Sampling Prostate Cancer Tissue for Biobanking: An MRI-guided Targeted Technique to Remove Biopsy Punches from Fresh Tumor Tissue

Biobanking involves the collection and storage of biological tissue specimens or fluids for research purposes. To biobank prostate cancer specimens, first, obtain an axial or transverse plane MRI image of the prostate to identify the tumor. Subsequently, obtain the corresponding coronal or frontal image to mark the accurate tumor location.

Next, collect the tumor-bearing prostate. Using tissue-marking inks, paint the left and the right side of the organ to denote surgical margins and identify the correct orientation of tissue pieces during subsequent sampling.

Place the marked prostate on a pre-assembled slicing apparatus such that its base and apex face the opposite walls, the posterior side faces down, and the anterior side faces up. Place pins around the prostate to obtain a tight fit.

Measure the prostate length from base to apex. Compare it with the coronal image to spot the tumor position. Locate the pins closest to the tumor region. Fit slicing blades on either side of the marked pins. Cut the tissue to obtain a transverse slice carrying the tumor.

Using the axial MRI image as a guide, locate the tumor on the slice. Punch out the desired area of the tumor. Store the specimen for downstream biobanking applications.

After the specimen has been collected, sterilize the laminar flow hood and prostate-slicing apparatus with 70% ethanol, and weigh the prostate on a standard scale in grams. Then, paint the right side with blue ink and the left side of the specimen with black ink, covering the full capsule and seminal vesicles with ink to allow discrimination of the surgical margins.

To slice the prostate, place the tissue with the base and apex facing opposite walls of the apparatus with the posterior side down and the anterior side up. Place gold pins around the tissue specimen, pushing the prostate inward slightly, if necessary, to achieve a snug fit, and measure the prostate length from the base to the apex to compare this measurement to the prostate length as measured by MRI.

If the prostate has shrunk, adjust the anticipated slicing position by the appropriate percentage of the reduction. Next, measure from the base to the desired transverse slice and select the pin that sits closest to this measurement to slice around. Wearing chainmail gloves to prevent injury, place the blades of the slicing device on either side of the identified pin, and use the spacer to keep the blades 5 millimeters apart.

To acquire the slice, use long strokes to slowly but firmly move the blades downward, forward, and backward, confirming by feel that a full slice has been separated before disassembling the apparatus. Then, remove the walls and pins, and use gloves to carefully transfer the slice onto a sterile piece of corkboard.

After acquiring the specimen, visually inspect the transverse slice for comparison with the axial MRI image. In some cases, the tumor area may appear paler than the surrounding tissue. Palpate the transverse slice gently. The tumor may feel firmer than the surrounding tissue. Using the axial MRI image as a guide, select one or more areas for sampling, and use a 6-millimeter punch to push down on the tissue area of interest.

Twist the tissue punch on the spot and down against the cork to ensure a full separation, using a sharp scalpel to separate the biopsy sample from the specimen as necessary. When the sample has been acquired, remove the punch and use the plunger to eject the sample into the appropriate container for the subsequent downstream analysis.

• Biobanking - Collection and storage process of biological specimens for research.
• Prostate MRI - Medical imaging used to identify and locate prostate tumors.
• Prostate Tumor Sample - A portion of the prostate tumor collected for study.
• Fresh Tissue Biopsy - A procedure to obtain a fresh tissue sample from the body for diagnosis.
• Prostate Orientation - Refers to the positioning and direction of the prostate gland during medical procedures.

• Introduce Biobanking – It’s the process of preserving biological samples (e.g., prostate cancer tissue).
• Key Concepts – Highlighting the procedures of locating and sampling prostate tumors (e.g., prostate MRI video).
• Underlying Mechanisms – Discuss the biopsy and sampling techniques used (e.g., fresh tissue biopsy).
• Connect to Experiment – Explain how the collected sample is prepared and stored for downstream applications.

• What is biobanking and how does it help in preserving prostate cancer tissues?
• How do medical practitioners locate and sample prostate tumors?
• What procedures are followed during a fresh tissue biopsy?

• Practical Applications – Discuss how biobanking aids in medical and biological research (e.g., prostate cancer biobank).
• Industry Impact – Highlights the role of biobanking in healthcare and medical research (e.g., cancer research).
• Societal Importance – Touch on the broader benefits of biobanking for disease study and target drug development (e.g., health progress).
• Link to Scientific Advancements – Brief note on how biobanking supports new medical discoveries and innovations.