Interstitial pulsed-dose-rate brachytherapy for the treatment of squamous cell anal carcinoma: A retrospective single institution analysis.

OBJECTIVE: To examine the outcome of patients receiving interstitial pulsed-dose-rate brachytherapy (PDR-BT) after pelvic radiation therapy for treatment of an anal squamous cell carcinoma. METHODS AND MATERIALS: Twenty-one patients were identified: 13, six, and two with stages I, II, and III tumors, respectively. After receiving received pelvic irradiation +/- concurrent chemotherapy, patients were delivered a PDR-BT boost to the residual tumor, with intention to deliver a minimal total dose of 60 Gy. The greatest dimension of residual tumor at the time of brachytherapy procedure was 12.5 mm (range: 0-20 mm). Brachytherapy implantation was performed according to the Paris system, only one plane implant being used. RESULTS: Median dose delivered through BT was 20 Gy (range: 10-30 Gy). Median number of pulses was 48 (range: 20-80 pulses). Median treated volume was 9 cm(3) (range: 5-16 cm(3)). Median dose per pulse was 40 cGy (range: 37.5-50 cGy). No Grade 3 or more acute toxicity was reported. No Grade 3 or more delayed toxicity was seen among 18 patients with more than 6 months follow-up. Median followup was 47 months (range: 6-73 months). Twenty patients (95%) were alive at last follow-up. Tumor relapses were experienced in four patients (19%), including local relapse in three patients (14%). CONCLUSION: With almost 4 years median followup, this study confirms previous data suggesting that PDR-BT is effective and safe in this indication. Local control rate and toxicity were in the range of what was seen with continuous low-dose-rate BT.

Clinical Experience with Pulse Dose Rate Brachytherapy for Conservative Treatment of Penile Carcinoma and Comparison with Historical Data of Low Dose Rate Brachytherapy.

AIMS: To assess the efficacy of pulse dose rate (PDR) interstitial brachytherapy in the treatment of carcinoma of the penis and to compare with historical data of low dose rate (LDR) brachytherapy. MATERIALS AND METHODS: We reviewed the clinical records of 27 consecutive patients treated in our institution with exclusive PDR brachytherapy for a squamous cell carcinoma of the penis. The median tumour greatest diameter was 20 mm (range: 10-50 mm). Twenty-three patients (85%) had tumours limited to the glans and/or prepuce and four patients (15%) also had inguinal lymph node metastases. Implantations were carried out according to the Paris system and treatments were delivered with PDR brachytherapy. RESULTS: The median brachytherapy dose was 60 Gy (range: 60-70 Gy). The median treated volume was 28 cm(3) (range: 8-62 cm(3)). The median reference isodose rate was 0.4 Gy/pulse/h (range: 0.4-0.5 Gy/pulse/h). The median number of pulses was 150 (range: 120-175 pulses). With a median follow-up of 33 months (range: 6-64 months), tumour relapses in the penis were reported in four patients (15%). All patients with only local relapse (n = 3) were successfully salvaged with partial amputation. The estimated overall survival rate at 3 years was 95% (95% confidence interval: 83-100%). No grade 3 or more acute reaction was observed. Delayed ulcerations and stenoses requiring at least one meatal dilatation were reported in two (9%) and five (22%) patients without local relapse. The treated volume was significantly correlated to the risk of clinically relevant delayed toxicity. CONCLUSIONS: The efficacy/toxicity results of PDR brachytherapy for the treatment of penile carcinoma are comparable with those obtained with LDR brachytherapy in historical cohorts.

[Pulsed-dose rate brachytherapy in cervical cancers: why, how?]. / Curiethérapie de débit de dose pulsé dans les cancers du col utérin : pourquoi, comment ?

The end of the production of 192 iridium wires terminates low dose rate brachytherapy and requires to move towards pulsed-dose rate or high-dose rate brachytherapy. In the case of gynecological cancers, technical alternatives exist, and many teams have already taken the step of pulsed-dose rate for scientific reasons. Using a projector source is indeed a prerequisite for 3D brachytherapy, which gradually installs as a standard treatment in the treatment of cervical cancers. For other centers, this change implies beyond investments in equipment and training, organizational consequences to ensure quality.

High flux of relativistic electrons produced in femtosecond laser-thin foil target interactions: characterization with nuclear techniques.

We present a protocol to characterize the high energy electron beam emitted in the interaction of an ultraintense laser with matter at intensities higher than 10(19) W cm(-2). The electron energies and angular distributions are determined as well as the total number of electrons produced above a 10 MeV threshold. This protocol is based on measurements with an electron spectrometer and nuclear activation techniques, combined with Monte Carlo simulations based on the GEANT3 code. The method is detailed and exemplified with data obtained with polypropylene and copper thin solid targets at a laser intensity of 2x10(19) W cm(-2). Special care is taken of the different sources of uncertainties. In particular, the reproducibility of the laser shots is considered.