Comparative Treatment Planning on Localized Prostate Carcinoma

Abstract

IMRT enabled dose reductions to OARs in the medium dose range compared to 3-D conformal radiotherapy. A rather simple two-field proton-based treatment technique further reduced doses to OARs compared to photon-beam radiotherapy. The advantageous dose distribution of proton-beam therapy for prostate cancer may result in reduced side effects, which needs to be confirmed in clinical studies.

Radiotherapy Treatment of Early-Stage Prostate Cancer with IMRT and Protons: A Treatment Planning Comparison

“…The 3D-conformal proton therapy plans were optimized for actual treatment courses delivered at MGH, and used standard strategies to minimize the effect of the delivery uncertainties. The reduction, with 3D-CPT vs. IMRT, of the mean dose to rectum (by 26%, on average) and bladder (by 20%) was not as significant as previously reported (12,13). While IMRT achieved significant improvement in bladder sparing (e.g., V 60 , V 70 ), neither appeared to have a clear advantage in rectal sparing in the high-dose range (over 70% of the GTV prescription).…”

“…Intensity-modulation (with either photons or protons, using the same 5-field configuration) improved target dose homogeneity, reduced normal tissue irradiation in the low and medium range (≤70% of the target dose), and allowed for escalation of the median target dose from 81 to 99 Gy. More recently, Mock et al compared treatment plans for 3D-CPT and photon IMRT for 5 patients, using the prescription dose of 70 Gy (13). The difference in the rectum and bladder volumes that received 70% of the prescription dose was found to be insignificant, while the mean doses to healthy organs were reduced by between 40% and 80% with protons.…”

“…Cella et al compared 3D-conformal and intensity-modulated proton and photon plans for a single case of prostate cancer (12); and Mock et al compared 3D-conformal photon and proton plans with photon IMRT for 5 patients (13). However, the proton range uncertainty was not taken into account in the design of treatment plans.…”

A review of the impact of photon and proton external beam radiotherapy treatment modalities on the dose distribution in field and out-of-field; implications for the long-term morbidity of cancer survivors

“…The maximum dose in the different OARs for conventional technique is much higher than for the other techniques. For proton beams the data varies to a large extent and no general conclusion can [9] Hypopharynx Parotid 3DCRT, protons (scanned) 5 Pirzkall et al [56] mainly H&N Spinal cord 3DCRT 9 Lomax et al [52] H&N Several organs Standard photons, protons (scanned) 4 Lomax et al [53] Breast Lung, heart Protons (scanned) 1 Johansson et al [51] Breast Lung, heart Standard, protons (scanned) 11 Cella et al [8] Prostate Rectum 3DCRT, protons (scanned) 1 Mock et al [54] Prostate Rectal wall 3DCRT, protons (passive) 5 Aoyama et al [49] Prostate Rectal wall 3DCRT, tomotherapy 5 Johansson et al [50] Rectal ca Small bowel 3DCRT, protons (scanned) 16 Lomax et al [52] Pelvic Several organs Standard photons, protons 4 Weber et al [12] Paraspinal Several organs Protons (scanned) 5 Mu et al [11] Spinal Several organs 3DCRT, protons (scanned) 5…”

The effects of motion on the dose distribution of proton radiotherapy for prostate cancer

“…The proton dose distributions are similar or better in the high‐dose region, depending on the lateral penumbra of the proton beam. ( 5 – 6 ) The applied dose distributions have similar dependencies on interfractional anatomic motions as dose distributions by IMRT. ( 7 ) According to existing planning studies, ( 8 – 10 ) intensity‐modulated proton radiotherapy (IMPT) using pencil beam scanning techniques (PBS) can further improve the dose distributions achieved by passively scattered protons, and can give superior dose distributions than current IMRT techniques.…”