Treatment of pancreatic cancer tumors with intensity-modulated radiation therapy (IMRT) using the volume at risk approach (VARA): Employing dose-volume histogram (DVH) and normal tissue complication probability (NTCP) to evaluate small bowel toxicity

Landry, Jerome C.; Yang, Gary; Ting, Joseph; Staley, Charles A.; Torres, William E.; Esiashvili, Natia; Davis, Lawrence W.

doi:10.1016/s0958-3947(02)00094-8

Cited by 84 publications

(45 citation statements)

References 12 publications

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“…Several publications on pancreatic cancer have demonstrated the superiority of IMRT in reducing radiation doses to surrounding normal organs in comparison to three-dimensional conformal radiotherapy [2,4,23,24,34]. Our analysis in ten patients revealed that RA allowed for an improved CI relative Table 3.…”

Section: Discussionmentioning

confidence: 72%

“…A "small-bowel region" was defined which consisted of the abdominal content after subtracting the PTV, all OARs and the vertebral bodies, with the posterior border extending to the dorsum of the lumbar vertebral body, but excluding the retroperitoneal space [30]. Our definition of a "small-bowel region" also included the mesentery and intraperitoneal fat, which is in contrast with prior reports describing bowel dose-volume relationships using bowel loop contouring [23,24].…”

Section: Methodsmentioning

confidence: 99%

“…Measures to reduce toxicity include omitting prophylactic radiotherapy of regional lymph nodes [27], decreasing mobility margins by individualized assessment and incorporation of target mobility [33], and the use of more conformal radiotherapy techniques. In particular, use of intensity-modulated radiotherapy (IMRT) is associated with lower renal and bowel doses compared to conventional planning [2,4,23,24,31,34,37].…”

Section: Introductionmentioning

confidence: 99%

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Volumetric Modulated Arc Therapy for Advanced Pancreatic Cancer

et al. 2010

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Background: Intensity-modulated radiotherapy (IMRT) allows for improved sparing of organs at risk (OARs) in advanced pancreatic cancer. A planning study evaluated if volumetric modulated arc therapy (RapidArc™ [RA]) could be used as an alternative to IMRT in such cases. Patients and Methods: In ten patients, five-field IMRT (5f-IMRT) plans with fixed gantry positions were compared to RA plans using similar constraints for planning target volume (PTV) and OARs. PTV coverage, conformity indices (CI), and OAR doses were compared. One patient was treated using RA and calculated dose distributions were measured in coronal planes in a solid-water phantom. Results: RA plans showed superior mean CI of 1.09 ± 0.02 (± 1 SD [standard deviation]) versus 1.20 ± 0.10 in 5f-IMRT (p = 0.003). Both techniques achieved similar sparing of the right kidney, but RA significantly reduced left kidney doses with V 15 of 7.2% ± 5.3% and 15.9% ± 11.1%, respectively; p = 0.02. RA modestly decreased mean doses to liver (13.8 vs. 15.1 Gy; p = 0.003), stomach (16.7 vs. 17.9 Gy; p = 0.017), small bowel (19.8 vs. 22.1 Gy; p < 0.001), and duodenum (38.8 vs. 41.9 Gy; p = 0.004). Film dosimetry revealed excellent agreement between calculated and measured dose distributions. The delivery time for RA was < 3 min. Conclusion: RA planning achieved superior CI for pancreatic tumors compared to 5f-IMRT, and modestly reduced OAR doses. Fast treatment delivery using RA may decrease the risk of intrafractional organ motion. Ergebnisse: RA-Pläne zeigten einen günstigeren CI von 1,09 ± 0,02 (± 1 SD [Standardabweichung]) gegenüber 1,20 ± 0,10 bei 5f-IMRT (p = 0,003). Mit beiden Techniken gelang eine zufriedenstellende Dosisreduktion der rechten Niere, mittels RA konnten jedoch die V 15 der linken Niere signifikant reduziert werden (7,2% ± 5,3% vs. 15,9% ± 11,1% bei IMRT; p = 0,02). Geringer zeigte sich die Reduktion der mittleren Dosis der Leber (13,8 vs. 15,1 Gy; p = 0,003), des Magens (16,7 vs. 17,9 Gy; p = 0,017), des Dünndarms (19,8 vs. 22,1 Gy; p < 0,001) und des Duodenums (38,8 vs. 41,9 Gy; p = 0,004). Filmdosimetrische Überprüfungen zeigten hervorragende Übereinstimmungen bezüglich kalkulierter und tatsächlicher Dosisverteilung. Die Gesamtbestrahlungszeit betrug < 3 min. Schlussfolgerung: Mittels RA-Planung lässt sich im Vergleich zur 5f-IMRT sowohl ein günstigerer CI als auch moderate Dosisreduktion in den OAR erreichen. Durch die rasche Dosisapplikation vermindert sich das Risiko intrafraktionärer Bewegung der OAR.Schlüsselwörter: Pankreaskarzinom · "Volumetric modulated arc therapy" · Intensitätsmodulierte Radiotherapie · Planungsstudie · Risikoorgane

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Section: Discussionmentioning

confidence: 72%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Volumetric Modulated Arc Therapy for Advanced Pancreatic Cancer

et al. 2010

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“…The results revealed that the IMRT plan significantly lowers the NTCP for the rectum while a small gain in TCP was found. In a similar study by Landry et al [23] a total number of 10 patients with adenocarcinoma of the pancreatic head were planned simultaneously with 3D-CRT and inverseplanned IMRT and compared. In the IMRT plans, small bowel received 25% less dose which lead to three times lower NTCP for IMRT plans.…”

Section: Application Of Tcp/ntcp For Plan Comparisonmentioning

confidence: 99%

“…Although, the main purpose of TCP/NTCP calculations has been to provide a surrogate tool for plan comparisons and optimum plan selection for a given treatment, there are many other investigations that have employed this approach to quantize the radiobiological consequences for different available modalities, and geometric errors, as well as comparing novel techniques for radiation therapy [2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Moreover, several studies have utilized radiobiological modeling to evaluate the effect of geometric errors in image guided radiation therapy (IGRT), while others have applied this modeling for brachytherapy planning as well as radiation therapy with heavy ion beams [25][26][27][28][29][30][31][32].…”

Section: Introductionmentioning

confidence: 99%

An Overview on the Clinical Application of Radiobiological Modeling in Radiation Therapy of Cancer

Mesbahi

Oladghaffari

2017

IJRRT

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Analyzing the dose distribution inside target volumes of cancer patients before radiation delivery and then selection of the biologically optimal dose distribution has been one of the crucial steps in recent treatment planning developments. Plan evaluation and optimization have been based on the physical dose distribution and dose-volume parameters for several decades. However, with the development of a. clinical radiobiology in both domains of tumor and normal tissue response to radiation, ii) existence of reliable clinical results, and b. emergence of new mathematical models in cancer biology and treatment, radiation scientists have been motivated to calculate tumor control probability (TCP) and normal tissue complication probability (NTCP) for modern complex clinical treatment plans. The prediction of clinical outcome in terms of TCP in radiation therapy and its development have been an interesting subject of investigations for several decades. Additionally, this process has provided new information on radiotherapy consequences such as increased local control rates and lower complications rates. It also has helped treatment teams to choose optimum plans for individual patients. In this overview, we will look into some of these studies and give emphasis on potential benefits of TCP/NTCP calculations in different areas of radiation therapy such as plan evaluation, and the uncertainties associated with dose delivery. Keywords: Radiation therapy; Treatment planning; Radiobiological modelling;Tumor control probability; Normal tissue complication probability An Overview on the Clinical Application of Radiobiological Modeling in Radiation Therapy of Cancer 2/7Copyright: ©2017 Mesbahi et al.The β i parameter denotes the repairable part of radiation damage which varies over the population of patients. Also i g shows the fraction of patients having as their radiosensitivity [4].There are several models for NTCP calculations using DVH, dosimetric data of each patient. [4] One of the most applied models is the Lyman-Kutcher-Burman (LKB) model [1]. The NTCP calculation in the LKB model is defined as:Where TD 50 (v) is the tolerance dose for a 50% complication probability caused by uniform irradiation to volume v, and where n is the volume exponent and m is a parameter that is inversely related to the steepness of the dose-response curve.The increasing number of publications on radiobiological modeling implies its progressive utilization in current clinical practice as well as in silico (computer) modelling research. Although, the main purpose of TCP/NTCP calculations has been to provide a surrogate tool for plan comparisons and optimum plan selection for a given treatment, there are many other investigations that have employed this approach to quantize the radiobiological consequences for different available modalities, and geometric errors, as well as comparing novel techniques for radiation therapy [2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Moreover, several studies have ut...

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Automated treatment planning as a dose escalation strategy for stereotactic radiation therapy in pancreatic cancer

Cilla

Ianiro

Romano

et al. 2020

J Applied Clin Med Phys

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Purpose: To assess the feasibility of automated stereotactic volumetric modulated arc therapy (SBRT-VMAT) planning using a simultaneous integrated boost (SIB) approach as a dose escalation strategy for SBRT in pancreatic cancer. Methods: Twelve patients with pancreatic cancer were retrospectively replanned. Dose prescription was 30 Gy to the planning target volume (PTV) and was escalated up to 50 Gy to the boost target volume (BTV) using a SIB technique in 5 fractions. All plans were generated by Pinnacle 3 Autoplanning using 6MV dual-arc VMAT technique for flattened (FF) and flattening filter-free beams (FFF). An overlap volume (OLV) between the PRV duodenum and the PTV was defined to correlate with the ability to boost the BTV. Dosimetric metrics for BTV and PTV coverage, maximal doses for serial OARs, integral dose, conformation numbers, and dose contrast indexes were used to analyze the dosimetric results. Dose accuracy was validated using the PTW Octavius-4D phantom together with the 1500 2D-array. Differences between FF and FFF plans were quantified using the Wilcoxon matched-pair signed rank. Results: Full prescription doses to the 95% of PTV and BTV can be delivered to patients with no OLV. BTV mean dose was >90% of the prescribed doses for all patients at all dose levels. Compared to FF plans, FFF plans showed significant reduced integral doses, larger number of MUs, and reduced beam-on-times up to 51% for the highest dose level. Despite plan complexity, pre-treatment verification reported a gamma pass-rate greater than the acceptance threshold of 95% for all FF and FFF plans for 3%-2 mm criteria. Conclusions: The SIB-SBRT strategy with Autoplanning was dosimetrically feasible. Ablative doses up to 50 Gy in 5 fractions can be delivered to the BTV for almost all patients respecting all the normal tissue constraints. A prospective clinical trial based on SBRT strategy using SIB-VMAT technique with FFF beams seems to be justified.

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Treatment of pancreatic cancer tumors with intensity-modulated radiation therapy (IMRT) using the volume at risk approach (VARA): Employing dose-volume histogram (DVH) and normal tissue complication probability (NTCP) to evaluate small bowel toxicity

Cited by 84 publications

References 12 publications

Volumetric Modulated Arc Therapy for Advanced Pancreatic Cancer

Volumetric Modulated Arc Therapy for Advanced Pancreatic Cancer

An Overview on the Clinical Application of Radiobiological Modeling in Radiation Therapy of Cancer

Automated treatment planning as a dose escalation strategy for stereotactic radiation therapy in pancreatic cancer

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