Ulf Lamprecht

Quality assurance for clinical studies in regional deep hyperthermia

BackgroundA guideline is provided for the implementation of regional deep hyperthermia treatments under strict rules of quality assurance. The objective is to guarantee a comparable and comprehensible method in the treatment and scientific analysis of hyperthermia. The guideline describes regional deep hyperthermia (RHT) and MR-controlled partial body hyperthermia (PBH) of children, young and adult patients. According to this guideline, hyperthermia treatment is always applied in combination with chemotherapy and/or radiotherapy.MethodsThe guideline is based on practical experience from several hyperthermia centers. The procedure allows applying jointly coordinated standards and quality control in hyperthermia for studies.ResultsThe guideline contains recommendations for hyperthermia treatments, including indication, preparation, treatment, and standardized analysis.HintergrundZur Durchführung von qualitätsgesicherten Tiefenhyperthermiebehandlungen wurde eine Leitlinie erstellt. Ziel war, ein vergleichbares und nachvollziehbares Vorgehen bei der Behandlung und der wissenschaftlichen Auswertung von Hyperthermiebehandlungen zu gewährleisten. Die Leitlinie beschreibt die „Regionale Tiefenhyperthermie“ (RHT) und die „MR-kontrollierte Teilkörperhyperthermie“ (PBH) von Kindern, jugendlichen und erwachsenen Patienten. Hyperthermie im Sinne der Leitlinie wird als Kombinationsbehandlung mit einer Chemo- und/oder Strahlentherapie durchgeführt.MethodikDie Leitlinie basiert auf praktischen Erfahrungen mehrerer Hyperthermiezentren. Dieses Vorgehens erlaubt abgestimmte Standards in der Anwendung und der Qualitätskontrolle in der Hyperthermie für Studien.ErgebnisseDiese Leitlinie enthält Empfehlungen für Hyperthermiebehandlungen mit Indikationsstellung, Vorbereitung, Durchführung und standardisierter Auswertung.

Thermoradiotherapy for locally recurrent breast cancer with skin involvement

Purpose: This retrospective analysis investigated the effectiveness and side-effects of combined hyperthermia and radiation therapy in locally recurrent breast cancer after primary modified radical mastectomy. The aim of the thermoradiotherapy was to reduce the substantial risk of symptomatic chest wall disease. Materials and methods: Between May 1995-August 1998, 39 extensively pre-treated women with progressive locoregional chest wall tumours were treated with local radiofrequency hyperthermia, given twice a week immediately before radiotherapy. Sixty-two per cent of the patients had received previous radiotherapy, with a median dose of 50Gy, 64% had received chemotherapy, 36% hormonal therapy, and 13% local therapy with miltefosin, respectively. Nine patients were treated for microscopic residual disease after local tumour excision (R1-resection) and 30 patients for gross macroscopic nodular recurrences. Twenty-seven patients had two adjacent hyperthermia fields at the ipsilateral chest wall to cover the whole irradiation area. Each field received a median of seven local hyperthermia sessions (range 2-12, average 5.6 sessions) just before radiation therapy, with a median dose of 60Gy (range 30-68Gy). The monitored maximumaverage and averageaverage epicutaneous temperatures were 42.1°C and 41.0°C, respectively. Maximumaverage and averageaverage intratumoural temperatures of 43.0°C and 41.1°C, respectively, were achieved in nine chest wall recurrences with intratumoural temperature probes. Concurrent hormonal therapy was administered in 48%, and concurrent chemotherapy in 10% of patients. Results: Median overall survival time was 28 months (Kaplan Meier), with 71% and 54% of patients living 1 and 2 years after thermoradiotherapy. The median time to local failure has not been reached, local tumour control after 2 years being 53%. Actuarial 1 and 2 year local tumour controls for microscopic residual disease were 89%, and for macroscopic nodular recurrences 71% and 46%, respectively (p = 0.09). Actuarial 1 and 2 year local tumour controls after treatment with a total dose of less than 60Gy were 51% and 38%, respectively, and, after a total dose greater than 60Gy, 84% and 60% (p = 0.01), respectively. Actuarial 1 year local tumour control was 92% after complete tumour remission, versus 57% after partial remission (p = 0.002). Three of the 39 patients died of cancer en cuirasse, 13 patients due to distant metastases. Acute thermoradiotherapy related erythema, dry desquamation and moist desquamation were seen in 28.2%, 30.7%, and 30.7% of patients, respectively. Soft tissue necrosis occurred in two patients with previous post-operative delayed wound healing, and in one patient above a silicon implant. Conclusion: This study showed that, in extensively pre-treated patients with locally recurrent breast cancer, local tumour control after thermoradiotherapy depended on tumour resectability, response of macroscopic tumour to thermoradiotherapy, and total irradiation dose.PURPOSE This retrospective analysis investigated the effectiveness and side-effects of combined hyperthermia and radiation therapy in locally recurrent breast cancer after primary modified radical mastectomy. The aim of the thermoradiotherapy was to reduce the substantial risk of symptomatic chest wall disease. MATERIALS AND METHODS Between May 1995-August 1998, 39 extensively pre-treated women with progressive locoregional chest wall tumours were treated with local radiofrequency hyperthermia, given twice a week immediately before radiotherapy. Sixty-two per cent of the patients had received previous radiotherapy, with a median dose of 50 Gy, 64% had received chemotherapy, 36% hormonal therapy, and 13% local therapy with miltefosin, respectively. Nine patients were treated for microscopic residual disease after local tumour excision (R1-resection) and 30 patients for gross macroscopic nodular recurrences. Twenty-seven patients had two adjacent hyperthermia fields at the ipsilateral chest wall to cover the whole irradiation area. Each field received a median of seven local hyperthermia sessions (range 2-12, average 5.6 sessions) just before radiation therapy, with a median dose of 60 Gy (range 30-68 Gy). The monitored maximum(average) and average(average) epicutaneous temperatures were 42.1 degrees C and 41.0 degrees C, respectively. Maximum(average) and average(average) intratumoural temperatures of 43.0 degrees C and 41.1 degrees C, respectively, were achieved in nine chest wall recurrences with intratumoural temperature probes. Concurrent hormonal therapy was administered in 48%, and concurrent chemotherapy in 10% of patients. RESULTS Median overall survival time was 28 months (Kaplan Meier), with 71% and 54% of patients living 1 and 2 years after thermoradiotherapy. The median time to local failure has not been reached, local tumour control after 2 years being 53%. Actuarial 1 and 2 year local tumour controls for microscopic residual disease were 89%, and for macroscopic nodular recurrences 71% and 46%, respectively (p = 0.09). Actuarial 1 and 2 year local tumour controls after treatment with a total dose of less than 60 Gy were 51% and 38%, respectively, and, after a total dose greater than 60 Gy, 84% and 60% (p = 0.01), respectively. Actuarial 1 year local tumour control was 92% after complete tumour remission, versus 57% after partial remission (p = 0.002). Three of the 39 patients died of cancer en cuirasse, 13 patients due to distant metastases. Acute thermoradiotherapy related erythema, dry desquamation and moist desquamation were seen in 28.2%, 30.7%, and 30.7% of patients, respectively. Soft tissue necrosis occurred in two patients with previous post-operative delayed wound healing, and in one patient above a silicon implant. CONCLUSION This study showed that, in extensively pre-treated patients with locally recurrent breast cancer, local tumour control after thermoradiotherapy depended on tumour resectability, response of macroscopic tumour to thermoradiotherapy, and total irradiation dose.

Pathological complete response and sphincter-sparing surgery after neoadjuvant radiochemotherapy with regional hyperthermia for locally advanced rectal cancer compared with radiochemotherapy alone

Purpose: To evaluate the influence of regional hyperthermia on rates of complete pathological response (pCR) and sphincter-sparing surgery in the context of an up-to-date radiochemotherapy protocol for locally advanced rectal cancer. Methods: Between 2007 and 2010, 106 patients with locally advanced cancer of the middle and lower rectum were admitted to neoadjuvant radiochemotherapy either with (n = 61) or without (n = 45) regional hyperthermia. A retrospective comparison was performed between two groups: 45 patients received standard treatment consisting of 5040 cGy in 28 fractions to the pelvis and 5-fluorouracil (RCT group) and 61 patients received the same treatment in combination with regional hyperthermia (HRCT group). Target temperature was 40.5°C for at least 60 min. Total mesorectal excision was performed routinely. Results: pCR was seen in 6.7% of patients in the RCT group and 16.4% in the HRCT group. Patients who received at least four hyperthermia treatments (n = 40) achieved a significantly higher pCR rate (22.5%) than the remaining 66 patients (p = 0.043). Rates of sphincter-sparing surgery were similar in both groups with 64% in the RCT group and 66% in HRCT. When considering only low-lying tumours located within 8 cm of the anal verge prior to treatment, the rate of sphincter-sparing surgery was 57% in the HRCT group compared with 35% in the RCT group (p = 0.077). Conclusion: The combination of regional hyperthermia and neoadjuvant radiochemotherapy may lead to an increased pCR rate in locally advanced rectal cancer. Patients with low-lying tumours especially may benefit when additional downsizing allows sphincter-preserving surgery.

Thermoradiotherapy of the chest wall in locally advanced or recurrent breast cancer with marginal resection

Background and purpose: Evaluation of the efficacy of combined hyperthermia and radiotherapy (TRT) in high-risk breast cancer patients with microscopic involved margins (R1) after mastectomy or with resected locoregional, early recurrence with close margins or R1-resection. Main endpoint was local tumour control (LC); secondary endpoints were overall survival (OS), disease free survival (DFS) and acute toxicity. Material and methods: Between 1997–2001, 50 patients were treated with TRT. Thirteen patients (group 1) received a post-operative TRT in a high-risk situation (free margin <1 cm or R1, N+), 37 patients (group 2) received TRT after close/R1 resection of a locoregional recurrence. Thirteen out of 37 patients in group 2 already had had two-to-seven recurrences prior to TRT. Median radiation dose was 60 Gy (range: 44–66.4 Gy), the additional local hyperthermia (>41°C, 60 min) was given twice a week. Median follow-up for patients at risk was 28 months. All statistical tests were done using Statistica® software. Results: Actuarial OS for all patients at 3 years accounted for 89%, DFS for 68% and LC for 80%. Actuarial OS was 90% for group 1 and 89% for group 2, with four patients having died so far. DFS at 3 years was 64% in group 1 and 69% in group 2, actuarial 3 year LC was 75% and 81%, respectively. For patients with recurrent chest wall disease, there was no difference concerning local control between patients who underwent TRT with or without prior radiation. No prognostic factors could be detected due to the small number of patients investigated. The combined modality treatment was well tolerated. Grade IV toxicity, according to the Common Toxicity Criteria, did not occur. Conclusion: The results concerning local tumour control and overall survival in these high-risk patients are promising, especially for TRT for the treatment of local recurrences. A longer follow-up is needed to estimate late toxicity.

Guideline for the clinical application, documentation and analysis of clinical studies for regional deep hyperthermia

ObjectivesThese guidelines contain recommendations for the implementation of quality-assured hyperthermia treatments. The objective is to guarantee an internationally comparable and easily understandable method for hyperthermia treatment and for the subsequent scientific analysis of the treatment results. The guidelines describe “regional deep hyperthermia” (RHT) and MR-controlled “partial body hyperthermia” (PBH) of children, adolescents and adult patients. Hyperthermia in terms of these guidelines is defined as a treatment combining chemotherapy and/or radiation therapy.MethodsThese guidelines are based on practical experience from several hyperthermia centres in Europe. Our collaborative effort has ensured coordinated standards and quality control procedures in regional deep and partial body hyperthermia. The guidelines were developed by the Atzelsberg Research Group of the IAH (http://www.hyperthermie.org) of the German Cancer Society (“Deutsche Krebsgesellschaft”) to specifically ensure that the multi-institutional studies initiated by the Atzelsberg Research Group are executed following a single, uniform level of quality.ResultsThe guidelines contain recommendations for procedural methods for treatment using hyperthermia. They commence with diagnosis, which is followed by preparation and treatment and concludes with standardised analysis for the reporting of results.ZusammenfassungHintergrundDiese Leitlinie enthält Empfehlungen zur Durchführung von qualitätsgesicherten Hyperthermiebehandlungen. Ziel ist, ein vergleichbares und nachvollziehbares Vorgehen bei der Behandlung und der wissenschaftlichen Auswertung der Hyperthermie zu gewährleisten. Die Leitlinie beschreibt die „Regionale Tiefenhyperthermie“ (RHT) und die „MR-kontrollierte Teilkörperhyperthermie“ (PBH) von Kindern, Jugendlichen und erwachsenen Patienten. Die Hyperthermie im Sinne dieser Leitlinie wird als Kombinationsbehandlung mit einer Chemo- und/oder Strahlentherapie durchgeführt.MethodikDie vorgestellte Leitlinie basiert auf praktischen Erfahrungen von mehreren Hyperthermiezentren. Dieses Vorgehens erlaubt gemeinsam abgestimmte Standards in der Anwendung und der Qualitätskontrolle in der Hyperthermie für Studien, die im Rahmen des Atzelsberger Arbeitskreises in der Interdisziplinären Arbeitsgruppe Hyperthermie (http://www.hyperthermie.org) in der Deutschen Krebsgesellschaft und dem Technischen Komitee der „European Society for Hyperthermic Oncology“ (ESHO) entwickelt wurden, um sicher zu stellen, dass multizentrische Studien, die vom Atzelsberger Arbeitskreis entwickelt wurden, nach einem standardisierten, einheitlichen Qualitätsmaßstab durchgeführt werden.ErgebnisseDiese Leitlinie enthält Empfehlungen für das Vorgehen bei Hyperthermiebehandlungen von der Indikationsstellung, der Vorbereitung, der Durchführung bis zur standardisierten Auswertung.Die deutschsprachige Version des Beitrags ist auf SpringerLink unter „Supplemental“ zu finden.

Physikalische Grundlagen und klinische Durchführung der interstitiellen Brachytherapie der Prostata mit Jod-125

Hintergrund: Durch interstitielle Brachytherapie mit Jod-125-Seeds kann das lokal begrenzte Prostatakarzinom erfolgreich therapiert werden. Es wird die Technik der transperinealen Permanentimplantation von Jod-125-Seeds mit intraoperativer Bestrahlungsplanung vorgestellt, die für eine Therapie des Prostatakarzinoms bis zum Studium T2a geeignet ist. Material und Methode: Einige Wochen vor der Seedimplantation wird mithilfe von transrektalem Ultraschall (TRUS) das Prostatavolumen bestimmt, um die benötigte Anzal der Jod-125-Seeds abzuschätzen. Zu Beginn der Behandlung wird die Prostata durch zwei perineal gesetzte Nadeln fixiert. Anschließend wird eine ultraschallbasierte, intraoperative Bestrahlungsplanung durchgeführt, mit der die Verteilung der Seeds in der Prostata optimiert wird. Zur interstitiellen Brachytherapie werden RAPID STRANDS® verwendet, d. h. die Jod-125-Seeds sind in einem versteiften Vicrylgewebe in 1-cm-Abständen eingebettet. Bei der Applikation der Jod-125-Seeds wird die transversale Positionierung der Applikationsnadeln mit TRUS und die kraniokaudale Positionierung der Applikationsnadeln mithilfe einer Durchleuchtungseinheit und TRUS überwacht. Ungefähr 4 Wochen nach der Seedimplantation wird mithilfe von CT-Schichtbildern eine postoperative Berechnung der Dosisverteilung der applizierten Seeds durchgeführt. Ergebnisse: Das Verfahren hat den Vorteil, dass Ultraschallbildaufnahme, Bestrahlungsplanung und Seedapplikation bei unveränderter Prostatalage durchgeführt werden. Bei der Applikation ermöglicht die kombinierte Bildgebung aus TRUS und Durchleuchtung eine sichere Platzierung der Seeds in der Prostata. Schlussfolgerung: Die Methoden zur Berechnung der tatsächlich erreichten Dosisverteilung müssen noch optimiert werden, da die postoperative Überprüfung des individuellen Ergebnisses bisher nur mit methodisch bedingten Schwierigkeiten möglich ist.Background: Interstitial brachytherapy with I-125 seeds can be used for successful treatment of early stage prostate cancer. There is presented the technique of permanent transperineal implantation of I-125 seeds with intraoperative treatment planning which is suited for the treatment of prostate cancer up to the clinical stage of T2a. Material and Methods: Some weeks before the implantation of the seeds the prostate volume is determined using transrectal ultrasound (TRUS) so as to estimate the required number of I-125 seeds. At the outset of the treatment the prostate is stabilized by two perineally inserted needles. Subsequently there is carried out an ultrasound guided treatment planning that allows to optimize the distribution of the seeds within the prostate. In interstitial brachytherapy we use RAPID STRANDS®, i. e. the I-125 seeds are embedded in vicryl suture at distances of 1 cm. During implantation of the I-125 seeds the transversal placement of the applicator needles is controlled by TRUS and the cranio-caudal placement of the applicator needles is controlled using the fluoroscopic unit as well as TRUS. About 4 weeks after the implantation of the seeds there is carried out a postoperative computation of the dose distribution of the implant using CT imaging. Results: The procedure possesses the advantage that ultrasound imaging, treatment planning and seed implantation are carried out with the prostate remaining in an unaltered position. During implantation the combined imaging of TRUS and fluoroscopy allows a safe placement of the seeds with in the prostate. Conclusion: The methods for the calculation of the actually attained dose distribution must still be optimized, because the postoperative examination of the individual results has so far been possible only with difficulties resulting from methodological inconveniences.

Comparison of different adjuvant radiotherapy approaches in childhood bladder/prostate rhabdomyosarcoma treated with conservative surgery.

Background and PurposeMultimodality treatment approaches provide high local control and satisfying overall survival (OS) for children with localized bladder and/or prostate rhabdomyosarcoma (BP-RMS). However, current strategies including surgery and conventional radiotherapy are compromised by high rates of long-term genitourinary adverse effects. Therefore, a planning study combining organ preserving surgery with three different innovative adjuvant radiotherapy approaches was performed.Patients and MethodsA case of a 21-month-old boy with BP-RMS treated with polychemotherapy according to the CWS 2002-P protocol, prostatectomy, partial cystectomy, and adjuvant high dose rate brachytherapy (HDR-BT) was used to perform a planning study comparing HDR-BT with intensity-modulated radiotherapy (IMRT) and intensity-modulated proton therapy (IMPT) planning.ResultsAll modalities provide good coverage of the target volume and spare critical normal tissues. Rectum doses could be reduced by 2/3 using IMPT and by 1/3 using BT compared to IMRT. In terms of sparing the pelvis growth plates, BT and IMPT are also superior to IMRT.ConclusionAll modalities provide good sparing of normal tissue. BT and IMPT are superior to IMRT with regard to doses on rectum and growth plates. BT is equivalent to IMPT in adequately selected tumors.ZusammenfassungHintergrund und ZielDie multimodale Therapie von Rhabdomyosarkomen von Blase und Prostata (BP-RMS) in Frühstadien bei Kindern führt zu hohen lokalen Kontrollraten. Ein Nachteil aktueller Strategien beruht auf den Spätfolgen für den Urogenitaltrakt. Daher wurde nach organerhaltendem chirurgischem Vorgehen eine Planungsstudie mit drei innovativen adjuvanten Strahlentherapie-Strategien durchgeführt.Patienten und MethodenAnhand des realen Falles eines 21 Monate alten Jungen mit BP-RMS, der mit einer Polychemotherapie nach CWS-2002-P-Protokoll, partieller Zystektomie, Prostatektomie und Brachytherapie (BT) behandelt worden war, führte man eine Planungsstudie durch, um die BT mit einer optimierten intensitätsmodulierten Radiotherapie (IMRT) und einer Protonenbestrahlung (IMPT) zu vergleichen.ErgebnisseAlle drei Radiotherapie-Modalitäten ermöglichten eine gute Zielvolumenerfassung und Normalgewebsschonung. Allerdings war die Rektumbelastung bei der IMPT um zwei Drittel und bei der BT um ein Drittel geringer als bei der IMRT. Darüber hinaus ermöglicht die Anwendung der BT und IMPT im Vergleich zur IMRT eine niedrigere Belastung des Beckenskeletts.SchlussfolgerungAlle Radiotherapie-Modalitäten ermöglichen eine gute Normalgewebeschonung. BT und IMPT sind der IMRT bezüglich der Rektum- und Wachstumsfugenschonung überlegen. Die BT ist der IMPT bei adäquat ausgewählten Tumoren ebenbürtig.

Quality assurance guidelines for superficial hyperthermia clinical trials: I. Clinical requirements

Abstract Quality assurance guidelines are essential to provide uniform execution of clinical trials and treatment in the application of hyperthermia. This document provides definitions for a good hyperthermia treatment and identifies the clinical conditions where a certain hyperthermia system can or cannot adequately heat the tumour volume. It also provides brief description of the characteristics and performance of the current electromagnetic (radiative and capacitive), ultrasound and infra-red heating techniques. This information helps to select the appropriate heating technique for the specific tumour location and size, and appropriate settings of the water bolus and thermometry. Finally, requirements of staff training and documentation are provided. The guidelines in this document focus on the clinical application and are complemented with a second, more technical quality assurance document providing instructions and procedure to determine essential parameters that describe heating properties of the applicator for superficial hyperthermia. Both sets of guidelines were developed by the ESHO Technical Committee with participation of senior STM members and members of the Atzelsberg Circle.

Physikalisch-technische Qualitätssicherung und Strahlenschutz bei der Monotherapie der Prostata mit Jod-125-Seeds

Hintergrund: Das lokal begrenzte Prostatakarzinom kann durch interstitielle Brachytherapie mit Jod-125-Seeds erfolgreich therapiert werden. Es wird ein hierzu geeignetes klinikinternes physikalisch-technisches Qualitätssicherungsprogramm vorgestellt. Weiterhin werden die Anforderungen der neuen deutschen Strahlenschutzverordnung (StrlSchV), die am 1. August 2001 in Kraft getreten ist, berücksichtigt. Material und Methoden: Für die Jod-125-Monotherapie der Prostata werden RAPID STRANDS® (Amersham Health, Braunschweig, Germany) verwendet. Die Ermittlung der Körperdosis des beruflich strahlenexponierten Personals wird entsprechend den Vorgaben der neuen StrlSchV nach den neuen Messgrößen Hp (10) und Hp (0,07) vorgenommen. Die Kenndosisleistung der Seeds wird mit einer kalibrierten Schachtkammer vom Typ HDR 1000 Plus und mit einem Elektrometer vom Typ MAX 4000 gemessen. Die sonographischen Schichtbilder der Prostata werden mit einem Falcon-Ultraschallgerät vom Typ 2101 (B-K Medical A/S, Dänemark) aufgenommen. Für die Bestrahlungsplanung wird das Programm VariSeed (Fa. Varian, Darmstadt, Deutschland) verwendet. Die korrekte Beladung der Nadeln wird vor Applikation autoradiographisch kontrolliert. Nach Applikation werden im OP-Raum Strahlenschutzmessungen durchgeführt. Ergebnisse: Beim Personal ergaben sich, bezogen auf jeweils zwei Applikationen, für die Tiefen-Personendosis Hp (10) Messwerte zwischen 0 μSv und 14 μSv. Bei der Überwachung der Strahlenexposition der Hände ergaben sich Oberflächen-Personendosiswerte Hp (0,07) von bis zu 1 mSv. Die Kenndosisleistungswerte der RAPID STRANDS® lagen alle im 95%-Konfidenzintervall, das vom Hersteller zugesichert wird. Die Autoradiographieaufnahmen dokumentierten – bis auf einen Fall – die korrekte Nadelbeladung. Die interstitielle transperineale Applikation der Jod-125-Seeds konnte bei allen Patienten wie geplant erfolgen. Der OP-Raum zeigte bisher bei den Strahlenschutzmessungen keine Kontamination. Schlussfolgerung: Das vorgestellte physikalisch-technishce Qualitätssicherungsprogramm deckt den physikalisch-technischen Bereich der klinikinternen Qualitätssicherung ab und ließ sich problemlos in den Behandlungsablauf integrieren. Es hat folgende Vorteile: Die autoradiographische Dokumentation der korrekt beladenen Nadeln ist der Nachweis dafür, dass die Voraussetzung für die Erzeugung der verordneten Dosisverteilung erfüllt ist. Die klinikinterne Bestimmung der Kenndosisleistung ist die Grundlage zur korrekten Dosisapplikation.Background: Early stage prostate cancer can be treated successfully by interstitial brachytherapy with 125-iodine seeds. A quality-assurance programme is presented that was designed for this purpose for internal clinical use. Furthermore the requirements of the new German Ordinance Governing Radiation Protection (StrlSchV) that came into force on August 1, 2001, are taken into account. Material and Methods: For the 125-iodine monotherapy of the prostate we used RAPID STRANDS® (Amersham Health, Braunschweig, Germany). According to the guidelines of the new Ordinance Governing Radiation Protection, the determination of the body dose of the staff is made to rely on the new measurement quantities Hp (10) and Hp (0.07). The nominal air kerma rate of the seeds is measured with a calibrated well-chamber of the type HDR 1000 Plus and an electrometer of the type MAX 4000 (Standard Imaging Inc., USA). The ultrasound images of the prostate are produced by an ultrasound device of the type Falcon 2101 (B-K Medical, Denmark). For treatment planning the programme VariSeed (Varian, Darmstadt, Germany) was employed. Correct loading of the needles is controlled by autoradiography before implantation. After the implantation radiation-protection measurements in the operating room are carried out. Results: As regards the personnel, for the depth personal dose equivalent Hp(10) and relating to two applications each, measurement values between 0 μSv and 14 μSv resulted. The control of the radiation exposure of the hands revealed superficial personal dose values Hp (0.07) of up to 1 mSv. The nominal air kerma rates of the RAPID STRANDS® were all lying within the 95% confidence interval guaranteed by the producer. The autoradiographs documented – except for one case – the correct loading of the needles. The interstitial transperineal prostate implantation of the 125-iodine seeds succeeded as planned with all patients. Until now no contamination of the operating room was detected by the radiation-protection measurements. Conclusion: The physical-technical quality assurance programme presented here covers the whole physical-technical range of the internal clinical quality assurance and could be integrated into the course of the treatment without any problems. It has th following advantages: The autoradiographic documentation of the correctly loaded needles serves as proof that the prerequisite for the production of the prescribed physical dose distribution is fulfilled. The internal clinical determination of the nominal air kerma rate is the basis for a correct dose application.

Hyperfractionated 192Ir Brachytherapy for Recurrent Retroperitoneal Sarcoma: a Technique for Delivery of Local Tumor Boost Dose

Background: Radical surgery is the treatment of first choice for retroperitoneal sarcoma. However, locoregional relapse is frequently observed leading to death in the majority of patients. The role of radiotherapy is not well defined in the management of retroperitoneal sarcoma. Yet, there is evidence that adjuvant irradiation does improve local tumor control. Material and Methods: In order to deliver sufficiently high radiation doses to the retroperitoneum, different techniques for application of a local tumor boost dose in addition to external beam treatment have been proposed. We present a technique of hyperfractionated 192Ir brachytherapy (HFIR) of the tumor bed via intraoperatively implanted plastic catheters. Postoperative CT-based image-guided brachytherapy was performed. In two consecutive patients with recurrent retroperitoneal sarcoma, treatment was delivered twice daily with single doses of 1.5–2.0 Gy in 5–10 mm tissue depth up to a total dose of 18–32.5 Gy. Results: HFIR of the tumor bed was easily accomplished facilitating delivery of high radiation doses to the retroperitoneum. No major late effects of treatment have been observed with a follow-up of 15 and 28 months, respectively. Details of the brachytherapy procedure are presented. Conclusion: HFIR via intraoperatively implanted catheters in the retroperitoneum is a technique suitable for application of a local tumor boost dose. Thus, sufficiently high doses of radiation mandatory for long-lasting local tumor control can be delivered in the tumor bed of the retroperitoneum without exceeding normal tissue radiotolerance in this unfavorable disease.Hintergrund: Die radikale Resektion ist die Therapie der Wahl bei der Behandlung retroperitonealer Sarkome (RPS). Lokalrezidive werden jedoch regelmäßig beobachtet und sind die häufigste Todesursache bei diesen Patienten. Die Rolle der Strahlentherapie bei der Behandlung von RPS ist nur unzureichend definiert, es gibt aber Hinweise darauf, dass die Bestrahlung die lokale Tumorkontrolle verbessern kann. Die Applikation ausreichend hoher Strahlendosen im Retroperitoneum unter Schonung der Risikoorgane ist hingegen problematisch. Zur lokalen Dosisaufsättigung im Retroperitoneum wurden daher unterschiedliche Techniken vorgeschlagen. Material und Methodik: Wir stellen eine Technik zur Brachytherapie über intraoperativ in das Tumorbett eingebrachte Katheter vor. Bei zwei Patientinnen mit Rezidiven eines RPS wurde nach CT-basierter bildgestützter Bestrahlungsplanung eine hyperfraktionierte 192Ir-Brachytherapie mit 2 × 1,5–2,0 Gy pro Tag in 5–10 mm Gewebetiefe bis zu einer Gesamtdosis von 18 bzw. 32,5 Gy durchgeführt. Ergebnisse: Die vorgestellte Brachytherapietechnik erwies sich als einfach durchführbar und ermöglichte die Applikation hoher Strahlendosen im Retroperitoneum. Chronische Nebenwirkungen traten bei einer Nachbeobachtungszeit von 15 bzw. 28 Monaten nicht auf. Daten der Literatur zur Bestrahlung von RPS werden diskutiert. Schlussfolgerung: Die hyperfraktionierte 192Ir-Brachytherapie des Retroperitoneums ist eine problemlos durchführbare Technik, mit deren Hilfe eine Dosisaufsättigung im Tumorbett bei einem günstigen Nebenwirkungsspektrum erreicht werden kann.