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

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.

Why Are We Studying Sentinel Lymph Nodes?

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.

Why Are You Being Invited to Participate?

You are being invited to participate because the characteristics of your 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 you. However, the information obtained from your participation 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 your decision, you will have the opportunity to discuss the purpose of the study, the study procedures, possible benefits and risks, and alternative treatment options with your doctor. Your decision not to participate, or to withdraw from the study at a later time, will not affect your right to receive appropriate medical care.

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.