Michael Lotter

Accelerated Partial Breast Irradiation: 5-Year Results of the German-Austrian Multicenter Phase II Trial Using Interstitial Multicatheter Brachytherapy Alone After Breast-Conserving Surgery

PURPOSE To evaluate the impact of accelerated partial breast irradiation on local control, side effects, and cosmesis using multicatheter interstitial brachytherapy as the sole method for the adjuvant local treatment of patients with low-risk breast cancer. METHODS AND MATERIALS 274 patients with low-risk breast cancer were treated on protocol. Patients were eligible for the study if the tumor size was < 3 cm, resection margins were clear by at least 2 mm, no lymph node metastases existed, age was >35 years, hormone receptors were positive, and histologic grades were 1 or 2. Of the 274 patients, 175 (64%) received pulse-dose-rate brachytherapy (D(ref) = 50 Gy). and 99 (36%) received high-dose-rate brachytherapy (D(ref) = 32.0 Gy). RESULTS Median follow-up was 63 months (range, 9-103). Only 8 of 274 (2.9%) patients developed an ipsilateral in-breast tumor recurrence at the time of analysis. The 5-year actuarial local recurrence-free survival probability was 98%. The 5- year overall and disease-free survival probabilities of all patients were 97% and 96%, respectively. Contralateral in-breast malignancies were detected in 2 of 274 (0.7%) patients, and distant metastases occurred in 6 of 274 (2.2%). Late side effects ≥ Grade 3 (i.e., breast tissue fibrosis and telangiectasia) occurred in 1 patient (0.4%, 95%CI:0.0-2.0%) and 6 patients (2.2%, 95%CI:0.8-4.7%), respectively. Cosmetic results were good to excellent in 245 of 274 patients (90%). CONCLUSIONS The long-term results of this prospective Phase II trial confirm that the efficacy of accelerated partial breast irradiation using multicatheter brachytherapy is comparable with that of whole breast irradiation and that late side effects are negligible.

Accelerated partial breast irradiation with iridium-192 multicatheter PDR/HDR brachytherapy: Preliminary results of the German-Austrian multicenter trial

Purpose:To evaluate perioperative morbidity, toxicity, and cosmetic outcome in patients treated with interstitial brachytherapy to the tumor bed as the sole irradiation modality after breast-conserving surgery.Patients and Methods:From November 1, 2000 to January 31, 2004, 176 women with early-stage breast cancer became partakers in a protocol of tumor bed irradiation alone using pulsed-dose-rate (PDR) or high-dose-rate (HDR) interstitial multicatheter implants. Patients became eligible, if their tumor was an infiltrating carcinoma ≤ 3 cm in diameter, the surgical margins were clear by at least 2 mm, the axilla was surgically staged node-negative, the tumor was estrogen and/or progesterone receptor-positive, well or moderately differentiated (G1/2), the tumor did not contain an extensive intraductal component (EIC) and the patient’s age was > 35 years. Implants were positioned using a template guide, delivering either 49.8 Gy in 83 consecutive hours (PDR) or 32.0 Gy in two daily fractions over 4 days (HDR). Perioperative morbidity, toxicity, and cosmetic outcome were assessed. Interim findings of the first 69 patients, who were treated in this multicenter trial, after a median follow-up of 24 months (range, 15–39 months) are presented.Results:One of the 69 patients (1.4%) developed a bacterial infection of the implant. No other perioperative complications, for example bleeding or hematoma, were observed. Acute toxicity was low: 2.9% of the patients (2/69) experienced mild radiodermatitis. Late toxicity: hypersensation/mild pain 7.2% (5/69), intermittent but tolerable pain 1.4% (1/69), mild dyspigmentation 10.1% (7/69), mild fibrosis 11.6% (8/69), moderate fibrosis 1.4% (1/69), mild telangiectasia (< 1 cm2) 11.6% (8/69), and moderate teleangiectasia (1–4 cm2) 1.4% (1/69). Good to excellent cosmetic results were observed in 92.4% of the patients evaluated. All patients (n = 176) remained disease-free to the date of evaluation.Conclusion:This analysis indicates that accelerated partial breast irradiation with iridium-192 interstitial multicatheter PDR/HDR implants is feasible with low perioperative morbidity, low acute and mild late toxicity, and does not significantly affect cosmetic results at a median follow-up of 24 months.Ziel:Evaluierung von perioperativer Morbidität, Akut- und Spättoxizität sowie des kosmetischen Ergebnisses nach alleiniger interstitieller Pulsed-Dose-Rate-(PDR-)/High-Dose-Rate-(HDR-)Multikatheter-Brachytherapie des Tumorbetts mit 192-Iridium nach brusterhaltender Operation.Patienten und Methodik:Zwischen 11/2000 und 01/2004 erhielten 176 Frauen nach brusterhaltender Operation eine alleinige PDR-/HDR-Brachytherapie des Tumorbetts. Einschlusskriterien in diesem multizentrischen Protokoll waren u. a. ein maximaler Tumordurchmesser von 3 cm, ein negativer Nodalstatus (pN0), eine R0-Resektion mit mindestens 2 mm Sicherheitssaum, nur gut oder mäßig differenzierte Karzinome (G1/2), östrogen- und/oder progesteronrezeptorpositive Tumoren, kein Nachweis einer EIC („extensive intraductal component“) und ein Patientinnenalter von mindestens 35 Jahren. Die PDR-Brachytherapie wurde mit 49,8 Gy in 83 aufeinander folgenden stündlichen Pulsen, die HDR-Brachytherapie bis 32,0 Gy in zwei täglichen Fraktionen über 4 Tage appliziert. Ergebnisse der ersten 69 Patientinnen bezüglich Morbidität, Toxizität und Kosmetik werden präsentiert. Die mediane Nachbeobachtungszeit betrug in dieser Analyse 24 Monate (Bereich: 15–39 Monate).Ergebnisse:Eine der evaluierten 69 Patientinnen (1,4%) entwickelte eine bakterielle Infektion des Implantats. Weitere perioperative Komplikationen, z. B. Blutungen oder Hämatome, wurden nicht beobachtet. Die Akuttoxizität war gering: 2,9% der Patientinnen (2/69) zeigten die Symptome einer Grad-1-Radiodermatitis. Spättoxizität: Überempfindlichkeit/gelegentliches Stechen im Narbenareal 7,2% (5/69), intermittierende, aber tolerable Schmerzen 1,4% (1/69), milde Dyspigmentation 10,1% (7/69), milde Fibrosierung 11,6% (8/69), moderate Fibrosierung 1,4% (1/69), milde Teleangiektasiebildung (< 1 cm2) 11,6% (8/69) und moderate Teleangiektasiebildung (1–4 cm2) 1,4% (1/69). Ein exzellentes oder gutes kosmetisches Ergebnis wurde bei 92,4% der Patientinnen gefunden. Zum Zeitpunkt der Auswertung waren alle behandelten Patientinnen (n = 176) krankheitsfrei.Schlussfolgerung:Diese Analyse zeigt, dass die alleinige interstitielle PDR-/HDR-Multikatheter-Brachytherapie des Tumorbetts nach brusterhaltender Operation mit niedriger perioperativer Komplikationsrate, geringer Akuttoxizität und milder Spättoxizität bei einer medianen Nachbeobachtungszeit von 24 Monaten durchführbar ist und das kosmetische Ergebnis bislang nicht signifikant beeinflusst.

The role of pulsed-dose-rate brachytherapy in previously irradiated head-and-neck cancer ☆

PURPOSE The purpose of this prospective study was to analyze the value of interstitial pulsed-dose-rate (PDR) brachytherapy (iBT) with regard to local control and the incidence of side effects in patients with head-and-neck cancer in a previously irradiated area. METHODS AND MATERIALS From October 1997 to September 2001, 43 patients with head-and-neck cancer in a previously irradiated area (31 patients with recurrent cancer) were treated with iBT alone or in combination with external beam radiation. Thirty-four of 43 patients received interstitial PDR brachytherapy (DREF=20-60 Gy) as part of their curative treatment regimen alone or in combination with external radiation. Nine patients were implanted for palliative purposes. The pulses were delivered 24 h/day with a time interval of 1 h between two pulses. The dose per pulse (dp) ranged from 0.4-0.7 Gy. Sixteen of 43 (37%) patients also received cisplatin or carboplatin with 5-fluorouracil during the time of the iBT. Additionally 20/43 (47%) patients were treated with interstitial hyperthermia. Thirteen of 43 (30%) patients received external beam radiation in a dose range from 20-67 Gy. A follow-up of all patients was done to analyze local control and survival, and acute and delayed toxicity. This analysis was performed after a median follow-up of 24 months (6-48 months). RESULTS Local tumor control was achieved in 34 of a total of 43 patients (79%) and in 30/34 patients (88%) treated for curative intention. Distant metastases were observed in 5/43 (12%) patients. The 2-year local recurrence-free survival rates, disease-free survival rates, and overall survival rates according to the Kaplan-Meier method for all patients were 68%, 62%, and 49%, respectively, and for patients treated with curative intention they were 80%, 77% and 66%, respectively. There was no statistical difference in the probability of local recurrence in patients subgrouped by recurrent tumor vs. secondary primary, tumor size, grading and lymphangiosis. The application of chemotherapy or hyperthermia did not have significant influence on the therapy results. Soft tissue necrosis was the only serious side effect seen in 2/43 patients (4.7%). No other serious side effects were observed. CONCLUSIONS Interstitial pulsed-dose-rate brachytherapy for patients with previously irradiated head-and-neck cancer is an effective therapy with minimal toxicity. The role of chemotherapy and hyperthermia in these patients remains unclear. Further randomized studies with larger patient numbers are necessary to draw a definite conclusion.

Accelerated Partial Breast Irradiation with Iridium-192 Multicatheter PDR/HDR Brachytherapy

Purpose:To evaluate perioperative morbidity, toxicity, and cosmetic outcome in patients treated with interstitial brachytherapy to the tumor bed as the sole irradiation modality after breast-conserving surgery.Patients and Methods:From November 1, 2000 to January 31, 2004, 176 women with early-stage breast cancer became partakers in a protocol of tumor bed irradiation alone using pulsed-dose-rate (PDR) or high-dose-rate (HDR) interstitial multicatheter implants. Patients became eligible, if their tumor was an infiltrating carcinoma ≤ 3 cm in diameter, the surgical margins were clear by at least 2 mm, the axilla was surgically staged node-negative, the tumor was estrogen and/or progesterone receptor-positive, well or moderately differentiated (G1/2), the tumor did not contain an extensive intraductal component (EIC) and the patient’s age was > 35 years. Implants were positioned using a template guide, delivering either 49.8 Gy in 83 consecutive hours (PDR) or 32.0 Gy in two daily fractions over 4 days (HDR). Perioperative morbidity, toxicity, and cosmetic outcome were assessed. Interim findings of the first 69 patients, who were treated in this multicenter trial, after a median follow-up of 24 months (range, 15–39 months) are presented.Results:One of the 69 patients (1.4%) developed a bacterial infection of the implant. No other perioperative complications, for example bleeding or hematoma, were observed. Acute toxicity was low: 2.9% of the patients (2/69) experienced mild radiodermatitis. Late toxicity: hypersensation/mild pain 7.2% (5/69), intermittent but tolerable pain 1.4% (1/69), mild dyspigmentation 10.1% (7/69), mild fibrosis 11.6% (8/69), moderate fibrosis 1.4% (1/69), mild telangiectasia (< 1 cm2) 11.6% (8/69), and moderate teleangiectasia (1–4 cm2) 1.4% (1/69). Good to excellent cosmetic results were observed in 92.4% of the patients evaluated. All patients (n = 176) remained disease-free to the date of evaluation.Conclusion:This analysis indicates that accelerated partial breast irradiation with iridium-192 interstitial multicatheter PDR/HDR implants is feasible with low perioperative morbidity, low acute and mild late toxicity, and does not significantly affect cosmetic results at a median follow-up of 24 months.Ziel:Evaluierung von perioperativer Morbidität, Akut- und Spättoxizität sowie des kosmetischen Ergebnisses nach alleiniger interstitieller Pulsed-Dose-Rate-(PDR-)/High-Dose-Rate-(HDR-)Multikatheter-Brachytherapie des Tumorbetts mit 192-Iridium nach brusterhaltender Operation.Patienten und Methodik:Zwischen 11/2000 und 01/2004 erhielten 176 Frauen nach brusterhaltender Operation eine alleinige PDR-/HDR-Brachytherapie des Tumorbetts. Einschlusskriterien in diesem multizentrischen Protokoll waren u. a. ein maximaler Tumordurchmesser von 3 cm, ein negativer Nodalstatus (pN0), eine R0-Resektion mit mindestens 2 mm Sicherheitssaum, nur gut oder mäßig differenzierte Karzinome (G1/2), östrogen- und/oder progesteronrezeptorpositive Tumoren, kein Nachweis einer EIC („extensive intraductal component“) und ein Patientinnenalter von mindestens 35 Jahren. Die PDR-Brachytherapie wurde mit 49,8 Gy in 83 aufeinander folgenden stündlichen Pulsen, die HDR-Brachytherapie bis 32,0 Gy in zwei täglichen Fraktionen über 4 Tage appliziert. Ergebnisse der ersten 69 Patientinnen bezüglich Morbidität, Toxizität und Kosmetik werden präsentiert. Die mediane Nachbeobachtungszeit betrug in dieser Analyse 24 Monate (Bereich: 15–39 Monate).Ergebnisse:Eine der evaluierten 69 Patientinnen (1,4%) entwickelte eine bakterielle Infektion des Implantats. Weitere perioperative Komplikationen, z. B. Blutungen oder Hämatome, wurden nicht beobachtet. Die Akuttoxizität war gering: 2,9% der Patientinnen (2/69) zeigten die Symptome einer Grad-1-Radiodermatitis. Spättoxizität: Überempfindlichkeit/gelegentliches Stechen im Narbenareal 7,2% (5/69), intermittierende, aber tolerable Schmerzen 1,4% (1/69), milde Dyspigmentation 10,1% (7/69), milde Fibrosierung 11,6% (8/69), moderate Fibrosierung 1,4% (1/69), milde Teleangiektasiebildung (< 1 cm2) 11,6% (8/69) und moderate Teleangiektasiebildung (1–4 cm2) 1,4% (1/69). Ein exzellentes oder gutes kosmetisches Ergebnis wurde bei 92,4% der Patientinnen gefunden. Zum Zeitpunkt der Auswertung waren alle behandelten Patientinnen (n = 176) krankheitsfrei.Schlussfolgerung:Diese Analyse zeigt, dass die alleinige interstitielle PDR-/HDR-Multikatheter-Brachytherapie des Tumorbetts nach brusterhaltender Operation mit niedriger perioperativer Komplikationsrate, geringer Akuttoxizität und milder Spättoxizität bei einer medianen Nachbeobachtungszeit von 24 Monaten durchführbar ist und das kosmetische Ergebnis bislang nicht signifikant beeinflusst.

Pulsed-dose rate brachytherapy with concomitant chemotherapy and interstitial hyperthermia in patients with recurrent head-and-neck cancer

PURPOSE We attempted in our clinic to evaluate the efficacy and feasibility of a simultaneous application of a cis-platinum-based chemotherapy and interstitial hyperthermia to interstitial pulsed-dose rate (PDR) brachytherapy in patients with recurrent head-and-neck cancer. METHODS AND MATERIALS Between April 1999 and September 2001, 15 patients with recurrent head-and-neck cancer were treated with PDR brachytherapy, chemotherapy, and interstitial hyperthermia. All patients had received prior radiation therapy. A dose per pulse of 0.46 to 0.55 Gy was given up to a median total dose of 55 Gy. Simultaneously to the PDR brachytherapy, chemotherapy was given with cis-platinum 20 mg/m2 as a short i.v. infusion each day and 5-fluorouracil 800 mg/m2 by continuous infusion from Day 1 to Day 5. After the PDR brachytherapy was finished, all patients were treated with a single session of interstitial hyperthermia. RESULTS All the patients could receive the whole treatment. After treatment, only mild oral mucositis occurred. One patient developed soft tissue ulceration. None of the patients developed osteoradionecrosis. After a median follow-up of 6 months, the local tumor control rate was 80% (12 of 15), and the 2-year overall survival was 67% (10 of 15). CONCLUSIONS The intensification of the interstitial PDR brachytherapy with chemotherapy and hyperthermia is feasible and safe, and the preliminary results are encouraging.

EARLY RESULTS OF PULSED-DOSE-RATE INTERSTITIAL BRACHYTHERAPY FOR HEAD AND NECK MALIGNANCIES AFTER LIMITED SURGERY

PURPOSE The aim of this study was to evaluate the relative incidence of toxicity and local control in patients with head and neck malignancies who underwent interstitial pulsed-dose-rate (PDR) brachytherapy (iBT). PATIENTS AND METHODS From October 1997 to December 1998, 61 patients underwent interstitial PDR brachytherapy procedures in our department; 47 were patients with head and neck cancer. Forty patients received brachytherapy as part of their curative treatment regimen, and 7 patients were implanted for palliative purposes and excluded from the analysis of therapy efficacy. Twenty-four patients had interstitial brachytherapy procedures alone with D(REF) = 50 Gy; in 23 patients, iBT procedures were performed with D(REF) = 24 Gy in combination with external radiation. A dose per pulse (dp) of 0.5 Gy was prescribed for 38/47 patients, and a dp = 0.7 Gy for 9/47 patients. The pulses were delivered 24 h a day, with a time interval of 1 h between two pulses, resulting in an effective dose rate of 0.5 Gy/h or 0.7 Gy/h. A follow-up of the patients was done to analyze acute and delayed toxicity, local control, and survival. The analysis was performed after median follow-up of 12 months (5-18 months). RESULTS After a median follow-up of 12 months, soft tissue necrosis was seen in one patient and bone necrosis in another. No other serious side effects were observed. Permanent locoregional tumor control was achieved in 37 of 40 patients. No distant metastases were observed. CONCLUSIONS PDR interstitial brachytherapy with 0.5-0.7 Gy/h is a safe therapy. These preliminary results suggest that PDR interstitial brachytherapy of head and neck cancer is comparable with low-dose-rate (LDR) brachytherapy.

Radiation exposure of the heart, lung and skin by radiation therapy for breast cancer: A dosimetric comparison between partial breast irradiation using multicatheter brachytherapy and whole breast teletherapy

BACKGROUND AND PURPOSE Accelerated partial breast irradiation by means of multicatheter brachytherapy shows great promise in the modern treatment of early breast cancer combining high efficacy in preventing tumour recurrence with low levels of toxicity. The present work attempts a dosimetric comparison between this treatment modality and conventional whole breast external beam radiotherapy by looking at differences in risk organ exposure to radiation. PATIENTS AND METHODS The planning CT data sets of 16 consecutive patients with left-sided breast cancer who received external beam radiotherapy to the whole breast followed by a boost to the tumour bed using multicatheter interstitial brachytherapy after breast conserving surgery were used to create two independent physical treatment plans - one for an external radiotherapy, one for sole partial breast brachytherapy in each case assuming a total reference dose of 50Gy for each patient. Dose-volume parameters D(0.1cc), D(0.5cc), D(1cc,)D(2cc), D(5cc,)D(10cc), D(25cc), D(50cc), V(100), V(90), V(50), V(10), V(5) for the ipsilateral lung, the heart and the adjacent skin were calculated and compared between the two treatment modalities. RESULTS All organs at risk showed a substantially lower radiation exposure in the brachytherapy plan. This was most pronounced for the heart with values differing by a factor of four. Although somewhat less marked this was also true for the ipsilateral lung and the adjacent skin with exposure ratios of three and two, respectively. CONCLUSIONS With the use of multicatheter interstitial brachytherapy substantial reductions in the radiation exposure of risk organs can be achieved in comparison to whole breast external beam radiotherapy. These are likely to translate into profound clinical benefits.

The Role of Interstitial Brachytherapy in the Treatment of Vaginal and Vulvar Malignancies

Background:Irradiation has established itself as a treatment for vulvar and vaginal malignancies. Due to the sensitive nature of the vulvar and vaginal tissues, interstitial brachytherapy (iBT) provides an effective, gentle and individualized therapy.Patients and Methods:Patients with vulvar (nine of 22) and vaginal (13 of 22) malignancies were treated using interstitial pulsed-dose-rate brachytherapy (PDR-iBT). Twelve out of 22 patients were additionally treated using external-beam therapy to the pelvis and regional lymph nodes. The median total dose of PDR-iBT administered to patients with vulvar carcinoma was 55.0 Gy. The median total PDR dose administered to patients with vaginal malignancies amounted to 20.25 Gy.Results:The median follow-up time for patients with vulvar cancer was 19 months and for patients with vaginal malignancies 27 months. Acute mucositis or skin reactions during iBT were observed in 15 of 22 patients. Two of 22 patients showed delayed side effects. After 6 months, 77.8% of the patients with vulvar cancer (seven out of nine) and 100% of the patients with vaginal malignancies (13 out of 13) achieved complete local remission. One patient out of nine with vulvar carcinoma developed local recurrence, four out of nine regional recurrence, and two out of nine developed regional recurrence and had local tumor following therapy. In patients with malignancies of the vagina, no cases of local recurrence were observed, but distant metastases were found in five out of 13 patients. At the time of analysis, eleven out of 22 patients with vulvar or vaginal carcinoma were still alive.Conclusion:IBT achieved good local control without serious delayed side effects in both localizations. However, survival is limited by regional or distant metastases.Hintergrund:Die Strahlentherapie hat sich bei der Behandlung von Tumoren der Vulva und Vagina etabliert. Da es sich in der Regel um ältere Patientinnen handelt und das Gewebe von Vulva und Vagina sehr sensibel ist, besteht mit der interstitiellen Brachytherapie (iBT) eine effektive und schonende Behandlungsmöglichkeit.Patienten und Methodik:22 Patientinnen mit Tumoren der Vulva und Vagina wurden mittels Pulsed-Dose-Rate-(PDR-)Brachytherapie behandelt, 12/22 Patientinnen zusätzlich mittels perkutaner Strahlentherapie nach der Brachytherapie. Der Median der PDR-iBT-Gesamtdosis betrug bei den Patientinnen mit Vulvakarzinom 55 Gy, bei den Patientinnen mit Vaginaltumoren 20,25 Gy.Ergebnisse:Das Nachsorgeintervall bei den Patientinnen mit Vulvakarzinom betrug im Median 19 Monate und bei den Patientinnen mit Vaginalkarzinom im Median 27 Monate. Akute Haut- und Schleimhautreaktionen durch die iBt wurden bei 15/22 Patientinnen beobachtet. 2/22 Patientinnen mit Vulva- und Vaginaltumoren zeigten Spätnebenwirkungen. Nach 6 Monaten fand sich bei 77,8% der Patientinnen mit Vulvakarzinom und bei 100% der Patientinnen mit Vaginaltumoren eine komplette Remission. 1/9 Patientinnen mit Vulvakarzinom entwickelte ein Lokalrezidiv, bei 4/9 trat ein Regionalrezidiv auf, und 2/9 entwickelten ein Regionalrezidiv und waren nach Therapie lokal nicht in kompletter Remission. Bei Patientinnen mit Vaginaltumoren wurden keine Lokalrezidive, bei 5/13 Patientinnen jedoch Fernmetastasen diagnostiziert. Zum Zeitpunkt der Analyse lebten noch 11/22 Patientinnen.Schlussfolgerung:Durch die iBT wird bei beiden Tumorlokalisationen eine gute lokale Kontrolle ohne schwere Spätnebenwirkungen erreicht. Das Gesamtüberleben ist jedoch durch Regionalrezidive und Fernmetastasierungen limitiert.

Accelerated partial-breast irradiation with interstitial implants: the clinical relevance of the calculation of skin doses.

Purpose:To describe relative skin dose estimations and their impact on cosmetic outcome in interstitial multicatheter accelerated partial-breast irradiation (APBI).Patients and Methods:Between April 2001 and January 2005, 105 consecutive patients with early breast cancer were recruited in Erlangen, Germany, for this substudy of the German-Austrian APBI phase II trial. 51% (54/105) received pulsed-dose-rate (PDR), and 49% (51/105) high-dose-rate (HDR) brachytherapy. Prescribed reference dose for HDR brachytherapy was 32 Gy in eight fractions of 4 Gy, twice daily. Prescribed reference dose in PDR brachytherapy was 49.8 Gy in 83 consecutive fractions of 0.6 Gy every hour. Total treatment time was 3–4 days. With a wire cross on the skin surface during the brachytherapy-planning procedure the minimal, mean and maximal relative skin doses (SDmin%, SDmax%, SDmean%) were recorded. Endpoint of this evaluation was the cosmetic outcome in relation to the relative skin doses.Results:Median follow-up time was 38 months (range, 19–65 months). Cosmetic results for all patients were excellent in 57% (60/105), good in 36% (38/105), and fair in 7% (7/105). The SDmin% (27.0% vs. 31.7%; p = 0.032), SDmean% (34.2% vs. 38.1%; p = 0.008), and SDmax% (38.2% vs. 46.4%; p = 0.003) were significantly lower for patients with excellent cosmetic outcome compared to patients with a suboptimal outcome. SDmean% (37.6% vs. 34.2%; p = 0.026) and SDmax% (45.4% vs. 38.2%; p = 0.008) were significantly higher for patients with good cosmetic outcome compared with the patients with excellent results.Conclusion:The appraisal of skin doses has been shown to be relevant to the achievement of excellent cosmetic outcome. Further investigations are necessary, especially on the basis of CT-based brachytherapy planning, to further improve the treatment results of multicatheter APBI.Ziel:Entwicklung einer Methode zur Abschätzung von relativen Hautdosen bei der akzelerierten Teilbrustbestrahlung (APBI) in interstitieller Multikathetertechnik und Untersuchung des Einflusses der ermittelten Hautdosen auf das kosmetische Ergebnis.Patienten und Methodik:Zwischen 04/2001 und 01/2005 wurden 105 Patientinnen mit einem brusterhaltend operierten, prognostisch günstigen Mammakarzinom in diese Substudie der Deutsch-Österreichischen Teilbrustbestrahlungsstudie (Phase II) eingebracht. 51% (54/105) erhielten eine Pulsed-Dose-Rate-(PDR-) und 49% (51/105) eine High-Dose-Rate-(HDR-)Brachytherapie. Die HDR-Brachytherapie erfolgte mit acht Fraktionen à 4 Gy bis 32 Gy, zwei Fraktionen pro Tag. Die PDR-Brachytherapie-Dosis betrug 49,8 Gy mit 83 stündlichen Pulsen à 0,6 Gy. Die Gesamtbehandlungszeit betrug 3–4 Tage. Mit Hilfe eines auf die Hautoberfläche aufgeklebten Drahtkreuzes wurden die relativen minimalen, mittleren und maximalen Hautdosen (SDmin%, SDmean%, SDmax%) beschrieben. Endpunkt der Analyse war das kosmetische Ergebnis in Abhängigkeit von den relativen Hautdosen.Ergebnisse:Die mediane Nachbeobachtungszeit betrug 38 Monate (19–65 Monate). Das kosmetische Ergebnis war sehr gut in 57% (60/105), gut in 36% (38/105) und mäßig in 7% (7/105) der Fälle. Die relativen Hautdosen SDmin% (27,0% vs. 31,7%; p = 0,032), SDmean% (34,2% vs. 38,1%; p = 0,008) und SDmax% (38,2% vs. 46,4%; p = 0,003) waren in der Gruppe der Patientinnen mit sehr gutem kosmetischen Ergebnis signifikant niedriger als bei den übrigen Patientinnen mit suboptimalem Ergebnis. SDmean% (37,6% vs. 34,2%; p = 0,026) und SDmax% (45,4% vs. 38,2%; p = 0,008) waren bei Patientinnen mit guter Kosmetik signifikant höher als bei sehr gutem Ergebnis.Schlussfolgerung:Es konnte erstmals für die interstitielle Multikatheter-APBI gezeigt werden, dass die an der Hautoberfläche deponierte Strahlendosis die Wahrscheinlichkeit für das Erreichen eines sehr guten kosmetischen Ergebnisses mit beeinflusst. Weiterführende Untersuchungen sind erforderlich, insbesondere auf der Basis der CT-gestützten Brachytherapieplanung, um das kosmetische Ergebnis nach interstitieller Multikatheter-APBI noch weiter zu optimieren.

ACCELERATED PARTIAL BREAST IRRADIATION WITH INTERSTITIAL IMPLANTS: RISK FACTORS ASSOCIATED WITH INCREASED LOCAL RECURRENCE

PURPOSE To analyze patient, disease, and treatment-related factors regarding their impact on local control after interstitial multicatheter accelerated partial breast irradiation (APBI). METHODS AND MATERIALS Between November 2000 and April 2005, 274 patients with early breast cancer were recruited for the German-Austrian APBI Phase II trial (ClinicalTrials.gov identifier: NCT00392184). In all, 64% (175/274) of the patients received pulsed-dose-rate (PDR) brachytherapy and 36% (99/274) received high-dose-rate (HDR) brachytherapy. Prescribed reference dose for HDR brachytherapy was 32 Gy in eight fractions of 4 Gy, twice daily. Prescribed reference dose in PDR brachytherapy was 49.8 Gy in 83 consecutive fractions of 0.6 Gy each hour. Total treatment time was 3 to 4 days. RESULTS The median follow-up time was 64 months (range, 9-110). The actuarial 5-year local recurrence free survival rate (5-year LRFS) was 97.7%. Comparing patients with an age <50 years (49/274) vs. ≥50 years (225/274), the 5-year LRFS resulted in 92.5% and 98.9% (exact p = 0.030; 99% confidence interval, 0.029-0.032), respectively. Antihormonal treatment (AHT) was not applied in 9% (24/274) of the study population. The 5-year LRFS was 99% and 84.9% (exact p = 0.0087; 99% confidence interval, 0.0079-0.0094) in favor of the patients who received AHT. Lobular histology (45/274) was not associated with worse local control compared with all other histologies (229/274). The 5-year LRFS rates were 97.6% and 97.8%, respectively. CONCLUSIONS Local control at 5 years is excellent and comparable to therapeutic successes reported from corresponding whole-breast irradiation trials. Our data indicate that patients <50 years of age ought to be excluded from APBI protocols, and that patients with hormone-sensitive breast cancer should definitely receive adjuvant AHT when interstitial multicatheter APBI is performed. Lobular histology need not be an exclusion criterion for future APBI trials.