Improved staging of breast cancer through lymphatic mapping and sentinel node biopsy

Radioguided Occult Lesion Localization: Technical Procedures and Clinical Applications

PURPOSE

Regarding radioguided surgery, the concept of "radioguided occult lesion localization" (ROLL) is based on both preoperative interventional imaging and intraoperative radioguided detection of a clinically occult neoplastic lesion.

METHODS

This methodology consists in the direct administration into the lesion of Tc-macroaggregated human albumin formed by relatively large particles retained at the injection site, which direct radioguided excisional biopsy.

RESULTS

This modality has expanded from the classic application of ROLL for nonpalpable breast lesions to other tumors, such as solitary pulmonary nodules or recurrences from differentiated thyroid carcinoma. In 2011, in order to improve the classification of different radioguided surgical procedures, ROLL applications were included in the more complete concept of GOSTT (Guided intraOperative Scintigraphic Tumor Targeting). This concept was introduced to include the entire range of basic and advanced radioguided procedures necessary to supply a "road map" for the surgeon.

CONCLUSIONS

The terms ROLL and GOSTT have further developed by incorporating novel modalities such as hybrid tracers for simultaneous fluorescence and radioactive signal detection and innovative navigation systems based on mixed-reality protocols.

Navigation of a robot-integrated fluorescence laparoscope in preoperative SPECT/CT and intraoperative freehand SPECT imaging data: a phantom study

Robot-assisted laparoscopic surgery is becoming an established technique for prostatectomy and is increasingly being explored for other types of cancer. Linking intraoperative imaging techniques, such as fluorescence guidance, with the three-dimensional insights provided by preoperative imaging remains a challenge. Navigation technologies may provide a solution, especially when directly linked to both the robotic setup and the fluorescence laparoscope. We evaluated the feasibility of such a setup. Preoperative single-photon emission computed tomography/X-ray computed tomography (SPECT/CT) or intraoperative freehand SPECT (fhSPECT) scans were used to navigate an optically tracked robot-integrated fluorescence laparoscope via an augmented reality overlay in the laparoscopic video feed. The navigation accuracy was evaluated in soft tissue phantoms, followed by studies in a human-like torso phantom. Navigation accuracies found for SPECT/CT-based navigation were 2.25 mm (coronal) and 2.08 mm (sagittal). For fhSPECT-based navigation, these were 1.92 mm (coronal) and 2.83 mm (sagittal). All errors remained below the <1-cm detection limit for fluorescence imaging, allowing refinement of the navigation process using fluorescence findings. The phantom experiments performed suggest that SPECT-based navigation of the robot-integrated fluorescence laparoscope is feasible and may aid fluorescence-guided surgery procedures.

Hybrid radioguided occult lesion localization (hybrid ROLL) of (18)F-FDG-avid lesions using the hybrid tracer indocyanine green-(99m)Tc-nanocolloid

PURPOSE

To assess if combined fluorescence- and radio-guided occult lesion localization (hybrid ROLL) is feasible in patients scheduled for surgical resection of non-palpable (18)F-FDG-avid lesions on PET/CT.

METHODS

Four patients with (18)F-FDG-avid lesions on follow-up PET/CT that were not palpable during physical examination but were suspected to harbor metastasis were enrolled. Guided by ultrasound, the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was injected centrally in the target lesion. SPECT/CT imaging was used to confirm tracer deposition. Intraoperatively, lesions were localized using a hand-held gamma ray detection probe, a portable gamma camera, and a fluorescence camera. After excision, the gamma camera was used to check the wound bed for residual activity.

RESULTS

A total of six (18)F-FDG-avid lymph nodes were identified and scheduled for hybrid ROLL. Comparison of the PET/CT images with the acquired SPECT/CT after hybrid tracer injection confirmed accurate tracer deposition. No side effects were observed. Combined radio- and fluorescence-guidance enabled localization and excision of the target lesion in all patients. Five of the six excised lesions proved tumor-positive at histopathology.

CONCLUSION

The hybrid ROLL approach appears to be feasible and can facilitate the intraoperative localization and excision of non-palpable lesions suspected to harbor tumor metastases. In addition to the initial radioguided detection, the fluorescence component of the hybrid tracer enables high-resolution intraoperative visualization of the target lesion. The procedure needs further evaluation in a larger cohort and wider range of malignancies to substantiate these preliminary findings.

Breast conservation: Current results and future perspectives at the European Institute of Oncology

In the recent 10 years breast cancer treatments' scenario is radically changed. Extraordinary new surgical approaches give more and more conservative solutions both for the breast and especially for the axilla avoiding dissection in more than 80% of early cases. Instrumental early diagnosis and clinical prediction are now able to identify very initial cases often in premalignant stage. Technology arrived in the operating theatre for the intraoperative radiotherapy treatments giving to the patients the better quality of life with the help also of the plastic surgeons. There are still near horizons to reach: modern neo-adjuvant and adjuvant treatments are going quickly from the laboratory to patient's bed.

Should the hunt for internal mammary chain sentinel nodes begin? An evaluation of 150 breast cancer patients

BACKGROUND

The aim of this study was to determine the visualization rate, identification rate, and clinical implications of biopsy of sentinel nodes in the internal mammary chain (IMC) in patients with breast cancer.

METHODS

From January 1999 to December 2002, 691 sentinel node procedures were performed. Preoperative lymphoscintigraphy was performed after injection of (99m)Tc-labeled nanocolloid into the tumor (.2 mL; 115 MBq; 3.1 mCi). The sentinel node was surgically identified with the aid of patent blue dye and a gamma ray detection probe.

RESULTS

The sentinel node in the IMC could be harvested in 130 (87%) of the 150 patients in whom it was visualized on the images and contained metastases in 22 (17%) of these 130 cases. In nine patients (7%), the IMC sentinel node was tumor positive, whereas the axilla was tumor-free. Stage migration was seen in all patients with a tumor-positive IMC sentinel node (17%). There was a change of management in 38 (29%) of the 130 patients: institution or omission of radiotherapy to the IMC, adjuvant systemic therapy, or omission of an axillary lymph node dissection.

CONCLUSIONS

Pursuit of IMC sentinel nodes improves the staging of patients with breast cancer and enables treatment to be better adjusted to the needs of the individual patient.

Stage migration after biopsy of internal mammary chain lymph nodes in breast cancer patients

BACKGROUND

Involvement of the internal mammary chain lymph nodes (IMNs) is associated with worsened prognosis in breast cancer. Use of lymphoscintigraphy to visualize sentinel nodes reveals that IMNs often receive lymph from the area containing the tumor.

METHODS

We biopsied IMNs in 182 patients because there was radiouptake to the IMNs or because the tumor was located in the medial portion of the breast. After tumor removal, pectoralis major fibers were divided to expose intercostal muscle. A portion of intercostal muscle adjacent to the sternum was removed. Lymph nodes and surrounding fatty tissue in the intercostal space were freed, removed, and analyzed histologically. The pleural cavity was breached in four cases (2.2%), with spontaneous resolution.

RESULTS

IMNs were found in 160 (88%) of 182 patients; 146 (94.4%) were negative and 14 (8.8%) were positive. The latter received internal mammary chain radiotherapy. The axilla was negative in 4 of 14 cases and positive in 10.

CONCLUSIONS

IMNs can be quickly and easily removed via the breast incision with insignificant risk and no increase in postoperative hospitalization. The patients with a positive IMN migrated from N0 (4 cases) or N1 (10 cases) to N3, prompting modification of both local (radiotherapy to internal mammary chain) and systemic treatment; without IMN sampling, they would have been understaged.

Anatomy and physiology of lymphatic drainage of the breast from the perspective of sentinel node biopsy

Knowledge of the anatomy and physiology of the lymphatic system is helpful when considering a particular sentinel node biopsy technique. The delicate balance between internal and external pressures in a lymphatic channel can be influenced by the injection volume and by massage in a negative or positive way. The narrow openings in the interendothelial junctions determine the speed of clearance of particles with a certain size, and this has implications for the timing of lymphoscintigraphy and surgery. Tracer uptake and lymph flow are highly variable and depend on a number of factors, some of which are beyond our control. The lymphatic anatomy is not completely understood despite numerous studies since the end of the 18th century. Several topics have been elucidated in more recent studies and through experience with sentinel node biopsy. First, although axillary drainage is the principal lymphatic path of the breast, any drainage pattern from any quadrant of the breast can occur. Second, most lymph from the breast flows to the nodal basins with a direct course, not passing through the subareolar plexus. Another relevant point is that gentle massage encourages lymph flow and facilitates sentinel node detection. What problems do we still face in clinical practice? The optimum size and number of labeled colloid particles remain to be established. The optimum volume of the tracer also remains to be determined. But the main controversy concerns the injection site. Although the intradermal injection technique has attractive practical features, there is currently insufficient certainty that drainage of tracer injected anywhere in or underneath the skin of the breast reflects drainage from the cancer. Connections between collecting lymphatic vessels from the tumor site and the collecting vessels from the skin and subdermal lymphatics can explain the concordance between intraparenchymal and superficial injections in most patients. To determine the technique that yields the best sentinel node identification rate with the lowest possible false-negative rate would require a large randomized trial with all patients undergoing a complete lymph node dissection and evaluation of all other axillary lymph nodes with serial sections and immunohistochemistry. Current knowledge about sensitivity is based on examination of the other axillary nodes with hematoxylin and eosin staining and not with immunohistochemistry, with the exception of two studies. (33,76) In addition, a complete level I to III dissection may not have been done in all patients, and it is not certain that pathologists removed and examined all the nodes from the specimens. The proposed study seems impossible now that routine axillary node dissection has been abandoned by the larger centers around the world. Choosing the most attractive approach requires determining the aim of lymphatic mapping. A superficial injection technique may be adequate when the purpose is to spare patients without lymph node metastases in the axilla an unnecessary axillary node dissection. An intraparenchymal injection technique should be used when the additional purpose is to determine the stage as accurately as possible and to identify sentinel nodes elsewhere.

Non-visualization of sentinel lymph node in patients with breast cancer

Histological evaluation of the first draining lymph node (sentinel node) in the axilla of patients with breast cancer has dramatically altered the surgical approach to these patients, with sparing of the axilla if no tumour cells are identified. In a fraction of patients imaged after peri-tumoural injection of the breast, there is no visualization of the sentinel node. We retrospectively analysed the status of patients whose nodes were visualized and of patients whose nodes failed to visualize, to define the variables associated with non-visualization of the sentinel node. Seventy-four breast cancer patients were imaged following peri-tumoural injection of filtered 99Tc(m)-sulfur colloid, immediately and up to 5.5 h post-injection. The scintigraphic data were analysed with reference to the patient's age, histology, grade, site and size of tumour, previous diagnostic procedure and time interval to scan, using univariate analysis and a logistic regression model. A sentinel node was visualized in 53 of 74 women (72%). Comparison of patients with non-visualized versus visualized sentinel nodes disclosed no statistically significant univariate relation to age of the patients (P = 0.10), size of tumour (P = 0.46), site (P = 0.26), histology [invasive ductal carcinoma in 16 of 20 (80%) non-visualized cases, and in 43 of 53 (81%) visualized patients], prior excision biopsy (P = 0.36) and time interval to surgery (P = 0.29). Tumour grade was the only significant variable on univariate analysis (P = 0.03), though multivariate analysis showed that none of the independent parameters were statistically significant. In 39 patients with an upper outer quadrant tumour, the location of the sentinel node was not limited to the axilla and even crossed the midline of the breast. Our results show that none of the independent variables is associated with non-visualization of sentinel lymph node on preoperative lymphoscintigraphy of patients with breast cancer, though the tumour grade may have contributed to non-visualization of this node. The non-axillary drainage from upper outer quadrant tumours suggests the routine use of lymphoscintigraphy prior to axillary dissection.