Four-dimensional CT analysis of vocal cords mobility for highly focused single vocal cord irradiation

Osman, Sarah; Boer, Hans C.J. de; Heijmen, B.; Levendag, Peter C.

doi:10.1016/j.radonc.2008.05.016

Cited by 23 publications

(20 citation statements)

References 43 publications

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“…Future studies might serve to reduce dose further when appropriate to the arytenoids, the uninvolved contralateral cord, the cricopharyngeal inlet, and portions of the thyroid gland. Already, four-dimensional CT data have been reported from an investigation of the feasibility of single vocal cord radiation in early glottic cancer (55). Additional safe and effective small-volume dose escalation could reduce treatment duration.…”

Section: Discussionmentioning

confidence: 99%

Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1–2 Glottic Cancer

Rosenthal

Fuller

Barker

et al. 2010

International Journal of Radiation Oncology*Biology*Physics

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Purpose To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience. Methods and Materials Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets from 6 T1–2 conventionally treated glottic cancer patients were used to create both conventional IMRT plans. We developed a simplified IMRT planning algorithm with three fields and limited segments. Conventional and IMRT plans were compared using generalized equivalent uniform dose and dose–volume parameters for in-field carotid arteries, target volumes, and organs at risk. We have treated 11 patients with this simplified IMRT technique. Results Intensity-modulated radiotherapy consistently reduced radiation dose to the carotid arteries (p < 0.05) while maintaining the clinical target volume coverage. With conventional planning, median carotid V35, V50, and V63 were 100%, 100%, and 69.0%, respectively. With IMRT planning these decreased to 2%, 0%, and 0%, respectively (p < 0.01). Radiation planning and treatment times were similar for conventional radiotherapy and IMRT. Treatment results have been excellent thus far. Conclusions Intensity-modulated radiotherapy significantly reduced unnecessary radiation dose to the carotid arteries compared with conventional lateral fields while maintaining clinical target volume coverage. Further experience and longer follow-up will be required to demonstrate outcomes for cancer control and carotid artery effects.

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Section: Discussionmentioning

confidence: 99%

Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1–2 Glottic Cancer

Rosenthal

Fuller

Barker

et al. 2010

International Journal of Radiation Oncology*Biology*Physics

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“…It was found that the movement of the vocal cords with breathing is minimal (6). In another study, it was shown that it is possible to reduce the interfraction setup errors to submillimeter values using cone beam CT scans in an on-line correction protocol (7).…”

Section: Introductionmentioning

confidence: 99%

Imrt in Image-Guided Single Vocal Cord Irradiation

Osman¹,

Astreinidou²,

Keskin-Cambay³

et al. 2009

Radiotherapy and Oncology

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Purpose: We have been developing an image-guided single vocal cord irradiation technique to treat patients with stage T1a glottic carcinoma. In the present study, we compared the dose coverage to the affected vocal cord and the dose delivered to the organs at risk using conventional, intensity-modulated radiotherapy (IMRT) coplanar, and IMRT non-coplanar techniques. Methods and Materials: For 10 patients, conventional treatment plans using two laterally opposed wedged 6-MV photon beams were calculated in XiO (Elekta-CMS treatment planning system). An in-house IMRT/beam angle optimization algorithm was used to obtain the coplanar and non-coplanar optimized beam angles. Using these angles, the IMRT plans were generated in Monaco (IMRT treatment planning system, Elekta-CMS) with the implemented Monte Carlo dose calculation algorithm. The organs at risk included the contralateral vocal cord, arytenoids, swallowing muscles, carotid arteries, and spinal cord. The prescription dose was 66 Gy in 33 fractions. Results: For the conventional plans and coplanar and non-coplanar IMRT plans, the population-averaged mean dose ± standard deviation to the planning target volume was 67 ± 1 Gy. The contralateral vocal cord dose was reduced from 66 ± 1 Gy in the conventional plans to 39 ± 8 Gy and 36 ± 6 Gy in the coplanar and non-coplanar IMRT plans, respectively. IMRT consistently reduced the doses to the other organs at risk. Conclusions: Single vocal cord irradiation with IMRT resulted in good target coverage and provided significant sparing of the critical structures. This has the potential to improve the quality-of-life outcomes after RT and maintain the same local control rates.

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“…Targeting only the involved vocal cord with RT could further improve voice quality, and reduce the radiation exposure of the surrounding OAR. Osman et al (9)(10)(11)(12), Levendag et al (13) and Kwa et al (14) explored the technical feasibility, and dosimetric advantages, of targeting only a single affected vocal cord with IMRT for T1a glottic cancer.…”

Section: Discussionmentioning

confidence: 99%

“…However, to date, few studies have investigated the possibility of changing the target volume. Only one institution in the Netherlands has investigated limiting the IMRT target volume to a single affected vocal cord for T1a glottic cancer (9)(10)(11)(12)(13)(14); their studies revealed that IMRT with a limited target volume was associated with a reduction in the irradiation of adjacent normal tissue. However, the oncological outcomes of limiting the target volume to a single vocal cord throughout the course of RT remain to be elucidated.…”

Section: Introductionmentioning

confidence: 99%

Volumetric modulated arc radiotherapy of the whole larynx, followed by a single affected vocal cord, for T1a glottic cancer: Dosimetric analysis of a case

Yeo

2016

Molecular and Clinical Oncology

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Abstract. Radiation therapy (RT) and endolaryngeal surgery are standard treatments for early-stage glottic cancer. They have closely matched oncological outcomes; however, it is debatable which method is superior in terms of functional outcomes. Several dosimetric studies have demonstrated that, compared with conventional RT, intensity-modulated RT (IMRT) reduces unnecessary radiation of the adjacent normal tissues, including the carotid artery and thyroid gland. However, RT targets the whole larynx, whereas endolaryngeal surgery is a highly focused treatment involving the en bloc resection of a tumor with safety margins. For T1a glottic cancer, in which the tumor is limited to one vocal cord, the technical feasibility of targeting IMRT on the single vocal cord affected has been investigated; however, the clinical feasibility and the possibility of inferior local control remain to be elucidated. In the present case study, IMRT was used to treat the whole larynx first, and then to treat a single vocal cord. The patient in the present study had T1a glottic cancer, and received volumetric modulated arc therapy with a total dose of 63 Gy/28 fractions. The first treatment phase (40.5 Gy/18 fractions) targeted the whole larynx to eliminate subclinical disease. The second treatment phase (22.5 Gy/10 fractions) targeted only the involved vocal cord. During this treatment phase, the exposure of the non-involved right vocal cord, the right carotid artery and the thyroid gland to the radiation was lower compared with the continuation of the initial treatment approach. These findings suggested that changing the target volume from the whole larynx to the affected vocal cord during the course of IMRT is feasible for T1a glottic cancer, and that it may reduce functional side effects while maintaining oncological outcomes.

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Four-dimensional CT analysis of vocal cords mobility for highly focused single vocal cord irradiation

Cited by 23 publications

References 43 publications

Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1–2 Glottic Cancer

Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1–2 Glottic Cancer

Imrt in Image-Guided Single Vocal Cord Irradiation

Volumetric modulated arc radiotherapy of the whole larynx, followed by a single affected vocal cord, for T1a glottic cancer: Dosimetric analysis of a case

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