Volumetric modulated arc therapy (VMAT) for skin field cancerisation of the nose - A technique and case report

We describe three cases of keratoacanthomas (KAs) following definitive volumetric modulated arc therapy (VMAT) for skin field cancerisation (SFC). One lesion arose on a back in an area that had received a total of 30.6 Gy in 17 fractions. It first became apparent at 24 days post RT and resolved without treatment by 150 days. The other arose on a nasal alar in the beam penumbra that received 36Gy in 25 fractions, appearing at 57 days and resolving without treatment by 85 days. A third case occurred in an immunosuppressed patient. She developed KAs in one of two areas irradiated with lesions appearing at 21 days post RT and finally resolving at 300 days despite acitretin. The area received a total dose of 41.4 Gy in 23 fractions. Spontaneous resolution of index KA confirmed the diagnosis in all cases. On average, the patients were 79 years of age, the area bearing the KA had received an average of 36Gy in 22 fractions. The average onset of the KAs was 24 days or 3.5 weeks or one month after RT, and always soon after reepithelization was completed. Resolution was at an average of 168 days or 24 weeks or 6 months after the completion of RT. In all three cases other lesions arose adjacent to them and, in each case, one of these other lesions was excised with histopathology confirming squamo-proliferative lesions. There has been no recurrence at least 6 months after the last follow up. To our knowledge these are the first three cases of KA described following definitive VMAT for SFC. The possibility of KA arising after RT does need to be considered during the consent process.

Section: Treatment Prescription and Progressmentioning

confidence: 99%

Keratoacanthomas following definitive volumetric modulated arc radiotherapy for skin field cancerization

Fogarty¹,

Mullin²,

Lochhead³

et al. 2019

“…Higher dose delivery is possible using a simultaneous integrated boost (SIB) approach. 11 Draining lymph node fields need palpating, and signs of perineural invasion need to be excluded. Investigations will be driven by the history and examination.…”

Section: Examinationmentioning

confidence: 99%

“…The areas drawn on the patient are copied onto plastic sheets as templates 11 which are then stored electronically in the patient's file. This record allows fields to be reproduced in the future to determine if disease recurrence is in-field, at field edge, or out of field.…”

Section: Rt Planning Simulationmentioning

confidence: 99%

A radiation oncology approach for using definitive radiotherapy with volumetric modulated arc therapy (VMAT) for skin field cancerisation (SFC)

Fogarty¹,

Christie²,

Kaminski³

et al. 2018

Self Cite

Patients with long histories of chronic ultraviolet radiation exposure can suffer from skin field cancerisation (SFC). They can have poor oncological outcomes and quality of life (QoL) with itch, flaking skin, and suboptimal cosmesis. Current treatments have high rates of treatment failure and non-compliance. Definitive radiotherapy (RT) with volumetric modulated arc therapy (VMAT) has been proposed as a possible treatment modality in this clinical setting. This article provides a theoretical background to assist radiation oncologists (ROs) to implement this technique in their skin cancer practice. The article covers the importance of the relationship between the skin physician and the RO, how to best understand the patient with SFC, patient assessment, preparation for RT, and RT planning and treatment. The article also highlights the difficulty in measuring toxicities with the currently available tools and suggests future research options for affected patients. Clinical studies to further refine the use of RT in patients with SFC are warranted.

“…9 New radiation techniques have been developed, especially volumetric modulated arc therapy (VMAT) which is a further evolution of intensity modulated radiotherapy (IMRT). [10][11][12] VMAT allows definitive radiation treatment of large convex fields (e.g. scalp, forehead, cheeks, forearms and legs).…”

Section: Introductionmentioning

confidence: 99%

Volumetric modulated arc therapy (VMAT) for extensive skin field cancerisation (ESFC) – exploring the limits of treatment volumes with a case series of backs

Wong¹,

Christie²,

Hellyer³

et al. 2020

Skin field cancerisation arises from prolonged sun exposure and increases with age. Multiple areas of the skin can be involved resulting in poor quality of life and cosmesis and even death. The long-term efficacy of traditional treatments such as topical creams is disappointing. Volumetric modulated arc therapy (VMAT) is a relatively new radiation technique that allows the definitive treatment of large convex fields. Extra dose can also be delivered simultaneously using a boost technique to proven areas of macroscopic invasive disease. In what we believe is the first publication of its kind, we present a retrospective case series of 15 patients with 21 areas treated with VMAT to the back. Treatment is feasible but areas of skin cancerisation over 800 cm2 should not be treated in one course but broken into smaller fields separated by adequate breaks. Care should be taken when treating large areas of the spine as pancytopenia may result and routine blood counts between treatment courses should be considered. More research is warranted to confirm the dose and efficacy outcomes, but this technique may represent a new therapeutic option for patients with extensive skin field cancerisation of the back.