Borys R. Krynyckyi

Technical aspects of performing lymphoscintigraphy: optimization of methods used to obtain images.

Sentinel node detection is an important part of the clinical management of newly diagnosed melanoma. Now there is a similar or even greater enthusiasm for sentinel node evaluation in patients with breast carcinoma. However, controversies exist regarding the dose, volume, and route of administration. Even the role of lymphoscintigraphy itself, in contrast to using only a hand-held gamma probe during surgery for sentinel node detection, is being debated. Nevertheless, many centers and surgeons find that lymphoscintigraphy images are valuable in the treatment of patients and they use lymphoscintigraphy as a guide during surgery and to confirm the results obtained with the hand-held probe. Centers just beginning to use lymphoscintigraphy may find the images especially useful. Given this fact, the authors wanted to define the practical and technical aspects of performing lymphoscintigraphy in patients with breast cancer and examined various methods for the optimization of the technique of image acquisition. The suggested technique is generally free of the controversies noted above and applies to most patients. It includes various maneuvers that aim to improve the rate of sentinel node visualization using the gamma camera and the accuracy of node detection. The recommendations presented here should prove useful for both those experienced and for those centers just beginning to use the technique of lymphoscintigraphy.

Areolar-cutaneous "junction" injections to augment sentinel node count activity.

Purpose The authors report on a modified lymphoscintigraphy protocol for increasing activity in the sentinel node (SN) through a specific technique (LymphoBoost). It consists of an areolar–cutaneous “junction” injection, using a very shallow, high-volume, high-specific-activity injection of 100% filtered Tc-99m sulfur colloid, as an adjunct to their standard protocol. Materials and Methods Results from a previously optimized protocol (group 1, n = 28) were compared with those from their new protocol (group 2, n = 85), which consisted of two sets of consecutively applied (within 12 to 20 minutes) injections: group 2A composed of perilesional and intradermal injections (similar to the previous group 1) followed by group 2B LymphoBoost injections within 12 to 20 minutes in the same patients. Regions of interest were drawn around the SN and the injection sites (IS) at the end of the studies to calculate the end-of-study SN:IS ratio for both group 1 and group 2 studies. The SN:IS ratio is generally independent of dose and is a measurement of the “efficiency” of getting activity from the IS to the SN. Results The mean SN:IS ratio in group 2 was 3.34 times greater than that in group 1 studies (P < 0.0005). The median SN:IS ratio was 3.53 times greater in the group 2 studies. Many cases showed a dramatic increase in SN counts before the LymphoBoost injection was even completed, with more than 5% of injected activity reaching nodes at the end of the study in some patients. Multiple different lymphatic pathways were noted, but all led to the same node(s). No significant disagreement between group 2A and group 2B results was noted. Conclusions Areolar–cutaneous junction injections, performed under these conditions, augment SN activity dramatically in most patients. Hotter nodes provide several benefits, especially when next-day surgery is contemplated, and should also reduce the extent of dissection needed to remove the sentinel node.

The Efficacy of Sestamibi Parathyroid Scintigraphy for Directing Surgical Approaches Based on Modified Interpretation Criteria

Purpose With the increasing use of targeted parathyroidectomy, the accuracy of sestamibi parathyroid scintigraphy (SPS) in determining the best surgical approach has become more clinically relevant than its sensitivity for detecting all abnormal glands. The reported accuracy of SPS does not represent the true efficacy of SPS for directing targeted parathyroidectomy, because many authors reported accuracy on the basis of abnormal glands. The authors assessed the efficacy of SPS based on modified interpretation criteria to determine specifically whether SPS influences the surgeon’s choice of a targeted versus a conventional approach to parathyroidectomy. Methods The authors reviewed the SPS studies (both dual-isotope subtraction and Tc-99m sestamibi dual-phase techniques) performed in 80 patients with primary hyperparathyroidism. All patients had surgery with histologic diagnoses, intraoperative PTH assays, and clinical follow-up. Results Of 75 patients with solitary adenomas, 9 SPS studies were negative, equivocal, or showed two or more foci, and 66 studies showed a solitary focus on the correct side. Of these 66 studies, 63 showed a lesion in the correct quadrant (e.g., superior or inferior) and 3 predicted the correct side only but a wrong quadrant. The positive-predictive value of SPS was 100% for correctly identifying the side of the adenoma (thus correctly directing unilateral surgery) and 95.5% for correctly identifying the quadrant of the solitary adenoma. Conclusion The positive-predictive value of SPS for directing the surgical approach (but not for detecting individual lesions) that reveals a single focus is very high based on our modified interpretation criteria.

Drainage Across Midline to Sentinel Nodes in the Contralateral Axilla in Breast Cancer

The authors report a case of recurrent breast carcinoma in the right chest in a patient who earlier had a right breast mastectomy. Injection of Tc-99m sulfur colloid into the lesion site in the right midchest revealed drainage to a very faint node in the contralateral axilla on the left, an unexpected site, and none to the ipsilateral axilla, the expected site. Disease was found in the left axilla in the sentinel nodes. Lymphoscintigraphy added valuable information in the management of this patient.

Effect of high specific-activity sulfur colloid preparations on sentinel node count rates

&NA; Purpose: Preliminary results by other investigators suggest that increasing the specific activity of Tc‐99m nanocolloid preparations increases the measured counts in sentinel nodes compared with lower specific‐activity (SA) preparations using the same initial injected dose. The authors set out to determine whether a similar result could be perceived with Tc‐99m sulfur colloid (SC) preparations. Methods: Twenty‐three consecutive patients (low SA group) with successful visualization of sentinel nodes by lymphoscintigraphy before our standard protocol was changed to a higher SA preparation were compared with 28 patients (high SA group) just after the switch. Injection techniques were similar in both groups: peritumoral injections at two to four points of a mixture of half‐filtered (0.22 &mgr;m filter) and unfiltered Tc‐99m sulfur colloid in 6 ml followed immediately by intradermal injections of filtered sulfur colloid above the tumor. Activity levels for both types of injections ranged from 3.7 to 11.1 mBq (100 to 300 &mgr;Ci). Preparation of the higher SA mixture of sulfur colloid was achieved by using only one eighth of the sulfur colloid vial contents when the same activity (125 mCi) of Tc‐99 was added. Regions of interest were drawn around the images of sentinel nodes and the initial injection site in the anterior and lateral projections. Ratios of sentinel node to initial injection site count were calculated for both groups. Results: The mean ratio of sentinel node to injection site count in the high SA group was 2.9 times greater than that in the low SA group. The median ratio value was 2.7 times greater in the high SA group. Conclusion: These preliminary results suggest higher counts in the sentinel node are possible with a higher SA preparation.

Using the intraoperative hand held probe without lymphoscintigraphy or using only dye correlates with higher sensory morbidity following sentinel lymph node biopsy in breast cancer: A review of the literature

BackgroundThere are no studies that have directly investigated the incremental reduction in sensory morbidity that lymphoscintigraphy images (LS) and triangulated body marking or other skin marking techniques provide during sentinel lymph node biopsy (SLNB) compared to using only the probe without LS and skin marking or using only dye. However, an indirect assessment of this potential for additional sensory morbidity reduction is possible by extracting morbidity data from studies comparing the morbidity of SLNB to that of axillary lymph node dissection.MethodsA literature search yielded 13 articles that had data on sensory morbidity at specific time points on pain, numbness or paresthesia from SLNB that used radiotracer and probe or used only dye as a primary method of finding the sentinel node (SN). Of these, 10 utilized LS, while 3 did not utilize LS. By matching the data in studies not employing LS to the studies that did, comparisons regarding the percentage of patients experiencing pain, numbness/paresthesia after SLNB could be reasonably attempted at a cutoff of 9 months.ResultsIn the 7 studies reporting on pain after 9 months (> 9 months) that used LS (1347 patients), 13.8% of patients reported these symptoms, while in the one study that did not use LS (143 patients), 28.7% of patients reported these symptoms at > 9 months (P < 0.0001). In the 6 studies reporting on numbness and/or paresthesia at > 9 months that used LS (601 patients), 12.5% of patients reported these symptoms, while in the 3 studies that did not use LS (229 patients), 23.1% of patients reported these symptoms at > 9 months (P = 0.0002). Similar trends were also noted for all these symptoms at ≤ 9 months.ConclusionBecause of variations in techniques and time of assessing morbidity, direct comparisons between studies are difficult. Nevertheless at a minimum, a clear trend is present: having the LS images and skin markings to assist during SLNB appears to yield more favorable morbidity outcomes for the patients compared to performing SLNB with only the probe or performing SLNB with dye alone. These results are extremely pertinent, as the main reason for performing SLNB itself in the first place is to achieve reduced morbidity.

Concomitant paravertebral FDG uptake helps differentiate supraclavicular and suprarenal brown fat uptake from malignant uptake when CT coregistration is not available

Objectives: Fluorine-18 fluorodeoxyglucose (F-18 FDG) uptake in brown adipose tissue (BAT) in the supraclavicular, superior mediastinal, paravertebral, and suprarenal/perinephric regions has been recognized. Of these 4 areas, uptake in the supraclavicular, mediastinal, and suprarenal areas may be difficult to differentiate from malignancy for those who interpret PET images only without CT coregistration or fusion. We assessed the prevalence and concomitance of F-18 FDG uptake in these 4 BAT regions. Methods: A total of 1495 F-18-FDG PET studies were reviewed. Distinct patterns compatible with BAT uptake in the 4 regions were graded and correlated with each other. Results: Of the 1495 studies, supraclavicular uptake was seen in 40 (2.7%), paravertebral uptake in 29 (1.9%), mediastinal uptake in 23(1.5%), and suprarenal uptake in 11 (0.7%). Of the 40 studies showing supraclavicular uptake, paravertebral uptake was also seen in 27 (68%), mediastinal uptake in 23 (58%), and suprarenal uptake in 11 (28%). Alternatively, of the 29 studies showing paravertebral uptake, all but 2 studies (93%) also had concomitant supraclavicular uptake. No studies showed isolated mediastinal or suprarenal uptake. All studies with mediastinal uptake also had supraclavicular uptake, and all studies with suprarenal uptake also had paravertebral uptake. Conclusions: Virtually all of mediastinal and suprarenal BAT uptake was associated with supraclavicular and paravertebral uptake, respectively. Nearly all paravertebral uptake coexisted with supraclavicular uptake. Even when CT coregistration is not available, concomitant paravertebral uptake can help differentiate suprarenal uptake and somewhat less typical supraclavicular BAT uptake from malignant uptake, and concomitant supraclavicular uptake can help differentiate mediastinal uptake from malignant uptake.

Lymphoscintigraphy and triangulated body marking for morbidity reduction during sentinel node biopsy in breast cancer.

Current trends in patient care include the desire for minimizing invasiveness of procedures and interventions. This aim is reflected in the increasing utilization of sentinel lymph node biopsy, which results in a lower level of morbidity in breast cancer staging, in comparison to extensive conventional axillary dissection. Optimized lymphoscintigraphy with triangulated body marking is a clinical option that can further reduce morbidity, more than when a hand held gamma probe alone is utilized. Unfortunately it is often either overlooked or not fully understood, and thus not utilized. This results in the unnecessary loss of an opportunity to further reduce morbidity.Optimized lymphoscintigraphy and triangulated body marking provides a detailed 3 dimensional map of the number and location of the sentinel nodes, available before the first incision is made. The number, location, relevance based on time/sequence of appearance of the nodes, all can influence 1) where the incision is made, 2) how extensive the dissection is, and 3) how many nodes are removed. In addition, complex patterns can arise from injections. These include prominent lymphatic channels, pseudo-sentinel nodes, echelon and reverse echelon nodes and even contamination, which are much more difficult to access with the probe only. With the detailed information provided by optimized lymphoscintigraphy and triangulated body marking, the surgeon can approach the axilla in a more enlightened fashion, in contrast to when the less informed probe only method is used. This allows for better planning, resulting in the best cosmetic effect and less trauma to the tissues, further reducing morbidity while maintaining adequate sampling of the sentinel node(s).

Appearance of descended superior parathyroid adenoma on SPECT parathyroid imaging.

An ectopic superior parathyroid adenoma (SPA) descends inferoposteriorly and can migrate to the posterior mediastinum. It often appears on sestamibi planar parathyroid imaging as an inferior lesion, which can be misleading to inexperienced surgeons. Its correct identification before surgery will be of great help for correct surgical planning. We assessed the appearance of descended SPA on SPECT imaging. Methods: Sestamibi SPECT imaging studies performed on 103 patients who had parathyroid adenomas with their origin and locations confirmed by surgery and histology were retrospectively reviewed. Abnormal foci seen on the SPECT images were grouped as to location relative to the thyroid gland as superior (S), middle (M), and inferior (I). The proximity between the focus and the thyroid on the sagittal SPECT images was graded from 0 to 2 with 2 being widely separated. Results: Of the 103 SPECT studies, 89 were positive. Eleven of the 89 visualized foci were at the S level: all were SPA. Ten foci were at the M level, including 6 SPA and 4 inferior parathyroid adenomas (IPA). There were 68 foci at the I level; none (0%) of 56 in the I0 location, 2 (25%) of 8 foci in the I1 location, and all (100%) of 4 abnormal foci in the I2 location were descended SPAs. Conclusion: The more posteriorly located the abnormal focus, the higher the probability of descended SPA. Recognition of the characteristic appearance of descended SPA on SPECT imaging can have a significant impact on the surgical approach and prevent failed neck exploration.

Focally increased activity in the lateral aspect of the mid cervical spine on bone scintigraphy is almost always benign in nature.

Objectives: Abnormal bone scan findings in the spine are often nonspecific. The confidence level for the differential diagnosis between metastases and benign or degenerative changes may vary depending on their appearance, location or intensity. The recognition of a specific pattern for certain benign conditions and its subcategorization will increase the credibility of bone scan interpretation while retaining a high level of sensitivity. We report one such finding, focally increased activity on the lateral side of the cervical spine on the posterior view, most common at the C3–C5 level (“mid-cervical-lateral-focus”). Methods: Of 481 patients with various cancers who had at least 2 whole-body bone scans, 6 months or more apart, 41 patients were judged to show this characteristic “mid-cervical-lateral-focus” on at least one scan. Final diagnosis (metastasis vs. benign) for each “mid-cervical-lateral-focus” was made based on clinical grounds and serial bone scans. Results: The bone scan showed definite multiple metastases in 15 patients, and the differential diagnosis for the “mid-cervical-lateral-focus” was already clinically irrelevant in these patients. Nevertheless, the “mid-cervical-lateral-focus” was finally judged to be benign in 14 of these 15 patients and in all remaining 26 patients without other obvious metastases. The only “mid-cervical-lateral-focus” judged to be a metastatic focus was not only clinically redundant, but also the most intense among all the “mid-cervical-lateral-foci.” in this series (too intense to be interpreted as benign). Conclusion: The typical “mid-cervical-lateral-focus” pattern is extremely unlikely to represent metastases (virtually 0% in patients without other obvious metastases). This knowledge helps exclude metastases on bone scans.