Development of Feedback Microwave Thermotherapy in Symptomatic Benign Prostatic Hyperplasia

Sammanfattning: Abstract: The purpose of this thesis was to evaluate ProstaLund Feedback Treatment® (PLFT®) and the CoreTherm® device with regard to biophysics, mechanisms of action, treatment indications, additional techniques, efficacy and safety in the treatment of patients with benign prostatic hyperplasia (BPH). The application of two biophysical equations in the PLFT software is explained. The calculations provide the intraprostatic ?blood flow index? and amount of accumulated coagulation necrosis during treatment. The accuracy of the ?cell kill? calculations is compared to gadolinium-enhanced magnetic resonance imaging (MRI) and histology. The accumulated ?cell kill? monitored on-line during PLFT is considered a useful tool for helping the doctor to tailor the individual ?thermal dose? to each patient. The clinical efficacy, 1 and 5 years after PLFT and Trans-urethral Resection of the Prostate (TURP), is compared showing no statistically significant differences. Serious adverse events were more frequent after TURP. Expanded treatment indications for PLFT, to including patients with persistent urinary retention and patients with heavily enlarged prostates (>100 g), were studied in a retrospective survey and in a prospective randomized multicentre study comparing PLFT with surgery (TURP and open surgery). Responder rate after PLFT was close to 80% and statistically equivalent to surgery after 6 months. Serious adverse events were less frequent after PLFT. The intraprostatic blood flow works like a heat sink by transporting heat away from the treatment area during thermotherapy. This is the explanation for the unpredictable outcome and frequent treatment failures described after low-energy transurethral microwave thermotherapy. High-energy TUMT can compensate for this in many ways but results in significant patient discomfort from micturition urge, burning sensations and pain.

A new device, the Schelin Catheter®, makes it possible to inject and infiltrate the prostate by the transurethral route. Injections in several locations with local anaesthetics containing epinephrine have a twofold aim: 1) to minimize the intraprostatic blood flow and 2) to achieve good analgesia. Treatment time was reduced by 50% and the total energy required was reduced by 60% when using this technique. The effects of the epinephrine on the intraprostatic blood flow were also verified with positron emission tomography, [15O]H2O-PET.

The results in this thesis show that the efficacy, safety and methodological improvements of PLFT now make it a challenger to surgery (TURP and open surgery) as a convenient, office based and more available option. This truly minimally invasive treatment is an attractive option for patients that can replace surgery for the majority of patients with clinical BPH. It also reduces the cost to the taxpayer.