Inverse planning and inverse implanting for breast interstitial brachytherapy. Introducing a new anatomy specific breast interstitial template (ASBIT).

An innovative template, based on thoracic cage surface reconstructions for breast interstitial brachytherapy was developed. Hybrid-inverse-planning-optimisation-based implantations and brachytherapy plans, using three custom anthropomorphic breast phantoms, were utilised for its validation. A user independent, inverse planning and inverse implanting technique is proposed.

Combined high dose rate brachytherapy and external beam radiotherapy for clinically localised prostate cancer.

PURPOSE: To report the clinical outcomes and treatment-related toxicities after combined high-dose-rate (HDR) brachytherapy (BRT) with external beam radiotherapy (EBRT) for patients with clinically localised high-risk prostate cancer. MATERIAL AND METHODS: Between 2008 and 2012, three hundred and three consecutive patients with organ-confined high-risk prostate cancer were treated with definitive radiotherapy consisting of HDR-BRT followed by supplemental EBRT. The transrectal 3D-ultrasound-based HDR-BRT boost consisted of two single-fraction implants of 10.5 Gy, prescribed to the 90% of the gland (D90), for a total physical dose of 21.0 Gy delivered to the prostatic gland. EBRT was delivered with conventional fractionation, prescribing 45.0 Gy to the prostatic gland and seminal vesicles. Biochemical failure was defined according to the Phoenix Consensus Criteria, genitourinary (GU)/gastrointestinal (GI) toxicity was evaluated using the Common Toxicity Criteria for Adverse Events (version 3.0). RESULTS: The median follow-up was 71.6 months. The 7-year overall survival, biochemical control and metastasis-free-survival rates for the entire cohort were 85.7%, 88.3% and 93.8%, respectively. Androgen deprivation therapy was initiated prior to treatment for 92.7% of patients with a median duration of 12 months. Toxicity was scored per event with late Grade 2, 3 and 4 GU adverse events and was found to be 15.3%, 2.2% and 0.3%, respectively. Late Grade 2 GI toxicity accounted for 0.3% with no instances of Grade 3 or higher late adverse events. CONCLUSION: HDR-BRT with supplemental EBRT results in low biochemical relapse-free survival rates associated with a very low incidence of higher-grade late adverse events.

High dose rate brachytherapy as monotherapy for localised prostate cancer.

BACKGROUND AND PURPOSE: To evaluate the oncological outcome of a three-implant high dose rate (HDR) brachytherapy (BRT) protocol as monotherapy for clinically localised prostate cancer. MATERIAL AND METHODS: Between February 2008 and December 2012, 450 consecutive patients with clinically localised prostate cancer were treated with HDR monotherapy. The cohort comprised of 198 low-, 135 intermediate- and 117 high risk patients being treated with three single-fraction implants of 11.5Gy delivered to an intraoperative real-time, transrectal ultrasound defined planning treatment volume up to a total physical dose of 34.5Gy with an interfractional interval of 21days. Fifty-eight patients (12.8%) received ADT, 32 of whom were high- and 26 intermediate-risk. Biochemical failure was defined according to the Phoenix Consensus Criteria and genitourinary/gastrointestinal toxicity evaluated using the Common Toxicity Criteria for Adverse Events version 3.0. RESULTS: The median follow-up time was 56.3months. The 60-month overall survival, biochemical control and metastasis-free-survival rates were 96.2%, 95.0% and 99.0%, respectively. Toxicity was scored per event with late Grade 2 and 3 genitourinary adverse events of 14.2% and 0.8%, respectively. Late Grade 2 gastrointestinal toxicity amounted 0.4% with no instances of Grade 3 or greater late adverse events to be reported. CONCLUSIONS: Our results confirm HDR BRT to be a safe and effective monotherapeutic treatment modality for clinically localised prostate cancer.

Iridium-Knife: Another knife in radiation oncology.

PURPOSE: Intratarget dose escalation with superior conformity is a defining feature of three-dimensional (3D) iridium-192 (192Ir) high-dose-rate (HDR) brachytherapy (BRT). In this study, we analyzed the dosimetric characteristics of interstitial 192Ir HDR BRT for intrathoracic and cerebral malignancies. We examined the dose gradient sharpness of HDR BRT compared with that of linear accelerator-based stereotactic radiosurgery and stereotactic body radiation therapy, usually called X-Knife, to demonstrate that it may as well be called a Knife. METHODS AND MATERIALS: Treatment plans for 10 patients with recurrent glioblastoma multiforme or intrathoracic malignancies, five of each entity, treated with X-Knife (stereotactic radiosurgery for glioblastoma multiforme and stereotactic body radiation therapy for intrathoracic malignancies) were replanned for simulated HDR BRT. For 3D BRT planning, we used identical structure sets and dose prescription as for the X-Knife planning. The indices for qualitative treatment plan analysis encompassed planning target volume coverage, conformity, dose falloff gradient, and the maximum dose-volume limits to different organs at risk. RESULTS: Volume coverage in HDR plans was comparable to that calculated for X-Knife plans with no statistically significant difference in terms of conformity. The dose falloff gradient-sharpness-of the HDR plans was considerably steeper compared with the X-Knife plans. CONCLUSIONS: Both 3D 192Ir HDR BRT and X-Knife are effective means for intratarget dose escalation with HDR BRT achieving at least equal conformity and a steeper dose falloff at the target volume margin. In this sense, it can reasonably be argued that 3D 192Ir HDR BRT deserves also to be called a Knife, namely Iridium-Knife.

Image-guided interstitial high-dose-rate brachytherapy in the treatment of inoperable recurrent head and neck malignancies: An effective option of reirradiation.

BACKGROUND: In recurrent head and neck cancer, therapeutic options are limited and high-quality evidence is rare. The purpose of this report was to present our experience of CT-guided interstitial high-dose rate (HDR) brachytherapy in 4 challenging cases of inoperable recurrent head and neck cancer. METHODS: A 53-year-old man with mucosal melanoma of the paranasal sinuses, a 61-year-old man with myofibroblastic sarcoma of the nasal cavity, a 51-year-old woman with nasopharyngeal cancer, and a 44-year-old woman with orbital leiomyosarcoma were treated with reirradiation by HDR brachytherapy after previous comprehensive therapy, including full course external radiotherapy (RT). RESULTS: All patients showed response to brachytherapy with 1 patient experiencing locoregional failure. The mean lesion-specific disease control was 15 months. Currently, 1 patient is alive and 3 patients died after mean 20 months after treatment. CONCLUSION: In patients with inoperable recurrent head and neck cancer, CT-guided interstitial HDR brachytherapy can play a role in providing palliation and tumor control. © 2017 Wiley Periodicals, Inc. Head Neck 39: E61-E68, 2017.

Comparison of different fractionation schedules toward a single fraction in high-dose-rate brachytherapy as monotherapy for low-risk prostate cancer using 3-dimensional radiobiological models.

PURPOSE: The aim of the present study was the investigation of different fractionation schemes to estimate their clinical impact. For this purpose, widely applied radiobiological models and dosimetric measures were used to associate their results with clinical findings. METHODS AND MATERIALS: The dose distributions of 12 clinical high-dose-rate brachytherapy implants for prostate were evaluated in relation to different fractionation schemes. The fractionation schemes compared were: (1) 1 fraction of 20 Gy; (2) 2 fractions of 14 Gy; (3) 3 fractions of 11 Gy; and (4) 4 fractions of 9.5 Gy. The clinical effectiveness of the different fractionation schemes was estimated through the complication-free tumor control probability (P+), the biologically effective uniform dose, and the generalized equivalent uniform dose index. RESULTS: For the different fractionation schemes, the tumor control probabilities were 98.5% in 1×20 Gy, 98.6% in 2×14 Gy, 97.5% in 3×11 Gy, and 97.8% in 4×9.5 Gy. The corresponding P+ values were 88.8% in 1×20 Gy, 83.9% in 2×14 Gy, 86.0% in 3×11 Gy, and 82.3% in 4×9.5 Gy. With use of the fractionation scheme 4×9.5 Gy as reference, the isoeffective schemes regarding tumor control for 1, 2, and 3 fractions were 1×19.68 Gy, 2×13.75 Gy, and 3×11.05 Gy. The optimum fractionation schemes for 1, 2, 3, and 4 fractions were 1×19.16 Gy with a P+ of 91.8%, 2×13.2 Gy with a P+ of 89.6%, 3×10.6 Gy with a P+ of 88.4%, and 4×9.02 Gy with a P+ of 86.9%. CONCLUSIONS: Among the fractionation schemes 1×20 Gy, 2×14 Gy, 3×11 Gy, and 4×9.5 Gy, the first scheme was more effective in terms of P+. After performance of a radiobiological optimization, it was shown that a single fraction of 19.2 to 19.7 Gy (average 19.5 Gy) should produce at least the same benefit as that given by the 4×9.5 Gy scheme, and it should reduce the expected total complication probability by approximately 40% to 55%.

High dose rate brachytherapy as monotherapy for localised prostate cancer: a hypofractionated two-implant approach in 351 consecutive patients.

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.

Computed tomography-guided interstitial high dose rate brachytherapy for centrally located liver tumours: a single institution study.

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.

High-dose-rate interstitial brachytherapy as monotherapy for clinically localized prostate cancer: treatment evolution and mature results.

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.

Hypofractionated accelerated computed tomography-guided interstitial high-dose-rate brachytherapy for liver malignancies.

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 4 cm and located adjacent to the liver hilum and bile duct bifurcation. The median tumor volume was 99 cm(3) (range, 46-1348 cm(3)). The median age was 64 years (range, 27-85 years). The HDR-BRT delivered a median total physical dose of 13.0 Gy (range, 7.0-32.0 Gy) in twice daily fractions of median 7.0 Gy (range, 4.0-10.0 Gy) in 14 patients and in once daily fractions of median 8.0 Gy (range, 7.0-14.0 Gy) 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.

4D analysis of influence of patient movement and anatomy alteration on the quality of 3D U/S-based prostate HDR brachytherapy treatment delivery.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Effect of using different U/S probe Standoff materials in image geometry for interventional procedures: the example of prostate.

PURPOSE: This study investigates the distortion of geometry of catheters and anatomy in acquired U/S images, caused by utilizing various stand-off materials for covering a transrectal bi-planar ultrasound probe in HDR and LDR prostate brachytherapy, biopsy and other interventional procedures. Furthermore, an evaluation of currently established water-bath based quality assurance (QA) procedures is presented. MATERIAL AND METHODS: Image acquisitions of an ultrasound QA setup were carried out at 5 MHz and 7 MHz. The U/S probe was covered by EA 4015 Silicone Standoff kit, or UA0059 Endocavity balloon filled either with water or one of the following: 40 ml of Endosgel(®), Instillagel(®), Ultraschall gel or Space OAR™ gel. The differences between images were recorded. Consequently, the dosimetric impact of the observed image distortion was investigated, using a tissue equivalent ultrasound prostate phantom - Model number 053 (CIRS Inc., Norfolk, VA, USA). RESULTS: By using the EA 4015 Silicone Standoff kit in normal water with sound speed of 1525 m/s, a 3 mm needle shift was observed. The expansion of objects appeared in radial direction. The shift deforms also the PTV (prostate in our case) and other organs at risk (OARs) in the same way leading to overestimation of volume and underestimation of the dose. On the other hand, Instillagel(®) and Space OAR™ "shrinks" objects in an ultrasound image for 0.65 mm and 0.40 mm, respectively. CONCLUSIONS: The use of EA 4015 Silicone Standoff kit for image acquisition, leads to erroneous contouring of PTV and OARs and reconstruction and placement of catheters, which results to incorrect dose calculation during prostate brachytherapy. Moreover, the reliability of QA procedures lies mostly in the right temperature of the water used for accurate simulation of real conditions of transrectal ultrasound imaging.

Radiobiological evaluation of the influence of dwell time modulation restriction in HIPO optimized HDR prostate brachytherapy implants.

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 modulation 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 radiobiological 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 ([Formula: see text]) 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.