Concurrent Delivery of Interstitial Thermobrachytherapy in Cancer Treatment


Project ID:  D2017-09



Low dose rate (LDR) brachytherapy in prostate cancer treatment is a modality requiring surgical insertion of radioactive seeds in the prostate. The technology offers precise delivery of radiation to the tumoricidal mass while significantly reduces dose to surrounding normal tissue. Hyperthermia, when used with LDR, enhances the treatment of cancer, especially if delivered concurrently with radiation therapy through interstitial ferromagnetic seed implants. However, compared to a conventional seed implant, the number of implanted seeds will be increased to accommodate effective delivery of hyperthermia and compensate for heat dissipation through blood flow. To enhance effectiveness of the current state of art in LDR brachytherapy of prostate, there is a need for an improved, more efficient, effective, system for the delivery of interstitial concurrent thermo brachytherapy in the treatment of solid tumors.

Invention Description:
Researchers at the University of Toledo have developed a patented thermo-brachytherapy (TB) seed for concurrent delivery of hyperthermia and brachytherapy to treat solid tumors. The TB seeds provide complementary adjuvant therapy delivering brachytherapy and hyperthermia to cancer cells simultaneously. This significantly increases the efficiency of tumor cell kill, studies show. The novel invention uses seeds that combine sealed radioactive source with ceramic ferrite core serving as a self-regulating hyperthermia source when placed in an alternating electromagnetic field. This is in contrast to clinically available technology where hyperthermia is delivered by microwave and ultrasound applicators, resulting in limited penetration and the inherent need for invasive thermometry. A typical prostate implant procedure requires placing 80 to 120 seeds through 15-25 needles.  The combination of I-125 and the ceramic ferrite materials in a single seed reduces trauma to the tissues compared to the circumstance where additional thermal probes are separately placed for hyperthermia delivery.


Cancer: Treatment of solid tumors where concurrent hyperthermia and brachytherapy is needed



  • The use of permanent seeds aid patients who fail radiation and become resistant to hormonal manipulations, and systemic cytotoxic chemotherapy.
  • The sealed radioactive source serves as a self-regulating hyperthermia source when placed in an alternating electromagnetic field.
  • Improved response rate.
  • The permanent seeds are readily available for fractionated heat treatments during cytotoxic chemotherapy.
  • Concurrent delivery of both modalities offered in our approach permits maximum hyperthermia-induced radiosensitivity.
  • These implanted seeds may be used at a later time for salvage therapy in case of cancer recurrence.

IP Status: US 9,750,954

European pending: EP 3 391 937 A1




Patent Information:
For Information, Contact:
Stephen Snider
AVP Tech Transfer
The University of Toledo
419 530 6225
E. Parsai
Diana Shvydka
Gregory Warrell