Annette Hougaard Chakera

Factors of importance for scintigraphic non-visualisation of sentinel nodes in breast cancer

PurposeThe aim of this study was to analyse different factors of possible significance for non-visualisation of sentinel nodes (SNs) by preoperative lymphoscintigraphy, in order to enable improvement of the success rate of SN visualisation through modification or alteration of some of the factors.Methods Between March 1998 and January 2003 we analysed a series of 442 women with unilateral stage T1 and clinical N0 breast cancer. Lymphoscintigraphy was performed after periareolar or peritumoural injection of 99mTc-albumin nanocolloid, with image acquisition after 2–6xa0h or 18–24xa0h. Until January 2001, all patients received around 20xa0MBq tracer, irrespective of time to operation. From January 2001, patients injected on the day before surgery received at least 100xa0MBq while patients injected on the day of surgery received around 50xa0MBq.Results An SN was visualised in 87% of the patients, and at surgery the SN was detected with the hand-held gamma probe in 42% of the remaining patients. By multiple logistic regression analysis, statistically significant independent variables that increased the risk for non-visualisation were increasing age (p=0.0007), increasing body weight (p=0.0189) and peritumoural injection (p<0.0001). Significant interaction was found for imaging time and injected activity (p=0.0017).ConclusionThis study conclusively shows that the risk of unsuccessful SN imaging increases with age and body weight. Our findings suggest that the scintigraphic success rate may be improved by periareolar (rather than peritumoural) injection. Early and late imaging procedures are equally efficient, but if a late imaging procedure is used, activity (adjusted for physical decay) in the patient on day 2 should be more than 10xa0MBq.

Radiation doses to staff involved in sentinel node operations for breast cancer.

Background:u2002 The use of radioactive compounds for sentinel node biopsy is now a generally accepted part of the surgical treatment of breast cancer and melanoma, with the risk of radiation exposure to the operating team. The aim of this investigation was to study the levels of this exposure in relation to the permissible radiation dose limits.

Sentinel node biopsy for melanoma: a study of 241 patients.

The aim of this study was to evaluate the sentinel node biopsy (SNB) technique for melanoma using both radiocolloid and blue dye in 241 clinically N0 patients with melanomas >1.0u2009mm, or thinner lesions exhibiting regression/ulceration. We showed that an increase in injected radioactivity increased both the number of visualized nodes at lymphoscintigraphy and the number of SNs removed surgically. At least one SN was removed in 98% (236) of patients, and all nodes were identified with the probe. Seventy-four per cent of the 194 patients injected with blue dye had stained SNs. In 46% (144) of the lymph node basins, there was a discrepancy between the nodes visualized at lymphoscintigraphy and the nodes removed at surgery. There were 38 unusually located nodes. Only eight of these were removed surgically; none contained metastases. SN metastases were detected in 22% (53) of patients. There were nine haematoxylin and eosin (HE)-negatives, all of which were found by immunohistochemistry. The false negative rate for the SNB procedure was 4% (2/55). The complication rate was 6% after SNB and 29% after complete node dissection. In conclusion, SN status is a strong prognostic factor in melanoma patients, and SNB has made the approach to radical lymphadenectomy more rational.

EANM practice guidelines for lymphoscintigraphy and sentinel lymph node biopsy in melanoma

PurposeSentinel lymph node biopsy is an essential staging tool in patients with clinically localized melanoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with melanoma.MethodsThese practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, national nuclear medicine societies, the European Society of Surgical Oncology (ESSO) and the European Association for Research and Treatment of Cancer (EORTC) melanoma group. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI).ConclusionThe present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of melanoma patients.

Radiation exposure to surgical staff during F-18-FDG-guided cancer surgery

PurposeHigh-energy gamma probes have recently become commercially available, developed for 18F-FDG probe-guided surgery. The radiation received by the staff in the operating room might limit the use of it, but has never been determined. We therefore wanted to measure the absorbed staff doses at operations where patients had received a preoperative injection of 18F-FDG.MethodsThrity-four patients with different cancers (breast cancer, melanoma, gastrointestinal cancers, respectively) were operated. At every operation the surgeon was monitored with a TLD tablet on his finger of the operating hand and a TLD tablet on the abdomen. The surgeon and anaesthesiologist were also monitored using electronic dosimeters placed in the trousers lining at 25 operations.ResultsThe dose rate to the surgeon’s abdominal wall varied between 7.5–13.2xa0μSv/h, depending on tumour location. The doses to the anaesthesiologists and the finger doses to the surgeon were much lower. About 350–400xa0MBq, i.e. ca. eight times higher activities than those used in the present study are supposed to be necessary for guiding surgery. It can be calculated from the body doses measured that a surgeon can perform between 150–260xa0h of surgery without exceeding permissible limits for professional workers.ConclusionsThe radiation load to the operating staff will generally be so small that it does not present any limitation for FDG-guided surgery. However, it is recommended to monitor the surgical staff considering that the surgeon may be exposed to other radiation sources, and since the staff often includes women of child-bearing age.

The diagnostic value of adding dynamic scintigraphy to standard delayed planar imaging for sentinel node identification in melanoma patients

PurposeThe aim of this study was to compare early dynamic imaging combined with delayed static imaging and single photon emission computed tomography (SPECT)/CT with delayed, planar, static imaging alone for sentinel node (SN) identification in melanoma patients.MethodsThree hundred and seven consecutive melanoma patients referred for SN biopsy (SNB) were examined using combined imaging. Secondary interpretation of only the delayed static images was subsequently performed. In 220 patients (72%), complete surgical and pathological information relating to the SNB was available. The number of SNs identified and number of patients with positive SNs were compared between the two interpretations of the imaging studies and, when available, related to pathology data.ResultsA slightly higher number of SNs (mean 0.12/patient) was identified when interpreting only delayed static images compared to combined imaging. In a direct patient-to-patient comparison, the number of SN(s) identified on the combined vs static images only showed moderate agreement (kappa value 0.56). In 38 patients (17%), positive SNs were identified by the combined procedure compared to 35 (16%) by static imaging only. Thus by static imaging only, tumour-positive SNs were not identified in 3 of 38 patients (8%).ConclusionFor SN identification in melanoma patients, dynamic imaging combined with delayed static imaging and SPECT/CT is superior to delayed static imaging only because the latter is more likely to fail to identify SNs containing metastases.

In-transit sentinel nodes must be found: implication from a 10-year follow-up study in melanoma.

The aim was to study the occurrence of in-transit nodes at a preoperative lymphoscintigraphy for patients with primary melanoma, and to reveal their potential role in prognosis. From 1984 to 1996, 911 patients, hospitalized for wide excision of a clinically localized primary cutaneous head–neck or truncal melanoma, had a static lymphoscintigraphy on the day before surgery as part of a prospective protocol. Lymph nodes were in no case removed at the time of scintigraphy. Recurrence and survival patterns were compared for patients with in-transit nodes with the remaining patients with only regional nodes. Follow-up time was a minimum of 10 years. In-transit nodes were visualized by lymphoscintigraphy in 6% of the patients, 18% of whom had a later recurrence in this region. The melanomas in the in-transit node group were slightly thicker, and ulceration was slightly more frequent (neither significant). The in-transit node group had significantly more lymph node basins visualized at scintigraphy compared with the remaining group of patients with only regional nodes. The risk of recurrence and/or death from melanoma was significantly worse (P<0.05) in the in-transit node group compared with the remaining patients. The clinical significance of the in-transit nodes, occasionally seen in melanoma patients (also in stage Ia), may suggest a slightly poorer prognosis and a substantial risk of a later recurrence in the in transit region. We therefore recommend that in-transit nodes must be found and examined exactly as is done with locoregional sentinel nodes.

One-day or two-day procedure for sentinel node biopsy in melanoma?

PurposeWe compared the outcome of a 1-day and a 2-day sentinel node (SN) biopsy procedure, evaluated in terms of lymphoscintigraphic, surgical and pathological findings.MethodsWe studied 476 patients with melanoma from two melanoma centres using static scintigraphy and blue dye. A proportional odds model was used for statistical analysis.ResultsThe number of SNs visualized at scintigraphy increased significantly with time from injection to scintigraphy and activity left in the patient at scintigraphy, and depended on the melanoma location. The number of SNs removed at surgery increased with the number of SNs visualized at scintigraphy and time from injection to surgery. The frequency of nodal metastasis increased with increasing thickness and Clark level of the melanoma, and was highest for two SNs visualized at scintigraphy.ConclusionThis study showed that early vs. late imaging and surgery do make a difference on the outcome of the SN procedure and confirmed the importance of the scintigraphic visualization of all true SNs.

Radionuclide leakage monitoring during hyperthermic isolated limb perfusion for treatment of local melanoma metastasis in an extremity

The aim is to describe the importance of leakage monitoring in hyperthermic isolated limb perfusion (ILP). It is generally recommended that leakage should not exceed 10% because of risk of systemic toxicity.

Radiation exposure to surgical staff during hyperthermic isolated limb perfusion with 99mTechnetium labeled red blood cells

Purpose: Hyperthermic isolated limb perfusion (HILP) is an effective method in the treatment of recurrent melanomas and soft tissue sarcomas. To avoid systemic toxicity, leakage from the limb perfusate into the systemic circulation is real-time monitored by administration of a radioactive agent to the limb circuit. This has made HILP safe for the patient. However, the radiation exposure to the surgical staff has never been measured and could be a limiting factor for the use of HILP. The purpose of the present study was to measure and evaluate the radiation exposure to the surgical staff performing HILP with 99mTechnetium labeled red blood cells. Materials and methods: Thirteen patients had HILP performed in 11 lower limbs and two upper limbs at our inpatient clinic between October 2006 and February 2007. The surgeon and nurse had thermoluminescence dosimetry (TLD) chips attached to the finger pulp and to the ring area of the left fourth finger, as well as an electronic dosimeter attached to the anterior lining of the trousers. The anesthesiologist and perfusion technologist also carried electronic dosimeters. Results: The surgeon had the highest radioactive exposure with an average dose per procedure to the finger pulp of 16.2 µSv, to the ring area of 8.5 µSv, and to the abdominal wall of 4.2 ± 0.6 µSv. Conclusions: HILP with 99mtechnetium-labeled red blood cells does not constitute a safety risk to the operating team with respect to radioactive exposure. Routine dose monitoring of the staff or special precautions for fertile women are not necessary.