Transferring innovative freehand SPECT to the operating room: first experiences with sentinel lymph node biopsy in malignant melanoma

PURPOSE

The purpose of this study was to report on the first experiences with freehand single-photon emission-computed tomography (freehand SPECT) in sentinel lymph node biopsy (SLNB) in patients with malignant melanoma. Freehand SPECT is a novel imaging modality combining gamma probes, surgical navigation systems, and emission tomography algorithms, designed to overcome some of the limitations of conventional gamma probes.

METHODS

In this study 20 patients with malignant melanoma underwent conventional planar scintigraphy prior to surgery. In the operating room, the number and location of separable SLNs were detected first by a pre-incisional scan with freehand SPECT to render a 3D-image of the target site and afterwards by a scan with a conventional gamma probe. After SLNB another scan was performed to document the removal of all targeted SLNs.

RESULTS

Planar scintigraphy identified 40 SLNs in 26 nodal basins. Pre-incisional freehand SPECT mapped 38 of these nodes as well as one additional node in one patient (95.0% node based sensitivity). The results of freehand SPECT were identical to those of planar scintigraphy in 25 basins, while it missed one basin (96.2% basin based sensitivity). In comparison, the gamma probe failed to detect 7 nodes in 4 basins (82.5% node based sensitivity and 84.6% basin based sensitivity). After resection freehand SPECT detected 9 remaining radioactive spots, two of whichwere resected as they matched the position of SLNs detected on preoperative planar scintigraphy.

CONCLUSIONS

Freehand SPECT provides a real-time, intraoperative 3D-image of the radioactive labelled SLNs, facilitating their detection and resection.

First Experiences with Navigated Radio-Guided Surgery Using Freehand SPECT

Background

Sentinel lymph node biopsy (SLNB) in melanoma using one-dimensional gamma probes is a standard of care worldwide. Reports on the performance are claimed by most groups to successfully detect the SLNs during the surgical procedure in almost 100% of the patients. In clinical practice, however, several issues remain which are usually not addressed: the difficulty of intraoperative detection of deeply located nodes, SLN detection in obese patients or in the groin and the impossibility to make a scan of the entire wound after SLN resection to avoid false negative testing for eventually remaining SLNs.

Materials and Methods

The concept behind freehand SPECT is to combine a gamma probe as used for conventional radio-guided surgery with a tracking system as used in neurosurgical navigation. From this combination and a proper algorithm framework the 3D reconstruction of radioactivity distributions and displaying these intraoperatively is possible.

Conclusion

In summary, the feasibility of freehand SPECT could be shown and provides an image-guided SLNB and a truly minimally invasive and optimized surgical procedure.

In melanoma, beta-catenin is a suppressor of invasion

Cell-type specific signalling determines cell fate under physiological conditions, but it is increasingly apparent that also in cancer development the impact of any given oncogenic pathway on the individual cancer pathology is dependent on cell-lineage specific molecular traits. For instance in colon and liver cancer canonical Wnt signalling produces increased cytoplasmic and nuclear localised beta-catenin, which correlates with invasion and poor prognosis. In contrast, in melanoma increased cytoplasmic and nuclear beta-catenin is currently emerging as a marker for good prognosis and thus appears to have a different function compared to other cancer types; however this function is unknown. We discovered that in contrast to its function in other cancers, in melanoma, beta-catenin blocks invasion. We demonstrate that this opposing role of nuclear beta-catenin in melanoma is mediated through MITF, a melanoma-specific protein that defines the lineage background of this cancer type. Downstream of beta-catenin MITF not only suppresses the Rho-GTPase regulated cell-morphology of invading melanoma cells, but also interferes with beta-catenin induced expression of the essential collagenase MT1-MMP, thus affecting all aspects of an invasive phenotype. Importantly, overexpression of MITF in invasive colon cancer cells modifies beta-catenin directed signalling and induces a ‘melanoma-phenotype’. In summary, the cell type specific presence of MITF in melanoma affects beta-catenin’s pro-invasive properties otherwise active in colon or liver cancer. Thus our study reveals the general importance of considering cell-type specific signalling for the accurate interpretation of tumour markers and ultimately for the design of rational therapies.

Allergenicity of wine containing processing aids: a double-blind, placebo-controlled food challenge

BACKGROUND

The European Union requires allergenic food ingredients to appear on labels in order to protect allergic consumers.

OBJECTIVE

To determine whether traces of egg-, milk-, and fish-derived processing aids used in winemaking might elicit clinical reactions in food-allergic patients.

METHODS

Five German wines were fined with a high dose of egg albumin, lysozyme, milk casein, fish gelatin, or isinglass, and filtered. Fourteen adults with allergy to egg (n = 5), milk (n = 5), or fish (n = 4) were included. Skin prick tests were performed with fining agents, and fined and unfined wines. All patients underwent double-blind placebo-controlled food challenges with fined and unfined wines.

RESULTS

Skin prick tests were positive to hen's egg (n = 5), ovalbumin (n = 5), lysozyme (n = 4), cow's milk (n = 5), casein (n = 4), and cod (n = 3), but not to isinglass or fish gelatin (n = 0). Positive skin prick test results were observed for wines fined with albumin (n = 3), lysozyme (n = 2), casein (n = 1), gelatin (n = 0), and isinglass (n = 3), and for unfined wines (n = 1-2 in each patient group), with no significant differences between groups. Seventy-five percent of skin test-positive patients had specific immunoglobulin E to other allergens present in wine (eg, carbohydrates). The provocation test revealed no reactions to fined or unfined wines.

CONCLUSIONS

Although concentrated fining agents containing ovalbumin, lysozyme, and casein were allergenic in the skin prick test, no patient reacted adversely in the provocation test to fined wine. Wines treated with fining agents at commercial concentrations appear not to present a risk to allergic individuals when filtered,

[Reticular erythematous plaques]

Reticular erythematous mucinosis (REM) syndrome primarily affects young women; the skin lesions usually appear on the chest and upper back. REM is diagnosed on the basis of the clinical picture and histological findings. REM syndrome is often associated with lupus erythematosus tumidus. Both diseases respond well to treatment with chloroquin. Topical tacrolimus and the use of a pulsed dye laser have fewer side effects and have also proved to be effective.