For targeted radionuclide therapies, treatment planning usually consists of theadministration of standard activities without accounting for the patient-specific activitydistribution, pharmacokinetics and dosimetry to organs at risk. The OEDIPE software is auser-friendly interface which has an automation level suitable for performing personalizedMonte Carlo 3D dosimetry for diagnostic and therapeutic radionuclide administrations. Meanabsorbed doses to regions of interest (ROIs), isodose curves superimposed on apersonalized anatomical model of the patient and dose-volume histograms can be extractedfrom the absorbed dose 3D distribution. Moreover, to account for the differences inradiosensitivity between tumoral and healthy tissues, additional functionalities have beenimplemented to calculate the 3D distribution of the biologically effective dose (BED),mean BEDs to ROIs, isoBED curves and BED-volume histograms along with the EquivalentUniform Biologically Effective Dose (EUD) to ROIs. Finally, optimization tools areavailable for treatment planning optimization using either the absorbed dose or BEDdistributions. These tools enable one to calculate the maximal injectable activity whichmeets tolerance criteria to organs at risk for a chosen fractionation protocol. This paperdescribes the functionalities available in the latest version of the OEDIPE software toperform personalized Monte Carlo dosimetry and treatment planning optimization in targetedradionuclide therapies.

Purpose: Comparison of prostate seed implant treatment plans is currently based on evaluation of dose-volume histograms and doses to the tumour and normal structures. However, these do not account for effects of varying dose-rate, tumour repopulation and other biological effects. In this work, incorporation of the radiobiological response is used to obtain a more inclusive and clinically relevant treatment plan evaluation tool.

Materials and Methods: Ten patients were evaluated. For each patient, six different treatment plans were created on the Prowess system. Plans with iodine-125 used a prescription dose of 145 Gy while plans with palladium-103 used 115 Gy. The biologically effective dose was used together with the tumour control probability and the normal tissue complication probabilities of urethra, bladder, rectum and surrounding tissue to evaluate the effectiveness of each treatment plan. Results from the radiobiological evaluation were compared to standard dose quantifiers.

Results: The use of response probabilities is seen to provide a simpler means of treatment evaluation compared to standard dose quantifiers. This allows for different treatment plans to be quickly compared. Additionally, the use of radiobiologically-based plan evaluation allows for optimisation of seed type and initial seed strengths to find the ideal balance of TCP and NTCP.

Conclusion: The goal of this work was to incorporate the biological response to obtain a more complete and clinically relevant treatment plan evaluation tool. This resulted in a simpler means of plan evaluation that may be used to compare and optimise prostate seed implant treatment plans.

A workshop dedicated to cancer risks associated withlow-dose internal contamination was organised in March 2011, inParis, in the framework of the DoReMi (Low Dose Research towardsMultidisciplinary Integration) European Network of Excellence. Theaim was to identify the best epidemiological studies that providean opportunity to develop a multidisciplinary approach to improvethe evaluation of the cancer risk associated with internal contamination.This workshop provided an opportunity for in-depth discussions betweenresearchers working in different fields including (but not limitedto) epidemiology, dosimetry, biology and toxicology. Discussionsconfirmed the importance of research on the health effects of internalcontamination. Several existing epidemiological studies providea real possibility to improve the quantification of cancer riskassociated with internal emitters. Areas for future multidisciplinary collaborationswere identified, that should allow feasibility studies to be carriedout in the near future. The goal of this paper is to present anoverview of the presentations and discussions that took place duringthis workshop.

ACORRN was established in response to the sharp decline in the number of clinical academics and radiation biologists over the past ten years. The network was launched in 2005 to help revitalise radiotherapy and radiobiology research in the UK by networking and supporting individuals and groups. ACORRN is governed by a Steering Committee, comprising members of the UK research community and receives advice from an International Scientific Advisory Committee. Since its inception ACORRN has established a national office to support researchers, providing practical advice and assistance on funding streams, grant applications, ethics legislation and approval as well as facilitating collaborative research meetings. ACORRN has also developed several working parties, research interest groups and an interactive website (www.acorrn.org) which is actively used within the research community. The website serves as a hub of information allowing researchers to locate and contact each other and search for information on projects, institutions and opportunities, quickly and easily.

The Academic Clinical Oncology and Radiobiology Research Network (ACORRN) was launched in 2005 by the National Cancer Research Institute (NCRI) to revitalise radiotherapy (RTX) and radiobiology (RB) research in the UK [Price P. Clin Oncol 2005; 17:299–304]. The network was established in response to the sharp decline over the past 10 years in the number of clinical academics and radiation biologists. The decline had left the UK's radiotherapy and RB communities with insufficient infrastructure and capacity, despite radiotherapy experiencing one of the most rapid advances in technology and computerisation of any field in medicine.

Des cellules d’un cancer humain (mélanome) particulièrement résistant à des doses classiques de radiothérapie médicale (rayons X de haute énergie) ont été irradiées avec des neutrons de 14 MeV à des doses étagées de 5 centiGrays (cGy) jusqu’à 1,12 Gray (Gy), à deux débits de doses, l’un très faible (0,8 mGy mn-1), l’autre modéré (40 mGy mn-1). L’effet biologique a été étudié par deux techniques : analyse de la survie cellulaire et des anomalies chromosomiques. Un aspect inhabituel de la forme de la courbe de survie a été mis en évidence au très faible débit de dose : mort cellulaire aiguë à 5 cGy suivie d’un plateau de survie de 10 à 32,5 cGy. Le taux d’aberrations chromosomiques induites suit lui-même un plateau au très faible débit de dose, de 10 à 30 cGy. Ces phénomènes disparaissent à plus fort débit de dose, ce qui suggère l’existence d’un seuil de déclenchement de la réparation cellulaire et une saturation vers 35 cGy. Ces résultats ont un intérêt pour la radiobiologie des neutrons et la radioprotection.

An ensemble of new techniques has been developed to study cell metabolism. These include: CO2 production monitoring, cell irradiation with soft X rays produced with a laser-plasma source, and study of oscillations in cell metabolic activity via spectral analysis of experimental records. Soft X-rays at about 0.9 keV, with a very low penetration in biological material, were chosen to produce damages at the metabolic level, without great interference with DNA activity. The use of a laser-plasma source allowed a fast deposition of high doses. Monitoring of CO2 production allowed us to measure cell metabolic response immediately after irradiation in a continuous and noninvasive way. Also a simple model was developed to calculate X-ray doses delivered to the different cell compartments following a Lambert–Bouguet–Beer law. Results obtained on Saccharomyces cerevisiae yeast cells in experiments performed at Rutherford Appleton Laboratory are presented.

Summary

Background and objective: Irradiation of intraoperative cell salvage blood has recently been used to inactivate tumour cells before retransfusion, during cancer surgery. No information is available about a potential inflammatory response of the recipient to the retransfusion of irradiated intraoperative cell salvage blood. This pilot study was conducted to investigate the possible release of the pro-inflammatory mediators, tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), eotaxin and monocyte chemo-attractant protein-1 (MCP-1), in the serum of recipients by intraoperative retransfusion of irradiated intraoperative cell salvage blood.

Methods: Nine patients undergoing gynaecological cancer surgery were included in this study. Intraoperative cell salvage blood was irradiated with 50 Gy and retransfused to the patient. Serum and intraoperative cell salvage blood concentrations of TNF-α, IL-1β, eotaxin and MCP-1 were repeatedly analysed before and after retransfusion, respectively before and after irradiation.

Results: Traces of mediators were detected in intraoperative cell salvage blood but no increase due to irradiation was observed. Following transfusion of intraoperative cell salvage blood, minute quantities (all <30 pg mL−1) of mediators were detected in the serum of patients. However, there was no significant upregulation compared to serum values before retransfusion.

Conclusions: These results provide evidence that retransfusion of irradiated intraoperative cell salvage blood might represent a blood-saving strategy in cancer surgery without an immunological inflammatory response as shown by a lack of upregulation of inflammatory mediators.