Interobserver variability in delineation of target volumes in head and neck cancer

Abstract Purpose: This study compared the plan dosimetry between the intensity-modulated radiation therapy (IMRT) and field-in-field (FIF) technique for head-and-neck cancer using the Elekta Monaco treatment planning system (TPS). Materials and methods: A total of 20 head-and-neck cancer patients were selected in this study. IMRT and FIF plans for the patients were created on the Monaco TPS (ver. 5.11.02) using the 6-MV photon beam generated by the Elekta Synergy linear accelerator. The dose–volume histograms, maximum doses, minimum doses, mean doses of the target volumes and organs-at-risk (OARs), conformity index (CI), homogeneity index (HI) and monitor units (MUs) were determined for each IMRT and FIF plan. All IMRT plans passed the patient-specific quality assurance tests from the 2D diode array measurements (MatriXX Evolution System, IBA Dosimetry, Germany). Results: The results showed that the dose distribution to the target volumes of IMRT plans was better than FIF plans, while the dose (mean or max dose) to the OAR was significantly lower than FIF plan, respectively. IMRT and FIF resulted in planning target volume coverage with mean dose of 71·32 ± 0·76 and 73·12 ± 0·62 Gy, respectively, and HI values of 0·08 ± 0·01 (IMRT) and 0·19 ± 0·06 (FIF). The CI for IMRT was 0·98 ± 0·01 and FIF was 0·97 ± 0·01. For the spinal cord tolerance (maximum dose < 45 Gy), IMRT resulted in 39·85 ± 2·04 Gy compared to 41·37 ± 2·42 Gy for FIF. In addition, the mean doses to the parotid grand were 27·27 ± 7·48 and 48·68 ± 1·62 Gy for the IMRT and FIF plans, respectively. Significantly more MUs were required in IMRT plans than FIF plans (on average, 846 ± 100 MU in IMRT and 467 ± 41 MU in FIF). Conclusions: It is concluded that the IMRT technique could provide a better plan dosimetry than the FIF technique for head-and-neck patients.

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PD-0052: Interobserver variability in organ at risk delineation in head and neck cancer

Radiotherapy and Oncology ◽

10.1016/s0167-8140(21)00078-5 ◽

2020 ◽

Vol 152 ◽

pp. S19-S20

Author(s):

J. Van der Veen ◽

A. Gulyban ◽

S. Willems ◽

F. Maes ◽

S. Nuyts

Keyword(s):

At Risk ◽

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Interobserver Variability ◽

Organ At Risk

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Interobserver variability in organ at risk delineation in head and neck cancer.

10.21203/rs.3.rs-39575/v2 ◽

2020 ◽

Author(s):

Julie van der Veen ◽

Akos Gulyban ◽

Siri Willems ◽

Frederik Maes ◽

Sandra Nuyts

Keyword(s):

Artificial Intelligence ◽

At Risk ◽

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Interobserver Variability ◽

Treatment Plan ◽

Consensus Guidelines ◽

International Consensus ◽

Organ At Risk

Abstract Background: In radiotherapy inaccuracy in organ at risk (OAR) delineation can impact treatment plan optimisation and treatment plan evaluation. Brouwer et al. showed significant interobserver variability (IOV) in OAR delineation in head and neck cancer (HNC) and published international consensus guidelines (ICG) for OAR delineation in 2015. The aim of our study was to evaluate IOV in the presence of these guidelines. Methods: HNC radiation oncologists (RO) from each Belgian radiotherapy centre were invited to complete a survey and submit contours for 5 HNC cases. Reference contours (OARref) were obtained by a clinically validated artificial intelligence-tool trained using ICG. Dice similarity coefficients (DSC), mean surface distance (MSD) and 95% Hausdorff distances (HD95) were used for comparison.Results: Fourteen of twenty-two RO (64%) completed the survey and submitted delineations. Thirteen (93%) confirmed the use of delineation guidelines, of which six (43%) used the ICG. The OARs whose delineations agreed best with the OARref were mandible (median DSC 0.9, range [0.8-0.9]; median MSD 1.1mm, range [0.8-8.3], median HD95 3.4mm, range [1.5-38.7]), brainstem (median DSC 0.9 [0.6-0.9]; median MSD 1.5mm [1.1-4.0], median HD95 4.0mm [2.3-15.0]), submandibular glands (median DSC 0.8 [0.5-0.9]; median MSD 1.2mm [0.9-2.5], median HD95 3.1mm [1.8-12.2]) and parotids (median DSC 0.9 [0.6-0.9]; median MSD 1.9mm [1.2-4.2], median HD95 5.1mm [3.1-19.2]). Oral cavity, cochleas, PCMs, supraglottic larynx and glottic area showed more variation. RO who used the consensus guidelines showed significantly less IOV (p=0.008).Conclusion: Although ICG for delineation of OARs in HNC exist, they are only implemented by about half of RO participating in this study, which partly explains the delineation variability. However, this study highlights that guidelines alone do not suffice to eliminate IOV and that more effort needs to be done to accomplish further treatment standardisation, for example with artificial intelligence.

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DOSIMETRIC ANALYSIS OF ADAPTIVE RADIOTHERAPY(ART) IN LOCALLY ADVANCED HEAD AND NECK CANCER

10.36106/ijar/1500130 ◽

2021 ◽

pp. 1-4

Author(s):

Jahnabi Das ◽

Bibhash Chandra Goswami ◽

Luit Das ◽

Smriti Goswami ◽

Kangkan Jyoti Deka ◽

...

Keyword(s):

Spinal Cord ◽

Radiation Therapy ◽

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Maximum Dose ◽

Locally Advanced ◽

Target Volume ◽

Advanced Head ◽

Target Volumes

PURPOSE/OBJECTIVE: The objective of this study is to evaluate the dosimetric parameters in adaptive radiotherapy for locally advanced head and neck cancers METHODS AND MATERIALS: This is a Hospital-based Prospective study conducted in the period from Dec 2020 to March 2021. Histologically proven Head and Neck Carcinoma patients with Stage III to IV (locally advanced) were selected for the study. A total of 10 patients receiving denitive, conformal radiation therapy to the head and neck region were evaluated for the study. After the acquisition of CT images, target volumes, OARs were contoured in the planning CT. Images were again acquired midway during the planned course of radiation therapy. Body contours, target volumes, and organs at risk were redrawn on the new set of images. Two sets of additional treatment plans were generated: 1) a non-optimized plan (plan 2), which is an overlay of the original plan (plan 1) on the new set of contours, and 2) an optimized plan(plan 3) with the new set of contours. These 3 sets of plans were then compared for dosimetric differences. RESULTS: Four patients had locally advanced nasopharyngeal cancers, 4 patients had locally advanced oropharyngeal cancers, 2 patients had locally advanced hypopharyngeal cancer. The average reduction in gross tumour volume was 37.1 ml. The average changes in right and left parotid volume were 5.94 and 5.49 ml, respectively. With the non-optimized plan, the average increase in the maximum dose to the spinal cord was 9.8% (58.96-68.76; p= 0.156). With reoptimization, the maximum dose to the spinal cord decreased from 68.76% to 54.97% (mean difference, -13.79%, p=0.03). The average D99 for the planning target volume( dose received by 99% of the target volume) was 98.68% and 98.65% with the original and reoptimized plans, respectively. Most of the patients during radiation had Grade 2 skin toxicity and Grade 2 mucositis which was managed conservatively. CONCLUSIONS: This study demonstrates that during radiation there is gross changes of volumes in locally advanced head and neck cancers and thus adaptive radiation therapy plays a pivotal role in locally advanced head and neck cancer

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Rapid advances in auto-segmentation of organs at risk and target volumes in head and neck cancer

Radiotherapy and Oncology ◽

10.1016/j.radonc.2019.03.004 ◽

2019 ◽

Vol 135 ◽

pp. 130-140 ◽

Cited By ~ 13

Author(s):

M. Kosmin ◽

J. Ledsam ◽

B. Romera-Paredes ◽

R. Mendes ◽

S. Moinuddin ◽

...

Keyword(s):

At Risk ◽

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Organs At Risk ◽

Target Volumes

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Comparison between CT- and MRI-derived head and neck cancer target volumes using an integrated MRI-tri-60Co teletherapy device

Journal of Radiation Oncology ◽

10.1007/s13566-017-0337-0 ◽

2018 ◽

Vol 7 (2) ◽

pp. 147-155

Author(s):

Allen M. Chen ◽

Govind Raghavan ◽

Minsong Cao ◽

Argin G. Mikaielian ◽

Ali R. Sepahdari

Keyword(s):

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Target Volumes ◽

Ct And Mri

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Interobserver Variability in Organ at Risk Delineation in Head and Neck Cancer.

10.21203/rs.3.rs-39575/v1 ◽

2020 ◽

Author(s):

Julie van der Veen ◽

Akos Gulyban ◽

Siri Willems ◽

Frederik Maes ◽

Sandra Nuyts

Keyword(s):

Artificial Intelligence ◽

At Risk ◽

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Interobserver Variability ◽

Treatment Plan ◽

Consensus Guidelines ◽

International Consensus ◽

Organ At Risk

Abstract Background: In radiotherapy inaccuracy in organ at risk (OAR) delineation can impact treatment plan optimisation and treatment plan evaluation. Brouwer et al. showed significant interobserver variability (IOV) in OAR delineation in head and neck cancer (HNC) and published international consensus guidelines (ICG) for OAR delineation in 2015. The aim of our study was to evaluate IOV in the presence of these guidelines. Methods: HNC radiation oncologists (RO) from each Belgian radiotherapy centre were invited to complete a survey and submit contours for 5 HNC cases. Reference contours (OARref) were obtained by a clinically validated artificial intelligence-tool trained using ICG. Dice similarity coefficients (DSC), mean surface distance (MSD) and 95% Hausdorff distances (HD95) were used for comparison.Results: Fourteen of twenty-two RO (64%) completed the survey and submitted delineations. Thirteen (93%) confirmed the use of delineation guidelines, of which six (43%) used the ICG. The OARs whose delineations agreed best with the OARref were mandible (median DSC 0.9, range [0.8-0.9]; median MSD 1.1mm, range [0.8-8.3], median HD95 3.4mm, range [1.5-38.7]), brainstem (median DSC 0.9 [0.6-0.9]; median MSD 1.5mm [1.1-4.0], median HD95 4.0mm [2.3-15.0]), submandibular glands (median DSC 0.8 [0.5-0.9]; median MSD 1.2mm [0.9-2.5], median HD95 3.1mm [1.8-12.2]) and parotids (median DSC 0.9 [0.6-0.9]; median MSD 1.9mm [1.2-4.2], median HD95 5.1mm [3.1-19.2]). Oral cavity, cochleas, PCMs, supraglottic larynx and glottic area showed more variation. RO who used the consensus guidelines showed significantly less IOV (p=0.008).Conclusion: Although ICG for delineation of OARs in HNC exist, they are only implemented by about half of RO participating in this study, which partly explains the delineation variability. However, this study highlights that guidelines alone do not suffice to eliminate IOV and that more effort needs to be done to accomplish further treatment standardisation, for example with artificial intelligence.

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Dose Reduction to the Swallowing Apparatus and the Salivary Glands by De-Intensification of Postoperative Radiotherapy in Patients with Head and Neck Cancer: First (Treatment Planning) Results of the Prospective Multicenter DIREKHT Trial

Cancers ◽

10.3390/cancers12030538 ◽

2020 ◽

Vol 12 (3) ◽

pp. 538

Author(s):

Marlen Haderlein ◽

Stefan Speer ◽

Oliver Ott ◽

Sebastian Lettmaier ◽

Markus Hecht ◽

...

Keyword(s):

Head And Neck Cancer ◽

Head And Neck ◽

Salivary Glands ◽

Neck Cancer ◽

Standard Treatment ◽

Treatment Plan ◽

Postoperative Radiotherapy ◽

Target Volumes ◽

Treatment Plans ◽

Dose Reductions

Aim: Evaluating radiotherapy treatment plans of the prospective DIREKHT trial (ClinicalTrials.gov, NCT02528955) investigating de-intensification of radiotherapy in patients with head and neck cancer. Patients and Methods: The first 30 patients from the DIREKHT trial of the leading study centre were included in this analysis. Standard treatment plans and study treatment plans derived from the protocol were calculated for each patient. Sizes of planning target volumes (PTVs) and mean doses to organs at risk were compared using the Student’s t-test with paired samples. Results: Mean PTV3 including primary tumor region and ipsilateral elective neck up to a dose of 50 Gy in the study treatment plans was 662 mL (+/− 165 mL standard deviation (SD)) and therefore significantly smaller than those of the standard treatment plans (1166 mL (+/− 266 mL SD). In the medial and inferior constrictor muscles, cricopharyngeal muscle, glottic and supraglottic laryngeal areas, arytenoid cartilages, contralateral major salivary glands highly significant dose reductions (p < 0.0001) of more than 10 Gy were achieved in study treatment plan compared to standard treatment plan. Conclusion: De-intensification of radiotherapy led to smaller planning target volumes and clinical relevant dose reductions in the swallowing apparatus and in the contralateral salivary glands.

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