Particle therapyHelical tomotherapy and intensity modulated proton therapy in the treatment of dominant intraprostatic lesion: A treament planning comparison
Section snippets
Patients and imaging
Seven consecutive patients (median PSA: 6.26 ng/ml; median age: 76 years) with intermediate/high risk prostate cancer previously treated at San Raffaele Scientific Institute with HT were considered. All patients underwent T2-weighted, T1-weighted and DWI MRI, which showed evidence of DIL in the peripheral zone. Patients had comfortably full bladder and empty rectum for CT and MRI acquisitions. CT (GE Medical Systems) and MRI (1.5-Tesla Achieva, Philips Medical System) images were performed with 4
Target volumes
In general, HT and IMPT generated satisfactory dose distributions in PTV and PTVDIL (see Fig. 1). Target coverage parameters for the PTV (V95% and D99%) were on average significantly better in IMPT. In all patients but one, D99% was in favor of protons by 1.5–3 Gy; V107% and D1% were in favor of IMPT by 0–6.5 Gy (p > 0.05) and 1.5–2.5 Gy (p < 0.05), respectively.
Both techniques reached a median PTVDIL dose of 100 Gy and similar conformity (CI: HT = 1.49, IMPT = 1.44) and homogeneity (HI: HT = 0.24, IMPT =
Discussion
The interest for high dose escalation in the intraprostatic lesion is based on studies such as the one by Cellini et al. [3] on 118 patients irradiated at 65–70 Gy. The results of this study demonstrate that all recurrences within the prostate originated in the primary tumor site. Pucar et al. [4] confirmed the results by Cellini showing that the intra-prostatic relapse after external radiotherapy occurs at the site of primary dominant lesions. Recently, Maggio et al. [9] found that the median
Conflict of interest
None.
References (19)
- et al.
Unilateral prostate cancer cannot be accurately predicted in low-risk patients
Int J Radiat Oncol Biol Phys
(2010) - et al.
Higher than-conventional radiation doses in localized prostate cancer treatment: a meta-analysis of randomized, controlled trials
Int J Radiat Oncol Biol Phys
(2009) - et al.
Analysis of intraprostatic failures in patients treated with hormonal therapy and radiotherapy: implications for conformal therapy planning
Int J Radiat Oncol Biol Phys
(2002) - et al.
Clinically significant prostate cancer local recurrence after radiation therapy occurs at the site of primary tumor: magnetic resonance imaging and step-section pathology evidence
Int J Radiat Oncol Biol Phys
(2007) - et al.
Incorporating clinical measurements of hypoxia into tumor local control modelling of prostate cancer: implications for the α/β ratio
Int J Radiat Oncol Biol Phys
(2003) - et al.
Phase I–II study of hypofractionated simultaneous integrated boost with tomotherapy for prostate cancer
Int J Radiat Oncol Biol Phys
(2009) - et al.
Sparing the penile bulb in the radical irradiation of clinically localized prostate carcinoma: a comparison between MRI and CT prostatic apex definition in 3DCRT. Linac-IMRT and helical tomotherapy
Radiother Oncol
(2009) - et al.
Fit of a generalized Lyman normal tissue complication probability (NTCP) model to grade ⩾ 2 late rectal toxicity data from patients treated on protocol 94–06
Int J Radiat Oncol Biol Phys
(2007) - et al.
Rectal bleeding, fecal incontinence, and high stool frequency after conformal radiotherapy for prostate cancer: normal tissue complication probability modeling
Int J Radiat Oncol Biol Phys.
(2006)
Cited by (16)
Combining high dose external beam radiotherapy with a simultaneous integrated boost to the dominant intraprostatic lesion: Analysis of genito-urinary and rectal toxicityToxicity after integrated boost for prostate cancer
2016, Radiotherapy and OncologyCitation Excerpt :The purpose of the present study was to evaluate the impact of a SIB to the DIL on acute and late GU and rectal toxicity in a representative patient group with long follow up. Different reports have shown that dose escalation to the DIL is technically feasible [11,12,29–33] and deliverable [9,34] with an expected improved therapeutic ratio. In a recent study performed by Riches et al. a plan comparison was made between a uniform 74 Gy-IMRT plan and 74 Gy-IMRT plan with an additional 8 Gy focal boost.
What can particle therapy add to the treatment of prostate cancer?
2016, Physica MedicaCitation Excerpt :This is still a developing field in XRT too, where both the volume definition and the boost level are not established yet, even though several hundreds of patient have been treated with this approach [37]. To our knowledge, the investigation of boost to an intraprostatic lesion in proton therapy is limited to a treatment planning study [38], where 5-field intensity modulated proton therapy (IMPT) and helical tomotherapy (HT) were compared. The study showed that, even though both techniques were able to comply with the dosimetric constraints set in the planning protocol, IMPT achieved a better target coverage and, at the same time, a better rectal sparing, translating into an NTCP gain between 3% and 8%, depending on the model parameters.
The model-based approach to clinical studies in particle radiotherapy - A new concept in evidence based radiation oncology?
2013, Radiotherapy and Oncology