Clinical Implementation of an Online Adaptive Plan-of-the-Day Protocol for Nonrigid Motion Management in Locally Advanced Cervical Cancer IMRT

Heijkoop, S.T.; Langerak, Thomas; Quint, S.; Bondar, L. N.; Mens, Jan Willem M.; Heijmen, B.; Hoogeman, M.

doi:10.1016/j.ijrobp.2014.06.046

Cited by 144 publications

(143 citation statements)

References 16 publications

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“…Several adaptive strategies, both offline and online approaches, have been investigated [4,5]. The most widely reported approach for pelvic EBRT is the plan-library based plan-of-the-day strategy [6][7][8]. Prior to treatment, a patient-specific plan library is defined by generating multiple treatment plans corresponding to different target volumes.…”

Section: Introductionmentioning

confidence: 99%

Dosimetric advantages of a clinical daily adaptive plan selection strategy compared with a non-adaptive strategy in cervical cancer radiation therapy

et al. 2017

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Background: Radiation therapy (RT) using a daily plan selection adaptive strategy can be applied to account for interfraction organ motion while limiting organ at risk dose. The aim of this study was to quantify the dosimetric consequences of daily plan selection compared with non-adaptive RT in cervical cancer. Material and methods: Ten consecutive patients who received pelvic irradiation, planning CTs (full and empty bladder), weekly post-fraction CTs and pre-fraction CBCTs were included. Non-adaptive plans were generated based on the PTV defined using the full bladder planning CT. For the adaptive strategy, multiple PTVs were created based on both planning CTs by ITVs of the primary CTVs (i.e., GTV, cervix, corpus-uterus and upper part of the vagina) and corresponding library plans were generated. Daily CBCTs were rigidly aligned to the full bladder planning CT for plan selection. For daily plan recalculation, selected CTs based on initial similarity were deformably registered to CBCTs. Differences in daily target coverage (D 98% > 95%) and in V 0.5Gy , V 1.5Gy , V 2Gy , D 50% and D 2% for rectum, bladder and bowel were assessed. Results: Non-adaptive RT showed inadequate primary CTV coverage in 17% of the daily fractions. Plan selection compensated for anatomical changes and improved primary CTV coverage significantly (p < 0.01) to 98%. Compared with non-adaptive RT, plan selection decreased the fraction dose to rectum and bowel indicated by significant (p < 0.01) improvements for daily V 0.5Gy , V 1.5Gy , V 2Gy , D 50% and D 2% . However, daily plan selection significantly increased the bladder V 1.5Gy , V 2Gy , D 50% and D 2% . Conclusions: In cervical cancer RT, a non-adaptive strategy led to inadequate target coverage for individual patients. Daily plan selection corrected for day-to-day anatomical variations and resulted in adequate target coverage in all fractions. The dose to bowel and rectum was decreased significantly when applying adaptive RT.

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Section: Introductionmentioning

confidence: 99%

Dosimetric advantages of a clinical daily adaptive plan selection strategy compared with a non-adaptive strategy in cervical cancer radiation therapy

et al. 2017

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“…This is known as adaptive RT (ART) and several ART strategies have been investigated [4,5]. Similar to our current clinical practice, a practical approach frequently applied for pelvic EBRT is the plan-library based plan-of-the-day strategy [6,7]. Based on the pretreatment acquired target motion range, treatment plans corresponding to different target shapes and positions are created and using pre-fraction CBCT the plan best fitting the target shape is selected.…”

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confidence: 99%

“…Also in cervical cancer, this online adaptive strategy has the potential to correct for most interfraction target motion to ensure daily target coverage. However, OARs still receive substantial dose during photonbased image-guided ART (IGART) [6,7].…”

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Dosimetric advantages of proton therapy compared with photon therapy using an adaptive strategy in cervical cancer

et al. 2016

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Background Image-guided adaptive proton therapy (IGAPT) can potentially be applied to take into account interfraction motion while limiting organ at risk (OAR) dose in cervical cancer radiation therapy (RT). In this study, the potential dosimetric advantages of IGAPT compared with photonbased image-guided adaptive RT (IGART) were investigated. Material and methods For 13 cervical cancer patients, full and empty bladder planning computed tomography (CT) images and weekly CTs were acquired. Based on both primary clinical target volumes (pCTVs) [i.e. gross tumor volume (GTV), cervix, corpus-uterus and upper part of the vagina] on planning CTs, the pretreatment observed full range primary internal target volume (pITV) was interpolated to derive pITV subranges. Given corresponding ITVs (i.e. pITVs including lymph nodes), patient-specific photon and proton plan libraries were generated. Using all weekly CTs, IGART and IGAPT treatments were simulated by selecting library plans and recalculating the dose. For each recalculated IGART and IGAPT fraction, CTV (i.e. pCTV including lymph nodes) coverage was assessed and differences in fractionated substitutes of dose-volume histogram (DVH) parameters (V 15Gy , V 30Gy , V 45Gy , D mean , D 2cc ) for bladder, bowel and rectum were tested for significance (Wilcoxon signed-rank test). Also, differences in toxicity-related DVH parameters (rectum V 30Gy , bowel V 45Gy ) were approximated based on accumulated dose distributions. Results In 92% (96%) of all recalculated IGAPT (IGART) fractions adequate CTV coverage (V 95% 498%) was obtained. All dose parameters for bladder, bowel and rectum, except the fractionated substitute for rectum V 45Gy , were improved using IGAPT. Also, IGAPT reduced the mean dose to bowel, bladder and rectum significantly (p50.01). In addition, an average decrease of rectum V 30Gy and bowel V 45Gy indicated reductions in toxicity probabilities when using IGAPT. Conclusion This study demonstrates the feasibility of IGAPT in cervical cancer using a plan-library based plan-of-the-day approach. Compared to photon-based IGART, IGAPT maintains target coverage while significant dose reductions for the bladder, bowel and rectum can be achieved.

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“…This includes daily image guidance, adaptive planning and strict bladder and bowel preparation, all of which involve increased resources and clinical input. Even centres with years of experience in daily image guided adaptive radiation therapy still rely on backup 3-dimensional conformal plans for days where movement is larger than predicted [18].Due to the fact that IMRT has only recently been introduced into routine practice there remain some uncertainties regarding the magnitude of potential late effects. These include the peripheral dose increase consequences and the effects of IMRT on late second cancer risk.…”

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confidence: 99%

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confidence: 99%

Current Issues in Cervical Cancer Radiotherapy

Eminowicz¹

2017

Gynecol Obstet

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Cervical cancer is a significant global health burden being the 4th most common cause of cancer related death in women worldwide [1]. This is despite the introduction of primary and secondary prevention measures within the developed world. A high proportion of patients present with locally advanced disease, defined as FIGO stage 1B2 to IVA. In this group of patients the standard of care is to treat curatively with a combination of chemotherapy and radiation therapy using external beam therapy and brachytherapy. This leads to 5 year survival rates in the United Kingdom of 61% for FIGO stage IIB and 44% for FIGO stage IIIB [2]. Chemo-radiation can lead to significant morbidity due to dose delivered to the surrounding healthy organs at risk (OARs). 18%, 45% and 53% of patients experience low grade genitourinary, gastrointestinal and haematological toxicity respectively with 1.5%, 8% and 28% experiencing grade 3 or 4 genitourinary, gastrointestinal and haematological toxicity respectively. Late complications are less well documented and range from 5-25% of patients [3]. Cervical cancer can affect women at a young age and therefore minimisation of toxicity is vital.New radiation techniques are becoming more widely available which aim to improve the therapeutic ratio by reducing OAR dose. Intensity Modulated Radiotherapy (IMRT) and image guided brachytherapy (IGBT) are two recent advances which have been incorporated into standard practice for cervical cancer in many countries.IMRT is a radiation technique that enables dose to conform tightly to target volumes thereby increasing normal tissue sparing. It uses numerous beam segments and modulated beam intensity (or fluence) to deliver steep dose gradients and shapes, such as concave, that would otherwise be unachievable. In the treatment of gynaecological cancers this facilitates reductions of high doses to bladder, rectum, bone marrow and small bowel [4,5] which translates into reduced acute and chronic bowel and urinary toxicity; grade 3 diarrhoea 5.6% from 30.6% , acute gastrointestinal toxicity 53% from 95%, chronic gastrointestinal toxicity 11% from 50%, acute genitourinary toxicity 7% from 16% [6][7][8]. However, the safe delivery of IMRT relies upon accurate target volume delineation and a good understanding of target movement within the pelvis.A clinical target volume (CTV) is delineated during the radiation therapy planning process to determine where dose needs to be delivered. For cervical cancer, a clear consensus exists regarding what anatomical areas should be included within this CTV; tumour, cervix, uterus, bilateral parametria and upper vagina for primary CTV and common iliac, internal and external iliac, upper presacral and obturator nodes for nodal CTV. However, variation in delineation of this CTV has been documented with up to 19 cm differences and two fold volume differences [9][10][11]. This can lead to significant differences in doses delivered to areas at risk of microscopic disease if IMRT is applied [12] but can be reduced by clear guideline u...

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Clinical Implementation of an Online Adaptive Plan-of-the-Day Protocol for Nonrigid Motion Management in Locally Advanced Cervical Cancer IMRT

Cited by 144 publications

References 16 publications

Dosimetric advantages of a clinical daily adaptive plan selection strategy compared with a non-adaptive strategy in cervical cancer radiation therapy

Dosimetric advantages of a clinical daily adaptive plan selection strategy compared with a non-adaptive strategy in cervical cancer radiation therapy

Dosimetric advantages of proton therapy compared with photon therapy using an adaptive strategy in cervical cancer

Current Issues in Cervical Cancer Radiotherapy

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