significant differences in skin landmark position between the 2 modalities were present only in overweight patients and in large breasts. This, however, did not have a negative impact on successful intraoperative localization of SN with the gamma probe. Standing acquisition resulted to be a faster, easier, and more accurate examination protocol and can be used as the routine method for SN detection in breast lymphoscintigraphy.

Internal mammary node metastasis in breast cancer: Predictive models to determine status & management algorithms

Aim Internal mammary node (IMN) metastases are an important prognostic factor in breast cancer. However due to difficulty of access, most surgeons ignore these nodes, hence adjuvant treatment decisions may be compromised. Through mathematical modeling based on large datasets this study aims to estimate the current rate of IMN and sentinel node metastasis. Methods Models were created to estimate the current rate of axillary and IM sentinel node metastasis. Data from historical extended radical mastectomy series were analyzed to project contemporary rates of IMN metastasis. This information was coupled with derived models and contemporary datasets: a single-institution breast lymphoscintigraphy database (1992–2007) to establish lymphatic anatomy; and the Surveillance, Epidemiology and End-Results (SEER) registries in the US (2000–2003). Results Rates of IMN metastasis and positive sentinel nodes were estimated and models derived to assist with predicting IMN status in patients. If high definition peritumoral lymphatic mapping were available, the predicted rates of positive sentinel nodes in the axilla (AN) and internal mammary chain (IMN) would be equal. We predicted the overall rate of IMN metastasis is ∼39% the rate of positive sentinel AN. Conclusion Simplified models and algorithms can predict IMN status.

Optimal 57Co Flood Source Activity and Acquisition Time for Lymphoscintigraphy Localization Images

We evaluated different (57)Co flood source activities and acquisition times to obtain an optimal localization image for breast lymphoscintigraphy that would adequately outline the body and allow detection of nodes seen on the emission scan while minimizing unnecessary radiation exposure to the patient. An anthropomorphic thorax breast phantom representing an average-size patient was used to simulate nodes on a breast lymphoscintigraphy scan. The activities in the nodes at the time of acquisition ranged from 37 to 185 kBq (1-5 microCi). Four experiments were performed, consisting of 10-min emission and 3-min localization images. Anterior, posterior, and right and left lateral views of the thorax phantom were acquired, using each of 5 different (57)Co flood sources with activities ranging from 37 to 269 MBq (1.0-7.26 mCi). Ten 1-min localization images for each source were acquired and compared for quality. Three-minute localization images for 2 phantom thicknesses of 10 and 20 cm were acquired to determine the contrast-to-noise ratio for each (57)Co source. The total exposure was measured using an ion chamber survey meter. All sources allowed visualization of the lymphatic nodes in acquisitions as short as 3 min. Images using the 126-MBq (3.41-mCi) source demonstrated an adequate body outline along with visualization of all nodes seen on the emission image. The 37-MBq (1.0-mCi) source did not provide sufficient definition of the body outline, whereas the hotter sources decreased node visualization by increasing the background around the nodes at the same time that they increased the patient exposure. Node activity of 37 kBq (1 microCi) became undetectable on the anterior localization images yet was still visible on the lateral image because of greater attenuation of (57)Co photons. The estimated dose rate from the (57)Co sheet sources was 0.641 microSv/MBq/h. Acquiring a 3-min localization scan using a 126-MBq (3.41-mCi) source provided the best combination of clear-body outline and visualization of all nodes seen on the emission image. The estimated dose to the patient from the 126-MBq (3.41-mCi) sheet source was very low (8.7 microSv for unilateral and 13.1 microSv for bilateral). Node detectability decreased in localization images acquired using (57)Co sources of higher activity. This effect would be more pronounced in lymphoscintigrams of thin patients compared with those of patients of average thickness.

Contralateral or bilateral lymph drainage revealed by breast lymphoscintigraphy

Sentinel lymph node biopsy (SLNB) is a minimallyinvasive staging procedure for patients with breast cancer.Multiple studies have validated the accuracy of thisprocedure which has become the preferred and standard ofpractice for most surgeons treating breast cancer [1–3].Interestingly, a continuous evolution has been characteriz-ing SLN mapping. In 2002, it was accepted as officialcomponent in the staging process for invasive breastcarcinoma, and the American Joint Committee on CancerStaging Manual has modified the TNM classification forbreast cancer accordingly [4]. However, the AmericanSociety of Breast Surgeons had been recommending againstSLN mapping for patients with significant prior axillary orbreast surgery until December 2005 when the “ConsensusStatement on Guidelines for Performing Sentinel LymphNode Dissection in Breast Cancer” has been revised toinclude patients previously treated with surgery [5]. As faras patients with early breast cancer with no clinicalevidence of lymph node (LN) involvement (cT1-T2 cN0),exclusion criteria to perform breast lymphoscintigraphy(LS) have been thinning considerably in the recent past, andthe only current contraindication to perform breast LS is thepresence of lymphatic congestion (i.e. mastitis) [6–8]. Overthe past 10 years, more than 12,000 breast LS have beencarried out at our Institute, and only 11 cases have beencharacterised by contralateral or bilateral lymph drainage.Accordingly, this phenomenon has been described mostlyas case report [9–13] in literature. More recently, authorshave assessed the feasibility and usefulness of LS byreviewing cohorts of patients with recurrent breast cancerpreviously treated with surgery [14–20]. We here addressthe question with regards to what behaviour should be keptin case of display of contralateral or bilateral LNs on a LS.Should all LNs be excised and brought to pathology forexamination? To what extent should this finding affect thestaging and the treatment of the index breast neoplasia?On our experience we have found 11 cases of uncommonlymph drainage revealed by LS imaging as part of preoper-ative workup in patients with suspected or confirmed breastcancer. Sevenof the 11 patients had already beentreated withsurgery for aesthetic or curative purposes and radiotherapy(three patients) or radio-chemotherapy (two patients).Breast LS was performed according to the standardtechnique in use at IEO [21, 22], with subdermaladministration of 12-15 MBq of

SU‐FF‐I‐105: Dosimetric Comparison of Planar and 3‐Dimensional Methods of Anatomic Localization for Breast Lymphoscintigraphy

Purpose: To estimate the absorbed dose for a range of settings of CT topograms and scans to determine the best technique for node localization in breast lymphoscintigraphy while minimizing the dose to the patient. Method and Materials: This study was performed with an anthropomorphic thorax phantom on a Symbia‐T6® SPECT/CT to produce mechanically registered datasets [Siemens Medical Solutions USA, Hoffman Estates IL]. The data included a SPECT, anterior and lateral topograms, a CT, and static anterior and lateral emission scintigrams. CT topograms and scans were acquired at 80, 110, and 130 kVp with varied mAs settings to compare the quality of the images and dose estimates for lower dose settings. Scintigram and SPECT scans were fused to each topogram and CT, respectively, to allow for qualitative comparison of localization. Exposure measurements for topograms were acquired using an ion chamber at isocenter, and entrance skin doses were estimated for the CT topograms. A CTDI body phantom was used to acquire data for estimation of effective dose for the CT scans. Results: The skin dose for a CT topogram ranges from 0.089 mGy to 0.235 mGy, and the effective dose for the CT scan ranges from 0.308 mSv (lowest dose settings) to 5.265 mSv (clinical scan setting). Qualitative comparison showed the 80 kVp, 20 mA topogram and 110 kVp, 10 mAs CT to be sufficient for localization. The skin dose is 0.089 uSv and the effective dose is 0.392 uSv for these techniques, respectively. Conclusion: The absorbed dose to the patient can be substantially reduced for CT topograms and CTs that are to be used for localization. These do not have to be of diagnostic quality in order to provide enough anatomical information to localize the sentinel nodes in breast lymphoscintigraphy. Conflict of Interest: Research sponsored by Siemens Medical Solutions USA.

SU‐FF‐I‐107: Improving the Accuracy of CT Topograms for Node Localization in Breast Lymphoscintigraphy

Purpose: To characterize and compensate for fan‐beam distortion of a CT topogram, thereby improving a technique for localization using planar lymphoscintigram/topogram fusion by minimizing misregistration between modalities. Method and Materials: We are currently investigating the feasibility of fusing planar scintigrams and CT topograms as a means of localization for breast lymphoscintigraphy and determined a maximum expected lateral offset between modalities of ±2.8 cm for an average size patient. The spatial distortion due to the fan‐beam of the topogram is linearly related to offset from isocenter, suggesting the possibility of rescaling the topograms used for localization. In this work, we have adjusted the anterior topogram by determining the location of the node in the lateral scintigram and using the distance above or below isocenter to apply the appropriate magnification to the topogram so that it is correctly scaled for the plane of the node (vice versa for the lateral topogram). An IDL program [ITT Visual Information Solutions, Boulder CO] was written to facilitate the modification of the topograms; the program was tested with a data set of an anthropomorphic thorax phantom acquired using a hybrid SPECT/CT camera [Symbia®, Siemens Medical Solutions USA, Hoffman Estates IL]. Registration was visually assessed by fusing the scintigram with the original topogram, with the modified topogram, and with the fullthickness coronal‐projection CT to verify the localization. Results: The IDL program has been executed and is successfully modifying topograms to minimize distortion. The visual comparison of the scintigram/modified topogram and scintigram/full‐thickness coronal‐projection CT demonstrates less than ±0.34 cm offset. Conclusion: Appropriately magnified CT topograms have been generated and fused with planar scintigrams that have potential for producing images with improved anatomic localization for breast lymphoscintigraphy compared to the standard‐of‐care Co‐57 sheet source backlighting method. Conflict of Interest: Research sponsored by Siemens Medical Solutions USA.

Injection Techniques For Breast Lymphoscintigraphy: A Review

This review is a retrospective Meta analysis of 3133 patients evaluating injection techniques for breast lymphoscintigraphy in patients with early stage breast cancer. The optimal protocol for breast lymphoscintigraphy in early breast cancer patients was shown to employ areolar injection methods of radiocolloid over both blue dye and combined radiocolloid/blue dye techniques.