99mTc-Tilmanocept performance for sentinel node mapping in breast cancer, melanoma, and head and neck cancer: a systematic review and meta-analysis from a European expert panel

PURPOSE

Although multiple radiopharmaceuticals are currently available for sentinel node (SN) biopsy, 99mTc-tilmanocept is of particular interest due to its low molecular weight and specific binding capability for the mannose receptors of lymphatic reticuloendothelial cells. In the current systematic review and meta-analysis, we aimed to provide an update from a European expert panel on the performance of 99mTc-tilmanocept for SN biopsy.

METHODS

A systematic literature search of the PubMed/Medline and Embase databases was performed to identify studies on the use of 99mTc-tilmanocept for SN identification in oncological patients. The articles' methodological quality was assessed before inclusion. The pooled estimates of the pre-/intraoperative detection rates (DR; proportion of patients with ≥ 1 SN identified) and/or pN + sensitivity (SN + /pN + patients ratio), with 95% confidence intervals (CIs), were calculated for breast cancer, melanoma, and head and neck cancer.

RESULTS

Twenty-four articles were included in the systematic review, and twenty-one provided data for the meta-analysis. According to data availability, the 99mTc-tilmanocept-estimated pooled preoperative and intraoperative DRs were 0.94 (95%CI, 0.88-1.01) and 0.99 (0.98-1.00) for breast cancer, 0.98 (0.96-0.99) and 1.00 (0.99-1.00) for melanoma, and 0.97 (0.93-1.02) and 0.99 (0.96-1.01) for head and neck carcinoma. Finally, the pooled sensitivity for nodal metastasis in melanoma was 0.97 (95% CI, 0.92-1.03).

CONCLUSION

99mTc-tilmanocept is a promising radiotracer for SN mapping in patients with breast cancer, melanoma, or head and neck cancer. We strongly believe that multicenter trials are still needed to assess if 99mTc-tilmanocept is superior to other radiotracers used in clinical routine.

Effectiveness of an (18)F-FDG-PET based strategy to optimize the diagnostic trajectory of suspected recurrent laryngeal carcinoma after radiotherapy: The RELAPS multicenter randomized trial

PURPOSE

The purpose of this study is to evaluate the efficacy of (18)F-FDG-PET as first-line diagnostic investigation, prior to performing a direct laryngoscopy with biopsy under general anesthesia, in patients suspected of recurrent laryngeal carcinoma after radiotherapy.

PATIENTS AND METHODS

150 patients suspected of recurrent T2-4 laryngeal carcinoma at least two months after prior (chemo)radiotherapy with curative intent for resectable disease were randomized to direct laryngoscopy (CWU: conventional workup strategy) or to (18)F-FDG-PET only followed by direct laryngoscopy if PET was assessed 'positive' or 'equivocal' (PWU: PET based workup strategy), to compare the effectiveness of these strategies. Primary endpoint was the number of indications for direct laryngoscopies classified as unnecessary based on absence of recurrence, both on direct laryngoscopy and on six month follow up. Safety endpoints comprised resectability of recurrent lesions and completeness of surgical margins following salvage laryngectomy.

RESULTS

Intention-to-treat analyses were performed on all randomized patients (CWU: n=74, PWU: n=76). Tumor recurrence was similar in both groups: 45 patients (30%; 21 CWU, 24 PWU) within six months. In 53 patients in the CWU arm (72%, 95% CI: 60-81) unnecessary direct laryngoscopies were performed compared to 22 in the PWU arm (29%, 95% CI: 19-40) (p<0·0001). The percentage of salvage laryngectomies (resectability) and positive surgical margins were similar between CWU and PWU (81%, 63% respectively, p=0·17, and 29%, 7%, respectively, p=0.20). The prevalence of the combination of local unresectability and positive margins is in the CWU group 24% and in the PWU group 8%. No difference (p=0.32) in disease specific survival between both groups was found.

CONCLUSION

In patients with suspected laryngeal carcinoma after radiotherapy, PET as the first diagnostic procedure can reduce the need for direct laryngoscopy by more than 50% without jeopardizing quality of treatment.

Melanoma and nuclear medicine

Supported by a large body of published work, the contribution of nuclear medicine technologies to the assessment of melanoma has been increasing in recent years. Lymphoscintigraphy-assisted sentinel lymph node biopsy and PET are in continuous evolution with the aid of technological imaging advances, making it possible to fuse functional and anatomic images (e.g., with SPECT/CT, PET/CT and 3D rendering systems). The development of hybrid fluorescent-radioactive tracers that enable high-quality preoperative lymphoscintigraphy and SPECT/CT, and the optimization of modern intraoperative portable imaging technologies, such as free-hand SPECT and portable γ-cameras, are important innovations that have improved sentinel lymph node identification in complex anatomical areas, such as the pelvis and head and neck. Concurrently, ¹⁸F-fluorodeoxyglucose-PET has proved its usefulness in the clinical staging and treatment decision-making process, and there is also emerging evidence regarding its utility in the evaluation of therapeutic response. The potential uses of other novel PET radiotracers could open up a new field of use for this technique. In this article, we review the current and future role of nuclear medicine in the management of melanoma.

Tracer-cocktail injections for combined pre- and intraoperative multimodal imaging of lymph nodes in a spontaneous mouse prostate tumor model

To improve surgical guidance toward prostate draining lymph nodes, we investigate the potential of intraoperative fluorescence imaging and combined pre- and intraoperative multimodality imaging approaches. Transgenic adenocarcinoma mouse prostate mice with spontaneous prostate tumors are injected intratumorally with: 1. a cocktail of patent blue (Pb) and indocyanine green (ICG); 2. a cocktail of albumin radiocolloids (99mTc-NanoColl), Pb, and ICG; or 3. a cocktail of radiolabeled albumin (99mTc-Vasculosis), Pb, and ICG. The distribution of these imaging agents over the lymph nodes (LNs) are studied at different time points after injection. We find that at 60-min postinjection, ICG significantly improves the detection of the LNs compared to Pb, 53 versus 7%, respectively. Moreover, a cocktail of ICG and 99mTc-NanoColl improves the fluorescent detection rate to 86%, equalling that of the clinically applied 99mTc-NanoColl. A similar overlap is observed in our initial clinical pilot data. Fluorescent detection of the LNs using a ICG with 99mTc-Vasculosis gives similar results as "free" ICG (58%; 60 min). A 99mTc-NanoColl, Pb, and cocktail ICG enriches the standard 99mTc-NanoColl approach by adding optical detection of the sentinel lymph nodes. Furthermore, this approach improves fluorescent-based guidance and enables both accurate surgical planning and intraoperative detection, based on a single injection.

Predicting early chemotherapy response with technetium-99m methoxyisobutylisonitrile SPECT/CT in advanced non-small cell lung cancer

PURPOSE

The purpose of this study is to examine the prognostic value of prechemotherapy technetium-99m methoxyisobutylisonitrile ((99m)Tc-MIBI) uptake with single photon emission computed tomography/computed tomography (SPECT/CT) in relation to tumor size change measured by CT.

METHODS

Eleven patients with stage IIIB/IV non-small cell lung cancer (NSCLC) underwent (99m)Tc-MIBI SPECT/CT within 24 h before starting platinum-containing chemotherapy. Following the Response Evaluation Criteria in Solid Tumors guidelines, 20 lesions from the 11 patients were available for evaluation. Maximum (C (max)) and mean (C (mean)) MIBI counts were calculated for each lesion. One-dimensional (1D; longest diameter) and two-dimensional (2D; area of the largest transverse surface) tumor measurements were assessed by two observers on the diagnostic CT and the response assessment CT after two cycles of chemotherapy.

RESULTS

Bland-Altman analysis demonstrated no clinically significant bias between the observers. A solid correlation was found between (99m)Tc-MIBI C (mean) and change in the longest diameter (1D change) of the target lesion (rho = -0.62) using Spearman's rank correlation test. C (mean) also correlated negatively with change in the area of the largest transverse surface (2D change) of the target lesion (rho = -0.53). Furthermore, a correlation was established between (99m)Tc-MIBI C (max) and 1D change (rho = -0.56) in tumor size as well, though less strongly when compared to its C (mean) counterpart.

CONCLUSIONS

Our series demonstrated solid, negative correlations between prechemotherapy (99m)Tc-MIBI uptake and tumor size change measured by CT for advanced NSCLC, particularly with C (mean) and 1D change.

Prospective study on late renal toxicity following postoperative chemoradiotherapy in gastric cancer

PURPOSE

Postoperative chemoradiotherapy in gastric cancer improves locoregional control and survival. Reports on late toxicity, however, have been scarce thus far. Because renal toxicity is one of the most serious late complications in upper abdominal radiotherapy, we prospectively analyzed kidney function in patients who underwent postoperative chemoradiotherapy for gastric cancer.

PATIENTS AND METHODS

In 44 patients, Tc99m-thiatide renography was performed before and at regular intervals after postoperative chemoradiotherapy. The left-to-right (L/R) ratio was used as an index of the relative kidney function. Mean L/R values were calculated for four follow-up time intervals. For all patients, kidney V20 (percentage of the volume of the kidney that received more than 20 Gy) and mean dose of both kidneys were retrieved from the three-dimensional dose-volume histograms.

RESULTS

We observed a progressive decrease in left renal function of 11% (p = 0.012) after 6 months, up to 52% (p < 0.001) after >18 months. The V20 (left kidney) and mean left kidney dose were identified as parameters associated with decreased kidney function. Mean serum creatinine was increased from 74.6 micromol/L before treatment to 86.1 micromol/L at 1 year after chemoradiotherapy (p < 0.001). In patients with a follow-up of 18-28 months, one case of severe renovascular hypertension was observed.

CONCLUSION

A progressive relative functional impairment of the left kidney in patients after postoperative chemoradiotherapy for gastric cancer is demonstrated. To optimize the survival benefit that can be established with adjuvant regimens, strategies to minimize the dose to the kidneys and other critical organs should be explored.

Sentinel Node Biopsy Before Neoadjuvant Chemotherapy Spares Breast Cancer Patients Axillary Lymph Node Dissection

BACKGROUND

Neoadjuvant chemotherapy in breast cancer patients is a valuable method to determine the efficacy of chemotherapy and potentially downsize the primary tumor, which facilitates breast-conserving therapy. In 18 studies published about sentinel node biopsy after neoadjuvant chemotherapy, the sentinel node was identified in on average 89%, and the false-negative rate was on average 10%. Because of these mediocre results, no author dares to omit axillary clearance just yet. In our institute, sentinel lymph node biopsy is performed before neoadjuvant chemotherapy. The aim of this study was to evaluate our experience with this approach.

METHODS

Sentinel node biopsy was performed before neoadjuvant chemotherapy in 25 T2N0 patients by using lymphoscintigraphy, a gamma ray detection probe, and patent blue dye. Axillary lymph node dissection was performed after chemotherapy if the sentinel node contained metastases.

RESULTS

Ten patients had a tumor-positive axillary sentinel node, and one patient had an involved lateral intramammary node. Four patients had additional involved nodes in the completion lymph node dissection specimen. The other 14 patients (56%) had a tumor-negative sentinel node and did not undergo axillary lymph node dissection. No recurrences have been observed after a median follow-up of 18 months.

CONCLUSIONS

Fourteen (56%) of the 25 patients were spared axillary lymph node dissection when the sentinel node was found to be disease free. Performing sentinel node biopsy before neoadjuvant chemotherapy seems successful and reliable in patients with T2N0 breast cancer.

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.

Indium-111-antimyosin scintigraphy in the early detection of heart damage after anthracycline therapy in children

PURPOSE

To determine the value of indium-111-antimyosin ((111)In-AM) scintigraphy in the early detection of myocardial damage in children treated with doxorubicin.

PATIENTS AND METHODS

Twelve planar scintigrams were made of eight patients (seven children and one young adult; mean age, 12 years). Three scans were obtained before doxorubicin therapy in three patients, and nine scans were obtained during doxorubicin therapy in seven patients. The heart-to-lung ratio (HLR) was calculated. Left ventricular function was assessed by echocardiography before and during therapy by measuring the fractional shortening (FS).

RESULTS

The HLR of the three baseline scans was below 1.5, within the normal range for adults. Six of the seven patients whose scans were obtained during chemotherapy had abnormal HLR values (> 1.5). One patient had severe myocyte damage and showed an early increase in the HLR (2.3) after a cumulative doxorubicin dose of 150 mg/m(2). The FS measured by echocardiography was normal throughout therapy, and the final cumulative dose of doxorubicin was 450 mg/m(2). This patient developed fatal clinical heart failure 3 months after completion of chemotherapy. In one patient, who was pretreated with the cardioprotective agent dexrazoxane, the HLR remained within normal limits during therapy.

CONCLUSION

(111)In-AM scintigraphy seems to be suitable to detect early myocardial damage after a cumulative doxorubicin dose of 150 mg/m(2 )in children and may be useful for identifying children who are at increased risk of developing cardiac sequelae.

Imaging and retention measurements of selenium 75 homocholic acid conjugated with taurine, and the carbon 14 glycochol breath test to document ileal dysfunction due to late radiation damage

In order to assess ileal dysfunction in patients with complaints after pelvic radiation therapy, retention measurements and scintigraphic imaging with selenium 75 homocholic acid conjugated with taurine (75Se-HCAT), combined with the carbon 14 glycochol breath test, were evaluated in 39 patients. In 22 patients without ileal resection the results of the 75Se-HCAT test and the breath test differentiated between a normal functioning ileum (both tests negative) and ileal dysfunction as a cause of complaints (one or both tests positive). Among the patients with ileal dysfunction, the combination of both tests permitted those with bacterial overgrowth (breath test positive, 75Se-HCAT negative) to be separated from patients with evidence of bile acid malabsorption (75Se-HCAT positive, breath test positive or negative). In 17 patients with small-bowel resection, the 75Se-HCAT test helped to estimate the severity of bile acid malabsorption with implications for therapy. In this group the breath test was false-negative in 7 cases with abnormal 75Se-HCAT. Additional systematically performed scintigraphic imaging improved the accuracy of the 75Se-HCAT test, revealing cases with prolonged colonic accumulation of the radiopharmaceutical, causing spurious retention values. In conclusion, assessment of ileal dysfunction by nuclear medicine techniques in post-irradiation conditions provides information about the aetiology and therefore the possibility of adjustment in the clinical management.