Comparison of two hybrid sentinel node tracers: indocyanine green (ICG)-99mTc-nanocolloid vs. ICG-99mTc-nanoscan from a nuclear medicine and surgical perspective.

BACKGROUND: Lymph node (LN) metastasis is a relevant predictor for survival in patients with a.o. penile cancer (PeCa), malignant melanoma. The sentinel node (SN) procedure comprises targeted resection of the first tumour-draining SNs. Here, the hybrid tracer indocyanine green (ICG)-99mTc-nanocolloid has been used for several years to combine optical and nuclear detection. Recently, the resource of the nanocolloid precursor stopped production and the precursor was replaced by a different but chemically comparable colloid, nanoscan. Our aim was to study the performance of ICG-99mTc-nanoscan compared to ICG-99mTc-nanocolloid from a nuclear and surgical perspective. METHODS: Twenty-four patients with either PeCa or head-and-neck (H&N) melanoma and scheduled for a SN procedure were included. The initial group (n = 11) received ICG-99mTc-nanocolloid until no longer available; the second group (n = 13) received ICG-99mTc-nanoscan. Tracer uptake was assessed on lymphoscintigraphy and single-photon emission (SPECT). Intraoperatively, SNs were identified using gamma tracing and fluorescence imaging. Ex vivo (back-table) measurements were conducted to quantify the fluorescence emissions. Chemical analysis was performed to compare the ICG assembly on both precursors. RESULTS: The mean tracer uptake in the SNs was similar for ICG-99mTc-nanocolloid (2.2 ± 4.3%ID) and ICG-99mTc-nanoscan (1.8 ± 2.6%ID; p = 0.68). 3 SNs (interquartile range (IQR) 3-4) were detected on lymphoscintigraphy in PeCa patients receiving ICG-99mTc-nanoscan compared to 2 SNs (IQR 2-3) in PeCa patients receiving ICG-99mTc-nanocolloid (p = 0.045), no differences were observed in H&N patients. Back-table measurements of resected SNs revealed a lower total fluorescence intensity in the ICG-99mTc-nanoscan group (24*109 arbitrary units (A.U) IQR 1.6*109-14*109 in the ICG-99mTc-nanocolloid group versus 4.6*109 A.U. IQR 2.4*109-42*109 in the ICG-99mTc-nanoscan group, p = 0.0054). This was consistent with a larger degree of "stacked" ICG observed in the nanoscan formulation. No tracer-related adverse events were reported. CONCLUSIONS: Based on this retrospective analysis, we can conclude that ICG-99mTc-nanoscan has similar capacity for SN identification as ICG-99mTc-nanocolloid and can safely be implemented in SN procedures.

Head-to-head comparison of the hybrid tracer indocyanine green-99mTc-nanocolloid with 99mTc-Senti-Scint using sentinel node lymphoscintigraphy and single-photon emission computed tomography combined with computer tomography in melanoma.

OBJECTIVE: The hybrid tracer indocyanine green (ICG)-Tc-nanocolloid has been introduced for sentinel node imaging. However, until now, a comparison of this tracer with other radiocolloids with a larger particle size has not been effectuated. Based on a head-to-head evaluation in patients with melanoma, we have compared ICG-Tc-nanocolloid (particle size 5-80 nm) with Tc-Senti-Scint (particle size 100-600 nm) to establish differences in drainage pattern and sentinel node localization using lymphoscintigraphy and single-photon emission computed tomography combined with computer tomography (SPECT-CT) in melanoma patients scheduled for sentinel node biopsy. METHODS: Twenty-five patients (mean age: 56.9 years, range: 25-79 years) with a melanoma scheduled for SLN biopsy prior to (re)excision of the primary lesion (scar) were prospectively included following a two-day procedure. The first day, after Tc-Senti-Scint injection in four intradermal depots around the primary lesion or scar, early/delayed lymphoscintigraphy and SPECT-CT images were acquired. The injection sites were marked. The second day, after assessing lymph node radioactivity using planar scintigraphy, ICG-Tc-nanocolloid was injected at the previously marked skin points and imaging was performed. The paired planar and SPECT-CT images of both tracers were evaluated with respect to drainage patterns, SLN visualization and non-SLN appearing. RESULTS: Twenty-four out of 25 patients were evaluable. SLN visualization on a patient basis was 100% for ICG-Tc-nanocolloid and 96% for Tc-Senti-Scint, whereas uptake in non-SLNs was found in, respectively, 71% (17/24) and 61% (14/23). Concordance in drainage to 45 lymph node basins was 91%. Discordant drainage was found for two melanomas in the head-and-neck and one in the clavicular area. Unique lymph node basins were seen in 44/45 (98%) for ICG-Tc-nanocolloid and 42/45 (93%) for Tc-Senti-Scint. Concerning identified SLNs, the number was similar for both tracers (n = 58); however, more non-SLNs (65 vs 50) were visualized with ICG-Tc-nanocolloid than with Tc-Senti-Scint. CONCLUSION: A slightly higher SLN visualization accompanied by a tendency to depict more non-SLNs was found for ICG-Tc-nanocolloid. Excepting the head and neck area, an overall high concordance in drainage was found for both radiotracers. With an additional value for the hybrid tracer due to the combination of preoperative imaging and the additional visual signal in the operation room, added by the fluorescent component of the hybrid tracer, there was a preference for ICG-Tc-nanocolloid.

Unknown primary head and neck squamous cell carcinoma in the era of fluorodeoxyglucose-positron emission tomography/CT and intensity-modulated radiotherapy.

BACKGROUND: The diagnosis and treatment of head and neck carcinoma of unknown primary (CUP) have changed with the introduction of fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT and intensity-modulated radiotherapy (IMRT), with potential implications for outcome. METHODS: We conducted a retrospective analysis of 80 patients with head and neck CUP who were PET-staged and treated with curative intention using IMRT between 2006 and 2016 in the Netherlands Cancer Institute. Patient, tumor, and treatment demographics were recorded and oncologic outcomes were analyzed. RESULTS: Local control was 100% in mucosal irradiated patients. Regional control was 90%. Ten patients developed distant metastases, which were associated with N3, extracapsular extension (ECE) and lower neck positive lymph nodes. Overall survival (OS) at 5 years was 62% and disease-specific survival was 78%. ECE, N3 neck, multiple levels of positive lymph nodes, and positive lymph nodes in the lower neck were associated with worse prognosis. CONCLUSION: Locoregional outcome of head and neck CUP managed with modern techniques is good. Future research needs to focus on reducing toxicity and patients prone for distant metastasis.

Lymphatic drainage of melanomas located on the manubrium sterni to cervical lymph nodes: a case series assessed by SPECT/CT.

The lymphatic drainage of cutaneous melanomas located on the upper trunk is often complex and sometimes follows an unexpected pattern. Occasionally, even direct drainage to cervical lymph nodes is seen. In this case series, 3 patients with lymphatic drainage to the neck derived from melanomas located over the manubrium sterni are described. There appears to be a restricted area that involves the manubrium sterni from which lymphatic drainage to different cervical node basins appears more frequent. SPECT/CT was helpful in visualizing these patterns and for the localization of the sentinel nodes.

Reirradiation for head-and-neck cancer: delicate balance between effectiveness and toxicity.

PURPOSE: To analyze the effectiveness and toxicity of reirradiation (re-RT) for head-and-neck cancer. METHODS AND MATERIALS: A retrospective data analysis was performed of 58 patients who underwent re-RT with curative intent. Re-RT was given as definitive treatment in 53% of patients, whereas salvage surgery preceded reirradiation in 47%. The median cumulative RT dose was 119 Gy (range, 76-140). Concurrent chemotherapy was administered with re-RT (CRT) in 57% of patients. Event-free survival was defined as survival without recurrence and without serious toxicity (≥Grade 3). RESULTS: Median follow-up was 57 months (range, 9-140). Locoregional (LR) control was 50% at 2 and 5 years. The 2-year and 5-year overall survival (OS) was 42% and 34%. The following factors were associated with improved OS: postoperative re-RT (vs. primary re-RT), treatment with RT only (vs. CRT) and interval >3 years between previous RT and re-RT. For patients treated with postoperative re-RT and definitive re-RT, the 5-year OS was 49% and 20%, respectively. Patients treated with CRT had a 5-year OS of 13%. Serious (late) toxicity ≥Grade 3 was observed in 20 of 47 evaluable patients (43%). Three cases of treatment-related death were recorded. The 2- and 5-year serious toxicity-free interval was 59% and 55%, respectively. Associated with increased risk of serious toxicity were CRT and higher re-RT dose. The event-free survival rates at 2 and 5 years were 34% and 31%, respectively. CONCLUSIONS: Re-RT in head-and-neck cancer is associated with poor survival rates of 13-20% in patients with inoperable disease treated with primary (chemo-) re-RT. For this subgroup, however, no other curative options are available. Long-term disease control and survival can be achieved in patients who receive re-RT as an adjunct to surgical resection. The rates of serious toxicity after re-RT are high, with an incidence of approximately 45% at 5 years. Approximately 1 in 3 patients survived re-RT without recurrence and severe complications.