Purpose
HIFU (HIGH INTENSITY FOCUSED ULTRASOUND) FOR THE TREATMENT OF PROSTATE CANCER HAS A 10-30% RECURRENCE RATE. WHILE PSA IS USED TO CONTROL THE POSSIBILITY OF TUMOR REGROWTH, IT LACKS SPECIFICITY. IT HAS BEEN SHOWN THAT SUCCESSFUL TREATMENT OF VASCULAR TUMORS MARKEDLY DECREASES THE BLOOD FLOW. POWER DOPPLER ULTRASOUND AND COMPUTER AIDED CONTRAST ENHANCED MRI MAY BE USED AS A BASELINE BEFORE HIFU TREATMENT AND AS A FOLLOW UP AFTER TREATMENT TO MEASURE THE STABILITY OF THE TREATED CANCER.
Material and methods
HIFU IS AN EFFECTIVE AND NON INVASIVE TREATMENT FOR PROSTATE CANCER. IT IS A REPEATABLE PROCEDURE IN CASE OF TUMOR RECURRENCE. HIGHLY VASCULAR TUMORS ARE MORE AGGRESSIVE AND HAVE HIGHER GLEASON SUMS THAN AVASCULAR CANCERS. IN ORDER TO EARLIER DETECT RECURRENCE OF VASCULAR TUMORS, PATIENTS WERE SCANNED WITH A VOLUSON 3-D 730 ULTRASOUND UNIT AND A 1.5 T SIEMENS MRI USING A COMPUTER AIDED PROGRAM TO HIGHLIGHT HYPERVASCULAR REGIONS. FOLLOWING HIFU TREATMENT, PATIENTS WERE RE-IMAGED WITH BOTH MODALITIES TO DETECT NEOVASCULAR FOCI. PATIENTS WITH VASCULAR TUMOR RECURRENCE WERE OFFERED THE OPTION OF RE-TREATMENT WITH HIFU OR OTHER MODALITIES. A RISING PSA MAY BE DUE TO LOCAL RECURRENCE OR DISTANT METASTASES. THE DEMONSTRATION OF RECURRENT LOCAL TUMOR WOULD PERMIT THE RE-TREATMENT IN THE PROSTATE WITH REASSURANCE
Results
OVER A TWO YEAR PERIOD 256 PATIENTS WITH PROSTATE CANCER WERE PROSPECTIVELY SCANNED WITH A VOLUSON 730 EXPERT UNIT EMPLOYING ENDORECTAL 6-10 MHZ PROBE WITH 3D POWER DOPPLER IMAGING AND A 1.5 TESLA SIEMENS MRI WITHIN ONE WEEK. CONTRAST ENHANCED MRI UTILIZED COMPUTER ASSISTED RECONSTRUCTION. 22 PATIENTS WITH GLEASON SUMS 7-9 AND VASCULAR TUMORS CHOSE HIFU THERAPY PERFORMED WITH A SONABLATE 500 UNIT EMPLOYING REAL TIME ULTRASOUND GUIDANCE. 4 PATIENTS REQUIRED ADDITIONAL TREATMENT BASED ON NEW AREAS OF HYPERVASCULARITY DEMONSTRATED BY ULTRASOUND AND MRI IMAGING. 2 PATIENTS CHOSE REPEAT HIFU. 1 PATIENT CHOSE CRYOABLATION. 1 PATIENT CHOSE HORMONAL ABLATION. FOLLOW UP AT SIX AND TWELVE MONTHS SHOWED STABLE PSA /FALLING PSA AND NO RECURRENCE OF HYPERVASCULARITY BY IMAGING.
Conclusion
SUCCESSFUL DETECTION OF TUMOR RECURRENCE POST HIFU TREATMENT OF HIGH GRADE PROSTATE CANCERS OFFERS PATIENTS THE OPTION TO REPEAT THE HIFU PROCEDURE OR TO CHOOSE OTHER THERAPIES IN A TIMELY MANNER. WHILE PSA AND REPEAT BIOPSY HAVE BEEN USED TO MEASURE LOCAL TUMOR RECURRENCE, VASCULAR IMAGING WITH 3-D POWER DOPPLER ULTRASOUND AND MRI WITH COMPUTER ASSISTED DIAGNOSIS HAVE PROVED EFFECTIVE IN LOCALIZING RECURRENT DISEASE IN THE PROSTATE AS OPPOSED TO PSA INCREASES DUE TO DISTANT METASTASES. THIS HAS SPARED SOME PATIENTS REPEATED BIOPSIES.