Temoporfin mediated photodynamic therapy in patients with local persistent and recurrent nasopharyngeal carcinoma after curative radiotherapy: a feasibility study.

BACKGROUND: The treatment of persistent and recurrent nasopharyngeal carcinoma (NPC) remains a challenge, especially in Indonesia. We investigated the safety and efficacy of temoporfin mediated photodynamic therapy (PDT) for patients with local persistent and recurrent NPC. MATERIAL AND METHODS: Twenty-two patients with persistent and recurrent NPC (maximum tumor depth < 10mm) underwent PDT under local anesthesia with use of a nasopharyngeal light applicator. Three different drug doses and light intervals have been administered: treatment arm A: 0.15 mg/kg Foscan; 96 h drug-light interval; B: drug dose of 0.10 mg/, 48 h drug-light interval; C: drug dose of 0.075 mg/kg, 24 h drug-light interval. Toxicity was measured by using the CTCAE 3.1 scale. RESULTS: Arm A consisted of eight patients, arms B and C consisted of seven patients. The treatment procedure was well tolerable under local anesthesia. The most common grade III toxicities for all groups is headache (n = 7; 33%). No grade IV toxicity was seen. One patient died 2 days after treatment due to a misdiagnosed pneumonia. In 17 of the 22 patients a biopsy was performed after 40 weeks and showed no tumor in all biopsies. Arm A seems, in addition to comparable toxicity, clinically more effective than arms B and C. CONCLUSION: The present study demonstrated that temoporfin mediated photodynamic therapy is a relatively simple technique that can be utilized to treat residual or recurrent nasopharyngeal cancer, restricted locally to the nasopharynx.

SU-E-T-617: Towards Fully Automated Multi-Criterial Plan Generation: A Prospective Clinical Study.

PURPOSE: To prospectively compare plans generated with iCycle, an in-house developed algorithm for fully automated multi-criterial IMRT beam profile and beam orientation optimization (Breedveld, Med. Phys. 2012), and plans manually generated by dosimetrists with the clinical treatment planning system. METHODS: For 20 randomly selected head-and-neck cancer patients with various tumour locations (of whom 13 received sequential boost treatments) we offered the treating physician the choice between an automatically generated iCycle plan and a manually optimized plan following standard clinical procedures. While iCycle used a fixed'wish-list' with hard constraints and prioritised objectives, the dosimetrists manually selected the beam configuration and fine-tuned the constraints and objectives for each IMRT plan. Dosimetrists and treating physicians were not informed in advance whether a competing iCycle plan was made or not. The two plans were simultaneously presented to the physician who then selected the plan to be used for treatment. For the patient group, we quantified differences in PTV coverage and sparing of critical tissues. RESULTS: In 32/33 plan comparisons the physician selected the iCycle plan for treatment. This highly consistent preference for automatically generated plans was mainly caused by improved sparing for the large majority of critical structures. With iCycle, the NTCPs for parotid and submandibular glands were reduced by 2.4% ± 4.9% (maximum: 18.5%, p=0.001) and 6.5% ± 8.3% (maximum: 27%, p=0.005), respectively. The reduction in mean oral cavity dose was 2.8 Gy ± 2.8 Gy (maximum: 8.1 Gy, p=0.005). For swallowing muscles, esophagus and larynx, the mean dose reduction was 3.3 Gy ± 1.1Gy (maximum: 9.2 Gy, p<0.001). Moreover, for 15 patients, the target coverage was improved as well. CONCLUSIONS: In 97% of cases, the automatically generated plan was selected for treatment because of superior quality. Apart from improved plan quality, automatic plan generation is economically attractive because of reduced workload.

The clinical feasibility of deep hyperthermia treatment in the head and neck: new challenges for positioning and temperature measurement.

To apply high-quality hyperthermia treatment to tumours at deep locations in the head and neck (H&N), we have designed and built a site-specific phased-array applicator. Earlier, we demonstrated its features in parameter studies, validated those by phantom measurements and clinically introduced the system. In this paper we will critically review our first clinical experiences and demonstrate the pivotal role of hyperthermia treatment planning (HTP). Three representative patient cases (thyroid, oropharynx and nasal cavity) are selected and discussed. Treatment planning, the treatment, interstitially measured temperatures and their interrelation are analysed from a physics point of view. Treatments lasting 1 h were feasible and well tolerated and no acute treatment-related toxicity has been observed. Maximum temperatures measured are in the range of those obtained during deep hyperthermia treatments in the pelvic region but mean temperatures are still to be improved. Further, we found that simulated power absorption correlated well with measured temperatures illustrating the validity of our treatment approach of using energy profile optimizations to arrive at higher temperatures. This is the first data proving that focussed heating of tumours in the H&N is feasible. Further, HTP proved a valuable tool in treatment optimization. Items to improve are (1) the transfer of HTP settings into the clinic and (2) the registration of the thermal dose, i.e. dosimetry.

Stereotactic body radiation therapy for colorectal liver metastases.

BACKGROUND: Stereotactic body radiation therapy (SBRT) is a treatment option for colorectal liver metastases. Local control, patient survival and toxicity were assessed in an experience of SBRT for colorectal liver metastases. METHODS: SBRT was delivered with curative intent to 20 consecutively treated patients with colorectal hepatic metastases who were candidates for neither resection nor radiofrequency ablation (RFA). The median number of metastases was 1 (range 1-3) and median size was 2.3 (range 0.7-6.2) cm. Toxicity was scored according to the Common Toxicity Criteria version 3.0. Local control rates were derived on tumour-based analysis. RESULTS: Median follow-up was 26 (range 6-57) months. Local failure was observed in nine of 31 lesions after a median interval of 22 (range 12-52) months. Actuarial 2-year local control and survival rates were 74 and 83 per cent respectively. Hepatic toxicity grade 2 or less was reported in 18 patients. Two patients had an episode of hepatic toxicity grade 3. CONCLUSION: SBRT is a treatment option for patients with colorectal liver metastases who are not candidates for resection or RFA.

Four-dimensional stereotactic radiotherapy for early stage non-small cell lung cancer: a comparative planning study.

In this study we sought to assess the potential of the respiratory tumor tracking system of the CyberKnife to administer 3 fractions of 15 Gy in the treatment of early stage non-small cell lung cancer (NSCLC). The CyberKnife plans were compared to those developed for 3-D conformal radiotherapy (3-D CRT) administering 20 fractions of 3 Gy based on a slow CT. Ten patients with stage I NSCLC, who were previously treated with 3-D CRT, were re-planned with the CyberKnife treatment planning system. In the 3-D CRT plan, the planning target volume (PTV) included the gross tumor volume (GTV)(slow) and a 15-mm margin, whereas in the CyberKnife plan the margin was 8 mm. The physical doses from both treatment plans were converted to normalized total doses (NTD) using the linear quadratic model with an alpha/beta(tumor) of 10 Gy and alpha/beta(organs at risk (OAR)) of 3 Gy. The average minimal and mean doses administered to the PTV with the CyberKnife and 3-D CRT were 93 and 115.8 Gy and 61 and 66 Gy, respectively (p<0.0001). The mean V(20) of the CyberKnife and 3-D CRT plans were 8.2% and 6.8%, respectively (p=0.124). Both plans complied with the OAR constraints. In conclusion, 4-dimensional stereotactic radiotherapy can increase the minimal and mean biological dose with 51% and 75%, in comparison with 3-D CRT without significantly increasing the V(20), respectively.

Curative stereotactic robotic radiotherapy treatment for extracranial, extrapulmonary, extrahepatic, and extraspinal tumors: technique, early results, and toxicity.

We investigated the technique, early results and toxicity of curative stereotactic radiotherapy with the CyberKnife (Accuray Incorporated, Sunnyvale, California, USA) in 15 extracranial, extrapulmonary, extrahepatic, and extraspinal tumors. Fourteen tumors were located close to the bowel or esophagus. The PTV = GTV + 2-5 mm. The dose to the tumors varied from 10 fractions of 4 Gy up to 3 fractions of 20 Gy (median dose/fraction: 7 Gy; median number of fractions: 6), and depended on the proximity of the bowel. A small volume of the bowel was allowed to receive a dose of 6 Gy/fraction. The dose to the PTV was prescribed to the 75-85% isodose line. With a median follow up of 18 months, the 2-year local control and overall survival was 100%. Due to our flexible fractionation schedules, we were able to prescribe the dose to at least 90% of the PTV (median 95%) without increasing the dose to the bowel > 6 Gy/fraction. Five acute side effects were seen in four patients: two patients had transient grade 1 lymph edema in the leg, one patient complained of grade 1 pain in the abdomen and diarrhea, and one patient complained of grade 1 radiation dermatitis. Late toxicity such as grade 1 rectal bleeding, grade 1 diarrhea, grade 2 painful subcutaneous fibrosis, grade 2 pain in a surgical scar on the abdominal wall and an asymptomatic occlusion of the ureter was observed. Curative stereotactic radiotherapy treatment with the CyberKnife for extracranial, extrapulmonary, extrahepatic, and extraspinal, locally recurrent or solitary metastatic tumors is feasible and results in excellent local control and survival with low acute and late toxicity. A small volume of the bowel is able to tolerate a dose of 6 Gy per fraction for a maximum of 6 fractions.

Robotic radiosurgery vs. brachytherapy as a boost to intensity modulated radiotherapy for tonsillar fossa and soft palate tumors: the clinical and economic impact of an emerging technology.

As a basis for making decisions regarding optimal treatment for patients with tonsillar fossa and soft palate tumors, we conducted a preliminary investigation of costs and quality of life (QoL) for two modalities [brachytherapy (BT) and robotic radiosurgery] used to boost radiation to the primary tumors following external beam radiotherapy. BT was well established in our center; a boost by robotic radiosurgery was begun more recently in patients for whom BT was not technically feasible. Robotic radiosurgery boost treatment has the advantage of being non-invasive and is able to reach tumors in cases where there is deep parapharyngeal tumor extension. A neck dissection was performed for patients with nodal-positive disease. Quality of life (pain and difficulty swallowing) was established in long-term follow-up for patients undergoing BT and over a one-year follow-up in robotic radiosurgery patients. Total hospital costs for both groups were computed. Our results show that efficacy and quality of life at one year are comparable for BT and robotic radiosurgery. Total cost for robotic radiosurgery was found to be less than BT primarily due to the elimination of hospital admission and operating room expenses. Confirmation of robotic radiosurgery treatment efficacy and reduced morbidity in the long term requires further study. Quality of life and cost analyses are critical to Health Technology Assessments (HTA). The present study shows how a preliminary HTA of a new medical technology such as robotic radiosurgery with its typical hypofractionation characteristics might be based on short-term clinical outcomes and assumptions of equivalence.

Winner of the "New Investigator Award" at the European Society of Hyperthermia Oncology Meeting 2007. The HYPERcollar: a novel applicator for hyperthermia in the head and neck.

The purpose of this work was to define all features, and show the potential, of the novel HYPERcollar applicator system for hyperthermia treatments in the head and neck region. The HYPERcollar applicator consists of (1) an antenna ring, (2) a waterbolus system and (3) a positioning system. The specific absorption rate (SAR) profile of this applicator was investigated by performing infra-red measurements in a cylindrical phantom. Mandatory patient-specific treatment planning was performed as an object lesson to a patient with a laryngeal tumour and an artificial lymph node metastasis. Comfort tests with healthy volunteers have revealed that the applicator provides sufficient comfort to maintain in treatment position for an hour: the standard hyperthermia treatment duration in our centre. By phantom measurements, we established that a central focus in the neck can be obtained, with 50% iso-SAR lengths of 3.5 cm in transversal directions (x/y) and 9-11 cm in the axial direction (z). Using treatment planning by detailed electromagnetic simulations, we showed that the SAR pattern can be optimised to enable simultaneous encompassing of a primary laryngeal tumour and a lymph node metastasis at the 25% iso-SAR level. This study shows that the applicator enables a good control, and sufficient possibilities for optimisation, of the SAR pattern. In an ongoing clinical feasibility study, we will investigate the possibilities of heating various target regions in the neck with this apparatus.

Performance of a dedicated light delivery and dosimetry device for photodynamic therapy of nasopharyngeal carcinoma: phantom and volunteer experiments.

UNLABELLED: The objective of this study was to develop a light delivery and measurement device for photodynamic therapy (PDT) in the nasopharyngeal cavity, which achieves a homogeneous and reproducible fluence rate distribution to a target area and provides proper shielding of predefined risk areas. MATERIALS AND METHODS: A flexible silicone applicator was developed, incorporating light delivery and dosimetry fibers. The applicator can be inserted through the mouth and fixed in the nasopharyngeal cavity. Tissue optical phantoms were prepared on the basis of optical properties measured in vivo using diffuse reflectance spectroscopy (DRS). The fluence rate over the length of the applicator surface was measured in air, in tissue optical phantoms and in five healthy volunteers. RESULTS: The fluence rate distribution over the applicator surface in air and tissue optical phantom was found to be more homogeneous (SD/mean 3.8% and 18.3%, respectively) than the fluence rate distribution in five volunteers (SD/mean ranging from 19% up to 52%). The maximum observed fluence rate build-up in the nasopharynx varied between subjects and ranged from a factor of 4.1-6.9. Shielding of the risk area such as the soft palate and tongue was effective. CONCLUSIONS: In air and in tissue optical phantoms the fluence rate distribution of the device was highly homogeneous. The observed inter-subject and intra-subject variations in fluence rate in healthy volunteers originated from differences in optical properties and nasopharyngeal geometry. Light delivery based on a single tissue surface measurement will not be adequate. In situ dosimetric measurements are required to determine the light fluence delivered to a geometrically complex site such as the nasopharynx. These observations should be taken in consideration when developing light applicators for PDT of the nasopharynx and other non-uniform surfaces.

Lung tumor tracking during stereotactic radiotherapy treatment with the CyberKnife: Marker placement and early results.

Lung tumor tracking during stereotactic radiotherapy with the CyberKnife requires the insertion of markers in or close to the tumor. To reduce the risk of pneumothorax, three methods of marker placement were used: 1) intravascular coil placement, 2) percutaneous intrathoracal, and 3) percutaneous extrathoracal placement. We investigated the toxicity of marker placement and the tumor response of the lung tumor tracking treatment. Markers were placed in 20 patients with 22 tumors: 13 patients received a curative treatment, seven a palliative. The median Charlson Comorbidity Score was 4 (range: 1-8). Platinum fiducials and intravascular embolisation coils were used as markers. In total, 78 markers were placed: 34 intrathoracal, 23 intravascular and 21 extrathoracal. The PTV equaled the GTV + 5 mm. A median dose of 45 Gy (range: 30-60 Gy, in 3 fractions) was prescribed to the 70-85% isodose. The response was evaluated with a CTscan performed 6-8 weeks after the last treatment and routinely thereafter. The median follow-up was 4 months (range: 2-11). No severe toxicity due to the marker placement was seen. Pneumothorax was not seen. The local control was 100%. Four tumors in four patients showed a complete response, 15 tumors in 14 patients a partial response, and three tumors in two patients with metastatic disease had stable disease. No severe toxicity of marker placement was seen due to the appropriate choice of one of the three methods. CyberKnife tumor tracking with markers is feasible and resulted in excellent tumor response. Longer follow-up is needed to validate the local control.

In vivo fluence rate measurements during Foscan-mediated photodynamic therapy of persistent and recurrent nasopharyngeal carcinomas using a dedicated light applicator.

The objective of this study was to evaluate the performance of a dedicated light applicator for light delivery and fluence rate monitoring during Foscan-mediated photodynamic therapy of nasopharyngeal carcinoma in a clinical phase I/II study. We have developed a flexible silicone applicator that can be inserted through the mouth and fixed in the nasopharyngeal cavity. Three isotropic fibers, for measuring of the fluence (rate) during therapy, were located within the nasopharyngeal tumor target area and one was manually positioned to monitor structures at risk in the shielded area. A flexible black silicon patch tailored to the patient's anatomy is attached to the applicator to shield the soft palate and oral cavity from the 652-nm laser light. Fourteen patients were included in the study, resulting in 26 fluence rate measurements in the risk volume (two failures). We observed a systematic reduction in fluence rate during therapy in 20 out of 26 illuminations, which may be related to photodynamic therapy-induced increased blood content, decreased oxygenation, or reduced scattering. Our findings demonstrate that the applicator was easily inserted into the nasopharynx. The average light distribution in the target area was reasonably uniform over the length of the applicator, thus giving an acceptably homogeneous illumination throughout the cavity. Shielding of the risk area was adequate. Large interpatient variations in fluence rate stress the need for in vivo dosimetry. This enables corrections to be made for differences in optical properties and geometry resulting in comparable amounts of light available for Foscan absorption.

Endovascular brachytherapy for the prevention of restenosis after femoropopliteal angioplasty. Results of the VARA Trial.

AIM: Endovascular brachytherapy (EBT) has been proposed as a method to prevent restenosis. We performed a prospective randomised multicenter study to determine its efficacy for prophylaxis of restenosis after femoropopliteal percutaneous transluminal angioplasty (PTA). METHODS: Patients with symptomatic stenotic or totally occluding lesions in the femoropopliteal artery were randomised to be treated with PTA plus EBT or PTA alone. In case of EBT, 14 Gy was applied by an 192Ir source to the vessel wall. Clinical examination, ankle-brachial pressure index (ABPI) and duplex ultrasound were planned after 6 and 12 months. The primary endpoint was significant restenosis of the treated segment at duplex ultrasound after 12 months. RESULTS: Fifty-three of the 60 patients who eventually met the inclusion criteria could be studied. After 12 months, restenosis rates were 44% (12/27) in the PTA group versus 35% (8/23) in the PTA + EBT group (c2 test, P=0.51). There was no difference in mandatory reintervention between the 2 groups. Overall, EBT resulted in an absolute risk reduction of significant restenosis of 9%, yet in patients with totally occlusive disease this reduction was 32%. CONCLUSIONS: This study suggests an effect of EBT on the occurrence of restenosis only after PTA of occluded femoropopliteal lesions. Due to a too small number of patients analysed this difference is not statistically significant.

Long term outcome after intracoronary beta radiation therapy.

OBJECTIVES: To determine the long term outcome after intracoronary beta radiation therapy (IRT). SETTING: Tertiary referral centre. METHODS: The rate of major adverse cardiac events (MACE) was retrospectively determined in 301 consecutive patients who were treated with IRT. MACE was defined as death, myocardial infarction, or any reintervention. Long term clinical outcome was obtained from an electronic database of hospital records and from questionnaires to the patients and referring physicians. Long term survival status was assessed by written inquiries to the municipal civil registries. RESULTS: The mean (SD) follow up was 3.6 (1.2) years. The cumulative incidence of MACE at six months was 19.1%, at one year 36.4%, and at four years 58.3%. The target lesion revascularisation (TLR) rate at six months was 12.9%, at one year 28.3%, and at four years 50.4%. From multivariate analysis, dose < 18 Gy was the most significant predictor of TLR. At four years the cumulative incidence of death was 3.8%, of myocardial infarction 13.4%, and of coronary artery bypass surgery 11.3%. Total vessel occlusion was documented in 12.3% of the patients. CONCLUSIONS: In the long term follow up of patients after IRT, there are increased adverse cardiac events beyond the first six months.

Stereotactic arc therapy for small elongated tumors using cones and collimator jaws; dosimetric and planning aspects.

Stereotactic arc treatment of small intracranial tumors is usually performed with arcs collimated by circular cones, resulting in treatment volumes which are basically spherical. For nonspherical lesions this results in a suboptimal dose distribution. Multiple isocenters may improve the dose conformity for these lesions, at the cost of large overdosages in the target volume. To achieve improved dose conformity as well as dose homogeneity, the linac jaws (with a minimum distance of 1.0 cm to the central beam axis) can routinely be used to block part of the circular beams. The purpose of this study was to investigate the feasibility of blocking cones with diameters as small as 1.0 cm and a minimum distance between the jaw and the central beam axis of 0.3 cm. First, the reproducibility in jaw positioning and resulting dose delivery on the treatment unit were assessed. Second, the accuracy of the TPS dose calculation for these small fields was established. Finally, clinically applied treatment plans using nonblocked cones were compared with plans using the partially blocked cones for several treatment sites. The reproducibility in dose delivery on our Varian Clinac 2300 C/D machines on the central beam axis is 0.8% (1 SD). The accuracy of the treatment planning system dose calculation algorithm is critically dependent on the used fits for the penumbra and the phantom scatter. The average deviation of calculated from measured dose on the central beam axis is -1.0%+/-1.4% (1 SD), which is clinically acceptable. Partial cone blocking results in improved dose distributions for elongated tumors, such as vestibular schwannoma and uveal melanoma. Multiple isocenters may be avoided. The technique is easy to implement and requires no additional workload.

Reno, a European postmarket surveillance registry, confirms effectiveness of coronary brachytherapy in routine clinical practice.

PURPOSE: To assess, by a European registry trial, the clinical event rate in patients with discrete stenotic lesions of coronary arteries (de novo or restenotic) in single or multiple vessels (native or bypass grafts) treated with beta-radiation. MATERIALS AND METHODS: Between April 1999 and September 2000, 1098 consecutive patients treated in 46 centers in Europe and the Middle East with the Novoste Beta-Cath System were included in Registry Novoste (RENO). RESULTS: Six-month follow-up data were obtained for 1085 patients. Of 1174 target lesions, 94.1% were located in native vessels and 5.9% in a bypass graft; 17.7% were de novo lesions, 4.1% were restenotic, and 77.7% were in-stent restenotic lesions. Intravascular brachytherapy was technically successful in 95.9% of lesions. Multisegmental irradiation, using a manual pullback stepping maneuver to treat longer lesions, was used in 16.3% of the procedures. The in-hospital rate of major adverse cardiac events was 1.8%. At 6 months, the rate was 18.7%. Angiographic follow-up was available for 70.4% of the patients. Nonocclusive restenosis was seen in 18.8% and total occlusion in 5.7% of patients. A combined end point for late (30-180 days) definitive or suspected target vessel closure was reached in 5.4%, but with only 2% of clinical events. Multivariate analysis was performed for major adverse cardiac events and late thrombosis. CONCLUSIONS: Data obtained from the multicenter RENO registry study, derived from a large cohort of unselected consecutive patients, suggest that the good results of recent randomized controlled clinical trials can be replicated in routine clinical practice.

A clinical evaluation of implants in irradiated oral cancer patients.

In this prospective study, we determined the effects of the time interval between irradiation and implant therapy, implant location, bone-resection surgery, and irradiation dose on implant survival. We analyzed the survival of 446 implants inserted after radiotherapy over a period of up to 14 years in 130 consecutive patients treated for oral cancer. The 10-year overall Kaplan-Meier implant survival percentage is 78%. The difference in survival percentages of implants inserted < 1 year and >/= 1 year after irradiation (76% and 81%, respectively) is not significant. We concluded that implant survival is significantly influenced by the location (maxilla or mandible, 59% and 85%, respectively; p = 0.001), by the incidence of bone-resection surgery in the jaw where the implant was installed (p = 0.04), and by the irradiation dose at the implant site (< 50 Gray or >/= 50 Gray, p = 0.05).

Routine intracoronary beta-irradiation. Acute and one year outcome in patients at high risk for recurrence of stenosis.

AIMS: Intracoronary radiation is a promising therapy potentially reducing restenosis following catheter-based interventions. Currently, only limited data on this treatment are available. The feasibility and outcome in daily routine practice, however, is unknown. METHODS AND RESULTS: In 100 consecutive patients, intracoronary beta-radiation was performed with a (90)Strontium system (Novoste Beta-Cathtrade mark) following angioplasty. Predominantly complex (73% type B2 and C) and long lesions (length 24.3+/-15.3 mm) were included (37% de novo, 19% restenotic and 44% in-stent restenotic lesions). Radiation success was 100%. Mean prescribed dose was 19.8+/-2.5 Gy. A pullback procedure was performed in 19% lesions. Geographic miss occurred in 8% lesions. Periprocedural thrombus formation occurred in four lesions, dissection in nine lesions. During hospital stay, no death, acute myocardial infarction, or repeat revascularization was observed. Major adverse cardiac events occurred predominantly between 6 and 12 months after the index procedure with major adverse cardiac event-free survival of 66% at 12 months (one death, 10 Q-wave myocardial infarctions, 23 target vessel revascularizations; ranked for worst event). CONCLUSION: Routine catheter-based intracoronary beta-radiation therapy after angioplasty is safe and feasible with a high acute procedural success. The clinical 1-year follow-up showed delayed occurrence of major adverse cardiac events between 6 and 12 months after the index procedure.

Initial observation regarding changes in vessel dimensions after balloon angioplasty and stenting followed by catheter-based beta-radiation. Is stenting necessary in the setting of catheter-based radiotherapy?

AIMS: We sought to compare the effect of intracoronary beta-radiation on the vessel dimensions in de novo lesions using three-dimensional intravascular ultrasound quantification after balloon angioplasty and stenting. METHODS AND RESULTS: Forty patients (44 vessels; 28 balloon angioplasty and 16 stenting) treated with catheter-based beta-radiation and 18 non-irradiated control patients (18 vessels; 10 balloon angioplasty and 8 stenting) were investigated by means of three-dimensional volumetric intravascular ultrasound analysis post-procedure and at 6-8 months follow-up. Total vessel (EEM) volume enlarged after both balloon angioplasty and stenting (+37 mm(3) vs +42 mm(3), P=ns), but vessel wall volume (plaque plus media) also increased similarly (+33 mm(3) vs +49 mm(3), P=ns) in the irradiated patients. Lumen volume remained unchanged in both groups (+3 mm(3) vs -7 mm(3), P=ns). In the stent-covered segments, neointima at follow-up was significantly smaller in the irradiated group than the control group (8 mm(3) vs 27 mm(3), P=0.001, respectively), but the total amount of tissue growth was similar in both groups (33 mm(3) vs 29 mm(3), P=ns). CONCLUSIONS: Intracoronary beta-radiation induces vessel enlargement after balloon angioplasty and/or stenting, accommodating tissue growth. Additional stenting may not play an important role in the prevention of constrictive remodelling in the setting of catheter-based intracoronary beta-radiotherapy.

Angiographical follow-up after radioactive "Cold Ends" stent implantation: a multicenter trial.

BACKGROUND: Radioactive stents with an activity of 0.75 to 12 microCi have shown >40% edge restenosis due to neointimal hyperplasia and negative remodeling. This trial evaluated whether radioactive Cold Ends stents might resolve edge restenosis by preventing remodeling at the injured extremities. METHODS AND RESULTS: The 25-mm long (15-mm radioactive center and 5-mm nonradioactive ends) Cold Ends stents had an activity of 3 to 12 microCi at implantation. Forty-three stents were implanted in 43 patients with de novo native coronary artery disease. Two procedural, 1 subacute, and 1 late stent thrombosis occurred. A restenosis rate of 22% was observed with a shift of the restenosis, usually occurring at the stent edges of radioactive stents, into the Cold Ends stents. The most severe restenosis occurred at the transition zone from radioactive to nonradioactive segments, a region located in dose fall-off. CONCLUSION: Cold Ends stents did not resolve edge restenosis.