P. Kohr

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.

High-Dose-Rate (HDR) or Pulsed-Dose-Rate (PDR) Perioperative Interstitial Intensity-Modulated Brachytherapy (IMBT) for Local Recurrences of Previously Irradiated Breast or Thoracic Wall Following Breast Cancer

Purpose:In patients receiving salvage high-dose-rate (HDR) or pulsed-dose-rate (PDR) brachytherapy for a local recurrence on the chest wall or in the previously treated breast, clinical outcome and benefit were investigated. All patients had previously been treated with full-dose adjuvant external-beam irradiation (EBRT). Disease-free interval after salvage treatment, local tumor control and side effects were analyzed retrospectively.Patients and Methods:Between 1996 and 2002, a total of 32 consecutive patients were treated. 13 patients initially treated with mastectomy and postoperative irradiation and 19 patients initially treated with breast-conserving surgery and postoperative irradiation developed a local recurrence. The mean dose of previous radiation therapy was 58 Gy (range, 42–64 Gy), applied by conventional fractionation. After implantation ± surgery of recurrent disease and CT-based 3-D planning, 15 patients were irradiated with HDR-IMBT (intensity-modulated brachytherapy) with a mean dose of 28 Gy (range, 10–30 Gy, 2 × 2.5 Gy/day at 6-h daily interfraction interval) and 17 patients received PDR-IMBT with a mean dose 30 Gy (range, 10–45 Gy, 5 × 1 Gy/day at 2-h pulse intervals). Four patients underwent additional EBRT using a dose of 24–40 Gy electrons. Treatment was performed only on working days.Results:After a mean post-implant follow-up of 19 months (range, 1–83 months), no signs of local recurrence were observed in 20 of the 32 patients. In twelve patients, local recurrence occurred after a mean follow-up of 13 months (range, 1–78 months). 20 of the 32 patients experienced an additional systemic progress. In one patient, an EORTC/RTOG grade 3 side effect (ulceration of the skin) was described, which was followed by a local recurrence 12 months posttherapeutically.Conclusion:Perioperative interstitial HDR/PDR-IMBT of localized breast or thoracic wall recurrences following previous full-dose EBRT appears to be a meaningful salvage treatment with acceptable toxicity.Ziel:Die klinischen Ergebnisse und der Nutzen für vorbestrahlte Patientinnen, die aufgrund eines Thoraxwand- oder Lokalrezidivs nach brusterhaltender Therapie eine interstitielle High-Dose-Rate-(HDR-) oder Pulsed-Dose-Rate-(PDR-)Brachytherapie erhielten, wurden untersucht. In einer retrospektiven Beobachtungsstudie wurden das krankheitsfreie Überleben, die lokale Tumorkontrolle und die Toxizität analysiert.Patienten und Methodik:Zwischen 1996 und 2002 wurden 32 vorbestrahlte Patientinnen mit einem Lokalrezidiv behandelt. 13 Patientinnen waren initial mastektomiert und 19 Patientinnen brusterhaltend operiert worden. Alle Patientinnen waren im Bereich der Thoraxwand oder der Brust vorbestrahlt (mittlere Dosis 58 Gy, Spannweite 42–64 Gy). Nach CT-gestützter 3-D-Bestrahlungsplanung wurden 15 Patientinnen mit HDR-IMBT (intensitätsmodulierte Brachytherapie) mit einer mittleren Dosis von 28 Gy (10–30 Gy, 2 × 2,5 Gy/Tag, Intervall von 6 h) bestrahlt, und 17 Patientinnen erhielten eine PDR-IMBT mit einer mittleren Dosis von 30 Gy (10–45 Gy, 5 × 1 Gy/Tag, Pulsintervall 2 h). Vier der 32 Patientinnen erhielten zusätzlich eine perkutane Bestrahlung bis zu einer Dosis von 24–40 Gy mit Elektronen. An Wochenenden und Feiertagen erfolgten keine Bestrahlungen.Ergebnisse:Nach einem mittleren Intervall von 19 Monaten (1–83 Monaten) fand sich bei 20 der 32 Patientinnen kein Hinweis auf ein lokales Rezidiv. Zwölf Patientinnen entwickelten im Durchschnitt nach 13 Monaten (1–78 Monate) Lokalrezidive. Bei 20 der 32 Patientinnen kam es im Verlauf zu einem systemischen Progress. Bei einer Patientin trat 1 Jahr nach Therapie eine Grad-3-Nebenwirkung (Ulzeration der Haut) auf, gefolgt von einem lokalen Rezidiv.Schlussfolgerung:Die perioperative interstitielle HDR/PDR-IMBT der Thoraxwand oder der Brust bei der Behandlung von Lokalrezidiven nach vorheriger kompletter perkutaner Strahlentherapie scheint eine vertretbare Therapieoption mit einer akzeptablen Toxizitätsrate zu sein.

Quality assurance of brachytherapy afterloaders using a multi-slit phantom

Brachytherapy is a very successful treatment option for many different tumors. Consequently the quality assurance (QA) of afterloaders is of special interest. For many quality checks verification films are essential. Because currently in many clinics the film development units are replaced by computed radiography systems, the question arises of how to perform QA for afterloaders without conventional radiography films. In this note the use of a new designed multi-slit phantom demonstrates the possibility of performing QA checks with high sensitivity computed radiography systems. Because the presented phantom allows a method for imaging the radiation source it might be useful in the development of further QA techniques.

Comparison of CT- and Radiograph-Based Post-Implant Dosimetry for Transperineal 125I Prostate Brachytherapy Using Single Seeds and a Commercial Treatment-Planning Software

Background and Purpose:The objective of this investigation was a direct comparison of the dosimetry of CT-based and radiograph- based postplanning procedures for seed implants.Patients and Methods:CT- and radiograph-based postplans were carried out for eight iodine-125 (125I) seed implant patients with a commercial treatment-planning system (TPS). To assess a direct comparison of the dosimetric indices (D90, V100, V400), the radiograph-based seed coordinates were transformed to the coordinate system of the CT postplan. Afterwards, the CT-based seed positions were replaced by the radiograph-based coordinates in the TPS and the dose distribution was recalculated.Results:The computations demonstrated that the radiograph-based dosimetric values for the prostate (Dp90, Vp100, and Vp400) were on average lower than the values of the CT postplan. Normalized to the CT postplan the following mean values were found: Dp90: 90.6% (standard deviation [SD]: 9.0%), Vp100: 86.1% (SD: 14.7%), and Vp400: 79.4% (SD: 14.4%). For three out of the eight patients the Dp90 decreased to 90% of the initial CT postplan values. The reason for this dosimetric difference is supposed to be evoked by an error of the reconstruction software used. It was detected that the TPS algorithm assigned some sources to wrong coordinates, partly out of the prostate gland.Conclusion:The radiograph-based postplanning technique of the investigated TPS should only be used in combination with CT postplanning. Furthermore, complex testing procedures of reconstruction algorithms are recommended to minimize calculation errors.Hintergrund und Ziel:Das Ziel dieser Untersuchung war es, die Dosimetrie zweier häufig angewandter Nachplanungsverfahren bei Seed-Implantationen, die Computertomographie und die Röntgenbildrekonstruktion, direkt miteinander zu vergleichen.Patienten und Methodik:Die CT-Nachplanungen und Röntgenbildrekonstruktionen wurden in einem Kollektiv von acht Patienten mit Iod-125-(125I-)Implantaten anhand eines kommerziellen Seed-Planungssystems durchgeführt. Um eine direkte Evaluation der dosimetrischen Parameter (D90, V100, V400) zu erreichen, wurden die Koordinaten der Seeds aus den Röntgenbildrekonstruktionen in das Koordinatensystem der CT-Nachplanung transformiert. Im Planungssystem wurden die Seed-Koordinaten der CT-Nachplanung durch die Seed-Positionen der Röntgenfilmrekonstruktionen ersetzt, und die Dosisverteilung wurde erneut berechnet.Ergebnisse:Die Berechnungen ergaben, dass die auf Röntgenbildrekonstruktionen basierenden Werte der Prostata für Dp90, Vp100 und Vp400 im Mittel unter denen der CT-basierten Nachplanungen lagen. Auf die Werte der CT-Nachplanungen normiert stellten sich die Ergebnisse wie folgt dar: Dp90: 90,6% (Standardabweichung [SD]: 9,0%), Vp100: 86,1% (SD: 14,7%) sowie Vp400: 79,4% (SD: 14,4%). Bei drei der acht Patienten lag der Dp90-Wert unter 90% der Dosen der ursprünglichen CT-Nachplanung. Als Erklärung für die Diskrepanz der Dosimetrie in diesen Fällen werden Ungenauigkeiten im Rekonstruktionsalgorithmus der verwendeten Planungssoftware angenommen. Es zeigte sich, dass einzelnen Seeds fehlerhafte Koordinaten, teilweise sogar außerhalb der Prostata, zugeordnet worden waren.Schlussfolgerung:Der Rekonstruktionsalgorithmus des verwendeten Planungssystems sollte nur in Verbindung mit einer CTNachplanung verwendet werden. Des Weiteren wird eine gründliche Überprüfung verwendeter Algorithmen empfohlen, um Fehler bei der Rekonstruktionsberechnung zu minimieren.

GYROPLAN – Bildüberlagerung als Basis gezielter Tumortherapie

Zusammenfassung Es wird ein Computerprogramm zur Bilduberlagerung – speziell in der Strahlentherapie – vorgestellt, das in der Lage ist, mittels Landmarken digitalisierte Simulatorbilder mit MR- bzw. CT-Datensatzen zu uberlagern. Die leicht zu bedienende Apple-Macintosh-Software erlaubt auβerdem eine Divergenzkorrektur, stufenlose Gewichtung der Transparenz sowie das Durchblattern paralleler Bilddatensatze und ermoglicht es somit, unterschiedliche Bildgebungsverfahren schnell und einfach in der klinischen Praxis nutzbar zu machen. Dabei wurde eine Uberlagerungsgenauigkeit von 2.7 bis 3.4 mm unter Berucksichtigung der kumulativen Einflusse von MR-Bildverzerrung, Divergenzproblematik, Patientenverkippung, Patientenmorphologie und individuellem Benutzerfehler ermittelt.

154 O - Intermediate analysis at minimum 5 years follow-up of 70 patients with prostate cancer treated by external beam and brachytherapy

Objectives The combined transrectal ultrasound (TRUS) guided HDR-Brachytherapy (BT) and external beam treatment for nodal negative prostate cancer was introduced 1986 in our department. Material and methods 181 patients (pts.) with prostate cancer were treated by combined Brachy- and Teletherapy from 1986 to 1995. 70 pts. of those had a longer follow-up than 60 months (mean 76.3 months ranging from 5 to 9 years). The therapy protocol included 2 fractions of BT with 192 Ir (each 15 Gy), which were integrated in the teletherapy schedule. The HDR-BT was planed and applied using a template and based on TRUS-Volumetry of the prostate with the possibility of conformal treatment planing. The total dose was 50 Gy for subclinical disease and a boost of 30 Gy by HDR-BT for the prostate. Results Systemic progression was found in 11 pts. (16%), local progression in 2 pts.(3%) and both in 2 other pts. (3%). The 4 pts. out of 70 (6%) with local recurrence were according to the UICC-classification in T 3c -Stage (3 pts.), and T 2b -Stage (one pt.) respectivelly. All 4 pts. had tumors grade III (Mostofi). Late side effects: proctitis (grade III) in 3/70 pts., grade 1/II in 15% as well as cystitis grade III in 3/70 cases and 1/11 in 24%. The present data seems to be in favour of the Kiel method particularly in locally advanced and highgrade tumors.