The dosimetric consequences of anatomic changes in head and neck radiotherapy patients

Height, R.; Khoo, Vincent; Lawford, C.; Cox, Jennifer; Joon, Daryl Lim; Rolfo, Aldo; Wada, M.

doi:10.1111/j.1754-9485.2010.02209.x

Cited by 27 publications

(22 citation statements)

References 23 publications

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“…Sanguineti et al [62] studied weekly CT scans of eighty-five patients and concluded that the PG shrinkage is not linear (PGs shrunk most during the first half of treatment). Thirty-eight papers reported on PG anatomic changes [2,4,6,7,9,12,13,[15][16][17][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]47,48,50,53,56,57,59,60,[62][63][64][65][66]. The most common reported anatomic changes were volume loss (Table S1) and medial shifts of the PGs [17,[32][33][34]37,42,44,45,48,51,...…”

Section: Parotid Glandmentioning

confidence: 93%

“…Twenty-six papers described both anatomic and dosimetric changes during the course of radiation [2,4,6,[11][12][13][15][16][17]31,34,36,38,39,[41][42][43][44]46,48,54,59,61,63,65,66]. Two studies reported on dosimetric changes without referring to anatomic changes [18,51].…”

Section: Anatomic and Dosimetric Changesmentioning

confidence: 96%

“…A number of authors reported on changes in maximum doses or D 1% to the brainstem [2,6,15,16,18,31,34,[41][42][43]59] and the spinal cord [2,6,11,13,15,16,18,31,34,36,[41][42][43]59,66] during the course of treatment (results are listed in Table S3). Zhao et al [6] found the highest dose increase in D 1% of the spinal cord and the brainstem of on average 0.20 and 0.09 Gy per fraction, which would result in an accumulated excess dose of 5.6 and 2.5 Gy, respectively, for the entire treatment course.…”

Section: Brainstem and Spinal Cordmentioning

confidence: 96%

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Identifying patients who may benefit from adaptive radiotherapy: Does the literature on anatomic and dosimetric changes in head and neck organs at risk during radiotherapy provide information to help?

Brouwer

Steenbakkers

Langendijk

et al. 2015

Radiotherapy and Oncology

147

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In the last decade, many efforts have been made to characterize anatomic changes of head and neck organs at risk (OARs) and the dosimetric consequences during radiotherapy. This review was undertaken to provide an overview of the magnitude and frequency of these effects, and to investigate whether we could find criteria to identify head and neck cancer patients who may benefit from adaptive radiotherapy (ART). Possible relationships between anatomic and dosimetric changes and outcome were explicitly considered. A literature search according to PRISMA guidelines was performed in MEDLINE and EMBASE for studies concerning anatomic or dosimetric changes of head and neck OARs during radiotherapy. Fifty-one eligible studies were found. The majority of papers reported on parotid gland (PG) anatomic and dosimetric changes. In some patients, PG mean dose differences between planning CT and repeat CT scans up to 10 Gy were reported. In other studies, only minor dosimetric effects (i.e. <1 Gy difference in PG mean dose) were observed as a result of significant anatomic changes. Only a few studies reported on the clinical relevance of anatomic and dosimetric changes in terms of complications or quality of life. Numerous potential selection criteria for anatomic and dosimetric changes during radiotherapy were found and listed. The heterogeneity between studies prevented unambiguous conclusions on how to identify patients who may benefit from ART in head and neck cancer. Potential pre-treatment selection criteria identified from this review include tumour location (nasopharyngeal carcinoma), age, body mass index, planned dose to the parotid glands, the initial parotid gland volume, and the overlap volume of the parotid glands with the target volume. These criteria should be further explored in well-designed and well-powered prospective studies, in which possible relationships between anatomic and dosimetric changes and outcome need to be established.

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Section: Parotid Glandmentioning

confidence: 93%

Section: Anatomic and Dosimetric Changesmentioning

confidence: 96%

Section: Brainstem and Spinal Cordmentioning

confidence: 96%

See 1 more Smart Citation

Identifying patients who may benefit from adaptive radiotherapy: Does the literature on anatomic and dosimetric changes in head and neck organs at risk during radiotherapy provide information to help?

Brouwer

Steenbakkers

Langendijk

et al. 2015

Radiotherapy and Oncology

147

View full text Add to dashboard Cite

show abstract

“…Loo et al [23] in a recent evaluation of five cases showed a significant volume loss in both PGs without a correlation with radiation dose. Height et al [24] investigated the anatomical change in head and neck cancer and showed that both PGs (spared and unspared) decreased significantly in volume.…”

Section: Discussionmentioning

confidence: 99%

Parotid gland volumetric changes during intensity-modulated radiotherapy in head and neck cancer

Fiorentino¹,

Caivano²,

Metallo³

et al. 2012

BJR

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Objective: To evaluate volumetric changes of parotid glands (PGs) during intensitymodulated radiotherapy (IMRT) in head and neck cancer patients. Methods: During IMRT all patients underwent kilovolt cone-beam CT (CBCT) scans to verify the set-up positioning in a protocol study. On each CBCT scan, the PGs were retrospectively contoured and evaluated with a dose-volume histogram. Results: From February to June 2011, 10 patients were enrolled. 140 CBCT scans were registered (280 PGs): for each patient, a median of 14 CBCT scans were performed (range 14-16). At the start of radiation, the average volume for ipsilateral PGs (iPGs) was 18.77 ml (range 12.9-31.2 ml), whereas for contralateral PGs (cPGs) it was 16.63 ml (range 8.3-28.7 ml). At the last CBCT scan, the average volume loss was 43.5% and 44.0% for the iPG and cPG, respectively. When we analysed the percentage of volume loss, we observed that the volume decreased by linear regression (r 2 50.92 for iPG; r 2 50.91 for cPG), with an average volume loss rate of 1.5% per day for both PGs. During the third week of treatment the volume of both PGs reduced by 24-30%. Conclusion: Our data show that, during IMRT, the shrinkage of PGs should be taken into account. A replan could be indicated in the third week of radiotherapy.

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“…This is particularly important for patients with tumors adjacent to important normal intracranial and head-and-neck structures. For these patients, various immobilizers are used, and many studies have examined techniques to minimize geometrical discrepancies [1][2][3][4][5][6]. Bentel et al [1] describe a customized headrest to support the posterior head and neck.…”

Section: Related Studiesmentioning

confidence: 99%

Shape memory alloy (SMA)-based head and neck immobilizer for radiotherapy

Lee

Kim

Park

et al. 2015

Journal of Computational Design and Engineering

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Head-and-neck cancer is often treated with intensive irradiation focused on the tumor, while delivering the minimum amount of irradiation to normal cells. Since a course of radiotherapy can take 5-6 weeks or more, the repeatability of the patient posture and the fastening method during treatment are important determinants of the success of radiotherapy. Many devices have been developed to minimize positional discrepancies, but all of the commercial devices used in clinical practice are operated manually and require customized fixtures for each patient. This is inefficient and the performance of the fixture device depends on the operator's skill. Therefore, this study developed an automated head-and-neck immobilizer that can be used during radiotherapy and evaluated the positioning reproducibility in a phantom experiment. To eliminate interference caused by the magnetic field from computed tomography hardware, Ni À Ti shape-memory alloy wires were used as the actuating elements of the fixtures. The resulting positional discrepancy was less than 5 mm for all positions, which is acceptable for radiotherapy. & 2015 Society of CAD/CAM Engineers. Production and hosting by Elsevier. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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The dosimetric consequences of anatomic changes in head and neck radiotherapy patients

Cited by 27 publications

References 23 publications

Identifying patients who may benefit from adaptive radiotherapy: Does the literature on anatomic and dosimetric changes in head and neck organs at risk during radiotherapy provide information to help?

Identifying patients who may benefit from adaptive radiotherapy: Does the literature on anatomic and dosimetric changes in head and neck organs at risk during radiotherapy provide information to help?

Parotid gland volumetric changes during intensity-modulated radiotherapy in head and neck cancer

Shape memory alloy (SMA)-based head and neck immobilizer for radiotherapy

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