INTERSTITIAL HYPERTHERMIA IN CONJUNCTION WITH EXTERNAL
BEAM RADIOTHERAPY AND TEMPORARY INTERSTITIAL IMPLANT IN
THE TREATMENT OF ADENOCARCINOMA OF THE PROSTATE (ACP)
DANIEL J. HOMMEL, M.D., JEFFREY C. CARLTON, M.D., KENNETH W.
WOHLT, M.S. DEPT. OF RADIATION ONCOLOGY, UNITED MEDICAL
CENTER, CHEYENNE, WY USA
PURPOSE: The optimal treatment for adenocarcinoma of the prostate remains
controversial. There are even fewer reports regarding combined external beam
radiotherapy (EBRT), interstitial brachytherapy (IBT), and interstitial microwave
hyperthermia (IMHT). The following study was initiated to evaluate the efficacy, as well
as chronic complications, associated with EBRT, IBT and IMHT in the treatment of
adenocarcinoma of the prostate.
MATERIALS AND METHODS: From 1992 to present, 43 patients (39 of whom have
follow-up>3months.) with localized and/or locally advanced ACP (T1a ­ T3c) were
treated with EBRT, IBT and IMHT. EBRT consisted of either full pelvis or small field
delivering a dose of 45 ­ 50 Gy. The interstitial implant delivered 22-36 Gy over 45 ­ 50
hrs to a volume encompassing the prostatic capsule. The interstitial implant was
performed under dual plane ultrasound. IMHT consisted of 43 C for 45 min. Prior to
brachytherapy simulation, all patients underwent CT scanning of the implant to ensure
proper catheter placement. Gleason score ranged from 2-9 (mean 6, median 6) PSA
ranged from 3.8 ­ 80.4 (mean 17.6, median 11.1) No patients have been lost to follow-up
with a range of 1 ­ 35 months (mean 11 mos, median 13 mos).
RESULTS: As of this writing, all patients except 3 have a normal PSA and normal DRE.
One patient has had a biopsy proven recurrence with re-implant and now has a normal
PSA. One patient has a rising PSA (>0.75ng/ml/yr), but is still less than 4ng/ml. All
other patients have stable or decreasing PSA's. Twenty-four pts have a PSA </= 2ng/ml;
10 pts. Are > 2 </= 4; 4 pts are >4 </= 10 and 1 pt. is > 10ng/ml. Complications have
been exceptionally infrequent, Five pts. have reported an RTOG Grade 1 rectal
complication. There have been no chronic bladder complications. With regard to
impotence, 10 pts report a slight worsening of their erectile function and 2 pts report a
>50% worsening of their impotence with 2 pts reporting complete impotence.
CONCLUSIONS: IMHT in conjunction with radiotherapy as delivered by our technique
has shown excellent early results with exceptionally few side effects. This procedure
shows an excellent means of delivering aggressive local therapy to the prostatic volume,
which appears necessary for long term local control. In addition, by utilizing our
customized treatment methods (i.e. CT scanning post implant) we can not only provide
tailored brachytherapy dose delivery, but also customized and accurate heat delivery,
which to our knowledge had never been described before in this location. We will
describe our procedure in detail along with more current follow-up as well as including
pts. treated by this technique palliatively who have also shown extremely positive results.

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