PO-0259 Single-fraction adjuvant electronic brachytherapy after resection of conjunctival carcinoma

A retrospective study was performed to assess the outcomes of a single-fraction adjuvant electronic brachytherapy (e-BT) approach for patients with squamous cell conjunctival carcinoma (SCCC). Forty-seven patients with T1–T3 SCCC were included. All patients underwent surgery followed by a single-fraction adjuvant e-BT with a porTable 50-kV device. Depending on margins, e-BT doses ranged between 18 to 22 Gy prescribed at 2 mm depth, resembling equivalent doses in 2 Gy (EQD2) per fraction of 46–66 Gy (α/β ratio of 8–10 Gy and a relative biological effect (RBE) of 1.3). The median age was 69 (29–87) years. Most tumors were T1 (40.4%) or T2 (57.5%) with a median size of 7 mm (1.5–20). Margins were positive in 40.4% of cases. The median time from surgery to e-BT was nine weeks (0–37). After a median follow-up of 24 (17–40) months, recurrence occurred in only two patients (6 and 7 months after e-BT), yielding a median disease-free survival (DFS) of 24 (6–40) months and DFS at two years of 95.7%. Acute grade 2 conjunctivitis occurred in 25.5%. E-BT is a safe and effective for SCCC treatment, with clinical and logistic advantages compared to classical methods. Longer follow-up and prospective assessment are warranted.

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Comparison of Electronic Brachytherapy and Mohs Micrographic Surgery for the Treatment of Early-Stage Non-Melanoma Skin Cancer: A Matched Pair Cohort Study

SKIN The Journal of Cutaneous Medicine ◽

10.25251/skin.1.supp.113 ◽

2017 ◽

Vol 1 ◽

pp. s114

Author(s):

Rakesh Patel ◽

Robert Strimling ◽

Stephen Doggett ◽

Mark Willoughby ◽

Erick Mafong ◽

...

Keyword(s):

Cohort Study ◽

Skin Cancer ◽

Early Stage ◽

Matched Pair ◽

Mohs Micrographic Surgery ◽

Micrographic Surgery ◽

Electronic Brachytherapy ◽

Non Melanoma Skin Cancer ◽

Melanoma Skin

Abstract Not Available

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Stereotactic radiosurgery versus stereotactic radiotherapy for patients with vestibular schwannoma: a Leksell Gamma Knife Society 2000 debate

Journal of Neurosurgery ◽

10.3171/jns.2000.93.supplement_3.0090 ◽

2000 ◽

Vol 93 (supplement_3) ◽

pp. 90-92 ◽

Cited By ~ 48

Author(s):

Mark E. Linskey

Keyword(s):

Gamma Knife ◽

Stereotactic Radiotherapy ◽

Three Dimensional ◽

Late Recurrence ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Complication Rates ◽

Content Type ◽

Single Fraction ◽

Fine Print

✓ By definition, the term “radiosurgery” refers to the delivery of a therapeutic radiation dose in a single fraction, not simply the use of stereotaxy. Multiple-fraction delivery is better termed “stereotactic radiotherapy.” There are compelling radiobiological principles supporting the biological superiority of single-fraction radiation for achieving an optimal therapeutic response for the slowly proliferating, late-responding, tissue of a schwannoma. It is axiomatic that complication avoidance requires precise three-dimensional conformality between treatment and tumor volumes. This degree of conformality can only be achieved through complex multiisocenter planning. Alternative radiosurgery devices are generally limited to delivering one to four isocenters in a single treatment session. Although they can reproduce dose plans similar in conformality to early gamma knife dose plans by using a similar number of isocenters, they cannot reproduce the conformality of modern gamma knife plans based on magnetic resonance image—targeted localization and five to 30 isocenters. A disturbing trend is developing in which institutions without nongamma knife radiosurgery (GKS) centers are championing and/or shifting to hypofractionated stereotactic radiotherapy for vestibular schwannomas. This trend appears to be driven by a desire to reduce complication rates to compete with modern GKS results by using complex multiisocenter planning. Aggressive advertising and marketing from some of these centers even paradoxically suggests biological superiority of hypofractionation approaches over single-dose radiosurgery for vestibular schwannomas. At the same time these centers continue to use the term radiosurgery to describe their hypofractionated radiotherapy approach in an apparent effort to benefit from a GKS “halo effect.” It must be reemphasized that as neurosurgeons our primary duty is to achieve permanent tumor control for our patients and not to eliminate complications at the expense of potential late recurrence. The answer to minimizing complications while maintaining maximum tumor control is improved conformality of radiosurgery dose planning and not resorting to homeopathic radiosurgery doses or hypofractionation radiotherapy schemes.

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