Peter Niehoff

5-year results of accelerated partial breast irradiation using sole interstitial multicatheter brachytherapy versus whole-breast irradiation with boost after breast-conserving surgery for low-risk invasive and in-situ carcinoma of the female breast: a randomised, phase 3, non-inferiority trial

BACKGROUND In a phase 3, randomised, non-inferiority trial, accelerated partial breast irradiation (APBI) for patients with stage 0, I, and IIA breast cancer who underwent breast-conserving treatment was compared with whole-breast irradiation. Here, we present 5-year follow-up results. METHODS We did a phase 3, randomised, non-inferiority trial at 16 hospitals and medical centres in seven European countries. 1184 patients with low-risk invasive and ductal carcinoma in situ treated with breast-conserving surgery were centrally randomised to either whole-breast irradiation or APBI using multicatheter brachytherapy. The primary endpoint was local recurrence. Analysis was done according to treatment received. This trial is registered with ClinicalTrials.gov, number NCT00402519. FINDINGS Between April 20, 2004, and July 30, 2009, 551 patients had whole-breast irradiation with tumour-bed boost and 633 patients received APBI using interstitial multicatheter brachytherapy. At 5-year follow-up, nine patients treated with APBI and five patients receiving whole-breast irradiation had a local recurrence; the cumulative incidence of local recurrence was 1.44% (95% CI 0.51-2.38) with APBI and 0.92% (0.12-1.73) with whole-breast irradiation (difference 0.52%, 95% CI -0.72 to 1.75; p=0.42). No grade 4 late side-effects were reported. The 5-year risk of grade 2-3 late side-effects to the skin was 3.2% with APBI versus 5.7% with whole-breast irradiation (p=0.08), and 5-year risk of grade 2-3 subcutaneous tissue late side-effects was 7.6% versus 6.3% (p=0.53). The risk of severe (grade 3) fibrosis at 5 years was 0.2% with whole-breast irradiation and 0% with APBI (p=0.46). INTERPRETATION The difference between treatments was below the relevance margin of 3 percentage points. Therefore, adjuvant APBI using multicatheter brachytherapy after breast-conserving surgery in patients with early breast cancer is not inferior to adjuvant whole-breast irradiation with respect to 5-year local control, disease-free survival, and overall survival. FUNDING German Cancer Aid.

GEC/ESTRO recommendations on high dose rate afterloading brachytherapy for localised prostate cancer: an update.

BACKGROUND HDR afterloading brachytherapy (HDRBT) for prostate cancer is now established as an effective technique to achieve dose escalation in the radical treatment of localized prostate cancer. The previous guidelines published in 2005 from GEC ESTRO and EAU have been updated to reflect the current and emerging roles for HDRBT in prostate cancer. PATIENTS AND METHOD The indications for HDRBT in dose escalation schedules with external beam are wide ranging with all patients having localized disease eligible for this technique. Exclusion criteria are few encompassing patients medically unfit for the procedure and those with significant urinary outflow symptoms. RESULTS Recommendations for patient selection, treatment facility, implant technique, dose prescription and dosimetry reporting are given. CONCLUSIONS HDRBT in prostate cancer can be practiced effectively and safely within the context of these guidelines with the main indication being for dose escalation with external beam. HDRBT used alone is currently under evaluation and its role in focal treatment and recurrence will be areas of future development.

Feasibility of combined operation and perioperative intensity-modulated brachytherapy of advanced/recurrent malignancies involving the skull base

Purpose:To assess the technical feasibility and toxicity of combined operation and perioperative intensity-modulated fractionated interstitial brachytherapy (IMBT) in advanced-stage malignancies involving the skull base with the goal of preserving the patients’ senses of sight.Patients and Methods:This series consisted of 18 consecutive cases: ten patients with paranasal sinus carcinomas, five with sarcomas, two with primitive neuroectodermal tumors (PNETs), and one with parotid gland carcinoma. After, in most cases, subtotal surgical resection (R1–R2: carried out so that the patients’ senses of sight were preserved), two to twelve (mean five) afterloading plastic tubes were placed into the tumor bed. IMBT was performed with an iridium-192 stepping source in pulsed-dose-rate/high-dose-rate (PDR/HDR) afterloading technique. The total IMBT dose, ranging from 10 to 30 Gy, was administered in a fractionated manner (3–5 Gy/day, 5 days/week).Results:Perioperative fractionated IMBT was performed in 15 out of 18 patients and was well tolerated. Complications that partially prevented or delayed IMBT in some cases included cerebrospinal fluid leakage (twice), meningitis (twice), frontal brain syndrome (twice), afterloading tube displacement (twice), seizure (once), and general morbidity (once). No surgery- or radiation-induced injuries to the cranial nerves or eyes occurred. Median survival times were 33 months after diagnosis and 16 months after combined operation and IMBT.Conclusion:Perioperative fractionated IMBT after extensive but vision-preserving tumor resection seems to be a safe and well-tolerated treatment of advanced/recurrent malignancies involving the skull base. These preliminary data suggest that combined operation and perioperative fractionated IMBT is a palliative therapeutic option in the management of fatal malignancies involving the base of the skull, a strategy which leaves the patients’ visual acuity intact.Ziel:Prüfung der technischen Durchführbarkeit und Toxizität einer Kombinationsbehandlung aus Operation und perioperativer intensitätsmodulierter fraktionierter interstitieller Brachytherapie (IMBT) bei Malignomen fortgeschrittener Stadien mit Schädelbasisbefall mit dem Ziel, die Sehfunktion zu erhalten.Patienten und Methodik:Diese Serie bestand aus 18 konsekutiven Fällen: zehn Patienten mit Nasennebenhöhlenkarzinomen, fünf mit Sarkomen, zwei mit primitiven neuroektodermalen Tumoren (PNETs) und ein Patient mit Speicheldrüsenkarzinom. Nach zumeist subtotaler chirurgischer Resektion (R1–R2: ausgeführt unter Erhalt der Sehfunktion) wurden zwei bis zwölf (durchschnittlich fünf) Afterloading-Applikatoren im Tumorbett platziert. Die IMBT wurde mit einer wandernden Iridium-192-Strahlungsquelle im Pulsed-Dose-Rate/High-Dose-Rate-(PDR/HDR-)Afterloading-Verfahren durchgeführt. Die IMBT-Gesamtdosis von 10–30 Gy wurde fraktioniert mit 3–5 Gy täglich für 5 Tage/Woche appliziert.Ergebnisse:Die perioperative fraktionierte IMBT wurde bei 15 von 18 Patienten durchgeführt und gut vertragen. Komplikationen, welche die IMBT teilweise verhinderten oder verzögerten, umfassten: Liquorleck (zweimal), Meningitis (zweimal), Frontalhirnsyndrom (zweimal), Dislokation der Afterloading-Applikatoren (zweimal), Krampfanfall (einmal) und allgemeine Morbidität (einmal). Es traten keinerlei operations- oder bestrahlungsbedingte Schäden an den Hirnnerven oder Augen auf. Die mittleren Überlebenszeiten betrugen 33 Monate nach Diagnosestellung und 16 Monate nach kombinierter Operation und IMBT.Schlussfolgerung:Die perioperative fraktionierte IMBT nach ausgedehnter, die Sehfunktion jedoch erhaltender Tumorresektion scheint eine sichere und gut verträgliche Behandlungsmethode für fortgeschrittene Malignome mit Schädelbasisbefall zu sein. Diese vorläufigen Daten lassen den Schluss zu, dass die Kombination aus Operation und perioperativer fraktionierter IMBT eine palliative therapeutische Option bei Patienten mit ansonsten verhängnisvollen Malignomen mit Schädelbasisbefall darstellt, eine Strategie, welche die Sehschärfe des Patienten intakt lässt.

GEC-ESTRO multicenter phase 3-trial: Accelerated partial breast irradiation with interstitial multicatheter brachytherapy versus external beam whole breast irradiation: Early toxicity and patient compliance

BACKGROUND AND PURPOSE To compare early side effects and patient compliance of accelerated partial breast irradiation (APBI) with multicatheter brachytherapy to external beam whole breast irradiation (WBI) in a low-risk group of patients with breast cancer. MATERIAL AND METHODS Between April 2004 and July 2009, 1328 patients with UICC stage 0-IIA breast cancer were randomized to receive WBI with 50Gy and a boost of 10Gy or APBI with either 32.0Gy/8 fractions, or 30.1Gy/7 fractions (HDR-brachytherapy), or 50Gy/0.60-0.80Gy per pulse (PDR-brachytherapy). This report focuses on early side-effects and patient compliance observed in 1186 analyzable patients. ClinicalTrials.gov identifier: NCT00402519. RESULTS Patient compliance was excellent in both arms. Both WBI and APBI were well tolerated with moderate early side-effects. No grade 4 toxicity had been observed. Grade 3 side effects were exclusively seen for early skin toxicity (radiation dermatitis) with 7% vs. 0.2% (p<0.0001), and breast infection with 0% vs. 0.2% (p=n.s.) for patients treated with WBI and APBI. The incidence of grades 1-2 early side effects for WBI and APBI was 86% vs. 21% (p<0.0001) for skin toxicity, 2% vs. 20% (p<0.0001) for mild hematoma, and 2% vs. 5% (p=0.01) for mild breast infection rates, respectively. No differences had been found regarding grades 1-2 early breast pain (26% vs. 29%, p=0.23). CONCLUSIONS APBI with interstitial multicatheter brachytherapy was tolerated very well and dramatically reduced early skin toxicity in comparison to standard WBI.

Prophylaxe und Therapie akuter Strahlenfolgen an Haut und Schleimhaut

BACKGROUND In a German multicenter questionnaire, answered by 89 departments, we had examined the strategies to prevent or to treat the acute morbidity of the skin and mucosa associated to radiation therapy. In this work, the recommendations from the literature are compared to the results of the questionnaire. METHODS An extensive research on common data information systems (Medline, Cancerlit, DIMDI and others) was performed. The criteria included the organ related morbidity and therapeutic strategies for its reduction. The obtained data were compared to the results from the questionnaire. RESULTS The study data found by the research often demonstrate small patient numbers and little convincing results. However, as in the questionnaire, the joint principle seems to be the reduction of acute inflammatory tissue reaction by evasion of bacterial and mycotic overgrowth and reduction of exo- and endogenous toxins. CONCLUSIONS Further studies with more convincing results are required.ZusammenfassungHintergrundIn einer bundesweiten Erhebung war anhand eines offenen Fragebogens untersucht worden, welche Strategien zur Vorbeugung und Behandlung akuter strahlenassoziierter Gewebsreaktionen an Haut und Schleimhäuten verfolgt werden. Es hatte sich eine sehr große Varianz der Antworten ergeben. In der vorliegenden Arbeit wurde die aktuelle Literatur im Hinblick auf die Reduktion der akuten strahlentherapieassoziierten Morbidität untersucht.MethodeEs wurde eine umfangreiche Literaturrecherche (Medline, Cancerlit, DIMDI und andere) durchgeführt. Suchkriterien waren jeweils die organbezogene Morbidität sowie Verfahren zu deren Reduktion. Die Daten wurden mit den Ergebnissen der Umfrage korreliert.ErgebnisseDie durch die Recherche erhaltenen Untersuchungen weisen häufig eine kleine Fallzahl und oft wenig überzeugende Ergebnisse auf. Wie auch im Ergebnis der Umfrage ist als gemeinsames Wirkprinzip die Reduktion akuter Entzündungsreaktionen durch Vermeidung oder Behandlung von Superinfektionen und Reduktion weiterer gewebstoxischer Einflüsse zu erkennen.SchlußfolgerungenEs müssen weitere Untersuchungen mit überzeugenderen Ergebnissen durchgeführt werden.AbstractBackgroundIn a German multicenter questionnaire, answered by 89 departments, we had examined the strategies to prevent or to treat the acute morbidity of the skin and mucosa associated to radiation therapy. In this work, the recommendations from the literature are compared to the results of the questionnaire.MethodsAn extensive research on common data information systems (Medline, Cancerlit, DIMDI and others) was performed. The criteria included the organ related morbidity and therapeutic strategies for its reduction. The obtained data were compared to the results from the questionnaire.ResultsThe study data found by the research often demonstrate small patient numbers and little convincing results. However, as in the questionnaire, the joint principle seems to be the reduction of acute inflammatory tissue reaction by evasion of bacterial and mycotic overgrowth and reduction of exo- and endogenous toxins.ConclusionFurther studies with more convincing results are required.

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.

Proof of Direct Radiogenic Destruction of Collagen in Vitro

Background:Fibroses of vessels and soft tissue are side effects of radiotherapy. The authors assumed that there was an immediate direct radiogenic damage of collagen of bone, periosteum and skin.Material and Methods:15 porcine jaws samples (group 1) were exposed to a total dose of 60 Gy (cobalt-60, 2 Gy/day, five fractions/week). 15 jaws samples were stored accordingly (group 2, no irradiation, control). Collagen fragments of bone, periosteum and skin samples of groups 1 and 2 were isolated by ultrafiltration. Collagen types were characterized by SDS-PAGE measurement of the mature collagen cross-links hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) by high-performance liquid chromatography (HPLC) and analysis of hydroxyproline (Hyp) was used to determine the ratio of the amount of collagen fragments from irradiated as opposed to nonirradiated samples.Results:The concentrations of HP, LP and Hyp in ultrafiltrates of probes of irradiated bone, periosteum and skin were markedly increased (average factors for bone: 3.69, 1.84, and 3.40, respectively; average factors for periosteum: 1.55, 1.41, and 1.77, respectively; average factors for skin: 1.55, 1.60, and 2.23, respectively) as compared to nonirradiated probes. SDS-PAGE did show collagen types I and V in nonirradiated bone, I and III in nonirradiated skin, and I in nonirradiated periosteum samples. In irradiated samples, smeared bands illustrated fragmentation of the collagen molecule.Conclusion:The increased concentrations of HP, LP and Hyp in ultrafiltrates indicated increased concentrations of split collagen. Direct and instant radiogenic damage of (extracellular matrix of) bone, periosteum and skin tissue collagen could be demonstrated.Hintergrund:Fibrosierungen von Haut und Gefäßen sind Begleiterscheinungen einer Strahlentherapie. Die Autoren nehmen an, dass es eine direkte radiogene Kollagenschädigung an Knochen, Periost und Haut gibt.Material und Methodik:15 Schweinekieferproben (Gruppe 1) wurden mit einer Gesamtdosis von 60 Gy (2 Gy ED, fünf Fraktionen/Woche) an einem Telekobaltgerät bestrahlt. Als unbestrahlte Kontrollgruppe wurden 15 Schweinekieferproben unter gleichen Bedingungen aufbewahrt (Gruppe 2). Kollagenfragmente aus dem Knochen, dem Periost und der Haut beider Gruppen wurden mittels Ultrafiltration isoliert. Die verschiedenen Kollagentypen wurden mittels SDS-PAGE analysiert. Die gefundenen Mengen reifer Kollagenfragmente Hydroxylysylpyridinolin (HP) und Lysylpyridinolin (LP) der bestrahlten und unbestrahlten Proben wurden in Verhältnis zueinander gesetzt.Ergebnisse:Die Konzentrationen von HP, LP und Hyp (Hydroxyprolin) im Ultrafiltrat der bestrahlten Proben (Knochen, Periost und Haut) waren im Vergleich zur unbestrahlten Gruppe deutlich erhöht. Die jeweiligen durchschnittlichen Faktoren waren für Knochen um den Faktor 3,69, 1,84 bzw. 3,40, für das Periost um den Faktor 1,55, 1,41 bzw. 1,77 und für die Haut um den Faktor 1,55, 1,60 bzw. 2,23 erhöht. In der SDS-PAGE fanden sich in der unbestrahlten Gruppe Kollagen Typ I und V im Knochen, Typ I und III in der Haut und Typ I im Periost. Bei den bestrahlten Proben stellten sich nur verschmierte Bänder als Zeichen der Fragmentierung der Kollagenmoleküle dar.Schlussfolgerung:Die erhöhten Konzentrationen von HP, LP und Hyp im Ultrafiltrat deuten auf eine erhöhte Konzentration von gespaltetem Kollagen hin. Ein direkter radiogener Schaden der Extrazellulärmatrix sowie an Knochen-, Periost- und Hautgewebe konnte so in vitro nachgewiesen werden.

Interobserver variations of target volume delineation in multicatheter partial breast brachytherapy after open cavity surgery

PURPOSE To investigate interobserver variations of target volume delineations in accelerated partial breast irradiation with multicatheter brachytherapy (BT) and to assess the impact of guidelines on consistency of contouring. METHODS AND MATERIALS A contouring study with two phases in interstitial accelerated partial breast irradiation after open cavity surgery was conducted by the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology Breast Cancer Working Group. Contours of cavity and planning target volume (PTV) on preimplant and postimplant CT images were delineated. In Phase 1, nine radiation oncologists defined the target volumes of 5 patients, whereas in Phase 2, four observers draw the contours of 4 patients applying guidelines. In Phase 1, experience in breast BT after open cavity surgery was assessed. The delineations were compared between Phase 1 and Phase 2, the impact of guidelines was assessed, and cavity visualization score was related to consistency of delineations. RESULTS Significant interobserver variability in delineations of lumpectomy cavity and PTV was observed among the participants. Observers with BT experience after open cavity surgery outlined the cavity and PTV more consistently (conformity indexgen: 0.52 vs. 0.48 and 0.59 vs. 0.55 for preimplant and postimplant cavities). For all volumes, the mean Vmax/Vmin was 2.2 vs. 2.8. Having used guidelines all conformity indices increased significantly. For cavity, the increase was 14% and 11%, whereas for the PTV, 28% and 17% on the preimplant and postimplant CT images, respectively. A strong correlation was found between consistency of contours and cavity visualization score. CONCLUSIONS Simple guidelines on defining the lumpectomy cavity significantly increased the consistency of contouring. Reliable consistency of target volume definition can be expected only for good cavity visibility.

Perioperative Interstitial High-Dose-Rate Brachytherapy for the Treatment of Recurrent Keloids: Feasibility and Early Results

PURPOSE To prospectively evaluate high-dose-rate brachytherapy in the treatment of therapy-resistant keloids and report first results, with emphasis on feasibility and early treatment outcome. METHODS AND MATERIALS From 2009 to 2014, 24 patients with 32 recurrent keloids were treated with immediate perioperative high-dose-rate brachytherapy; 3 patients had been previously treated with adjuvant external beam radiation therapy and presented with recurrences in the pretreated areas. Two or more different treatment modalities had been tried in all patients and had failed to achieve remission. After (re-)excision of the keloids, a single brachytherapy tube was placed subcutaneously before closing the wound. The target volume covered the scar in total length. Brachytherapy was given in 3 fractions with a single dose of 6 Gy in 5 mm tissue depth. The first fraction was given within 6 hours after surgery, the other 2 fractions on the first postoperative day. Thus, a total dose of 18 Gy in 3 fractions was administered within 36 hours after the resection. RESULTS The treatment was feasible in all patients. No procedure-related complications (eg, secondary infections) occurred. Nineteen patients had keloid-related symptoms before treatment like pain and pruritus; disappearance of symptoms was noticed in all patients after treatment. After a median follow-up of 29.4 months (range, 7.9-72.4 months), 2 keloid recurrences and 2 mildly hypertrophied scars were observed. The local control rate was 94%. Pigmentary abnormalities were detected in 3 patients, and an additional 6 patients had a mild delay in the wound-healing process. CONCLUSIONS The early results of this study prove the feasibility and the efficacy of brachytherapy for the prevention of keloids. The results also suggest that brachytherapy may be advantageous in the management of high-risk keloids or as salvage treatment for failure after external beam therapy.

Prospective multi-center dosimetry study of low-dose Iodine-125 prostate brachytherapy performed after transurethral resection

Purpose To evaluate in a multicenter setting the ability of centers to perform pre-implant permanent prostate brachytherapy planning, fulfilling dosimetric goals and constraints based on the Groupe de Curiethérapie-European Society for Radiotherapy and Oncology guidelines in the setting of implantation after prior prostate transurethral resection (TURP). Material and methods A reference transrectal ultrasound image set of the prostate gland from a patient who had undergone TURP was used. Contouring of the prostate, clinical target volume and organs at risk was performed by the coordinating center. Goals and constraints regarding the dosimetry were defined. Results Seventeen of twenty-five centers invited to participate were able to import the Digital Imaging and Communications in Medicine-images into their planning computer and plan the implant using the defined guidelines. All centers were able to plan treatment, and achieve the recommended objectives and constraints. However, sector analysis has shown a risk of under-dosage in the anterior part of the prostate. Conclusions Correct pre-implantation planning with adherence to protocol guidelines and in compliance with defined dosimetric constraints seems feasible in a post-TURP setting, at least on a theoretical basis. A prospective study evaluating the outcome of prostate brachytherapy performed after TURP can therefore be undertaken with an expectation of a correct dosimetry in the multicenter setting.