Plaque radiotherapy in recurrent or incomplete-excised conjunctival squamous cell carcinoma and melanoma

To assess the results of brachytherapy in patients with recurrent or incomplete excised conjunctival squamous cell carcinoma [SCC] and malignant melanoma. Three patients underwent brachytherapy of one eye and one patient underwent brachytherapy of both eyes with ruthenium-106 [RU-106] plaques, all of them had a history of incomplete resection or recurrence of the tumor after surgery. All patients were male with an average age at diagnosis of 54 years [range, 34-76 years].The shape and the size of plaques were determined based on location and size of the suspected area. The plaque was inserted to deliver a target dose of 80-100 Gy in the region of conjunctival malignancy. The diagnosis was squamous cell carcinoma in three eyes and conjunctival melanoma in two eyes. All patients had surgical history of one to three previous excisions with or without cryotherapy before brachytherapy. There were microscopic residual tumors after excision in 2 eyes and recurrent lesion was evident in 3 other eyes. A mean dose of 95 Gy was delivered to the tumor bed. Complete tumor regression without any evidence of recurrent lesion was obtained in all five eyes. The patients were followed for 32 months on average [range, 18-42 months]. No radiation related complication was detected, with an exception of a dry eye in the last follow up. Brachytherapy with RU-106 plaque is an alternative method for treatment of selected patients with recurrent or residual conjunctival SCC and melanoma

Radiotherapy and radiosurgery for Cushing's disease

Patients with residual or recurrent Cushing's disease receive external beam radiotherapy (RT) with the aim of achieving long-term tumour control and normalization of elevated hormone levels. Treatment is given either as conventional radiotherapy using conformal techniques or as stereotactic radiotherapy, which is either used as fractionated treatment (SCRT) or as single fraction radiosurgery (SRS). We describe the technical aspects of treatment and report a systematic review of the published literature on the efficacy and toxicity of conventional RT, SCRT and SRS. There are no studies directly comparing the different radiation techniques and the reported results are inevitably of selected patients by investigators with interest in the treatment tested. Nevertheless the review of the published literature suggests better hormone and tumour control rates after fractionated irradiation compared to single fraction radiosurgery. Hypopituitarism represents the most commonly reported late complication of radiotherapy seen after all treatments. Although the incidence of other late effects is low, the risk of radiation injury to normal neural structures is higher with single fraction compared to fractionated treatment. Stereotactic techniques offer more localized irradiation compared with conventional radiotherapy, however longer follow-up is necessary to confirm the potential reduction of long-term radiation toxicity of fractionated SCRT compared to conventional RT. On the basis of the available literature, fractionated conventional and stereotactic radiotherapy offer effective treatment for Cushing's disease not controlled with surgery alone. The lower efficacy and higher toxicity of single fraction treatment suggest that SRS is not the appropriate therapy for the majority of patients with Cushing's disease.

Pacientes com doença de Cushing residual ou recorrente recebem radioterapia externa em feixe (RT) com o objetivo de alcançar um controle tumoral prolongado e a normalização dos níveis hormonais elevados. O tratamento é realizado tanto com RT convencional, usando técnicas conformacionais, ou com RT estereotáxica, que é usada tanto como tratamento fracionado (RTF) ou como radiocirurgia em procedimento único (RCU). Descreveremos os aspectos técnicos do tratamento e mostraremos uma revisão sistemática da literatura sobre a eficácia e toxicidade da RT convencional, da RTF e da RCU. Não existem estudos comparando diretamente as diferentes técnicas de radiação, e os resultados reportados são inevitavelmente os de pacientes selecionados pelos investigadores com interesse no tratamento testado. De qualquer maneira, a revisão dos dados publicados sugere que há melhores taxas de controle hormonal e tumoral após RTF em comparação com RCU. O hipopituitarismo representa a complicação tardia mais comumente relatada da RT, vista após todos os tipos de tratamento. Embora a incidência de outros efeitos tardios seja baixa, o risco de a radiação comprometer estruturas neurais normais é mais elevado com RCU do que com RTF. Técnicas estereotáxicas oferecem irradiação mais localizada se comparadas com a RT convencional, embora um acompanhamento prolongado seja necessário para confirmar a possível redução da toxicidade continuada da radiação na RTF em comparação com a RT convencional. Com base na literatura disponível, a RT fracionada convencional e a estereotáxica oferecem tratamento efetivo para a doença de Cushing não controlada isoladamente pela cirurgia. A baixa eficácia e alta toxicidade do tratamento em dose única sugere que a RCU não seja a terapia mais apropriada para a maioria dos pacientes com doença de Cushing.

Optimization of ablative dose for thyroid cancer

Esta investigación propone un protocolo de planificación individualizada de dosis ablativas basado en el metabolismo individual del paciente y en la medida de la masa de los remanescientes tiroideanos. Utilizando SPECT, el metabolismo de I-131 fue estudiado en 9 pacientes tiroidectomizados, y la actividad optima para la terapia fue calculada y comparada con la actividad fija establecida de 3.7 GBq (100 mCi), que és en general administrada. Fue observado que 78 por ciento de las pacientes podrian tener recibido actividades reduzidas de 131I (de 0.8-3.2 GBq (20-87 mCi)). Además, 33 por ciento destes pacientes podrian recibir actividades tan bajas que no necesitarian internamiento hospitalar. Visando facilitar los calculos de la actividad terapeutica optima de 131I hacia pacientes individuales, un programa de planificación de dosis simples y rápido fue criado (PlanDose). Este protocolo de cálculo de actividades de 131I específicas para el paciente permite una mejor determinación de la dosis ablativa necesaria en caso de pacientes con carcinoma diferenciado de la tiroide, y és un ejemplo de optimización de la práctica de protección radiologica.

This investigation proposes a protocol for planning of thyroid ablation therapy for individual patients, based on individual patient metabolic data and measured thyroid remnant masses. Using SPECT, I-131 uptake and clearance was studied in 9 patients who had undergone thyroidectomies, and the optimum activity for their therapy was calculated and compared to the established fixed activity of 3.7 GBq (100 mCi), which normally would have been assigned. It was observed that 7 of the patients could have received reduced activities of 131I (from 0.8-3.2 GBq (20-87 mCi)). In addition, 3 patients could have received low enough activities to have been discharged from the hospital. To facilitate the calculations of the optimum therapeutic activity of 131I for individual patients, a computer program was created (PlanDose). This protocol of calculated optimal patient-specific 131I activities allows a better determination of the necessary ablative dose for patients with differentiated carcinoma of the thyroid, and is an important example of optimization of the practice of radiation protection.

The efficacy of postoperative radiation therapy in patients with carcinoma of the buccal mucosa and lower alveolus with positive surgical margins.

PURPOSE: A retrospective analysis to determine the efficacy of postoperative radiation therapy, in patients of carcinoma of the buccal mucosa and lower alveolus with pathologically verified positive surgical margins (PSM). MATERIALS AND METHODS: Ninety-four patients were analysed, who underwent surgery plus postoperative radiation therapy. Twenty-nine patients (31%) had PSM. Other pathological factors like nodal stage, number of nodes, bone involvement etc. were also analysed. RESULTS: Disease free survival (DFS) of patients with a PSM was significantly worse when compared with those with negative surgical margins (NSM). Poor DFS was also observed for variables like nodal stage, number of nodes and extranodal extension and radiation dose. In multivariate analysis only two variables showed significant impact on DFS, those were surgical margins and number of nodes. CONCLUSION: To conclude in our study median dose of 60 Gy in PSM patients was not able to improve DFS and showed poor results as compared with NSM patients. There is also evidence from other studies, to suggest that post-operative radiation doses upto 60 Gy may not be sufficient to overcome this poor prognostic factor. To overcome this poor prognostic group patients, we in our institution are now employing radiation dose intensification and altered fractionation in an effort to improve our results. In physically fit patients we are trying to administer concomitant chemotherapy along with radiation treatment.