RESUMO
The purpose of this study is to discuss how to use an external radio-opaque template in the Diffusing Alpha-emitters Radiation Therapy (DaRT) technique's pre-planning and treatment stages. This device would help to determine the proper number of sources for tumour coverage, accounting for subcutaneous invasion and augmenting DaRT safety. The procedure will be carried out in a first phase on a phantom and then applied to a clinical case. A typical DaRT procedure workflow comprises steps like tumour measurements and delineation, source number assessment, and therapy administration. As a first step, an adhesive fiberglass mesh (spaced by 2 mm) tape was applied on the skin of the patient and employed as frame of reference. A physician contoured the lesion and marked the entrance points for the needles with a radio opaque ink marker. According to the radio opaque marks and metabolic uptake the clinical target volume was defined, and with a commercial brachytherapy treatment planning system (TPS) it was possible to simulate and adjust the spatial seeds distribution. After the implant procedure a CT was again performed to check the agreement between simulations and seeds positions. With the procedure described above it was possible to simulate a DaRT procedure on a phantom in order to train physicians and subsequently apply the novel approach on patients, outlining the major issues involved in the technique. The present work innovates and supports DaRT technique for the treatment of cutaneous cancers, improving its efficacy and safety.
RESUMO
AIMS AND BACKGROUND: The National Working Group on Prostate Radiotherapy of AIRO (Associazione Italiana Radioterapia Oncologica, Italian Association of Radiotherapeutic Oncology) was established in March 2001. A retrospective multi-center survey was performed to analyze the patterns of care for prostate cancer patients treated with postoperative radiotherapy following radical prostatectomy in Italy with regard to the year 2000. MATERIALS AND METHODS: A structured questionnaire was mailed to 47 Italian radiotherapy centers to assess patient accrual in the postoperative setting in the interval comprised between period January-December 2000. Numbers of patients treated for different stages, specific prognostic factors indicating the need for adjuvant radiotherapy, fractionation schedules and prescription doses were acquired as well as other clinically important factors such as radiotherapy timing and the use of hormone therapy. More technical features of the treatment, such as patient positioning, mode of simulation, typical field setup and dose prescription criteria were also included in the questionnaire. RESULTS: The questionnaire was returned by 24 radiotherapy Institutions (51%) with a total number of 470 patients treated postoperatively in the year 2000. An average of about 20 patients were enrolled by each radiotherapy center. The age range was 45-81 years. Radiotherapy was delivered within 6 months of radical prostatectomy in 297 patients (65.4%) (mean, 3.4 months). In 157 (34.6%), the treatment was delivered as a salvage approach for biochemical or micro-macroscopic recurrence. Most of patients had locally advanced stage disease (pT3-pT4) (76%). Unfavorable prognostic factors, such as positive margins, capsular invasion, Gleason pattern score > 7 were present in about 50% of patients. CONCLUSIONS: The study confirmed that important risk factors for recurrences are present in a significant percentage of patients treated by radical prostatectomy. The number of patients that would benefit from adjuvant radiotherapy is therefore potentially very large. Future prospective studies should be conducted to assess and to clarify the respective roles of adjuvant and salvage radiotherapy in prostate cancer patients.
