Sentinel Node Identification Using Gamma and Near-Infrared Imaging in TesticulAr MaLignancies (SIGNAL)

Sentinel Node Identification Using Gamma Detection and Near-Infrared Fluorescence in Testicular Malignancies

Testicular seminoma is a malignant tumor with a very high probability of cure. Current treatment approaches provide excellent long-term cancer outcomes. However, some standard treatments, including radiotherapy and platinum-based chemotherapy, may cause side effects both during treatment and many years after its completion. In the long term, these treatments may be associated with an increased risk of cardiovascular disease, metabolic disorders, and secondary malignancies.

Because most patients with seminoma are successfully cured and have a long life expectancy, an important goal of modern cancer treatment is not only to achieve effective cancer control, but also to reduce the potential long-term adverse effects of treatment.

One possible treatment approach is minimally invasive retroperitoneal lymph node dissection (RPLND), performed using laparoscopic or robot-assisted surgery. This procedure allows the disease stage to be determined more accurately by establishing whether cancer cells are present in the retroperitoneal lymph nodes. In some patients, surgery may potentially provide effective disease control without the need for subsequent radiotherapy or chemotherapy.

However, currently available imaging methods, including computed tomography (CT), cannot always accurately determine whether individual retroperitoneal lymph nodes contain cancer cells. Studies have shown that in some patients undergoing RPLND for suspected lymph node involvement, no cancer cells are subsequently found in the removed lymph nodes. Therefore, there is a need to develop more accurate methods for identifying the lymph nodes that are most likely to be the first sites of cancer spread.

This study investigates a method for identifying sentinel lymph nodes. Sentinel lymph nodes are the lymph nodes that first receive lymphatic drainage from the area of the primary tumor and may therefore be the first lymph nodes to which cancer cells spread.

In this study, two complementary methods will be used to identify sentinel lymph nodes. The first involves the administration of a small amount of a radiopharmaceutical containing technetium-99m (Tc-99m), followed by single-photon emission computed tomography combined with computed tomography (SPECT/CT). During surgery, these lymph nodes will also be identified using a special gamma-detection device.

The second method involves the use of indocyanine green (ICG), a fluorescent dye that allows the surgeon to visualize lymphatic drainage pathways and lymph nodes during surgery using near-infrared fluorescence imaging.

The combination of these two methods may allow more accurate identification of sentinel lymph nodes and provide a better understanding of lymphatic drainage from testicular tumors.

Participants are being invited to participate because the characteristics of their disease meet the eligibility criteria for this study.

The main purpose of the study is to determine how accurately and reliably sentinel lymph nodes can be identified in patients with testicular seminoma using a combination of radionuclide and fluorescence-guided techniques.

The information obtained from this study may help to develop a more individualized approach to the surgical treatment of patients with seminoma. In the future, accurate identification of sentinel lymph nodes may make it possible to reduce the extent of surgery in selected patients, potentially decreasing surgical trauma and the risk of postoperative complications. At the same time, accurate detection of cancer involvement in lymph nodes may help identify patients who require additional anticancer treatment, such as systemic chemotherapy.

It is important to understand that the approach being evaluated is investigational, and its advantages over currently established approaches have not yet been conclusively demonstrated. Therefore, participation in this study cannot guarantee any additional direct medical benefit to participants. However, the information obtained from participants may contribute to improving the diagnosis and treatment of patients with testicular seminoma in the future.

Participation in this study is entirely voluntary. Before making decision, participants will have the opportunity to discuss the purpose of the study, the study procedures, possible benefits and risks, and alternative treatment options with their doctor. Their decision not to participate, or to withdraw from the study at a later time, will not affect their right to receive appropriate medical care.

Study Overview

• Status: Recruiting
• Conditions: Germ Cell Tumor of Testis
• Intervention / Treatment: Procedure: sentinel lymph node mapping using technetium-99m (Tc-99m) and indocyanine green (ICG) with subsequent orchiectomy; Procedure: Standard treatment: orchiectomy followed by drug therapy and, if necessary, retroperitoneal lymphadenectomy

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: Mariya Berkut, PhD; Phone Number: + 7 9312870497; Email: berkutv91@gmail.com

Study Locations

• Russia
  • Sankt-Peterburg
    • Saint Petersburg, Sankt-Peterburg, Russia, 197758
      • Recruiting
      • FSBI "N.N. Petrov NMRC of oncology" MH of Russian Federation
      • Contact: Mariia Berkut, PhD; Phone Number: 89312870497; Email: berkutv91@gmail.com
      • Contact: Pavel Gorlin; Phone Number: +79538151173; Email: gorlin23@yandex.ru
      • Principal Investigator: Alexander Nosov, PhD, Professor
      • Sub-Investigator: Pavel Gorlin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

## Study Population Description

The study population will consist of **adult male patients (≥18 years of age) with a primary testicular tumor suspicious for a testicular germ cell tumor (TGCT)** who are candidates for radical inguinal orchiectomy (orchifuniculectomy).

Eligible patients will have a primary testicular tumor with a maximum diameter of **≤5 cm**, no evidence of distant metastatic disease (**cM0**), and limited or no radiologically detectable retroperitoneal lymph node involvement. The study will include patients with **cN0 disease and eligible serum tumor marker levels**, as well as selected patients with **cN1-cN2 disease** and limited retroperitoneal lymph node involvement, in accordance with the predefined eligibility criteria.

Patients with distant metastatic disease, advanced retroperitoneal lymph node involvement, S2-S3 serum tumor marker levels, previous specific anticancer treatment for a testicular germ cell tumor, or contraindications.

Description

Inclusion Criteria:

• Presence of a primary testicular tumor suspicious for a testicular germ cell tumor (TGCT) and considered an indication for radical inguinal orchiectomy (orchifuniculectomy);
• Male gender;
• Maximum diameter of the primary testicular tumor (cT) ≤5 cm;
• One of the following clinical nodal and serum tumor marker criteria:
• - cN0 disease with serum tumor markers corresponding to S1 category: alpha-fetoprotein (AFP) 0-5.8 IU/mL and β-human chorionic gonadotropin (β-hCG) >2.5 and <1,000 IU/mL; or
• -cN1-cN2 disease, with no more than two radiologically suspicious retroperitoneal lymph nodes, and serum tumor markers corresponding to S0-S1 category;
• No evidence of distant metastatic disease (cM0).
• Patient refusal to undergo adjuvant anticancer treatment (chemotherapy or radiotherapy) following radical inguinal orchiectomy, or unwillingness/inability to undergo close active surveillance.
• Ability to understand the study requirements and provision of written voluntary informed consent prior to participation in the study.

Exclusion Criteria:

• Maximum diameter of the primary testicular tumor (cT) >5 cm;
• Presence of distant metastatic disease (cM1);
• Serum tumor marker levels corresponding to S2-S3 category.
• Clinical stage cN1 with ≥2 retroperitoneal lymph nodes suspicious for metastatic involvement;
• Clinical stage cN3 disease;
• Any previous specific anticancer treatment for a testicular germ cell tumor, including systemic chemotherapy, radiotherapy, or prior retroperitoneal surgery for testicular cancer;
• Presence of any contraindication to minimally invasive surgery, administration of indocyanine green (ICG), or administration of the technetium-99m (Tc-99m)-labelled radiopharmaceutical used for sentinel lymph node mapping.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Standard-of-Care Group (Control Group); Patients in the control group will undergo standard diagnostic and therapeutic management according to current clinical practice. Following radical inguinal orchiectomy and histopathological assessment, each patient's case will be reviewed by a multidisciplinary tumor board. Subsequent management, including active surveillance, systemic chemotherapy, radiotherapy, or other treatment when indicated, will be determined according to the pathological findings, clinical stage, and applicable clinical guidelines.	Procedure: Standard treatment: orchiectomy followed by drug therapy and, if necessary, retroperitoneal lymphadenectomy; Participants assigned to the control group will receive standard-of-care treatment in accordance with current clinical guidelines and institutional practice. Patients will initially undergo radical inguinal orchiectomy with subsequent pathology examination. Following confirmation of the diagnosis and assessment of the pathological and clinical stage, each patient's case will be reviewed by a tumor board to determine the appropriate further treatment strategy (observation, chemotherapy or surgery). Depending on the clinical stage, pathological findings, prognostic factors, and tumor board decision, participants will receive standard care. Following systemic treatment, patients will undergo clinical and radiological response assessment. RPLND may be performed when clinically indicated based on residual retroperitoneal disease based on CT scans.
SLNB Group (Investigational Group); Participants in the investigational group will undergo sentinel lymph node mapping using technetium-99m (Tc-99m) and indocyanine green (ICG). Preoperative lymphatic mapping will be performed using SPECT/CT following administration of the Tc-99m-labelled radiopharmaceutical. During minimally invasive surgery, sentinel lymph nodes will be identified using gamma detection and near-infrared fluorescence imaging following ICG administration. Identified sentinel lymph nodes will be removed and subjected to histopathological and immunohistochemical examination. Retroperitoneal lymph node dissection will be performed according to the study protocol and the patient's clinical stage. Radical inguinal orchiectomy will subsequently be performed, and all surgical specimens will undergo histopathological examination.	Procedure: sentinel lymph node mapping using technetium-99m (Tc-99m) and indocyanine green (ICG) with subsequent orchiectomy; Patients enrolled in the investigational group will undergo dual-tracer sentinel lymph node mapping and sentinel lymph node biopsy (SLNB) using a technetium-99m (Tc-99m)-labelled radiopharmaceutical and indocyanine green (ICG), followed by retroperitoneal lymph node dissection (RPLND) and radical inguinal orchiectomy. Radiopharmaceutical Administration Approximately 24 hours before surgery, patients will undergo administration of a Tc-99m-labelled colloidal radiopharmaceutical. Under ultrasound guidance using a high-frequency linear transducer, 0.2 mL of the radiopharmaceutical, with an activity of 740-860 MBq and a particle size of approximately 1,000 nm, will be injected beneath the tunica albuginea in the projection of the primary testicular tumor. The radiopharmaceutical will be prepared immediately before administration. Preoperative SPECT/CT and Sentinel Lymph Node Mapping Approximately 3 hours after radiopharmaceutical administration, radionuclide imaging of the lymphatic dr

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
3-year relapse-free survival	Relapse-free survival is defined as the time from the date of completion of the initial surgical treatment to the first documented disease relapse or death from any cause, whichever occurs first.	36 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
incidence of postoperative complications within 30 days after surgery	Postoperative complications will be recorded separately for the laparoscopic and robot-assisted surgical approaches. Complications will be classified according to the Clavien-Dindo classification, with major complications defined as Clavien-Dindo grade III or higher.	30 days
treatment de-escalation rate	The treatment de-escalation rate will be defined as the proportion of patients in the investigational group who, following primary minimally invasive sentinel lymph node biopsy (SLNB) and subsequent histopathological assessment, have no indication for adjuvant systemic anticancer therapy. The indication for adjuvant systemic therapy will be determined based on the final pathological findings, disease stage, and multidisciplinary tumor board assessment in accordance with the applicable clinical guidelines. The treatment de-escalation rate will be calculated as the number of patients who do not require adjuvant systemic anticancer therapy following the SLNB-based surgical treatment strategy divided by the total number of evaluable patients undergoing the investigational procedure.	52 weeks

Collaborators and Investigators

• Sponsor: N.N. Petrov National Medical Research Center of Oncology

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2026
• Primary Completion (Estimated): April 1, 2028
• Study Completion (Estimated): April 1, 2029

Study Registration Dates

• First Submitted: August 17, 2026
• First Submitted That Met QC Criteria: August 17, 2026
• First Posted (Actual): August 20, 2026

Study Record Updates

• Last Update Posted (Actual): August 27, 2026
• Last Update Submitted That Met QC Criteria: August 25, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: minimal invasive surgery; sentinel node; germ cell tumor; seminoma; Gamma Detection
• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Germinoma; Neoplasms, Germ Cell and Embryonal; Seminoma; Testicular Germ Cell Tumor; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Indoles; Inorganic Chemicals; Elements; Metals; Metals, Heavy; Transition Elements; Elements, Radioactive; Radioisotopes; Isotopes; Technetium; Indocyanine Green
• Other Study ID Numbers: SIGNAL

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: De-identified individual participant data (IPD) may be shared upon reasonable request from qualified researchers, subject to approval by the study investigators and applicable institutional and ethical requirements. IPD will not be made publicly available due to patient confidentiality and data protection considerations. Any data sharing will be limited to information necessary to address the objectives of an approved research proposal.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No