A 76-year old patient with a complex, 5-year adenocarcinoma history, involving resection as well as multiple chemotherapy and radiation treatments developed recurrences in the pelvis. The lesions were invisible on CT, and the MDT recommended against additional surgery or radiotherapy due to the long history, and recommended cryoablation with CAS-One IR. CT/MRI fusion was performed, two needles were planned and placed, hydrodissection was performed to protect the intestines, the cryoablation was performed, and the treatment was a success covering 100% of the tumors, with no intraprocedural complications.
Lesions invisible on CT
Fusion video showing invisible lesion on CT, and visible on MRI
Planning of the first cryoablation needle
First cryoablation needle verification
Ablation Confirmation showing 100% lesion coverage with a 6mm MAM
Name: Dr. Carlo Tappero
Institution: HFR Fribourg, Switzerland
Patient age and sex: 76 year-old Female
Initial condition:
- Adenocarcinoma resection with amputation with permanent left colostomy of the lower rectum, pT3 pN0 pM0 in 2020.
- PET-CT and Pelvic MRI in 2023 revealed two hypermetabolic nodular lesions suspicious for locoregional recurrence in the left ischioanal fossa and left pelvis (precoccygeal). Pathology revealed cylindrical biopsies infiltrated by colorectal-type adenocarcinoma
- First-line chemotherapy: FOLFOX + Avastin initiated with good partial response.
- MDT recommended two more months of chemotherapy, followed by curative-intent chemoradiotherapy
- In 2025 MRI revealed a 6mm ring-enhancing lesion at the irradiated site in the left ischioanal fossa—indicative of recurrence.
- MDT recommended cryoablation with CAS-One IR as both resection and re-irradiation were not advised due to prior treatment history.
Treatment:
- CT-MRI was performed, as the lesions were very small (one was 6mm) and invisible on CT
- Hydrodissection was administered in order to protect the structures around the lesion
- One IceSphere, and one IceRod (Boston Scientific) probes were planned, simulated and placed in a converging manner
- One single needle advancement was applied with each needle
Result:
- Post-procedure imaging showed 100% tumor coverage with a minimal ablative margin of 6mm
- The patient remained hospitalized overnight and was discharged the following day
- A follow-up CT/MRI is scheduled in three months
Learn more about the stereotactic navigation system CAS-One IR.