NTCP modeling analysis of acute hematologic toxicity in whole pelvic radiation therapy for gynecologic malignancies – A dosimetric comparison of IMRT and spot-scanning proton therapy (SSPT)

Yoshimura, Takaaki; Kinoshita, Rumiko; Onodera, Shunsuke; Toramatsu, Chie; Suzuki, Ryusuke; Ito, Yoichi M.; Sugiyama, Takao; Matsuura, Tetsuya; Matsuzaki, Y; Umegaki, Kikuo; Shirato, Hiroki; Shimizu, Satoru

doi:10.1016/j.ejmp.2016.08.007

Cited by 17 publications

(27 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The total scores are assigned 100 points, with the specific allocation is as follows: S T metrics [1][2][3][4] with total points of 24 are used to calculate the points of CTV dose coverage [V46.8Gy (%), V50 Gy (%)], conformity number (CN) and homogeneity index (HI). The rest 76 points are S O metrics [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] are assigned to specific dosevolume parameters of five OARs, where rectum, bowel, bladder, sigmoid and femoral heads shared 23, 22, 15, 9 and 7 points, respectively. The details of score points are shown in Table 2.…”

Section: Quick Plan Reviewmentioning

confidence: 99%

“…As an advanced modality of radiotherapy for intensity modulated radiation therapy (IMRT) combined with an image guiding system, helical tomotherapy (HT) has been proven to be efficient for cervical cancer [2]. Due to the unique physical characteristic of Bragg peakand intensity modulated proton therapy (IMPT) would offer the best sparing healthy tissue as compared with IMRT, volumetric modulated arc therapy (VMAT), and HT, while maintaining excellent target coverage or conformity [3][4][5]. HT and IMPT share standard uncertainties in treatment delivery, including target definition, target motion, normal tissue motion, and patient setup uncertainties, which sets the margin from the clinical target volume (CTV) to planning target volume (PTV) based on clinical experience in the process of the radiotherapy [6].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of plan quality and robustness of IMPT and helical IMRT for cervical cancer

Shang

Wang

et al. 2020

Radiat Oncol

View full text Add to dashboard Cite

Background: Both plan quality and robustness were investigated through comparing some dosimetric metrics between intensity modulated proton therapy (IMPT) and helical tomotherapy based intensity modulated radiotherapy (IMRT) for cervical cancer. Methods: Both a spot-scanning robust (SRO) IMPT plan and a helical tomotherapy robust (TRO) IMRT plan were generated for each of 18 patients. In order to evaluate the quality of nominal plans without dose perturbations, planning scores (PS) on clinical target volume (CTV) and five organs at risk (OARs) based on clinical experience, and normal tissue complication probabilities (NTCP) of rectum and sigmoid were calculated based on Lyman-Kutcher-Burman (LKB) model. Dose volume histogram bands width (DVHBW) were calculated in 28 perturbed scenarios to evaluate plan robustness. Results: Compared with TRO, the average scores of SRO nominal plans were higher in target metrics [V 46.8Gy , V 50Gy , Conformity and Homogeneity](16.5 vs. 15.1), and in OARs metrics (60.9 vs. 53.3), including bladder [V 35 ,V 45 , D mean , D 2cc ], rectum [V 40 ,V 45 ,D 2cc ,D max ], bowel [V 35 ,V 40 ,V 45 , D max ], sigmoid [V 40 ,D max ] and femoral heads [V 30 ,D max ]. Meanwhile, NTCP calculation showed that the toxicities of rectum and sigmoid in SRO were lower than those in TRO (rectum: 2.8% vs. 4.8%, p < 0.05; sigmoid: 5.2% vs. 5.7%, p < 0.05). DVHBW in target coverage for the SRO plan was smaller than that for the TRO plan (0.6% vs. 2.1%), which means that the SRO plan generated a more robust plan in target. Conclusion: Better CTV coverage and OAR Sparing were obtained in SRO nominal plan. Based on NTCP calculation, SRO was expected to allow a small reduction in rectal toxicity. Furthermore, SRO generated a more robust plan in CTV target coverage.

show abstract

Section: Quick Plan Reviewmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evaluation of plan quality and robustness of IMPT and helical IMRT for cervical cancer

Shang

Wang

et al. 2020

Radiat Oncol

View full text Add to dashboard Cite

show abstract

“…Dosimetric studies have shown a potential sparing of bone marrow by spot-scanning PBT [ 22 , 23 ]. In previous work we conducted an in silico study in 13 postoperative gynecologic malignancy patients.…”

Section: Discussionmentioning

confidence: 99%

Prospective study to evaluate the safety of the world-first spot-scanning dedicated, small 360-degree gantry, synchrotron-based proton beam therapy system

Nishioka

Prayongrat

Ono

et al. 2018

Journal of Radiation Research

Self Cite

View full text Add to dashboard Cite

This is a report of a single-institution prospective study evaluating the safety of a spot-scanning dedicated, small 360-degree gantry, synchrotron-based proton beam therapy (PBT) system. Data collection was performed for 56 patients with 59 treatment sites who received proton beam therapy at Hokkaido University Hospital between March 2014 and July 2015. Forty-one patients were male and 15 were female. The median age was 66 years. The primary lesion sites were prostate (n = 17), bone/soft tissue (n = 10), liver (n = 7), lung (n = 6), central nervous system (n = 5), colon (n = 2), pancreas (n = 2), kidney (n = 2) and others (n = 5). Chemotherapy was administered in 11 patients. The prescribed total dose was from 20 to 76 GyE (Radiobiological equivalent dose, RBE = 1.1), with the median dose of 65 GyE in 4 to 35 fractions. No PBT-related Common Terminology Criteria for Adverse Events Grade 4 or 5 toxicities were observed; the incidence of early PBT-related Grade 4 adverse events was 0% (95% confidence interval 0 to 6.38%). The most common Grade 3 toxicities were hematologic toxicity (12.5%) unlikely to be related to the PBT. One patient developed a left femoral neck fracture (Grade 3) at 14.5 months after PBT for chondrosarcoma of the left pelvis. The pathological findings showed no other malignancies, suggesting that it was possibly related to the PBT. In conclusion, the spot-scanning dedicated, synchrotron-based PBT system is feasible, but further studies on its long-term safety and efficacy are warranted.

show abstract

“…In the treatment plan, the dose was prescribed to the clinical target volume (CTV). In our facility, the beam‐specific optimization margins for the CTV are specified . A treatment plan was prepared for each patient, and if necessary, a replan or boost plan was devised.…”

Section: Methodsmentioning

confidence: 99%

“…In our facility, the beam-specific optimization margins for the CTV are specified. 21,22 A treatment plan was prepared for each patient, and if necessary, a replan or boost plan was devised. The number of treatment plans for each category is listed in Table 2.…”

Section: C | Treatment Planningmentioning

confidence: 99%

Analysis of treatment process time for real‐time‐image gated‐spot‐scanning proton‐beam therapy (RGPT) system

Yoshimura

Shimizu

Hashimoto

et al. 2019

J Applied Clin Med Phys

Self Cite

View full text Add to dashboard Cite

We developed a synchrotron‐based real‐time‐image gated‐spot‐scanning proton‐beam therapy (RGPT) system and utilized it to clinically operate on moving tumors in the liver, pancreas, lung, and prostate. When the spot‐scanning technique is linked to gating, the beam delivery time with gating can increase, compared to that without gating. We aim to clarify whether the total treatment process can be performed within approximately 30 min (the general time per session in several proton therapy facilities), even for gated‐spot‐scanning proton‐beam delivery with implanted fiducial markers. Data from 152 patients, corresponding to 201 treatment plans and 3577 sessions executed from October 2016 to June 2018, were included in this study. To estimate the treatment process time, we utilized data from proton beam delivery logs during the treatment for each patient. We retrieved data, such as the disease site, total target volume, field size at the isocenter, and the number of layers and spots for each field, from the treatment plans. We quantitatively analyzed the treatment process, which includes the patient load (or setup), bone matching, marker matching, beam delivery, patient unload, and equipment setup, using the data obtained from the log data. Among all the cases, 90 patients used the RGPT system (liver: n = 34; pancreas: n = 5; lung: n = 4; and prostate: n = 47). The mean and standard deviation (SD) of the total treatment process time for the RGPT system was 30.3 ± 7.4 min, while it was 25.9 ± 7.5 min for those without gating treatment, excluding craniospinal irradiation (CSI; head and neck: n = 16, pediatric: n = 31, others: n = 15); for CSI (n = 11) with two or three isocenters, the process time was 59.9 ± 13.9 min. Our results demonstrate that spot‐scanning proton therapy with a gating function can be achieved in approximately 30‐min time slots.

show abstract

NTCP modeling analysis of acute hematologic toxicity in whole pelvic radiation therapy for gynecologic malignancies – A dosimetric comparison of IMRT and spot-scanning proton therapy (SSPT)

Abstract: The SSPT achieves significant reductions in the dose to BM without compromising target coverage, compared with IMRT. The NTCP value for HT3+ in SSPT was significantly lower than in IMRT.

Cited by 17 publications

References 35 publications

Evaluation of plan quality and robustness of IMPT and helical IMRT for cervical cancer

Evaluation of plan quality and robustness of IMPT and helical IMRT for cervical cancer

Prospective study to evaluate the safety of the world-first spot-scanning dedicated, small 360-degree gantry, synchrotron-based proton beam therapy system

Analysis of treatment process time for real‐time‐image gated‐spot‐scanning proton‐beam therapy (RGPT) system

Contact Info

Product

Resources

About