[show abstract][hide abstract] ABSTRACT: BACKGROUND: To report the clinical outcome of high dose rate brachytherapy as sole treatment for clinically localised prostate cancer. METHODS: Between March 2004 and January 2008, a total of 351 consecutive patients with clinically localised prostate cancer were treated with transrectal ultrasound guided high dose rate brachytherapy. The prescribed dose was 38.0 Gy in four fractions (two implants of two fractions each of 9.5 Gy with an interval of 14 days between the implants) delivered to an intraoperative transrectal ultrasound real-time defined planning treatment volume. Biochemical failure was defined according to the Phoenix Consensus and toxicity evaluated using the Common Toxicity Criteria for Adverse Events version 3. RESULTS: The median follow-up time was 59.3 months. The 36 and 60 month biochemical control and metastasis-free survival rates were respectively 98%, 94% and 99%, 98%. Toxicity was scored per event with 4.8% acute Grade 3 genitourinary and no acute Grade 3 gastrointestinal toxicity. Late Grade 3 genitourinary and gastrointestinal toxicity were respectively 3.4% and 1.4%. No instances of Grade 4 or greater acute or late adverse events were reported. CONCLUSIONS: Our results confirm high dose rate brachytherapy as safe and effective monotherapy for clinically organ-confined prostate cancer.
[show abstract][hide abstract] ABSTRACT: Purpose: The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization.Methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by comparing dose volume histogram and gEUD evaluators.Results: Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D10 or∕and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume.Conclusions: Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.
Medical Physics 04/2013; 40(4):041704. · 2.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: OBJECTIVES: To evaluate the clinical outcome of computed tomography (CT)-guided interstitial (IRT) high-dose-rate (HDR) brachytherapy (BRT) in the treatment of unresectable primary and secondary liver malignancies. This report updates and expands our previously described experience with this treatment technique. METHODS: Forty-one patients with 50 tumours adjacent to the liver hilum and bile duct bifurcation were treated in 59 interventions of CT-guided IRT HDR BRT. The tumours were larger than 4 cm with a median volume of 84 cm(3) (38-1,348 cm(3)). The IRT HDR BRT delivered a median total physical dose of 20.0 Gy (7.0-32.0 Gy) in twice daily fractions of median 7.0 Gy (4.0-10.0 Gy) in 19 patients and in once daily fractions of median 8.0 Gy (7.0-14.0 Gy) in 22 patients. RESULTS: With a median follow-up of 12.4 months, the local control for metastatic hepatic tumours was 89 %, 73 % and 63 % at 6, 12 and 18 months respectively. The local control for primary hepatic tumours was 90 %, 81 % and 50 % at 6, 12 and 18 months respectively. Severe side effects occurred in 5.0 % of interventions with no treatment-related deaths. CONCLUSIONS: CT-guided IRT HDR BRT is a promising procedure for the radiation treatment of centrally located liver malignancies. KEY POINTS: • Interstitial high-dose-rate brachytherapy (IRT HDR BRT) is a promising treatment for central liver tumours • CT-guided IRT HDR BRT is safe for treating extensive tumours • CT-guided IRT HDR BRT could play a role in managing unresectable hepatic malignancies.
[show abstract][hide abstract] ABSTRACT: Objectives: Tumour recurrence of glioblastoma multiforme (GBM) after initial treatment with surgical resection, radiotherapy and chemotherapy is an inevitable phenomenon. This retrospective cohort study compared the efficacy of interstitial high dose rate brachytherapy (HDR-BRT), re-resection and sole dose dense temozolomide chemotherapy (ddTMZ) in the treatment of recurrent glioblastoma after initial surgery and radiochemotherapy.
[show abstract][hide abstract] ABSTRACT: Tumour recurrence of glioblastoma multiforme (GBM) after initial treatment with surgical resection, radiotherapy and chemotherapy is an inevitable phenomenon. This retrospective cohort study compared the efficacy of interstitial high dose rate brachytherapy (HDR-BRT), re-resection and sole dose dense temozolomide chemotherapy (ddTMZ) in the treatment of recurrent glioblastoma after initial surgery and radiochemotherapy.
Retropective cohort study.
Primary level of care with two participating centres. The geographical location was central Germany.
From January 2005 to December 2010, a total of 111 patients developed recurrent GBM after initial surgery and radiotherapy with concomitant temozolomide. The inclusion criteria were as follows: (1) histology-proven diagnosis of primary GBM (WHO grade 4), (2) primary treatment with resection and radiochemotherapy, and (3) tumour recurrence/progression.
This study compared retrospectively the efficacy of interstitial HDR-BRT, re-resection and ddTMZ alone in the treatment of recurrent glioblastoma. PRIMARY AND SECONDARY OUTCOME MEASURES: Median survival, progression free survival and complication rate.
Median survival after salvage therapy of the recurrence was 37, 30 and 26 weeks, respectively. The HDR-BRT group did significantly better than both the reoperation (p<0.05) and the ddTMZ groups (p<0.05). Moderate to severe complications in the HDR-BRT, reoperation and sole chemotherapy groups occurred in 5/50 (10%), 4/36 (11%) and 9/25 (36%) cases, respectively.
CT-guided interstitial HDR-BRT attained higher survival benefits in the management of recurrent glioblastoma after initial surgery and radiotherapy with concurrent temozolomide in comparison with the other treatment modalities. The low risk of complications of the HDR-BRT and the fact that it can be delivered percutaneously in local anaesthesia render it a promissing treatment option for selected patients which should be further evaluated.
[show abstract][hide abstract] ABSTRACT: PURPOSE: To report the clinical outcome of high-dose-rate (HDR) interstitial (IRT) brachytherapy (BRT) as sole treatment (monotherapy) for clinically localized prostate cancer. METHODS AND MATERIALS: Between January 2002 and December 2009, 718 consecutive patients with clinically localized prostate cancer were treated with transrectal ultrasound (TRUS)-guided HDR monotherapy. Three treatment protocols were applied; 141 patients received 38.0 Gy using one implant in 4 fractions of 9.5 Gy with computed tomography-based treatment planning; 351 patients received 38.0 Gy in 4 fractions of 9.5 Gy, using 2 implants (2 weeks apart) and intraoperative TRUS real-time treatment planning; and 226 patients received 34.5 Gy, using 3 single-fraction implants of 11.5 Gy (3 weeks apart) and intraoperative TRUS real-time treatment planning. Biochemical failure was defined according to the Phoenix consensus, and toxicity was evaluated using Common Toxicity Criteria for Adverse Events version 3. RESULTS: The median follow-up time was 52.8 months. The 36-, 60-, and 96-month biochemical control and metastasis-free survival rates for the entire cohort were 97%, 94%, and 90% and 99%, 98%, and 97%, respectively. Toxicity was scored per event, with 5.4% acute grade 3 genitourinary and 0.2% acute grade 3 gastrointestinal toxicity. Late grade 3 genitourinary and gastrointestinal toxicities were 3.5% and 1.6%, respectively. Two patients developed grade 4 incontinence. No other instance of grade 4 or greater acute or late toxicity was reported. CONCLUSION: Our results confirm IRT-HDR-BRT is safe and effective as monotherapy for clinically localized prostate cancer.
International journal of radiation oncology, biology, physics 08/2012; · 4.59 Impact Factor
[show abstract][hide abstract] ABSTRACT: PURPOSE: To report our results of computed tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy (BRT) in the local treatment of inoperable primary and secondary liver malignancies. METHODS AND MATERIALS: Between 2000 and 2009, 31 patients underwent a total of 42 BRT procedures for 36 hepatic lesions exceeding 4cm and located adjacent to the liver hilum and bile duct bifurcation. The median tumor volume was 99cm(3) (range, 46-1348cm(3)). The median age was 64 years (range, 27-85 years). The HDR-BRT delivered a median total physical dose of 13.0Gy (range, 7.0-32.0Gy) in twice daily fractions of median 7.0Gy (range, 4.0-10.0Gy) in 14 patients and in once daily fractions of median 8.0Gy (range, 7.0-14.0Gy) in 17 patients. RESULTS: The median followup was 13.3 months with an overall survival rate of 66% at 1 year. The local control rate for patients with metastatic lesions was 79%, 59%, and 59%, and for the subgroup with primary hepatic tumors 88%, 50%, and 50% at 1, 2, and 3 years, respectively. Severe side effects occurred in 4.7% of BRT procedures with no treatment-related deaths. CONCLUSIONS: Our results confirm CT-guided interstitial HDR-BRT to be a safe procedure for the local treatment of inoperable liver malignancies unsuitable for thermal ablation.
[show abstract][hide abstract] ABSTRACT: Einleitung: Kritiker der intraoperativen Radiotherapie (IORT) bemängeln die Tatsache, dass das verabreichte Bestrahlungsvolumen aufgrund
fehlender intraoperativer Bildgebung nicht exakt dokumentierbar ist. Vorgestellt wird ein System zur chirurgischen Navigation
und Dokumentation der Flabposition für die intraoperative Brachytherapie in Flabtechnik. Methode: Das System besteht aus einem elektromagnetischen 3D-Digitizer und einer PC-Workstation. Analog zur Neuronavigation werden
präoperative Spiral-CT-Daten der Tumorregion zur Navigation und Dokumentation der Flabposition in den CT-Schnitten verwendet.
Die Registrierung erfolgt anhand eines externen Referenzsystems. Am Modellversuch und Patientenbeispiel wird die neue Methode
vorgestellt. Ergebnisse: Die mittlere Genauigkeit der Digitalisierung der 100 Kugelmittelpunkte am Beckenmodell liegt bei 2,6 ± 0,5 mm–3,7 ± 0,9 mm.
Die mittlere Navigationsgenauigkeit liegt bei 2,4 ± 0,8 mm–3,3 ± 0,8 mm. Diese Werte entsprechen unseren klinischen Erfahrungswerten,
die auf der Beurteilung des Operateurs beruhen. Schlussfolgerungen: Insbesondere aus strahlentherapeutischer Sicht ist die optimierte Flabpositionierung durch das Navigationssystem und die
Dokumentation der Dosisverteilung auf der Basis der intraoperativen Flabgeometrie eine wichtige qualitative Verbesserung in
Hinblick auf eine individuelle Bestrahlungsplanung. Die Wertigkeit der chirurgischen Navigation im Becken sollte Gegenstand
weiterer Untersuchungen sein.
Introduction: The fact that conventional intraoperative radiotherapy (IORT) does not give the opportunity for exact documentation of the
applied radiation volume and dose distribution has been criticised. We would like to introduce a system for surgical navigation
and documentation of the flab positioning for intraoperative brachytherapy in afterloading flab technique. Methods: Our system consists of an electromagnetic 3D digitizer and a PC workstation. Preoperatively taken spiral CT scans of the
tumour region are used for navigation and documentation of the flab positioning, analogous to the procedure in neuronavigation.
Registration is done via an external reference system attached to the iliac bone of the patient. Results: The mean accuracy of digitalization of the 100 spheres in a pelvis model is about 2.6 ± 0.5–3.7 ± 0.9 mm. Mean navigation
accuracy is 2.4 ± 0.8–3.3 ± 0.8 mm. These figures correspond to the clinical experience of our surgeons. Conclusions: The optimization of the flab positioning by CT-guided navigation and the more accurate documentation of the dose volume and
distribution in the patient is an important step towards improving the quality of individual radiotherapy. We are of the opinion
that surgical navigation in the pelvic region should be subject to additional investigation in order to optimize the procedure.
Der Chirurg 05/2012; 72(6):731-735. · 0.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: Ziel:
Untersuchung der Funktionsverbesserung nach Megavoltbestrahlungen bei schmerzhaften Fersenspornen und Evaluierung des langfristigen
Ansprechens sowie möglicher Prognoseparameter.
Patienten und Methodik:
305 Fälle (252 Patienten) wurden mit 2 × 1,0 Gy/Woche bis 6,0 Gy Gesamtdosis/Serie bestrahlt. 97 Fälle (31,8%) erhielten nach
einem Intervall von 6 Wochen eine zweite Serie. Der Therapieerfolg wurde anhand eines Funktionsscores am Ende jeder Bestrahlungsserie
sowie nach 6 Wochen und 6 Monaten dokumentiert. Das langfristige Ansprechen wurde nach einem Nachbeobachtungszeitraum von
≥ 2 Jahren bewertet.
Die Ansprechrate nach 6 Monaten betrug 85,6%. Das Behandlungsergebnis wurde bei 135/305 Fällen (44,3%) als sehr gut (Score:
90–100), bei 60/305 Fällen (19,7%) als gut (Score: 70–85), bei 63/305 Fällen (20,7%) als zufriedenstellend (Score: 45–65)
und bei 47/305 Fällen (15,4%) als schlecht (Score: 0–40) gewertet. 231/305 Fälle (75,7%) hatten nur noch geringe oder keine
Schmerzen. 296/305 (97,0%) wiesen keine oder leichte Einschränkungen bei der Arbeit und 253/305 (82,9%) bei alltäglichen Aktivitäten
auf. In 255/305 Fälle bestanden (83,6%) keine oder nur leichte Einschränkungen der Gehstrecke. Bei den Kontrolluntersuchungen
nach einem durchschnittlichen Beobachtungszeitraum von 48,4 Monaten fand sich eine Rezidivrate von 7,3% (15 Fälle). Alter,
Geschlecht und Beschwerdedauer vor Einleitung der Bestrahlung (≤6 Monate vs. > 6 Monate) erwiesen sich nicht als Prognoseparameter.
Relevante Früh- oder Spättoxizitäten wurden nicht beobachtet.
Die Megavoltbestrahlung ist eine sehr effektive, lang wirksame und nebenwirkungsarme Therapieoption bei der Behandlung schmerzhafter
Fersensporne. Der Funktionsscore erwies sich als praktikables Schema für die Dokumentation der Ergebnisse.
To evaluate results on the functional outcome and to determine prognostic factors and long-term response to low-dose megavoltage
Patients and Methods:
A total dose of 6.0 Gy given in two weekly fractions of 1.0 Gy was applied to 305 sites (252 patients). After 6 weeks, 97
sites (31.8%) received a second radiotherapy (RT) course. Assessment system was a function score which was documented before
RT, at the end of each RT course, and at 6 weeks and 6 months after treatment. After an observation period of ≥ 24 months,
a follow-up examination was attempted to evaluate the late response.
At 6-month follow-up, 85.6% responded with a score improvement. The outcome was excellent (score: 90–100) in 135/305 sites
(44.3%), good (score: 70–85) in 60/305 sites (19.7%), moderate (score: 45–65) in 63/305 (20.7%) sites, and poor (score: 0–40)
in 47/305 sites (15.4%). 231/305 sites (75.7%) had no or mild pain. 296/305 (97,0%) had no or only slight limitations in work
and 253/305 (82,9%) in daily activities. 255/305 (83,6%) had no or slight discomfort in gait. The long-term follow-up after
a mean observation period of 48.4 months revealed 15 recurrences (7.3%). The patients’ age, sex, and the duration of symptoms
before initiation of RT (≤ 6 months vs. > 6 months) did not prove to be prognostic factors. No early or late toxicity related
to the use of RT was detected.
Megavoltage 6-MV photon-beam irradiation is a safe, effective and long-acting treatment modality in the management of heel
spur patients. The function score has been proven to be a feasible method in clinical practice for evaluation of treatment
Strahlentherapie und Onkologie 04/2012; 182(12):733-739. · 4.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Background and Purpose:
The importance of tumor volume as a prognostic factor in high-grade gliomas is highly controversial and there are numerous
methods estimating this parameter. In this study, a computer-based application was used in order to assess tumor volume from
hard copies and a survival analysis was conducted in order to evaluate the prognostic significance of preoperative volumetric
data in patients harboring glioblastomas.
Patients and Methods:
50 patients suffering from glioblastoma were analyzed retrospectively. Tumor volume was determined by the various geometric
models as well as by an own specialized software (Volumio). Age, performance status, type of excision, and tumor location
were also included in the multivariate analysis.
The spheroid and rectangular models overestimated tumor volume, while the ellipsoid model offered the best approximation.
Volume failed to attain any statistical significance in prognosis, while age and performance status confirmed their importance
in progression-free and overall survival of patients.
Geometric models provide a rough approximation of tumor volume and should not be used, as accurate determination of size is
of paramount importance in order to draw safe conclusions in oncology. Although the significance of volumetry was not disclosed,
further studies are definitely required.
Hintergrund und Ziel:
Die Bedeutung des Tumorvolumens als prognostischer Faktor fur maligne Gliome ist nach wie vor umstritten. In dieser Studie
wurden eine computerbasierte Methode zur Beurteilung des Tumorvolumens anhand von magnetresonanztomographischen Bildern bei
Patienten mit Glioblastoma multiforme (GBM) durchgefuhrt und mittels einer Uberlebensanalyse die prognostische Bedeutung praoperativer
volumetrischer Daten untersucht.
Patienten und Methodik:
50 Patienten mit GBM, welche zwei unterschiedliche Chemotherapieregime erhalten hatten, wurden retrospektiv analysiert und
die Tumorvolumina durch verschiedene geometrische Modelle sowie eine spezielle Software (Volumio) gemessen. Alter, Performance-Status,
Tumorlokalisation sowie Art der Exzision wurden in der multivariaten Uberlebensanalyse berucksichtigt.
Die angewandten spharoiden und rektangularen geometrischen Modelle uberschatzten das Tumorvolumen, wohingegen die ellipsoiden
Modelle die beste Annaherung im Vergleich zu Volumio ermoglichten. Das Tumorvolumen erwies sich nicht als statistisch signifikanter
Prognosefaktor. In der multivariaten Analyse bestatigte sich die Bedeutung des Alters und des Performance-Status fur das progressionsfreie
Uberleben und das Gesamtuberleben der Patienten.
Geometrische Modelle bieten eine ungenaue Messung des Tumorvolumens und sollten in der klinischen Praxis nicht zur Anwendung
kommen, zumal die prazise Erfassung der Tumorgrose von entscheidender onkologischer Bedeutung ist. Obwohl die vorgelegten
Daten den Einfluss des Tumorvolumens als statistisch nicht signifikant zeigten, sind weitere Studien bezuglich der Bedeutung
dieses Parameters notwendig.
Strahlentherapie und Onkologie 04/2012; 185(11):743-750. · 4.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Modern HDR brachytherapy treatment for prostate cancer based on the 3D ultrasound (U/S) plays increasingly important role. The purpose of this study is to investigate possible patient movement and anatomy alteration between the clinical image set acquisition, made after the needle implantation, and the patient irradiation and their influence on the quality of treatment.
The authors used 3D U/S image sets and the corresponding treatment plans based on a 4D-treatment planning procedure: plans of 25 patients are obtained right after the needle implantation (clinical plan is based on this 3D image set) and just before and after the treatment delivery. The authors notice the slight decrease of treatment quality with increase of time gap between the clinical image set acquisition and the patient irradiation. 4D analysis of dose-volume-histograms (DVHs) for prostate: CTV1 = PTV, and urethra, rectum, and bladder as organs at risk (OARs) and conformity index (COIN) is presented, demonstrating the effect of prostate, OARs, and needles displacement.
The authors show that in the case that the patient body movement/anatomy alteration takes place, this results in modification of DVHs and radiobiological parameters, hence the plan quality. The observed average displacement of needles (1 mm) and of prostate (0.57 mm) is quite small as compared with the average displacement noted in several other reports [A. A. Martinez et al., Int. J. Radiat. Oncol., Biol., Phys. 49(1), 61-69 (2001); S. J. Damore et al., Int. J. Radiat. Oncol., Biol., Phys. 46(5), 1205-1211 (2000); P. J. Hoskin et al., Radiotherm. Oncol. 68(3), 285-288 (2003); E. Mullokandov et al., Int. J. Radiat. Oncol., Biol., Phys. 58(4), 1063-1071 (2004)] in the literature.
Although the decrease of quality of dosimetric and radiobiological parameters occurs, this does not cause clinically unacceptable changes to the 3D dose distribution, according to our clinical protocol.
Medical Physics 09/2011; 38(9):4982-93. · 2.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: Image-guided interstitial (IRT) brachytherapy (BRT) is an effective treatment option as part of a multimodal approach to the treatment of isolated lung tumors. In this study, we report our results of computed tomography-guided IRT high-dose-rate (HDR) BRT in the local treatment of inoperable primary and secondary intrathoracic malignancies.
Between 1997 and 2007, 55 patients underwent a total of 68 interventional procedures for a total of 60 lung lesions. The median tumor volume was 160 cm³ (range, 24-583 cm³). Thirty-seven patients were men and 18 were women, with a median age of 64 years (range, 31-93 years). The IRT-HDR-BRT delivered a median dose of 25.0 Gy (range, 10.0-32.0 Gy) in twice-daily fractions of 4.0 to 15.0 Gy in 27 patients and 10.0 Gy (range, 7.0-32.0 Gy) in once-daily fractions of 4.0 to 20.0 Gy in 28 patients.
The median follow-up was 14 months (range, 1-49 months). The overall survival rate was 63% at 1 year, 26% at 2 years, and 7% at 3 years. The local control rate for metastatic tumors was 93%, 82%, and 82% and for primary intrathoracic cancers 86%, 79%, and 73% at 1, 2, and 3 years, respectively. Pneumothoraces occurred in 11.7% of interventional procedures, necessitating postprocedural drainage in one (1.8%) patient.
In patients with inoperable intrathoracic malignancies, computed tomography-guided IRT-HDR-BRT is a safe and effective alternative to other locally ablative techniques.
Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 03/2011; 6(3):545-52. · 4.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: The Gorham-Stout syndrome (GSS) is a rare, benign idiopathic and progressive disorder causing massive osteolysis due to a vascular hyperproliferation replacing the bony structure. Clinical experience concerning the efficacy of radiation therapy (RT) is limited to about 50 of an overall 200 cases reported worldwide.
A 24-year-old bedridden woman had histologically proven GSS with destruction of the anterior pelvic girdle and received RT for a total dose of 45.0 Gy applied in 5 weekly fractions of 1.8 Gy. In addition, the patient received intravenously 4 mg zoledronic acid once a month. One year after the combined treatment, complete pain relief occurred, and the patient was able to walk without the use of appliances. Imaging studies revealed no progression of the osteolysis but only minimal signs of remineralization.
Combined treatment with RT and bisphosphonate administration can prevent the progression of osteolysis in GSS. Total doses of 40-45 Gy are recommended.
Strahlentherapie und Onkologie 02/2011; 187(2):140-3. · 4.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Despite significant improvements in the treatment of head and neck cancer (HNC), lymph node recurrences remain a clinical challenge after primary radiotherapy. The value of interstitial (IRT) brachytherapy (BRT) for control of lymph node recurrence remains unclear. In order to clarify its role a retrospective review was undertaken on the value of computed tomography (CT)-guided IRT high-dose-rate (HDR)-BRT in isolated recurrent disease from HNC.
From 2000 to 2007, 74 patients were treated for inoperable recurrent cervical lymphadenopathy. All patients had previously been treated with radical radiotherapy or chemoradiation with or without surgery. The HDR-BRT delivered a median salvage dose of 30.0 Gy (range, 12.0-36.0 Gy) in twice-daily fractions of 2.0-5.0 Gy in 71 patients and of 30.0 Gy (range, 10.0-36.0 Gy) in once-daily fractions of 6.0-10.0 Gy in three patients.
The overall and disease-free survival rates at one, two and three years were 42%, 19%, 6%, and 42%, 37% and 19%, respectively. The local control probability at one, two and three years was 67% at all three time points. Grade III-IV complications occurred in 13% of patients.
In patients with inoperable recurrent neck disease from HNC, hypofractionated accelerated CT-guided IRT-HDR-BRT can play an important role in providing palliation and tumor control.
Radiotherapy and Oncology 01/2011; 98(1):57-62. · 4.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: Purpose: One of the issues that a planner is often facing in HDR brachytherapy is the selective existence of high dose volumes around some few dominating dwell positions. If there is no information available about its necessity (e.g. location of a GTV), then it is reasonable to investigate whether this can be avoided. This effect can be eliminated by limiting the free modulation of the dwell times. HIPO, an inverse treatment plan optimization algorithm, offers this option. In treatment plan optimization there are various methods that try to regularize the variation of dose non-uniformity using purely dosimetric measures. However, although these methods can help in finding a good dose distribution they do not provide any information regarding the expected treatment outcome as described by radiobiology based indices.
Material and methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO and modu lation restriction (MR) has been compared to alternative plans with HIPO and free modulation (without MR). All common dose-volume indices for the prostate and the organs at risk have been considered together with measures. The clinical effectiveness of the different dose distributions was investigated by calculating the response probabilities of the tumors and organs-at-risk (OARs) involved in these prostate cancer cases. The radiobiological models used are the Poisson and the relative seriality models. Furthermore, the complication-free tumor control probability, P+ and the biologically effective uniform dose (D = ) were used for treatment plan evaluation and comparison.
Results: Our results demonstrate that HIPO with a modulation restriction value of 0.1-0.2 delivers high quality plans which are practically equivalent to those achieved with free modulation regarding the clinically used dosimetric indices. In the comparison, many of the dosimetric and radiobiological indices showed significantly different results. The modulation restricted clinical plans demonstrated a lower total dwell time by a mean of 1.4% that was proved to be statistically significant (p = 0.002). The HIPO with MR treatment plans produced a higher P+ by 0.5%, which stemmed from a better sparing of the OARs by 1.0%.
Conclusions: Both the dosimetric and radiobiological comparison shows that the modulation restricted optimization gives on average similar results with the optimization without modulation restriction in the examined clinical cases. Concluding, based on our results, it appears that the applied dwell time regularization technique is expected to introduce a minor improvement in the effectiveness of the optimized HDR dose distributions.
Journal of Contemporary Brachytherapy 10/2010; 2(3):117-128.
[show abstract][hide abstract] ABSTRACT: Modern HDR brachytherapy treatment for prostate cancer based on the 3D ultrasound (US) plays increasingly important role.
The purpose of this study is to investigate possible patient movement and anatomy alteration between the clinical image set
acquisition, made after the needle implantation, and the patient irradiation, and their influence on the quality of treatment.
We used 3D US image sets and treatment plans of 48 patients obtained right after the needle implantation (clinical plan is
based on this 3D image set) and before and after the treatment delivery. We notice the slight decrease of treatment quality
with increase of time between the clinical image set acquisition and the patient irradiation. Change of Dose-Volume-Histograms
(DVHs) for prostate, urethra, rectum and bladder and conformity index COIN are presented, which are the effect of prostate,
OARs and needles displacement.
We show that in the case that there is patient body movement/anatomy alteration this results in modification of DVHs. Still,
since we use each implant for one only fraction and the maximum time that the needles remain implanted is 69.2 min, all plans
based on pre and post irradiation imaging are fulfilling our protocol. The observed average displacement of needles (1 mm)
and of prostate (0.57 mm) is quite small as compared with the average displacement noted in several other reports1 − 4 in the literature and does not cause unacceptable treatment plans.
Keywords3D US-HRD brachytherapy-prostate-DVH-COIN