Objective The positron generated at the dose deposition site by using high-energy carbon ions to hit the material annihilate with the negative electron in the material to release the gamma photon.The positron-emitting isotope (PEI) distributions in the target volume are activated significantly by carbon ions.Therefore, the mean values of positron emission tomography (PET) activity could be related to the delivered doses to the clinical target volume from carbon ion.This specialty can be used for the image registration fusion of the carbon ion treatment planning computed tomography (CT) and treatment verification PET-CT.After radiation in the almost same decay period, the relationship between the different target volume and the PET-CT SUV of different every single fraction dose can be found, then the range of SUV for the radiation target could be decided.So this PET-CT standardized uptake value (SUV) range can also provide a reference for the correlation and consistency in planning target dose verification and evaluation for the clinical trial.Methods The head phantom was used as a simulation of the real human body, the 1 cc, 4 cc, and 10 cc cube volume target contouring were done in the TPS, the 90 degree fixed carbon ion beams were delivered in different single fraction effective dose of 2.5 GyE, 5 GyE, and 8 GyE.After the beam delivery, later the PET-CT scanning was performed and parameters of scanning followed the trial regulation.The MIM Maestro software was used for the image processing and fusion to determine the maximum, minimum, average, and total values of SUV in the virtual clinical target volumes for the different single fraction dose.Results The results showed that for the same target volume, the SUV range of target had an approximate linear correlation with effective dose of target (P=0.000).The same effective dose for the different target volumes got the same SUV range (P>0.05).Conclusions For the carbon ion treatment plan, the SUV range from image registration and fusion of planning CT and PET-CT after treatment can be used to make an evaluation for accuracy of the dose distribution.And this method also could be used in the hyper-fraction treatment plan.In the SUV range research of different decay periods, the similar method can be performed for the exploration.

Objective: To verify the safety and efficacy of IONTRIS particle therapy system (IONTRIS) in clinical implementation. Methods: Between 6.2014 and 8.2014, a total of 35 patients were enrolled into this trial: 31 males and 4 females with a median age of 69 yrs (range 39-80). Ten patients had locally recurrent head and neck tumors after surgery, 4 cases with thoracic malignancies, 1 case with hepatocellular carcinoma, 1 case with retroperitoneal sarcoma, and 19 cases with non-metastatic prostate carcinomas. Phantom dose verification was mandatory for each field before the start of radiation. Results: Twenty-two patients received carbon ion and 13 had proton irradiation. With a median follow-up time of 1 year, all patients were alive. Among the 16 patients with head and neck, thoracic, and abdominal/pelvic tumors, 2, 1, 12, and 1 cases developed complete response, partial response, stable disease, or disease progression, respectively. Progression-free survival rate was 93.8% (15/16). Among the 19 patients with prostate cancer, biological-recurrence free survival was 100%. Particle therapy was well tolerated in all 35 patients. Twenty-five patients (71.4%) experienced 33 grade 1 acute adverse effects, which subsided at 1 year follow-up. Six (17.1%) patients developed grade 1 late adverse effects. No significant change in ECOG or body weight was observed. Conclusions IONTRIS is safe and effective for clinical use. However, long term follow-up is needed to observe the late toxicity and long term result.