DGU Annual meeting 2006 in Hamburg

Influence of dose distribution on the quality of life after permanent seed implantation

Derakhshani P1, Spira G2, Kacpura W2, Neubauer S1

(1) Department of Urology, West German Prostate Center, Klinik am Ring, Cologne

(2) Department of Radiooncology, West German Prostate Center, Klinik am Ring, Cologne

Introduction:

We report on the influence of dose distribution on general and prostate-specific QoL after permanent seed implantation (PSI).

Methodology:

The data from 328 consecutive patients (04/2004 to 12/2005) with PSI in low-risk prostate cancer are evaluated. The dose parameters recorded were prostate volume, seed and needle count, V100 prostate, D90 prostate, D30 urethra and D10 rectum. Prior to the treatment and at times 3,6 and 12 months after the treatment, all patients receive a validated questionnaire set consisting of EORTC-QLQ-C30 with prostate module PR25, IIEF5 and IPSS of the AUA.

Results:

The parameters for micturition and intestinal function in the PR25 were significantly worse at times of 3 and 6 months after implantation than before treatment. After 12 months there was no significant difference. In the regression analysis, there was a significant correlation to volume and seed count for the micturition after 3 months. For intestinal function after 3 months, there was a significant correlation to the postoperative planning V100 prostate. Sexual function and general QoL were not significantly impaired during the observation period. Significant differences from the initial IPSS (7.05) were found after 3 (14.64), 6 (13.89) and 12 (8.01) months. In the regression analysis, IPSS was found to be related to needle count and D30 urethra after 6 months.

Conclusion:

Permanent seed implantation is a well-tolerated and established treatment option for localized prostate cancer. QoL was impaired in micturition and intestinal function, but returned to baseline after 12 months.

Quality of dose distribution in real-time modified dose planning for permanent seed implantation

Neubauer S1, Spira G2, Kacpura W2, Derakhshani P1

(1) Department of Urology, West German Prostate Center, Klinik am Ring, Cologne

(2) Department of Radiooncology, West German Prostate Center, Klinik am Ring, Cologne

Introduction and objectives:

LDR brachytherapy shows significantly higher rates of biochemical absence of recurrence in a D90 prostate>140Gy. Real-time modified dose planning (RPM) offers the possibility to adapt the dose plan immediately to intraoperative shifts of the seed position. We studied dose planning and implantation parameters under RPM.

Methodology:

Since the introduction of real-time planning, 689 consecutive patients have been treated with PSI between 10/02 and 12/05. The seeds were placed in a modified peripheral loading technique. The current ultrasound image was merged with intraoperative dose planning. An RPM was performed using the real seed position after each needle.

Results:

At an intraoperative prostate volume of 31.6 ml (11-88) an average of 45 seeds were implanted via 17 needles. The intraoperative dose planning resulted in the following mean dose parameters: D90 prostate 175.85 Gy (Range 133-194 Gy), V100 prostate 97.56% (Range 90-100%), D30 urethra 198.53 Gy (Range 158-227 Gy), D10 rectum 88.55 Gy (Range 34-129 Gy). In RPM, the mean dose parameters did not change significantly (D90 prostate gland 176.67 Gy, V100 prostate gland 97.40%, D30 urethra 198.94 Gy, D10 rectum 85.89 Gy). The actual implementation of the dose plan did not lead to a deterioration of the dose distribution under RPM. The dose parameters required by the American Brachytherapy Society (ABS) were not met in four cases. In these four cases with isolated cold spots, four to seven additional seeds were implanted.

Conclusion:

Changes in seed positions compared to intraoperative pre-planning did not result in a deterioration of dose parameters when using an RPM. The real-time modification is able to detect implant weaknesses and gives the dentist the possibility to compensate them intraoperatively.

Influence of urethral dose on therapy-induced dysuria after permanent seed implantation in localized prostate carcinoma

Spira G1 Derakhshani P2 Kacpura W1 Neubauer S2

(1) Department of Radiooncology, West German Prostate Center, Klinik am Ring, Cologne

(2) Department of Urology, West German Prostate Center, Klinik am Ring, Cologne

Introduction:

Dysuria is the most common side effect of permanent seed implantation (PSI) of prostate carcinoma and an important factor influencing the quality of life after surgery. We investigated the prognostic significance of the dose parameter D30 urethra for postoperative dysuria.

Patients and method:

In the period from 02/2001 to 6/2005,737 consecutive patients in clinical stage T1c-T2a were treated with PSI. The primary quality parameter for the dose distribution is a D90 prostate of more than 140 Gy.

The patients were classified according to D30 urethra: Group 1 D30 210 Gy (14.1%). The IPSS is collected before therapy and after 3/6/12/18/24/36 months. Dysuria was defined as a worsening of the IPSS by more than 4 points. Normalization is defined as reaching the initial value plus 1.

Results:

The average follow-up is 33.4 months. 85.9% (n= 633) of all patients were treated with a D90 of more than 140 Gy. The median D30 urethra was 201.4 Gy. At the time of 6 months after treatment, 38.6% of the group 1.65.1% of group 2 and 12.5% of group 3 of IPSS were returned to normal (baseline+1). The incidence of dysuria in all groups was 56.6% after 1 month, 53.9% after 3 months, 48.1% after 6 months and 14.5% after 12 months. The evaluation of patients according to Baseline IPSS (12 points) showed no significant difference after 6 months (62.8% vs. 64.1% normalization).

Conclusion:

In contrast to the D30 urethra, the pretherapeutic IPSS does not allow a prognostic statement for the time until the micturition is normalized. In addition to the risk factor prostate volume, which is frequently mentioned in the literature, the administered urethral dose plays an important role for the micturition quality according to PSI.

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