Orthovoltage radiotherapy in the management of medial canthal basal cell carcinoma

Depth Dose Enhancement in Orthovoltage Nanoparticle-Enhanced Radiotherapy: A Monte Carlo Phantom Study

BACKGROUND

This study was to examine the depth dose enhancement in orthovoltage nanoparticle-enhanced radiotherapy for skin treatment by investigating the impact of various photon beam energies, nanoparticle materials, and nanoparticle concentrations.

METHODS

A water phantom was utilized, and different nanoparticle materials (gold, platinum, iodine, silver, iron oxide) were added to determine the depth doses through Monte Carlo simulation. The clinical 105 kVp and 220 kVp photon beams were used to compute the depth doses of the phantom at different nanoparticle concentrations (ranging from 3 mg/mL to 40 mg/mL). The dose enhancement ratio (DER), which represents the ratio of the dose with nanoparticles to the dose without nanoparticles at the same depth in the phantom, was calculated to determine the dose enhancement.

RESULTS

The study found that gold nanoparticles outperformed the other nanoparticle materials, with a maximum DER value of 3.77 at a concentration of 40 mg/mL. Iron oxide nanoparticles exhibited the lowest DER value, equal to 1, when compared to other nanoparticles. Additionally, the DER value increased with higher nanoparticle concentrations and lower photon beam energy.

CONCLUSIONS

It is concluded in this study that gold nanoparticles are the most effective in enhancing the depth dose in orthovoltage nanoparticle-enhanced skin therapy. Furthermore, the results suggest that increasing nanoparticle concentration and decreasing photon beam energy lead to increased dose enhancement.

A new 3D printed applicator with radioactive gel for conformal brachytherapy of superficial skin tumors

Surface brachytherapy is an effective method in the treatment of skin cancer. Current skin brachytherapy techniques are based on the placement of a source of gamma or X-ray photons in a close distance from the skin to irradiate the lesion. Due to the nature of photons, radiation dose in these methods may affect healthy tissue as well as sensitive structures around the target. In order to minimize unwarranted and incidental exposure, we propose a new skin brachytherapy applicator based upon beta particles which have penetration ranges of a few millimeters in tissue. The proposed concept is radioactive gel housed within a pre-designed tumor-specific applicator matching the topology of the skin lesion. The particles mixed with the gel showed a uniform distribution pattern, which is an essential prerequisite in having a uniform dose profile on the skin surface. Based on the dose calculation data from the proposed concept, the dose delivered to the depth of 4500 μm in skin tissue is 10% of the dose delivered to the surface of the tumor, making it suitable is treating thin skin tumors especially when located on top of the bone. Through the innovative combination of radioactive gel and tumor-specific applicator, the radiation entering the skin surface can be personalized while minimizing the adverse effects of undesired exposure to the surrounding healthy tissue.

Radiation therapy techniques in the treatment of skin cancer: an overview of the current status and outlook

Nonmelanoma skin cancer (NMSC) is a major health concern due to its high incidence rate, its negative impact on the quality of life of patients as well as the associated economic burden to the healthcare system. Surgery is currently the primary treatment offered for skin cancer patients but not applicable or available in all cases. Radiation therapy (RT), with its long successful history in the management of cancer, has shown to be an effective alternative or complementary method in cutaneous oncology. Specifically, for dermatology applications, RT is very often the preferred option due to its favorable cosmetic results, besides the excellent control rate of the tumor. During the last 120 years since the introduction of treatments based on ionizing radiation, several techniques in this area have been developed. Radionuclide brachytherapy, electronic brachytherapy, X-ray therapies with kilovolt (kV) to megavolt (MV) photons and electron beam therapy are the established methods that are currently used on skin cancer patients. The purpose of this article is to overview these techniques and discuss the pros and cons of these methods in dermatology practices. Additionally, a new approach of beta RT of superficial skin tumors is discussed, which may offer exciting features in the management of NMSC.

Place de la radiothérapie dans le traitement du carcinome basocellulaire

Radiotherapy is an available but not well-known treatment for management of basal cell carcinoma. National organizations have established that standard therapy is complete surgical removal and radiation therapy is an option for inoperable tumors or those where the post-operative defect would be cosmetically disfiguring or functionally disabling. These therapeutic options, with histological sample, should be considered in the multidisciplinary management of patients with basal cell carcinoma. There are several types of radiotherapy: external radiation or interstitial brachytherapy, unfortunately, there is no consensus in the literature and the range of radiation regimens in common use is large. Very few randomized studies have been conducted to defi the optimum treatment in terms of recurrence rate, cosmetic outcome and side-eff In most of studies, the overall local control rate was between 80-100% and over 90% of patients reported good or excellent cosmetic outcome. Side-eff of radiotherapy most commonly reported are minor but in young patients one must be alert to the theoretical possibility of the induction of secondary malignancies. Cet article fait partie du numéro supplément Prise en charge des carcinomes basocellulaires difficiles à traiter réalisé avec le soutien institutionnel de Sun Pharma.

[Adjuvant contact radiotherapy for conjunctival malignancies: Preliminary results of a series of 14 patients treated with the Papillon 50 machine]

PURPOSE

To evaluate the results of an adjuvant contact irradiation using 50kV photons after resection of conjunctival malignancies.

MATERIALS AND METHOD

From 2012 to 2014, 14 patients (male: nine; female: five) have been treated by contact irradiation after resection of a malignant tumor of the conjunctiva (melanoma: five patients; malignant fibrous histiocytoma: one patient; carcinoma: eight patients) The treatment was performed using the Papillon 50 machine (Ariane). Three to four sessions were delivered, each giving a dose of 10Gy. The median follow-up in survivors was 33 months.

RESULTS

The tolerance was good. A cataract was seen in one patient, and a moderate eye dryness in one. There was no corneal ulcer. One patient died of intercurrent disease. One patient with carcinoma recurred locally.

CONCLUSION

Adjuvant contact radiotherapy provides a good local control after resection of conjunctival malignancies (melanoma, malignant histiocytofibroma, carcinoma). Thanks to its precision, this technique is well tolerated with a low rate of complications. Furthermore, it is delivered on an ambulatory basis.

Orthovoltage X-rays for Postoperative Treatment of Resected Basal Cell Carcinoma in the Head and Neck Area

Background:

Surgery is the golden standard for treating basal cell carcinomas. In case of positive tumor margins or recurrent disease, postoperative adjuvant or salvaging therapy is suggested to achieve good local control.

Objective:

To retrospectively report on local control and toxicity of postoperative radiotherapy by means of orthovoltage X-rays for residual or recurrent basal cell carcinoma after surgery in the head and neck area.

Methods:

Sixty-six surgically resected residual or recurrent basal cell carcinomas of the head and neck region were irradiated postoperatively by means of orthovoltage X-rays at the Netherlands Cancer Institute between January 2000 and February 2015.

Results:

After a median follow-up duration of 30.5 months, only 5 recurrences were reported. The 5-year local control rates at 1, 3, and 5 years were 100%, 87%, and 87%, respectively. The 5-year local control rate was 92% for immediate postoperative radiotherapy of incompletely resected basal cell carcinomas, 90% for recurrences after 1 previously performed excision, and 71% for multiple recurrences, namely, a history of more than 1 excision ( P = .437). Acute toxicity healed spontaneously within 3 months. Late toxicities were mild.

Conclusion:

Radiotherapy by means of orthovoltage X-ray is an excellent alternative for re-excision in case of incompletely resected or recurrent basal cell carcinomas that are at risk of serious functional and cosmetic impairments after re-excision, with a 5-year local control rate of 87% and a low toxicity profile.

Electron beam radiotherapy for the management of recurrent extensive ocular surface squamous neoplasia with orbital extension

Recurrent extensive ocular surface squamous neoplasia (OSSN) with orbital invasion can be successfully managed with external radiotherapy using electrons resulting in eye and vision salvage. We report a case of right eye recurrent OSSN in an immunocompetent adult Indian male, with extensive orbital involvement. The patient had two previous surgical excisions with recurrent disease. At this stage, conventionally exenteration is considered the treatment modality. However, he was treated with 5040 cGy radiotherapy (15eV electrons) resulting in complete disease regression. At the end of 3 years follow-up, the patient was disease free, maintained a vision of 20/25, with mild dry eye, well-managed with topical lubricants. Extensive OSSN with orbital invasion does not always need exenteration. External beam electron radiotherapy provides a noninvasive cure with organ and vision salvage and should be considered in extensive OSSN not amenable to simple excision biopsies. Long-term studies to evaluate the effect of radiation on such eyes are suggested.

Management of BCC and SCC of the Head and Neck

Background

For decades radiotherapy (RT) has been shown to treat skin cancers; however, the indications, delivery methods, and techniques for RT continue to evolve.

Methods

Relevant prospective and retrospective reports were reviewed that addressed outcomes with, indications for, and delivery techniques used with RT for the management of cutaneous basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the head and neck.

Results

Rates of local control higher than 90% are typically achievable for early-stage BCC and SCC of the head and neck. RT is often recommended for tumors located in cosmetically or functionally sensitive areas of the face, for patients who cannot tolerate anesthesia, for those taking anticoagulants, or for patients who prefer RT to other treatment options. A wide range of radiation doses, daily fractionation schedules, and radiation techniques have been shown to be effective for management. In general, postoperative local radiation is recommended following excision for patients with high-risk factors, including those whose tumors have close or positive margins, perineural invasion, invasion of the bone or nerves, or those with recurrent disease.

Conclusions

RT plays an integral role in the treatment of primary and postoperative cutaneous BCC and SCC of the head and neck. Prospective trials are in progress to address the roles of concurrent systemic therapy and RT for both cutaneous BCC and SCC.

Orthovoltage for basal cell carcinoma of the head and neck: Excellent local control and low toxicity profile

OBJECTIVES/HYPOTHESIS

Evaluation of treatment results of orthovoltage X-rays for a selection of previously untreated favorable basal cell carcinomas (BCC) in the head and neck area concerning local control, cosmetic and functional outcome, and toxicity profile.

METHODS

A consecutive series of patients with primarily treated BCCs who were irradiated by means of orthovoltage X-rays in the Netherlands Cancer Institute in Amsterdam between January 2000 and February 2015 were retrospectively evaluated.

RESULTS

Two hundred fifty-three BCCs in 232 patients were primarily treated with orthovoltage X-rays. The local control rates at 1, 3, and 5 years for this selection of basal cell carcinomas were 98.9%, 97.5%, and 96.3%, respectively. Tumor size was the only significant predictor for local control because BCCs < 20 mm had a significantly higher 5-year local control rate than lesions ≥ 20 mm (96.8% vs. 89.4%, P = 0.041). Acute toxicity healed spontaneously without medical intervention, and late toxicity rates were low. Functional impairments were negligible, and the cosmetic outcome was excellent.

CONCLUSION

Orthovoltage therapy for well-selected favorable BCCs in the head and neck area resulted in excellent local control rates, a low toxicity profile, and apparently satisfactory functional and cosmetic outcomes. Orthovoltage irradiation is a good alternative for surgery for BCCs with favorable histologic prognosis at locations that are at risk for postoperative functional or cosmetic changes, such as the nose or canthus.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:1796-1802, 2016.

Orthovoltage radiotherapy for nonmelanoma skin cancer (NMSC): Comparison between 2 different schedules

BACKGROUND

Radiotherapy is an established treatment for some types of patients with nonmelanoma skin cancer. A hypofractionated schedule has been proposed as a valuable option for elderly disabled patients to minimize the number of hospital visits.

OBJECTIVE

We sought to compare a weekly hypofractionated orthovoltage radiotherapy regimen with a standard daily one for the treatment of nonmelanoma skin cancer.

METHODS

A retrospective cohort study was performed on 436 tumors. Overall survival, disease-free survival, and cosmetic outcome were measured. Life-table analysis, Kaplan-Meier survival analysis, and multivariate Cox regression model were performed.

RESULTS

The hypofractionated regimen was not associated with increased recurrence rates and mortality, or with a poorer cosmetic outcome, when compared with the daily schedule.

LIMITATIONS

Absence of complete information about acute treatment toxicity and a shorter follow-up time for patients receiving the weekly schedule are limitations of this study.

CONCLUSIONS

A weekly hypofractionated regimen of orthovoltage radiotherapy seems to be the most appropriate approach in elderly disabled patients with nonmelanoma skin cancers.

Role of in vivo dosimetry with radiochromic films for dose verification during cutaneous radiation therapy

PURPOSE

To evaluate the role of in vivo dosimetry with radiochromic films for dose verification in cutaneous radiation therapy (RT).

METHODS

Five patients with 8 cutaneous or sub-cutaneous malignancies of the face, neck, trunk and extremity receiving RT were included. Orthovoltage, megavoltage photon therapies were applied based on anatomic location. The delivered dose for each target was measured with GAFCHROMIC EBT3TM film. The differences between the prescribed and measured doses in each target were analyzed based on the RT characteristics, target location and custom patient set up. The accuracy of EBT3TM film measurement was verified by measurements in a solid water phantom.

RESULTS

The mean measured dose was -3.2% (-9.6% to +2.3%, P=0.86) lower than prescribed over 23 measurements. A wide range of under dose was detected in orthovoltage therapy when a gap existed between skin and a closed-ended applicator surface. The magnitude of the under dosage was correlated with the degree of the gap (P=0.01). The phantom study confirmed the accuracy of GAFCHROMIC EBT3TM film measurement and found that the low measured dose in orthovoltage therapy was caused by the deviation from the inverse square law (ISL) of the beam output at extended source surface distance (SSD) for closed-ended applicators.

CONCLUSIONS

A significantly low delivered dose for extended SSD orthovoltage therapy was demonstrated during cutaneous RT. The dose fall-off with distance is not completely compensated by the ISL standoff correction for orthovoltage therapy. GAFCHROMIC EBT3™ film is a useful and accurate tool for quality assurance of patients receiving a curative intended cutaneous RT.

Radiotherapy treatment of non-melanoma skin cancer: a survey of current UK practice and commentary

OBJECTIVE

In the ongoing absence of available trial data, a national survey was carried out to provide details on radiotherapy treatment strategy for non-melanoma skin cancer (NMSC).

METHODS

A survey of clinical oncologists treating NMSC was performed. The respondents were asked for basic information on workload as well as a proposed treatment strategy for various clinical scenarios for patients of varying fitness.

RESULTS

A total of 43 completed and 20 partially completed surveys were received. There was a wide variation in the workload and additional disease sites that respondents had responsibility for. Kilovoltage radiotherapy was available to 81% of responders. The respondents' approach was affected by the fitness of patients, with longer fractionation regimes proposed for younger, fitter patients and shorter or non-standard fractionations more likely for the infirm elderly. Four daily fractionation regimes (18-20 Gy in 1 fraction, 35 Gy in 5 fractions, 45 Gy in 10 fractions and 55 Gy in 20 fractions) were most commonly suggested. There was a large degree of variation in non-standard fractions proposed with significant potential differences in radiobiological effect. Concern over the use of kilovoltage photons on skin over cartilage was apparent, as was a reluctance to use radiotherapy in areas of increased risk of poor wound healing.

CONCLUSION

The survey results largely showed practice to be in line with available published evidence. The variation seen in some areas, such as non-standard fractionation, would benefit from the publication of local outcomes to achieve a more consistent approach.

ADVANCES IN KNOWLEDGE

This study provides information on national practices and identifies variations, particularly within widespread use of non-standard fractionation.

Recent Advances in Ophthalmic Plastic Surgery: Part 1-Eyelid

PURPOSE

The objective of this study was to provide an update of the current literature in ophthalmic and facial plastic surgery, specifically related to disorders of the eyelid.

DESIGN

This was a review of published literature from January 2012 to June 2013 METHODS: The authors conducted a PubMed literature search of English-language articles published between January 2012 and June 2013 using the following search terms: eyelid, congenital, acquired, infection, inflammation, trauma, tumor, ptosis, entropion, ectropion, lagophthalmos, botulinum toxin, fillers, blepharoplasty, and miscellaneous topics related to the disorders of the eyelid. The authors included original articles, review articles, and case reports with relevant new information that is of potential clinical use to a comprehensive ophthalmologist as well as to the subspecialist.

RESULTS

Current literature on the disorders of the eyelid is replete with useful clinical information of relevance to a practicing ophthalmologist. Major advances have been reported in understanding of the surgical anatomy and its applications, ptosis, entropion, ectropion, lagophthalmos, infection, inflammation, trauma, and tumors.

CONCLUSIONS

There seems to be tremendous excitement in revisiting the anatomy and pathology and modifying the management protocols and surgical procedures to achieve optimal results, as the subspecialty continues to advance at a brisk pace.