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Advanced Pancreatic Cancer: High-Intensity Focused Ultrasound (HIFU) and Other Local Ablative Therapies.

BACKGROUND
 Locally advanced pancreatic cancer is a life-limiting tumor with a wide range of incapacitating symptoms such as cancer-associated pain. Several local ablative therapies with both thermal and non-thermal sources have recently received significant attention as modern treatment options for local tumor control and symptomatic improvement. The following review article provides an overview of currently available techniques and their outcomes including our own experience with high-intensity focused ultrasound (HIFU) being one of the most exciting and innovative modalities.


METHOD
 Our experiences with HIFU treatment are based on 89 pancreatic cancer patients (UICC III-IV). Outcomes such as treatment-related changes in symptoms particularly in cancer pain and quality of life as well as local tumor response, safety and survival were compared to reported studies concerning HIFU, radiofrequency and microwave ablation, cryoablation, irreversible electroporation and stereotactic body radiation therapy.


RESULTS
 Even though all strategies appeared to be feasible, the unique feature of noninvasiveness represents a substantial advantage of the HIFU procedure. In 85 % of HIFU-treated patients, long-lasting pain relief was achieved. 50 % of patients did not require any analgesic treatment 6 weeks post-ablation. Unfortunately, pain palliation and quality-of-life outcomes are only rarely reported for other local treatment modalities. Tumor mass reduction could be achieved with all ablative therapies, with a mean tumor volume reduction of 60 % after 6 months in HIFU-treated pancreatic tumors. Differences in treatment-associated morbidity were reported. However, they are only partially comparable due to unbalanced study populations.


CONCLUSION
 Various local ablative treatment modalities are available and feasible for tumor mass reduction of advanced pancreatic cancer but with different symptomatic benefit for patients. An effective and long-lasting reduction of cancer-related pain was observed following HIFU without insertion of needles or electrodes. Randomized controlled studies for head-to-head comparison of these modalities are warranted in the near future.


KEY POINTS
  · Several ablative therapies are available for the local treatment of inoperable pancreatic cancer.. · Tumor mass and symptom reduction are main goals of local therapies.. · HIFU differs based on its noninvasive approach and low complication rate.. · HIFU enables effective long-lasting pain relief in > 80 % of patients.. · HIFU-associated pain relief is independent of tumor stage and metastatic status..


CITATION FORMAT
· Marinova M, Wilhelm-Buchstab T, Strunk H. Advanced Pancreatic Cancer: High-Intensity Focused Ultrasound (HIFU) and Other Local Ablative Therapies. Fortschr Röntgenstr 2019; 191: 216 - 227.