Hagen Bertermann

Long-term outcome after elective irradiation of the pelvic lymphatics and local dose escalation using high-dose-rate brachytherapy for locally advanced prostate cancer

PURPOSE To report the 8-year outcome of local dose escalation using high-dose-rate conformal brachytherapy combined with elective irradiation of the pelvic lymphatics for localized prostate cancer. METHODS AND MATERIALS One hundred forty-four consecutively treated men (1986-1992) were recorded prospectively. Twenty-nine (20.14%) patients had T1b-2a tumors, and 115 (79.86%) patients had T2b-3 tumors according to, respectively, American Joint Committee on Cancer/Union Internationale Contre le Cancer 1992. All patients had a negative nodal status, proven by CT or MRI. The mean initial PSA value was 25.61 ng/mL (Initial value for 41.66% of patients was <10 ng/mL, for 21.52% was 10-20 ng/mL, and for 32.63% was >20 ng/mL). The total dose applied by external beam radiotherapy was 50 Gy in the pelvis and 40 Gy in the prostate. The high-dose-rate brachytherapy was delivered in two fractions, which were incorporated into the external beam treatment (after 20-Gy and 40-Gy external beam radiotherapy dose). The dose per fraction was 15 Gy for the PTV1 (peripheral prostate zone) and 9 Gy for the PTV2 (entire prostatic gland). Any patient free of clinical or biochemical evidence of disease was termed bNED. Actuarial rates of outcome were calculated by Kaplan-Meier and compared using the log-rank. Cox regression models were used to establish prognostic factors of the various measures of outcome. RESULTS The median follow-up was 8 years (range 60-171 months). The overall survival rate was 71.5%, and the disease-free survival rate was 82.6%. The bNED survival rate was 72.9%. Freedom from local recurrence for T3 stage was 91.3%, whereas for G3 lesions it was 88.23%. Freedom from distant recurrence for T3 stage was 82.6% and for G3 lesions 70.59%. Univariate survival analyses revealed that low stage (T1-2), low grade (G1-2), no hormonal therapy, initial PSA value less than 40 ng/mL, and PSA normalization <1.0 ng/mL after irradiation were associated with long survival. In multivariate analyses, initial PSA value, PSA kinetics after radiation therapy, and no adjuvant hormonal treatment were independent prognostic factors. Grade 3 late radiation toxicity (according to RTOG/EORTC scoring scheme) was 2.3% for the genitourinary system in terms of cystitis and 4.10% for the gastrointestinal system in terms of proctitis. Grades 4 and 5 genitourinary/gastrointestinal morbidity was not observed. A history of transurethral resection of the prostate with a median interval of less than 6 months from radiotherapy was associated with a high risk of genitourinary toxicity. CONCLUSION The 8-year results confirm the feasibility and effectiveness of combined elective irradiation of the pelvic lymphatics and local dose escalation using high-dose-rate brachytherapy for cure of localized and especially high-risk prostate cancer.

Prostate preservation by combined external beam and HDR brachytherapy in nodal negative prostate cancer

PurposeThe combined external beam- and high-dose rate brachytherapy (HDR-BT) of localized prostate cancer was introduced at Kiel University in 1986. The aim of this intermediate analysis was to judge the Kiel method of localized prostate cancer radiation treatment after ten years experience.Patients and MethodsIn the past ten years 174 patients with histological proven localized prostate cancer were subjected to combined tele-/HDR-brachytherapy. Local staging in all of the cases by transrectal ultrasound, nodal staging in the majority of the cases by CT or MRI. Average age of the patients was 68.2 years (44–84). According to AJCC/UICC staging T1B, T2, T3 was found in 2, 113 and 59 cases, respectively. Highly differentiated tumors (G1) were found in 27, moderately differentited (G2) in 87, poorly differentiated (G3) in 60 cases. The mean follow-up was 47.1 months with the median of 51.7 months. Total prescribed dose 50 Gy on the small pelvis and 70 Gy on the prostate capsule due to the integration of two, 15 Gy each, HDR-brachytherapy fractions in 6 weeks.ResultsTen patients died of prostate cancer and 18 of intercurrent diseases resulting in a 5 years overall survival rate of 83% and tumor specific survival rate of 94%. Twenty-one patients showed a clinical progression, of these 14 systemic, 5 local and 2 both systemic and local. Additional 16 patients had PSA elevation only. The 5-years biochemical and/or clinical progression-free survival in the cohort was 79% and 73% for the T3 tumors. Side effects were 27 cases of proctitis/colitis and 20 cases of dysuria/cystitis.ConclusionThe integrated HDR-BT combined with external beam radiation treatment is a method with excellent tumor control rates at five years superior to those of external beam treatment alone or external beam combined with iodine-125 implants. This form of radiotherapy would appear to be particularly well-suited to treatment of advanced localized (T3) tumors.