Implementation of HybridArc treatment technique in preoperative radiotherapy of rectal cancer: dose patterns in target lesions and organs at risk as compared to helical Tomotherapy and RapidArc.

PURPOSE: HybridArc is a novel treatment technique blending aperture-enhanced optimized arcs with discrete IMRT-elements, allowing selection of arcs with a set of static IMRT-beams. This study compared this new technique to helical Tomotherapy, and RapidArc, in preoperative radiotherapy of rectal cancer. MATERIAL AND METHODS: Twelve rectal cancer patients treated consecutively with Tomotherapy Hi-Art II system were simulated with HybridArc and RapidArc. Treatment plans were designed to deliver homogeneous dose of 46.0Gy to mesorectum and draining lymph nodes, with a simultaneous-integrated-boost to the primary tumor up to a total dose of 55.2Gy. Planning objectives were 95% of prescribed dose to 95% of PTVs, while minimizing the volume of small bowel receiving more than 15Gy (V15) and the mean bladder dose. Dose gradient towards simultaneous-integrated-boost (GI), calculated by dividing the volume receiving more then 52.4Gy (95% of PTV55.2Gy)to the volume of PTV55.2Gy, was kept below 1.5. Mean beam-on time and amount of MUs were also analyzed. RESULTS: PTV swere adequately covered by all plans. Significant advantage was found for Tomotherapy in sparing small bowel (V15 = 112.7cm(3)SD73.4cm(3)) compared to RapidArc (133.4cm(3)SD75.3cm(3)) and HybridArc (143.7cm(3)SD74.4cm(3)) (p < 0.01). The mean bladder dose was better with RapidArc (20.6GySD2.2Gy) compared to HybridArc (24.2Gy SD4.3Gy) and Tomotherapy (23.0GySD4.7Gy) (p < 0.01). The mean beam-on time was significantly lower (p < 0.01) for HybridArc (2.7min SD0.8) and RapidArc (2.5min SD0.5) compared to Tomotherapy (11.0min SD0.7). The total amount of MUs was significantly (p < 0.01) lower for RapidArc (547SD44)compared to HybridArc (949 SD153). CONCLUSIONS: HybridArc is a feasible solution for preoperative RT with a simultaneous-integrated-boost in rectal cancer patients. It achieved similar PTV coverage with significant lower beam-on time, but less efficient in sparing small bowel and bladder compared to Tomotherapy and RapidArc. The added value of HybridArc is that the treatment modality can be implemented on every LINAC equipped with Dynamic-Conform-Arc and IMRT treatment techniques, while maintaining the same QA-schemes.

Consultation of parents in actual end-of-life decision-making in neonates and infants.

The objective of this study was to assess how frequently end-of-life decisions (ELDs) with a possible or certain life-shortening effect in neonates and infants were discussed with parents, and to determine if consultation of parents was associated with the type of ELD, (clinical) characteristics of the patient, and socio-demographic characteristics of the physician. A retrospective study of all deaths of live born infants under the age of one year was conducted in Flanders, Belgium. For 292 of all 298 deaths in a 1-year period (between 1 August 1999 and 31 July 2000) the attending physician could be identified and was sent an anonymous questionnaire. All cases with an ELD and containing information regarding the consultation of parents were included. The response rate was 87% (253/292). In 136 out of 143 cases, an ELD was made and information on the consultation of parents was obtained. According to the physician, the ELD was discussed with parents in 84% (114/136) of cases. The smaller the gestational age of the infant, the more the parental request for an ELD was explicit (p=0.025). When parents were not consulted, the ELD was based more frequently on the fact that the infant had no chance to survive and less on quality-of-life considerations (p=0.001); the estimated shortening of life due to the ELD was small in all cases, but significantly smaller (p<0.001) if parents were not consulted. It is concluded that the majority of parents of children dying under the age of one year are consulted in ELD-making, especially for decisions based on quality-of-life considerations (95.1%). Parents of infants with a small gestational age more often explicitly requested an ELD.

The use of drugs with a life-shortening effect in end-of-life care in neonates and infants.

OBJECTIVE: The purpose was to describe the use of drugs with a possible or certain life-shortening effect in end-of-life care in infants and to evaluate the possibly lethal effect. DESIGN: For 292/298 deaths of live born infants (<1 year), in a 1-year period (between 1 August 1999 and 31 July 2000) in Flanders, Belgium, the attending physician could be identified and was sent an anonymous questionnaire. The questionnaires relating to deaths directly preceded by the administration of drugs were reviewed by a multi-disciplinary panel. RESULTS: The response rate was 86.6% (253/292). In 57 cases (22.5%), drugs were administered directly before death. In 17/57 cases, the physician explicitly intended to hasten death. In 16/17 cases information about the drug(s) was available: opioids were administered in 14, a muscle relaxant in 5 and potassium chloride in 3 cases. In 13 cases where the lethal effect could be evaluated, the panel judged that the drugs were effective in hastening death in 10 cases. In most cases the estimated life-shortening was <24 h. In 40/57 cases the physician administered drugs to alleviate pain and/or symptoms, taking into account a possible life-shortening effect without explicitly intending it. Opioids were administered in all 30 cases where information about the drug(s) was supplied. In 13 cases the lethal effect could be evaluated, and in 6 cases the panel judged that the drugs had hastened death. CONCLUSIONS: When life-shortening was explicitly intended, (dosages of) drugs were likely to be lethal. Drugs administered also clearly hastened death in some cases where life-shortening was not explicitly intended.