Breast cancer: variables affecting sentinel lymph node visualization at preoperative lymphoscintigraphy

Anatomical breast imaging-derived parameters do not provide incremental information in prediction of nonvisualization of sentinel lymph nodes on lymphoscintigraphy

OBJECTIVE

Accurate sentinel lymph node (SLN) staging is essential for both prognosis and treatment in patients with breast cancer. However, the preoperative lymphoscintigraphy may fail to visualize the SLN. The aim of this retrospective study was to investigate whether parameters derived from anatomical breast imaging can predict SLN nonvisualization on lymphoscintigraphy.

METHODS

For this retrospective study, all data of mammography, breast MRI, and lymphoscintigraphy of SLN procedures from January 2016 to April 2021 were collected and reviewed from the Amsterdam UMC database.

RESULTS

A total of 758 breast cancer patients were included in this study. SLN nonvisualization on planar lymphoscintigraphy at 2-h postinjection (pi) was 29.7% and was reduced after a second injection to 7.5% at late lymphoscintigraphy 4-h pi. Multivariable analysis showed that age ≥ 70 years ( P = 0.019; OR, 1.82; 95% CI, 1.10-3.01), BMI ≥ 30 kg/m 2 ( P = 0.031; OR, 1.59; 95% CI, 1.04-2.43), and nonpalpable tumors ( P = 0.034; OR, 1.54; 95% CI, 1.03-2.04) were independent predictors of SLN nonvisualization. Differences in tumor size, Breast Imaging-Reporting and Data System classification, or breast density were not significantly associated with SLN nonvisualization.

CONCLUSION

This study shows that, by using a multivariable analysis, risk factors for SLN nonvisualization in breast cancer patients during preoperative lymphoscintigraphy at 2-h pi are age ≥ 70 years, BMI ≥ 30 kg/m 2 , and nonpalpable tumors. Parameters derived from mammography or breast MRI, however, are not useful to predict SLN nonvisualization on lymphoscintigraphy.

Does failed mapping predict sentinel lymph node metastasis in cN0 breast cancer?

Aims: The clinical significance of nonvisualized sentinel lymph nodes (non-vSLNs) is unknown. The authors sought to determine the incidence of non-vSLNs on lymphoscintigraphy, the identification rate during surgery, factors associated with non-vSLNs and related axillary management. Patients & methods: A total of 30,508 consecutive SLN procedures performed at a single institution from 2000 to 2017 were retrospectively studied. Associations between clinicopathological factors and the identification of SLNs during surgery were assessed. Results: Non-vSLN occurred in 525 of the procedures (1.7%). In 73.3%, at least one SLN was identified intraoperatively. Nodal involvement was only significantly associated with SLN nonidentification (p < 0.001). Conclusion: Patients with non-vSLN had an increased risk for SLN metastasis. The detection rate during surgery was consistent, reducing the amount of unnecessary axillary dissection.

Factors predicting one or two sentinel lymph nodes to be accepted for sentinel lymph node biopsy alone after neoadjuvant therapy in initially node-positive breast cancer patients

BACKGROUND

Current guidelines recommend harvesting ≥3 sentinel nodes if sentinel lymph node biopsy (SLNB) alone is considered after neoadjuvant therapy (NAT) for initially node-positive (cN+) breast cancer. We attempted to investigate factors predicting one or two sentinel lymph nodes harvested to be accepted for SLNB alone after NAT in initially cN + patients.

METHODS

Overall, 157 patients who received NAT (clinically T1-3/N1-2/M0) and underwent SLNB were identified from a prospectively maintained database. Significant factors were identified using a multiple logistic regression model.

RESULTS

The overall SLN identification rate was 83.4%. Failed SLN identification was associated with a 2-day protocol using a single tracer (odds ratio: 0.331 [95% confidence interval {CI}: 0.132-0.830], p = 0.018), age >52 years (0.345 [0.131-0.913], p = 0.032), and lobular histology (0.156 [0.026-0.944], p = 0.043). The overall false-negative SLNB rate was 14.7%. Its increased risk was associated with radioactivity count >530 for any SLN during SLNB (96.4 [4.00-2320], p = 0.005), age ≥57 years (34.2 [1.92-610], p = 0.016), and taxane use (105 [1.02-10700], p = 0.049); its decreased risk was associated with more harvested SLNs (0.191 [0.054-0.669], p = 0.01) and dual tracers (0.101 [0.012-0.843], p = 0.034). A predictive model using these factors achieved an area under the curve of 0.935 (95% CI: 0.878-0.991).

CONCLUSION

When taxane was administered during NAT, the false-negative rate was predicted at <5% for patients aged <57 years, if 1-2 SLNs were harvested using dual tracers, and when the count of every SLN was lower than 530 after NAT in cN + breast cancer.

Predictive risk factors for sentinel lymph node nonvisualization on planar lymphoscintigraphy using an intratumoral injection in patients with primary breast cancer

OBJECTIVES

Lymphoscintigraphy is considered a useful tool to optimize sentinel lymph node (SLN) identification. Nonvisualization of the SLN is associated with a lower SLN identification rate. The aim of this study was to identify preoperative factors associated with SLN nonvisualization on lymphoscintigraphy.

PATIENTS AND METHODS

A total of 2050 consecutive SLN procedures were evaluated from clinically node-negative breast cancer patients. Planar lymphoscintigraphy was performed at 3 h after an intratumoral injection of technetium-99m-nanocolloid. This technique was used for extra-axillary SLN identification. Patient, tumor, and treatment characteristics were analyzed for association with SLN nonvisualization. Factors with a P-value less than 0.1 in univariate analysis were included in a multivariate logistic regression model.

RESULTS

The SLN visualization rate was 86.7%. In multivariate logistic regression, age of at least 70 years [odds ratio (OR): 3.24; 95% confidence interval (CI): 2.14-4.91)], BMI of at least 30 (OR: 1.93; 95% CI: 1.39-2.69), T3/T4-tumors (OR: 2.70; 95% CI: 1.37-5.32), medially/centrally located tumors (OR: 1.52; 95% CI: 1.17-1.99), previous mantle field radiation (OR: 4.04; 95% CI: 1.74-9.35), nonpalpable tumors (OR: 1.88; 95% CI: 1.36-2.60), and presence of iodine seeds (OR: 1.35; 95% CI: 1.02-1.78) were associated significantly with nonvisualization on lymphoscintigraphy. Nonvisualization was the strongest independent predictor of unsuccessful intraoperative SLN identification (P<0.001). Overall, the SLN identification rate was 97.7% because of the use of additional imaging and blue dye.

CONCLUSION

This study reports new tumor and treatment-related risk factors for nonvisualization on lymphoscintigraphy by using an intratumoral injection in primary breast cancer. We recommend a periareolar subcutaneous injection to improve SLN visualization in patients with limited prognostic and therapeutic relevance of internal mammary chain SLN identification.

Sentinel lymph node mapping using SPECT/CT and gamma probe in endometrial cancer: an analysis of parameters affecting detection rate

PURPOSE

SPECT/CT after pericervical injection of technetium-99 m-nanocolloid was shown to be suitable for sentinel lymph node (SLN) mapping in endometrial cancer (EC). The aim of this study was to analyze factors affecting successful SLN detection by means of SPECT/CT such as imaging findings, patient characteristics and tumor biology in a large cohort of patients.

METHODS

One hundred and forty-five consecutive patients suffering from EC who received pre-surgical SLN mapping at our institution between 2011 and 2016 were included in this analysis. SPECT/CT data of abdomen and pelvis (mean 4:20 ± 1:20 h p.i.) were acquired after pericervical injection of technetium-99 m-nanocolloid (mean 230 ± 45 MBq) in all patients. Surgical staging was performed on the day after. Acquisition parameters, patient characteristics, SPECT/CT findings as well as histopathological results were collected.

RESULTS

A total of 282 SLNs were identified by means of SPECT/CT. Overall, preoperative and intraoperative SLN detection rates were 86%, 76% and 74% respectively. The most important factor associated with failure to detect SLNs was the presence of high bone marrow on SPECT/CT (p = 0.005). Peritoneal/abdominal radioactivity was also associated with missed SLN detection in SPECT/CT (p = 0.02). However, the presence of liver/spleen uptake on its own was not predictive for detection failure. Low numbers of detected SLNs in SPECT/CT were slightly related with older age and lower injected activity. No significant influence was found for the parameters of tumor histology and stage, lymph node involvement and the time gap between injection and imaging.

CONCLUSIONS

Venous drainage as indicated by bone marrow uptake is the most important factor associated with scintigraphic SLN detection failure. Moreover, high peritoneal and abdominal activity was also associated with detection failure. Thus, meticulous application of the radiotracer is crucial in EC.

Sentinel node detection in early breast cancer with intraoperative portable gamma camera: UK experience

PURPOSE

Access to nuclear medicine department for sentinel node imaging remains an issue in number of hospitals in the UK and many parts of the world. Sentinella^® is a portable imaging camera used intra-operatively to produce real time visual localisation of sentinel lymph nodes.

METHODS

Sentinella^® was tested in a controlled laboratory environment at our centre and we report our experience on the first use of this technology from UK. Moreover, preoperative scintigrams of the axilla were obtained in 144 patients undergoing sentinel node biopsy using conventional gamma camera. Sentinella^® scans were done intra-operatively to correlate with the pre-operative scintigram and to determine presence of any residual hot node after the axilla was deemed to be clear based on the silence of the hand held gamma probe.

RESULTS

Sentinella^® detected significantly more nodes compared with CGC (p < 0.0001). Sentinella^® picked up extra nodes in 5/144 cases after the axilla was found silent using hand held gamma probe. In 2/144 cases, extra nodes detected by Sentinella^® confirmed presence of tumour cells that led to a complete axillary clearance.

CONCLUSIONS

Sentinella^® is a reliable technique for intra-operative localisation of radioactive nodes. It provides increased nodal visualisation rates compared to static scintigram imaging and proves to be an important tool for harvesting all hot sentinel nodes. This portable gamma camera can definitely replace the use of conventional lymphoscintigrams saving time and money both for patients and the health system.

Preoperative Scintigrams to Identify the Sentinel Lymph Node in Breast Cancer: a Waste of Time?

Sentinel lymph node biopsy (SLNB) remains the gold standard for assessing axillary node status in breast cancer. Preoperative scintigrams have been used to identify the sentinel lymph node (SLN); however, their use is controversial. Studies suggest they add little to successful SLN detection in theatre, immediately prior to node excision. They have been associated with high false negatives, time expense, patient dissatisfaction, and unnecessary costs. The aim of the present study was to evaluate the diagnostic accuracy of scintigrams in comparison to intraoperative SLN identification techniques. This study included all patients undergoing a SLNB for breast cancer from April 2010 to 2011. Scintigram reports, operation notes, and histology results were analyzed. Mann-Whitney U and chi-squared tests were used for statistical analysis of data. Two hundred nineteen female patients with a median age of 59.6 years (24.0-89.9 years) were included in this study. Scintigram was performed in 185 and not in 34 patients due to time constraints. Combined γ-probe and Isosulfan blue dye for SLN detection (intraoperative methods) have an identification rate of 98.2 % (p = 0.005), compared to 92.4 % (p = 0.088) from scintigrams alone. Scintigrams confer no additional advantage to the operating surgeon for successful SLN detection and excision in theatre. Intraoperative SLN identification is more accurate and reliable. Routine scintigram use is unjustified and should be withdrawn from current practice.

Breast cancer lymphoscintigraphy: Factors associated with sentinel lymph node non visualization

OBJECTIVE

To evaluate factors associated with non identification of the sentinel lymph node (SLN) in lymphoscintigraphy of breast cancer patients and analyze the relationship with SLN metastases.

MATERIAL AND METHODS

A single-center, cross-sectional and retrospective study was performed. Forty patients with lymphoscintigraphy without sentinel lymph node identification (negative lymphoscintigraphy - NL) were enrolled. The control group included 184 patients with SLN identification (positive lymphoscintigraphy - PL). Evaluated factors were age, body mass index (BMI), tumor size, histology, localization, preoperative breast lesion hookwire (harpoon) marking and SLN metastases. The statistical analysis was performed with uni- and multivariate logistic regression models and matched-pairs analysis.

RESULTS

Age (p=0.036) or having BMI (p=0.047) were the only factors significantly associated with NL. Being ≥60 years with a BMI ≥30 increased the odds of having a NL 2 and 3.8 times, respectively. Marking with hookwire seems to increase the likelihood of NL, but demonstrated statistical significance is lacking (p=0.087). The other tested variables did not affect the examination result. When controlling for age, BMI and marking with the harpoon, a significant association between lymph node metastization and NL was not found (p=0.565).

CONCLUSIONS

The most important factors related with non identification of SLN in the patients were age, BMI and marking with hook wire. However, only the first two had statistical importance. When these variables were controlled, no association was found between NL and axillary metastases.

Tumor-infiltrating lymphocyte response in cutaneous melanoma in the elderly predicts clinical outcomes

Tumor-infiltrating lymphocytes (TILs) and regression are manifestations of the host immune response to tumor, but their influence on outcome remains undefined. There is a paucity of data on the elderly who represent a growing proportion of melanoma patients. The aim of this study was to evaluate the influence of TILs and regression as an indirect measure of immunity on outcome in elderly patients with melanoma. From a prospective database, we identified 250 consecutive cutaneous melanoma patients aged at least 65 years at the time of diagnosis. Data were verified by record review. Within the primary melanoma, a brisk TIL response was present in 66 (31%), nonbrisk TILs in 36 (17%), and absent in 111 (52%). The presence of a brisk infiltrate conferred a three-fold increased risk of sentinel lymph node (SLN) metastasis (P=0.02). Despite this, nonbrisk or absent TILs were associated with a five-fold increased risk of recurrence (P=0.0001). In multivariate analysis, nonbrisk or absent TILs were independently associated with recurrence (P<0.0001), diminished 5-year disease-free survival (76 vs. 91%, P=0.0006), and 5-year melanoma-specific survival (82 vs. 95%, P=0.0008). Regression was not an independent predictor of SLN metastasis, disease-free survival, or melanoma-specific survival. Our study demonstrates that an active antitumor immune response exists in elderly melanoma patients that, paradoxically, predicts both SLN metastasis and improved melanoma-specific outcomes. Further investigation to characterize this lymphocytic infiltrate and to confirm its clinical significance as a predictor of nodal status, patient outcome, and response to immunotherapy in elderly melanoma patients appears warranted.

Prevalence and risk factors of intraoperative identification failure of sentinel lymph nodes in patients affected by breast cancer

INTRODUCTION

Sentinel lymph node biopsy (SLNB) has progressively replaced complete axillary lymph node dissection in the evaluation of breast cancer patients with clinically node-negative disease. Our study investigates the rate of and risk factors involved in sentinel node identification failure.

MATERIALS AND METHODS

We collected data on SLNBs performed during 2002-2010, focusing on tumor, patient, and breast characteristics, radioactivity parameters, and operators' experience. Data were analyzed by R (v2.14.2), considering significance at P values lower than 0.05.

RESULTS

Among 1050 women who underwent an SLNB, the rate of identification failure was 2% (23/1050), which, on bivariate analysis, was seen to be significantly influenced (P<0.05) by the preoperative and intraoperative low radiotracer uptake (axilla/lesion radiotracer uptake ratio<1%), low level of experience of the specialist in nuclear medicine, luminal A subtype, and radiotracer uptake localization in internal mammary lymph nodes. On multivariate analysis, significant risk factors for sentinel node identification failure were found to be: axilla/lesion radiotracer uptake ratio less than 1%, radiotracer uptake localization in internal mammary lymph nodes, and luminal A subtype. Considering only the preoperative variables in our multivariate analysis, axilla/lesion radiotracer uptake ratio less than 1%, negative lymph node scintiscan, and radiotracer uptake localization in internal mammary lymph nodes had an area under the curve (receiver operating characteristic curve) of 96% (95% confidence interval 92-100%). Further, we built a nomogram based on these simple parameters for counseling the patient about the probability of not finding the sentinel lymph node during the surgical procedure.

CONCLUSION

The relatively low prevalence of SLNB failure (2%) is indicative of the accuracy of the procedure when performed by experienced surgeons. The sentinel node identification failure in our population seemed to be related to biological tumor factors (luminal A subtype) and probably to physiological or pathological variations in the lymphatic drainage (axilla/lesion radiotracer uptake ratio<1% and radiotracer uptake localization in internal mammary lymph nodes).

Clinical and histopathological factors affecting failed sentinel node localization in axillary staging for breast cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) has become the standard of care in axillary staging of clinically node-negative breast cancer patients.

AIMS

To analyze reasons for failure of SLN localization by means of a multivariate analysis of clinical and histopathological factors.

METHODS

We performed a review of 164 consecutive breast cancer patients who underwent SLNB. A superficial injection technique was used.

RESULTS

9/164 patients failed to show nodes. In 7/9 patients no evidence of radioactivity or blue dye was observed. Age and nodal status were the only statistically significant factors (p < 0.05). For every unit increase in age there was a 9% reduced chance of failed SLN localization. Patients with negative nodal status have 90% reduced risk of failed sentinel node localization than patients with macro or extra capsular nodal invasion.

DISCUSSION

The results suggest that altered lymphatic dynamics secondary to tumour burden may play a role in failed sentinel node localization. We showed that in all failed localizations the radiocolloid persisted around the injection site, showing limited local diffusion only. While clinical and histopathological data may provide some clues as to why sentinel node localization fails, we further hypothesize that integrity of peri-areolar lymphatics is important for successful localization.

Sentinel lymph node biopsy and survival in elderly patients with cutaneous melanoma

BACKGROUND

Sentinel lymph node biopsy (SNB) is a widely adopted staging procedure in patients with cutaneous melanoma. The benefits of SNB have not been evaluated thoroughly in older age groups.

METHODS

This was a two-centre retrospective observational study of patients with melanoma aged at least 70 years undergoing SNB.

RESULTS

A total of 423 patients were included. SNB was successful in 405 patients (95·7 per cent), of whom 88 (21·7 per cent) had sentinel node metastasis. During a median follow-up of 2·5 years, recurrence developed in 80 patients (18·9 per cent). Nodal recurrence developed in eight sentinel node-negative patients, giving a false-negative rate of 8·3 per cent, a sensitivity of 91·7 per cent and an overall diagnostic accuracy of 98·0 per cent. A total of 46 patients (10·9 per cent) died from melanoma and 42 (9·9 per cent) from other causes. At 5 years, the relapse-free survival rate was 80·0 per cent in sentinel node-negative patients and 39 per cent in node-positive patients; cancer-specific survival rates were 88·6 per cent and 46 per cent respectively (P < 0·001). In multivariable analysis, sentinel node metastasis (P < 0·001), a Breslow thickness of at least 2·0 mm (P = 0·007) and presence of ulceration (P = 0·012) were independent prognostic factors for cancer-specific survival.

CONCLUSION

SNB is a feasible and accurate technique for detecting nodal metastases in older patients with melanoma. Sentinel node status is the most important predictor of cancer-specific outcome in the elderly.

Age-related lymphatic dysfunction in melanoma patients

BACKGROUND

Age-related outcomes have become increasingly common in evaluating patients with melanoma. For instance, as age increases, sentinel node (SN) nonidentification increases and SN positivity decreases. Furthermore, advanced age is a risk factor for in-transit disease. We hypothesized that increasing age is accompanied by alterations in lymphatic function, possibly explaining these findings.

METHODS

Our center's melanoma database was queried to identify patients who underwent successful sentinel node biopsy after lymphoscintigraphy. Records of those treated between 2000 and 2005 were reviewed for age, sex, drainage basin, intraoperative radioactivity, and SN pathology.

RESULTS

The 858 patients had a mean age of 55 years; 59% were men. Mean radioactivity in the hottest SN was 5232 counts per second; 179 patients (21%) had SN metastases. SN count rates were significantly and inversely related to age (P < .001 by Pearson correlation, analysis of variance, and chi(2) test). Mean counts per second were 6105, 5883, and 2720 for axillary, inguinal, and cervical basins, respectively (P < .01), and count rates in these basins were consistently lower with increasing age (neck and axilla, P < .001; groin, P = .060; Pearson correlation). Multivariate analysis confirmed an independent inverse association between age and count rates (P < .001), overall and within each primary tumor site.

CONCLUSIONS

Lymphatic function, as assessed by radiocolloid transit to and uptake within the SN, declines with age. Altered lymphatic function in older patients may modify metastatic patterns; knowledge of this may help clarify findings of reduced nodal positivity and increased in-transit disease in this population.

Sentinel lymph node detection and evidence of axillary lymphatic integrity after transaxillary breast augmentation: a prospective study using lymphoscintography

BACKGROUND

The transaxillary breast augmentation (TBA) technique has gained popularity because of several advantages. However, the impact of the procedure on breast lymphatic drainage and sentinel node (SN) detection remains controversial. The objective of this study was to evaluate the lymphatic patterns and SN detection rates after TBA by using lymphoscintigraphy (LSG).

METHODS

Twenty patients (40 breasts) who underwent TBA were evaluated by LSG immediately after periareolar injections of phytate-99 mTc at three time points: before TBA (Pre-LSG) and approximately 30 days (Recent-Post-LSG) and 6 months after TBA (Late-Post-LSG). Statistical analysis considered p \ 0.05 significant, or p \ 0.017 when Bonferroni correction was applied.

RESULTS

All breasts drained primarily to the axillary SN. The binomial test did not show statistical differences in lymphatic drainage patterns between Pre-LSG and Recent-Post-LSG (p = 1), Pre-LSG and Late-Post-LSG (p = 0.625), and Recent-Post-LSG and Late-Post-LSG (p = 0.625). The average number of hot SN was 1.28 in Pre-LSG, 1.10 in Recent-Post-LSG, and 1.23 in Late-Post-LSG, without significant differences (p = 0.202). The average time of the first SN appearance was not significantly different (p = 0.186). Analysis of SN uptake percentage showed a significant difference between Pre-LSG and Recent-Post-LSG (p = 0.009), with a reduction of drainage magnitude in Recent-Post-LSG.

CONCLUSION

The preservation of axillary lymphatic drainage after TBA allowed for SN detection in all studied breasts. It seems that the applied surgical technique played an important role in axillary lymphatic integrity.

Linfonodo sentinela após mamoplastia de aumento pela via transaxilar: estudo prospectivo controlado por meio de linfocintilografia em 43 pacientes

OBJETIVO: Verificar se a mamoplastia de aumento pela via transaxilar apresenta potencial de prejudicar a identificação futura do linfonodo sentinela. MATERIAIS E MÉTODOS: Estudo prospectivo controlado em que foram selecionadas 22 pacientes divididas em grupo pós-mamoplastia e grupo controle, totalizando 43 mamas (22 no grupo pós-mamoplastia e 21 no grupo controle) avaliadas por meio de linfocintilografia imediatamente após injeções periareolares de fitato-99mTc. Os testes estatísticos consideraram como diferenças significativas valores de p < 0,05. RESULTADOS: Todas as mamas do grupo pós-mamoplastia apresentaram drenagem linfática para a cadeia axilar, sem diferença com o grupo controle (p = 0,488). A média de linfonodos captantes foi de 1,27 ± 0,46 no grupo pós-mamoplastia e 1,33 ± 0,58 no grupo controle (p = 0,895). A média de tempo para visualização do primeiro linfonodo foi de 3,14 ± 4,42 minutos no grupo pós-mamoplastia e 5,48 ± 5,06 minutos no grupo controle, novamente sem diferença significativa (p = 0,136). CONCLUSÃO: A mamoplastia de aumento pela via transaxilar não acarretou prejuízo na identificação futura do linfonodo sentinela.

The value of radiotherapy on metastatic internal mammary nodes in breast cancer. Results on a large series

The 'regional nodal mapping', is a fundamental step to stage breast carcinoma. In addition to the axillary nodes status, the involvement of internal mammary nodes is an important prognostic factor. Six hundred and sixty-three patients with breast carcinoma, mainly in the inner quadrants, underwent a biopsy of internal mammary nodes. Positive internal mammary nodes were found in 68 out of 663 cases (10.3%) representing 27.2% of all cases with regional node metastases (250). When histologically proven metastases were detected, radiotherapy was administered to the internal mammary nodes chain. In 254 cases, the surgeon's exploration was guided by a gamma probe. Out of these cases, 28 (11.0%) showed metastatic involvement. Out of the other 409 cases, not radioguided, 40 showed positive nodes (9.8%). Patients with internal mammary metastases treated with radiotherapy and appropriate systemic treatment showed an excellent survival (95% at 5 years), a result which is in opposition to the previous experience, which stated that invasion of internal mammary nodes is an ominous prognostic sign. We assume that this excellent result is due to radiotherapy to internal mammary nodes and we propose that exploration of internal mammary nodes should be part of the staging process of carcinomas of the medial part of the breast.

Does Failure to Visualize a Sentinel Node on Preoperative Lymphoscintigraphy Predict a Greater Likelihood of Axillary Lymph Node Positivity?

BACKGROUND

Sentinel lymph node (SLN) mapping has become the standard of care for axillary staging in women with early-stage breast cancer. The purpose of the study was to investigate the hypothesis that nonvisualization of SLN on lymphoscintigraphy (LSG) predicts a subset of patients at risk of having a substantial burden of axillary tumor as evidenced by higher rate of lymph node involvement.

STUDY DESIGN

We retrospectively reviewed the records of 1,500 patients who underwent dual-tracer SLN mapping for breast cancer between 1999 and 2004. LSG were reported as negative or positive.

RESULTS

Ninety-one percent had axillary SLN(s) identified on LSG imaging. In 133 of 134 (99.3%) patients with a negative LSG, SLN(s) was identified intraoperatively either by blue dye or hand-held gamma detection. SLN was positive in 28.4% of LSG nonvisualized group and was positive in 29.1% of LSG visualized group (p>0.05). A significantly higher percentage of women older than 50 years of age had nonvisualization of SLN (p<0.0001). Body mass index (calculated as kg/m2) was >30 in 42.5% of LSG nonvisualized group and in 26.3% in LSG visualized group (p<0.0001).

CONCLUSIONS

Failure to demonstrate axillary uptake by LSG appears to be related to technical factors and patient-related factors, such as body mass index and older age, but does not adversely affect SLN identification. The equivalent rate of positive SLNs in patients with a positive or negative LSG supports the null hypothesis that "failure to visualize" on LSG does not identify a subset of patients at higher risk of being axillary lymph node positive.

Immediate dynamic lymphoscintigraphy delivers no additional value to lymphoscintigraphy 3 hr after tracer injection in sentinel lymph node biopsy in breast cancer patients

OBJECTIVE

Immediate dynamic imaging enables accurate definition of sentinel lymph nodes, whereas imaging 3 hr after tracer injection may lead to overestimation of the number of sentinel lymph nodes. A study was performed to define the value of lymphoscintigraphy immediately versus 3 hr after tracer injection in sentinel lymph node biopsy for breast cancer management.

METHODS

In 165 sentinel lymph node biopsy procedures preoperative immediate and 3 hr post-injection lymphoscintigraphy was performed after intraparenchymal tracer administration.

RESULTS

Lymph node visualization occurred in 63 immediate procedures (38%) versus in 163 procedures 3 hr post-injection (99%). In 17 procedures (10%) in which immediate lymphoscintigraphy had visualized sentinel lymph nodes, additional nodes had been seen on 3 hr post-injection lymphoscintigraphy. In eight of these procedures (5%) all nodes were detected in the same draining lymph node basin. Non-axillary sentinel lymph nodes were identified by preoperative lymphoscintigraphy in 28 procedures (17%) and improved staging in three patients (5%).

CONCLUSION

The only impact of immediate lymphoscintigraphy was the possible omission of removal of 1-2 sec-echelon nodes per patient in 5% of patients. We consider this yield too low to continue immediate lymphoscintigraphy in breast cancer patients.

Stereoscopic scintigraphic imaging of breast cancer sentinel lymph nodes

BACKGROUND

Lymphoscintigraphy is used preoperatively to identify sentinel lymph nodes (SLNs). Conventional planar scintigraphy cannot provide three-dimensional(3D) information for SLN biopsy. We applied stereoscopic imaging to preoperative lymphoscintigraphy to obtain 3D information and evaluated its usefulness.

METHODS

Forty-four clinical stage I breast cancer patients (1 male, 43 females; age, 59.4+/-11.4 years) were enrolled in this study. Three hours after the injection of Tc-99m, 10 degrees of oblique images and routine anterior and lateral images were acquired. Anterior and lateral stereoscopic images were obtained in all studies, except for 2 patients; only lateral views were done for those. Two experienced radiologists enumerated the visualized hot nodes.

RESULTS

Stereoscopic imaging delineated more hot axillary lymph nodes compared to routine planar imaging in 8 of 42 patients (19.0%) on anterior view, 5 of 44 patients (11.4%) on lateral view, and 11 of 44 patients (25.0%) on either the anterior or lateral view. Statistically significant differences were observed between stereoscopic and routine planar imaging method on the anterior (p=0.012) and the lateral views (p=0.043). The stereoscopic imaging provided 3D information and effectively separated closely located hot nodes that were viewed as one hot node on conventional planar images. Thirty-eight out of 42 cases (90%) with anterior stereoscopic images identified the same number or more axillary hot nodes compared with lateral stereoscopic images.

CONCLUSION

The stereoscopic imaging method could improve the preoperative identification of SLNs. This method is technically simple, and could be a powerful diagnostic tool for SLN imaging breast cancer.

Prospective Randomized Clinical Trial Comparing Intradermal, Intraparenchymal, and Subareolar Injection Routes for Sentinel Lymph Node Mapping and Biopsy in Breast Cancer

BACKGROUND

Multiple injection routes, including intradermal (ID), intraparenchymal (IP), and subareolar (SA), are used for 99mTc-sulfur colloid administration for sentinel lymph node (SLN) mapping and biopsy in breast cancer. The aim of this study was to compare localization by ID, IP, and SA injection routes based on preoperative lymphoscintigraphy and intraoperative identification.

METHODS

Four hundred prospectively randomized breast cancers underwent SLN mapping and biopsy.

RESULTS

Preoperative lymphoscintigraphy demonstrated localization to the axilla in 126/133 (95%) ID, 82/132 (62%) IP, and 96/133 (72%) SA (P < 0.001 ID vs. IP and ID vs. SA; P = 0.081 IP vs. SA), with a mean duration of preoperative lymphoscintigraphy of 139 +/- 18 minutes. Mean time to first localization when localization was demonstrated on preoperative lymphoscintigraphy was 8 +/- 14 minutes for ID, 53 +/- 49 for IP, and 22 +/- 29 for SA (P < 0.001 ID vs. IP and ID vs. SA; P = 0.003 IP vs. SA). Intraoperative identification of a SLN at the time of SLN biopsy was successful in 133/133 (100%) ID, 121/134 (90%) IP, and 126/133 (95%) SA (P < 0.001 ID vs IP; P = 0.014 ID vs. SA; P = 0.168 IP vs. SA), with a mean time from injection of 99mTc-sulfur colloid to start of SLN biopsy of 288 +/- 71 minutes. Mean intraoperative time to harvest the first SLN was 9 +/- 4 minutes for ID, 13 +/- 6 for IP, and 12 +/- 6 for SA (P < 0.001 ID vs. IP and ID vs. SA; P = 0.410 IP vs. SA).

CONCLUSIONS

The ID injection route demonstrated a significantly greater frequency of localization, decreased time to first localization on preoperative lymphoscintigraphy, and decreased time to harvest the first SLN. This represents the first prospective randomized clinical trial to confirm superiority of the ID route for administration of 99mTc-sulfur colloid during SLN mapping and biopsy in breast cancer.

[Influence of tumor location in patients with breast cancer on the sentinel node detection]

OBJECTIVE

To evaluate the influence of tumour quadrant localization on the sentinel node (SN) detection and the visualisation of internal mammary chain (IM) drainage by radioisotopic techniques. 316 patients with breast cancer were studied. Mean age 57 years (range 29-88). All patients received 37-74 MBq of 99mTc-albumin nanocolloid in 2 ml by peritumoral injection. The breast cancer was located in the upper outer quadrant in 189 patients, in the upper inner in 57, in the lower outer in 57, in the lower inner in 55 and in the subareolar area in 18 patients. At two hours p.i., anterior and lateral chest lymphographies were obtained. The SN location was marked on the patient skin with permanent ink. SN was identified intraoperatively by the gamma probe. Histopatological analysis included imprints, delayed hematoxilin-eosin, inmunohistochemistry CAM 19-2 and PCR.

RESULTS

The scintigraphy and surgical detection was in the upper outer quadrant of 90 % and 93 % respectively; in the lower outer quadrant of 91 % and 95 %, in the upper inner quadrant of 93 % and 95 %, in the lower inner quadrant 87 % and 95 % and in the subareolar area in 94 % and 83 %. The IM chain drainage was of 6 % in the UO, in the LO of 5 %, in the UI of 12 %, in the LI of 20 % and none in subareolar.

CONCLUSIONS

Our data suggest that sentinel node location (quadrant) is not a influential factor in the scintigraphy and surgical detection. Tumours localised in internal quadrant show a higher rate of IM chain drainage.

Factors affecting failed localisation and false-negative rates of sentinel node biopsy in breast cancer--results of the ALMANAC validation phase

BACKGROUND

Despite the widespread application of sentinel lymph node biopsy (SLNB) for early stage breast cancer, there is a wide variation in reported test performance characteristics. A major aim of this prospective multicentre validation study was to quantify detection and false-negative rates of SLNB and evaluate factors influencing them.

METHODS

Eight-hundred and fourty-two patients with clinically node-negative breast cancer underwent SLNB according to a standardised protocol that used a combination of radiopharmaceutical 99mTc-albumin colloid and Patent Blue V dye. SLNB was followed by standard axillary treatment at the same operation in all patients.

RESULTS

Sentinel lymph nodes (SLNs) were identified in 803 (96.1%) of 836 evaluable cases. The median number of SLNs removed per patient was 2 (range 1-9). There were 19 false negatives, resulting in a sensitivity of 263/282 (93.3%) and accuracy 782/803 (97.6%). SLNs were successfully identified by blue dye in 698 (85.6%), by isotope in 698 (85.6%), and by the combination of blue dye and isotope in 782 (96.0%) of 815 patients. Among 276 node positive patients, one or more positive SLNs were identified by blue dye in 251 (90.9%), by isotope in 246 (89.1%) and by the combination of blue dye and gamma probe in 258 (93.5%). Obesity, tumor location other than upper outer quadrant and non-visualisation of SLNs on the pre-operative lymphoscintiscan were significantly associated with failed localisation (p<0.001, p=0.008, p<0.001, respectively). The false-negative rate in patients with grade 3 tumors was 9.6%, compared with 4.7% in those with grade 2 tumors (p=0.022). The false-negative rate in patients who had one SLN harvested was 10.1%, compared with 1.1% in those who had multiple SLNs (three or more) removed (p=0.010).

CONCLUSION

SLNB can accurately determine whether axillary metastases are present in patients with early stage breast cancer with clinically negative axillary nodes. Both success and accuracy of SLNB are optimised by the combined use of blue dye and isotope. SLNB success decreases with increasing body mass, tumor location other than the upper outer quadrant and non-visualisation of hot nodes on the pre-operative lymphoscintiscan. This study demonstrates reduction in the predictive value of a negative SLNB in grade 3 tumors.

Results of preoperative lymphoscintigraphy for breast cancer are predictive of identification of axillary sentinel lymph nodes

The aim of this study was to identify the variables associated with successful peroperative sentinel lymph node (SLN) localization. We studied 201 patients with T1, T2, N0 invasive breast cancer who underwent a SLN procedure from 1999 to 2003. Of these 201 patients, 55 underwent peritumoral and 146 underwent periareolar radioisotope injection before the blue dye injection. All patients were operated on by breast conservative surgery and axillary dissection after SLN biopsy. Age, weight, menopausal status, previous biopsy, localization of the tumor, results of lymphoscintigraphy, site of radiotracer injection, tumor size, tumor grade, experience of surgeons, and the number of invaded axillary nodes were analyzed to determine whether they had any significant correlation with successful identification of SLN. Variables found to have a statistically significant influence on the SLN identification rate and on preoperative lymphoscintigraphy identification were introduced into a univariate and multivariate logistic regression model. In multivariate analysis, successful lymphoscintigraphy (P < 0.0001) and the absence of metastatic axillary nodes (P < 0.005) were associated with successful identification of SLNs. The peritumoral injection of radiotracer (P < 0.001), patient age > 60 years (P < 0.003), and localization of the tumor in the upper outer quadrant (P < 0.004) were associated with failure of lymphoscintigraphic visualization of SLN. The technique of SLN detection thus appears to be better for patients with low risk of invaded axillary lymph nodes.

Does imaging in sentinel node scintigraphic localization add value to the procedure in patients with breast cancer?

Imaging sentinel nodes with pre-operative lymphoscintigraphy effectively assures successful sentinel node identification. However, sentinel nodes are still identified in the majority of image negative patients. Given the logistics and cost required to perform pre-operative lymphoscintigraphy its routine use may not be justified. It may be valuable for surgeons in the learning phase and in obese patients who have increased risk of intra-operative failed localization. A negative pre-operative lymphoscintiscan predicts inability to localize with the hand-held gamma probe. Patients with no 'hot node' on the lymphoscintiscan are more likely to have failed localization using the gamma probe only. Therefore, blue dye should be used along with the gamma probe to optimize the localization rate in these patients.

Is early dynamic lymphoscintigraphy for detection of sentinel lymph nodes always achievable in breast tumor?

OBJECTIVE

In this article, we will discuss the achievement of early dynamic lymphoscintigraphic protocol and compare detection of sentinel node between benign and malignant breast tumors, and whether pathologic factor is related or not.

METHODS

During a six-month period, consecutive fifty-nine patients were enrolled into our study. The average age of patients was 47.6 +/- 9.8 years and all of them were clinically suspected of having breast cancer. The average tumor was 2.1 +/- 1.1 cm in size. First, Tc-99m sulfur colloid was injected around corners of palpable mass or biopsy cavity by the hybrid injection method. Immediately thereafter, dynamic protocol of lymphoscintigraphy, with 10 sec per frame for 60 frames was performed by established simultaneous dual-head vertical angle imaging technique. And delayed two-hour image was also acquired. All patients underwent surgery sixteen to twenty hours later and had a final pathological diagnosis.

RESULTS

Among 59 patients, 14 of them were diagnosed with fibroadenoma and the other 45 cases with malignant conditions, infiltrating duct carcinoma mostly. The average age of the two groups was similar. From the summation image of dynamic study, identified axillary sentinel nodal activity was found as 80% in the group of benign breast tumor, but only 48% in the group of malignant breast tumor. In more than 88% of patients, sentinel lymph node was detectable on the delayed two-hour image between the two groups.

CONCLUSIONS

Early dynamic protocol of pre-operative lymphoscintigraphy is helpful to clarify the relationship between the local lymphatic drainage basin and sentinel nodal uptake. However, this short period of protocol is not always achievable to detect sentinel node, especially in the group with breast malignant lesions.

Effect of lymphoscintigraphy drainage patterns on sentinel lymph node biopsy in patients with breast cancer

BACKGROUND

Sentinel lymph node (SLN) biopsy examination is an accepted method of staging breast cancer patients. SLN biopsy examination in patients with drainage to the internal mammary chain (IMC) nodes is controversial.

METHODS

A prospective study of SLN biopsy examination followed by axillary dissection was analyzed to determine how surgeons manage patients with IMC drainage and the rates of axillary SLN identification and positivity in these cases.

RESULTS

Lymphoscintigraphy was performed in 2196 (53.2%) of the 4131 patients in this study. IMC drainage was noted in 80 patients (3.6%). An axillary SLN was identified in 29 of the 40 patients with IMC drainage alone (72.5%). The rate of finding a positive axillary lymph node did not differ based on the lymphoscintigraphic pattern (P = .470).

CONCLUSIONS

Most surgeons do not perform IMC SLN biopsy procedures. Even when lymphoscintigraphy shows isolated drainage to IMC nodes, axillary SLNs usually are identified. Lymphoscintigraphy therefore has limited usefulness.

Factors predicting failure to identify a sentinel lymph node in breast cancer

BACKGROUND

Although sentinel lymph node (SLN) biopsy is widely accepted as a minimally invasive method of nodal staging, failure to identify an SLN mandates a level I/II axillary node dissection. The purpose of this study was to elucidate factors that independently predict failure to identify an SLN.

METHODS

Using a large multicenter prospective study of SLN biopsy for patients with invasive breast cancer, we performed univariate and multivariate regression analyses to determine clinicopathologic factors predictive of failure to identify an SLN.

RESULTS

Of the total 4131 patients in the study, an SLN was not identified in 249 (6.0%). Tumor location (P = .409), biopsy type (P = .079), surgery type (P = .380), and histologic subtype (P = .999) were not significant predictors of failure to identify an SLN. On multivariate analysis, age greater than 60 years (OR = 1.469; 95% CI, 1.116-1.934, P = .006), nonpalpable tumors (OR = 0.639; 95% CI, 0.479-0.852, P = .002), injection technique with blue dye alone (OR = 0.389, 95% CI, 0.259-5.86, P < .001), and surgical experience of less than 10 SLN biopsy cases (OR = 1.886; 1.428-2.492, P < .001) were significant independent predictors of failure to identify an SLN. Optimal SLN biopsy technique using an intradermal and/or subareolar injection of radioactive colloid and blue dye can improve SLN identification rates regardless of patient and tumor characteristics.

CONCLUSIONS

Patient age and tumor palpability significantly affect the ability to identify an SLN in patients with breast cancer. Optimal injection technique can significantly improve sentinel node identification rate regardless of these factors.

Fallacies of preoperative lymphoscintigraphy in detecting sentinel node in breast cancer

Background

Preoperative lymphoscintigraphy is one of the three methods of evaluating sentinel nodes in patients with breast cancer; however, it has been reported to have a high false negative rate.

Case presentations

We report here two cases where the preoperative lymphoscintigraphy was found to be fallacious. A 44-year-old female with T2N0 breast cancer underwent preoperative lymphoscintigraphy with Tc⁹⁹ sulfur colloid which failed to show any uptake in axilla or internal mammary chain. Intraoperative scintigraphy with blue dye and hand held gamma probe identified sentinel lymph node in axilla. Another patient with T2N0 lesion underwent preoperative lymphoscintigraphy which showed a sentinel lymph node in axilla and another in supraclevicular fossa. Intraoperative scintigraphy failed to show supraclevicular node however axillary node was correctly identified.

Conclusion

These two cases further strengthen the need to carry out triple test in identification of sentinel lymph node in patients with breast cancer. It also demonstrates the fallacies of preoperative lymphoscintigraphy.

Non-visualization of sentinel lymph nodes in penile carcinoma

PURPOSE

The purpose of this study was to analyse the incidence and cause of non-visualization of sentinel lymph nodes on preoperative lymphoscintigrams for penile cancer and its implications for further management.

METHODS

Preoperative lymphoscintigraphy was performed after injection of (99m)Tc-labelled nanocolloid in 123 clinically node-negative penile carcinoma patients. Anterior dynamic lymphoscintigraphy was performed during 20 min immediately after tracer injection. Subsequently, 5-min anterior and lateral static images were obtained 30 min and 2 h post injection.

RESULTS

Lymphatic drainage to both groins was seen in 98 patients (79%), unilateral drainage in 23 patients (19%) and no drainage at all in two patients (2%). Thus, in 27 (11%) of 246 groins, no sentinel node was visualized. The amount of administered tracer dose was associated with non-visualization (p=0.01). Unilateral drainage was initially interpreted as a normal physiological phenomenon. After the occurrence of a tumour-positive node in a non-visualized groin, we explore non-visualized groins by blue dye mapping and intraoperative palpation. Sentinel nodes were retrieved in four out of eight such groins, of which one contained metastasis.

CONCLUSION

In penile carcinoma patients, preoperative lymphoscintigraphy visualizes a sentinel node in 89% of groins. Visualization depends on the administered tracer dose. It is worthwhile to explore non-visualized groins. Sentinel nodes can be intraoperatively identified in more than half of these cases.

The Impact of Nonvisualization of Sentinel Nodes on Lymphoscintigraphy in Breast Cancer

BACKGROUND

This study aimed at evaluating the relationship between the nonvisualization of sentinel nodes (SNs) at lymphoscintigraphy and the intraoperative detection rate, radioactive counts in vivo, and histological status of SNs.

METHODS

Two hundred eighty patients with infiltrating breast carcinoma (T0, T(1)/T(2)) underwent preoperative lymphoscintigraphy before gamma probe-guided SN biopsy.

RESULTS

The surgical identification rate with a gamma probe was 84.6% (56 of 280) in lymphoscintigraphy-negative patients and 93.2% (224 of 280) in lymphoscintigraphy-positive patients (P < .05) after two subdermal periareolar injections. The average number of SNs per patient was 1.7 in lymphoscintigraphy-negative patients and 2.2 in lymphoscintigraphy-positive patients (P < .01), as assessed by gamma detection. The mean age of lymphoscintigraphy-negative patients was 62 +/- 10 years, versus 55 +/- 13 years for lymphoscintigraphy-positive patients (P < .001). The median radioactive count in dissected SNs identified by gamma detection was 204 cps (range, 4-618 cps) in lymphoscintigraphy-negative patients, versus 606 cps (range, 43-16,928 cps) in lymphoscintigraphy-positive patients (P < .001). The rate of macrometastatic SNs was 40% in lymphoscintigraphy-negative patients, versus 30% in lymphoscintigraphy-positive patients (not significant), whereas the size of involved SNs was 16.6 mm in lymphoscintigraphy-negative patients, versus 13.1 in lymphoscintigraphy-positive patients (P < .05). The micrometastasis detection rate in SNs from lymphoscintigraphy-negative patients was 6.25%, versus 23.3% in lymphoscintigraphy-positive patients (P < .01).

CONCLUSIONS

Negative lymphoscintigraphy was observed in 20% of patients and was more frequent in elderly patients. Negative lymphoscintigraphy was predictive of a lower surgical identification rate and fewer detected SNs. These SNs had fewer micrometastases, were fairly large, and tended to harbor metastases.

A critical review of variables affecting the accuracy and false-negative rate of sentinel node biopsy procedures in early breast cancer

Radionuclide sentinel lymph node localization and biopsy is a staging procedure that is being increasingly used to evaluate patients with invasive breast cancer who have clinically normal axillary nodes. The most important prognostic indicator in patients with invasive breast cancer is the axillary node status, which must also be known for correct staging, and influences the selection of adjuvant therapies. The accuracy of sentinel lymph node localization depends on a number of factors, including the injection method, the operating surgeon's experience and the hospital setting. The efficacy of sentinel lymph node mapping can be determined by two measures: the sentinel lymph node identification rate and the false-negative rate. Of these, the false-negative rate is the most important, based on a review of 92 studies. As sentinel lymph node procedures vary widely, nuclear medicine physicians and radiologists must be acquainted with the advantages and disadvantages of the various techniques. In this review, the factors that influence the success of different techniques are examined, and studies which have investigated false-negative rates and/or sentinel lymph node identification rates are summarized.

Impact of axillary nodal metastases on lymphatic mapping and sentinel lymph node identification rate in patients with early stage breast cancer

PURPOSE

The aim of this study was to define the impact of the presence of axillary nodal metastases on lymphatic mapping and sentinel lymph node (SLN) identification rate in patients with early breast cancer.

METHODS

Two hundred and forty-six lymphatic mapping procedures were performed with both labelled nanocolloid and blue dye, followed by SLN biopsy and/or complete axillary dissection. The following parameters were recorded: patient's age, tumour laterality and location, tumour size, tumour histology, tumour stage, tumour grade, lymphovascular invasion, radiotracer injection site (subdermal-peritumoural/peri-areolar), SLN visualisation at lymphoscintigraphy, SLN metastases (presence/absence, size) and other axillary metastases (presence/absence, number). Discriminant analysis was used to analyse the data.

RESULTS

SLNs were identified by labelled nanocolloid alone in 94.7% of tumours, by blue dye alone in 93.5% and by the combined technique in 99.2%. Discriminant analysis showed the gamma probe SLN identification rate to be significantly limited by the presence of axillary nodal metastases. In particular, the size of SLN metastases and the number of other axillary metastases were the most important variables in reducing the gamma probe SLN identification rate (p = 0.004 and p = 0.002, respectively). On the other hand, high tumour grade was the only parameter limiting the blue dye SLN identification rate.

CONCLUSION

The accuracy of lymphatic mapping with labelled nanocolloid is limited by the presence of axillary nodal metastases, and particularly by the degree of SLN tumoural invasion and the presence and number of other axillary nodal metastases. Neither of these elements seems to interfere with the blue dye identification rate. The combination of the two tracers maximises the SLN identification rate.

Clinical relevance of multiple sentinel nodes in patients with breast cancer

Background

Indiscriminate removal of axillary nodes may not be justified as it may potentially worsen the morbidity of the sentinel lymph node biopsy (SNB) procedure. This study examined the factors associated with removal of multiple sentinel lymph nodes and determined whether there was an upper threshold for the number of sentinel nodes that should be removed.

Methods

A total of 803 patients with breast cancer underwent successful SNB using peritumoral injection of 99mTc-labelled albumin colloid and Patent Blue V dye. SNB was followed by standard axillary treatment at the same operation in all patients.

Results

The mean number of sentinel nodes removed per procedure was 2·2 (range 1–9). Multiple sentinel nodes (mean 2·9, range 2–9) were found in 501 patients (62·4 per cent). The false-negative rate in patients who had one sentinel node harvested was 10 per cent, compared with 1 per cent in patients who had three or more nodes removed (P = 0·010). Factors associated with finding multiple sentinel nodes were age less than 50 years (P = 0·004), low body mass index (P &lt; 0·001), tumour in the outer half of the breast (P = 0·013), sentinel node visualization on lymphoscintigraphy (P &lt; 0·001) and an interval of 12 h or less between radioisotope injection and SNB (P = 0·014). For 99·6 per cent of node-positive tumours, metastasis was detected within the first four sentinel nodes removed.

Conclusion

The identification of multiple sentinel nodes, when present, reduced the false-negative rate. These data suggested that removal of more than four nodes was unnecessary.

Role of routine preoperative lymphoscintigraphy in sentinel node biopsy for breast cancer

Sentinel node biopsy (SNB) is rapidly emerging as the preferred technique for nodal staging in breast cancer. When radioactive colloid is used, a preoperative lymphoscintiscan is obtained to ease sentinel lymph node (SN) identification. This study evaluates whether preoperative lymphoscintigraphy adds diagnostic accuracy to offset the additional time and cost required. 823 breast cancer patients underwent SNB based on lymphoscintigraphy, intraoperative gamma probe detection, and blue dye mapping using 99 mTc-nanocolloid and Patent Blue V injected peritumourally. The SNB was followed by standard axillary treatment at the same operation. Preoperative lymphoscintigraphy was performed around 3 h after the radioisotope injection. Preoperative lymphoscintigraphy revealed SNs in 593 (72%) of the 823 patients imaged. SN visualisation on lymphoscintigraphy was less successful in large tumours and tumours involving the upper outer quadrant of the breast (P=0.046, P<0.001, respectively). Lymphoscintigraphy showed internal mammary sentinel nodes in 9% (62/707) patients. The SN was identified intraoperatively in 98% (581) patients who had SN visualised on preoperative lymphoscintigraphy, with a false-negative rate of 7%. In patients who did not have SN visualised on preoperative lymphoscintigraphy, the SN was identified at operation in 90% (204) patients, with a false-negative rate of 7%. The SN identification rate was significantly higher in patients with SN visualised on preoperative lymphoscintigraphy (P<0.001). SN identification rate intraoperatively using the gamma probe was significantly higher in the SN visualised group compared with the SN non-visualised group (95% vs. 68%; chi square (1 degrees of freedom (df)) P<0.001. There was no statistically significant difference in the false-negative rate and the operative time between the two groups. A mean of 2.3 (standard deviation (SD) 1.3) SNs per patient were removed in patients with SN visualised on preoperative lymphoscintigraphy compared with 1.8 (SD 1.2) in patients with no SN visualised on lymphoscintigraphy (P<0.001). Although SN visualisation on preoperative lymphoscintigraphy significantly improved the intraoperative SN localisation rate, SN was successfully identified in 90% of patients with no SN visualisation on lymphoscintigraphy. Given the time and cost required to perform routine preoperative lymphoscintigraphy, these data suggest that it may not be necessary in all cases. It may be valuable for surgeons in the learning phase to shorten the learning curve and in patients who have increased risk of intraoperative failed localisation (obese or old patients). A negative preoperative lymphoscintiscan predicts the inability to localise with the hand-held gamma probe. Therefore, if the SN is not visualised on lymphoscintigraphy then the addition of intraoperative blue dye is recommended to increase the likelihood of SN identification.