Effects of dose and dose-averaged linear energy transfer on pelvic insufficiency fractures after carbon-ion radiotherapy for uterine carcinoma

Mori, Yoshihisa; Okonogi, Noriyuki; Matsumoto, Shinnosuke; Furuichi, Wataru; Fukahori, Mai; Miyasaka, Yasuhiro; Murata, Kazutoshi; Wakatsuki, Masaru; Imai, Reiko; Koto, Masashi; Yamada, Shigeru; Ishikawa, Hitoshi; Kanematsu, Nobuyuki; Tsuji, Hiroshi

doi:10.1016/j.radonc.2022.10.008

Cited by 7 publications

(6 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Okonogi et al found no role of high LETd distribution or physical dose in the development of late rectal toxicity, apart from D RBE in patients treated with pelvic CIRT [54]. Similarly, Mori et al could not demonstrate any influence of high LETd on the development of sacral insufficiency fracture [55]. Nevertheless, evaluating the impact of LETd distribution on OARs to predict the risk of late toxicity is tricky, as the presence of high LETd distribution in the absence of the high D RBE in the same voxel is unlikely to induce organ damage that may result in severe RILSN.…”

Section: Discussionmentioning

confidence: 97%

“…Development of SIF is influenced by multiple factors apart from doses to the bone, such as tumor regression kinetics, mechanical stress, and location of the tumor (e.g., proximity to sacro-iliac joint) and dose to the bone. Recent report by Mori et al suggested that the development of SIF was directly influenced by doses to bone: D50% > 19.9 Gy (RBE), which was the only significant factor for predicting SIF [55]. Restricting doses to the bone is challenging as it depends upon the volume and location of the tumor, whereas RILSN is a potentially avoidable toxicity.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Sacral-Nerve-Sparing Planning Strategy in Pelvic Sarcomas/Chordomas Treated with Carbon-Ion Radiotherapy

Nachankar,

Schafasand,

Hug

et al. 2024

Cancers

View full text Add to dashboard Cite

To minimize radiation-induced lumbosacral neuropathy (RILSN), we employed sacral-nerve-sparing optimized carbon-ion therapy strategy (SNSo-CIRT) in treating 35 patients with pelvic sarcomas/chordomas. Plans were optimized using Local Effect Model-I (LEM-I), prescribed DRBE|LEM-I|D50% (median dose to HD-PTV) = 73.6 (70.4–76.8) Gy (RBE)/16 fractions. Sacral nerves were contoured between L5-S3 levels. DRBE|LEM-I to 5% of sacral nerves-to-spare (outside HD-CTV) (DRBE|LEM-I|D5%) were restricted to <69 Gy (RBE). The median follow-up was 25 months (range of 2–53). Three patients (9%) developed late RILSN (≥G3) after an average period of 8 months post-CIRT. The RILSN-free survival at 2 years was 91% (CI, 81–100). With SNSo-CIRT, DRBE|LEM-I|D5% for sacral nerves-to-spare = 66.9 ± 1.9 Gy (RBE), maintaining DRBE|LEM-I to 98% of HD-CTV (DRBE|LEM-I|D98%) = 70 ± 3.6 Gy (RBE). Two-year OS and LC were 100% and 93% (CI, 84–100), respectively. LETd and DRBE with modified-microdosimetric kinetic model (mMKM) were recomputed retrospectively. DRBE|LEM-I and DRBE|mMKM were similar, but DRBE-filtered-LETd was higher in sacral nerves-to-spare in patients with RILSN than those without. At DRBE|LEM-I cutoff = 64 Gy (RBE), 2-year RILSN-free survival was 100% in patients with <12% of sacral nerves-to-spare voxels receiving LETd > 55 keV/µm than 75% (CI, 54–100) in those with ≥12% of voxels (p < 0.05). DRBE-filtered-LETd holds promise for the SNSo-CIRT strategy but requires longer follow-up for validation.

show abstract

Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Sacral-Nerve-Sparing Planning Strategy in Pelvic Sarcomas/Chordomas Treated with Carbon-Ion Radiotherapy

Nachankar,

Schafasand,

Hug

et al. 2024

Cancers

View full text Add to dashboard Cite

show abstract

“…The weighted dose of relative biological effectiveness (RBE) (DRBE 50%), according to another study by Mori et al, was associated with an increased risk of SIF. When age > 50 years was taken into account, only current smoking behavior contributed to SIF; neither linear energy transfer dose (LETd) nor physical dose characteristics were significant risk factors [ 54 ]. The study by Ramlov et al found that PIFs are related to the dose and volume of irradiation to the elective pelvic target, rather than with lymph node boosts.…”

Section: Discussionmentioning

confidence: 99%

Insights into pelvic insufficiency fracture following pelvic radiotherapy for cervical cancer: a comparative review

Haque,

Hossen

2024

BMC Women's Health

View full text Add to dashboard Cite

Background Radiotherapy (RT)-induced pelvic insufficiency fractures (PIF) are prevalent in patients with cervical cancer. Inconclusive studies on PIF after cervical irradiation create uncertainty. This review examined PIF after RT in cervical patients, including its pathobiology, likely locations of fractures, incidence, clinical symptoms, and predisposing factors. We further discussed study limitations and therapeutic possibilities of PIF. Methods The following online resources were searched for relevant articles: Google Scholar and PubMed. The keywords ‘pelvic insufficiency fractures’, ‘cervical carcinoma’ and ‘cervical cancer’, as well as ‘chemoradiotherapy’, ‘chemoradiation’, and ‘radiotherapy’, were some of the terms that were used during the search. Results Patients with PIF report pelvic pain after radiation treatment for cervical cancer; the incidence of PIF ranges from 1.7 to 45.2%. Evidence also supports that among all patients treated with pelvic radiation, those who experienced pelvic insufficiency fractures invariably had at least one sacral fracture, making it the most frequently fractured bone in the body. Menopausal status, weight, BMI, age, and treatments and diagnosis modalities can influence PIF during radiotherapy. Conclusions In conclusion, our comparative review of the literature highlights significant heterogeneity in various aspects of PIF following radiation for patients with cervical cancer. This diversity encompasses prevalence rates, associated risk factors, symptoms, severity, diagnosis methods, preventive interventions, and follow-up periods. Such diversity underscores the complexity of PIF in this population and emphasizes the critical need for further research to elucidate optimal management strategies and improve patient outcomes.

show abstract

“…tumor) in order to evaluate the correlation of LET d with local recurrence, local control and overall survival or (b) in relation to different organs at risk (OAR), contrast enhancements in medical images or observed adverse events after treatment. While the latter is the focus of most of the clinical proton therapy studies, 20,21 in CIRT both aspects (a 22,23 and b 13,[24][25][26] ) are of interest. So far, contradicting results have been reported about the correlation of LET d with different adverse events 22 and quantitative evaluation criteria in terms of LET d are still scarce, potentially due to the complex and combined effect of dose and LET d .…”

mentioning

confidence: 99%

“…While the latter is the focus of most of the clinical proton therapy studies, 20,21 in CIRT both aspects (a 22,23 and b 13,[24][25][26] ) are of interest. So far, contradicting results have been reported about the correlation of LET d with different adverse events 22 and quantitative evaluation criteria in terms of LET d are still scarce, potentially due to the complex and combined effect of dose and LET d .…”

mentioning

confidence: 99%

Investigation on the physical dose filtered by linear energy transfer for treatment plan evaluation in carbon ion therapy

Schafasand,

Resch,

Nachankar

et al. 2023

Medical Physics

View full text Add to dashboard Cite

BackgroundLarge tumor size has been reported as a predicting factor for inferior clinical outcome in carbon ion radiotherapy (CIRT). Besides the clinical factors accompanied with such tumors, larger tumors receive typically more low linear energy transfer (LET) contributions than small ones which may be the underlying physical cause. Although dose averaged LET is often used as a single parameter descriptor to quantify the beam quality, there is no evidence that this parameter is the optimal clinical predictor for the complex mixed radiation fields in CIRT.PurposePurpose of this study was to investigate on a novel dosimetric quantity, namely high‐LET‐dose (, the physical dose filtered based on an LET threshold) as a single parameter estimator to differentiate between carbon ion treatment plans (cTP) with a small and large tumor volume.MethodsTen cTPs with a planning target volume, (large) and nine with a (small) were selected for this study. To find a reasonable LET threshold () that results in a significant difference in terms of , the voxel based normalized high‐LET‐dose () distribution in the clinical target volume (CTV) was studied on a subset (12 out of 19 cTPs) for 18 LET thresholds, using standard distribution descriptors (mean, variance and skewness).The classical dose volume histogram concept was used to evaluate the and distributions within the target of all 19 cTPs at the before determined . Statistical significance of the difference between the two groups in terms of mean and volume histogram parameters was evaluated by means of (two‐sided) t‐test or Mann‐Whitney‐U‐test. In addition, the minimum target coverage at the above determined was compared and validated against three other thresholds to verify its potential in differentiation between small and large volume tumors.ResultsAn of approximately was found to be a reasonable threshold to classify the two groups. At this threshold, the and were significantly larger () in small CTVs. For the small tumor group, the near‐minimum and median (and ) in the CTV were in average (0.31 ± 0.08) and (0.46 ± 0.06), respectively. For the large tumors, these parameters were (0.20 ± 0.01) and (0.28 ± 0.02). The difference between the two groups in terms of mean near‐minimum and median () was 2.7 Gy (11%) and 5.0 Gy (18%), respectively.ConclusionsThe feasibility of high‐LET‐dose based evaluation was shown in this study where a lower was found in cTPs with a large tumor size. Further investigation is needed to draw clinical conclusions. The proposed methodology in this work can be utilized for future high‐LET‐dose based studies.

show abstract

Effects of dose and dose-averaged linear energy transfer on pelvic insufficiency fractures after carbon-ion radiotherapy for uterine carcinoma

Cited by 7 publications

References 40 publications

Sacral-Nerve-Sparing Planning Strategy in Pelvic Sarcomas/Chordomas Treated with Carbon-Ion Radiotherapy

Sacral-Nerve-Sparing Planning Strategy in Pelvic Sarcomas/Chordomas Treated with Carbon-Ion Radiotherapy

Insights into pelvic insufficiency fracture following pelvic radiotherapy for cervical cancer: a comparative review

Investigation on the physical dose filtered by linear energy transfer for treatment plan evaluation in carbon ion therapy

Contact Info

Product

Resources

About