Medicina Nuclear e Radioterapia

Adjuvant radiotherapy is an integral part of breast cancer treatment, and there was a great evolution of radiotherapy techniques over the past few years. Intensity-modulated radiation therapy (IMRT) was developed in the 1990s as a modern technique aiming to spare normal tissues from toxic effects of radiotherapy. This study aimed at comparing the IMRT technique to the 3D-coformal radiotherapy technique (3D-CRT) in early breast cancer patients regarding the occurrence of acute skin toxicities and treatment-related lymphopenia (TRL). It is a prospective study conducted on 100 eligible patients who were divided equally between two groups; the first, are patients received adjuvant radiotherapy using IMRT technique and the second group were those who received 3D-CRT. Results showed that sever acute skin toxicity or moist desquamation in IMRT group was 6% vs. 18% in 3DCRT group (p<0.05). And, the sever TRL with IMRT technique was 9% compared 21% among those of the 3D-CRT group (p<0.05). The IMRT technique resulted in statistically significant lower incidence of sever acute skin toxicities as well as less sever TRL when compared with 3D-CRT technique.

Papillary and Follicular Differentiated thyroid carcinoma have a very good prognosis, such that survival in low-risk forms is comparable to a healthy person. However, the follicular thyroid carcinoma is typically more aggressive than the papillary one, so that in some patients the distant metastases represents the first clinical manifestation of the disease.

Although this is a rare condition, we can find asymptomatic distance metastases in the 18F-FDG PET/CT as “incidentalomas”, even in the absence of a primary tumor. This condition could be incorporated into the term occult thyroid carcinoma.

In patients with iodine avid metastatic differentiated follicular thyroid cancer, even if some metastatic lesions show pathological hypermetabolism to the 18F-FDG PET/CT scan, radioactive iodine therapy remains the treatment of choice. In this setting of patients the dosimetric study is mandatory.

Purpose: Whole brain radiation therapy remains standard for patients with multiple brain metastases not amenable to stereotactic irradiation. Incidental irradiation of the parotid glands can result in xerostomia. A novel technique (NT) using 3D conformal radiotherapy was used to decrease the radiation dose to the parotid glands and hence the risk of xerostomia.

Methods: CT simulations of 20 de-identified patients were randomly selected. For each patient, 3 different WBRT plans were generated. The first using the standard opposed laterals fields with the inferior border at C2, the second with the inferior border at C1 and the third using a NT. In the NT, we placed the isocenter 0.5-1 cm superior to the contoured parotid glands. Superior to the isocenter, two lateral fields were designed similar to the standard opposed laterals. Inferior to the isocenter, 2 oblique fields were used, conformal to the contoured brain, with a 1 cm collimation to the edge of the MLC. Prescription dose was 30 Gy in 10 fractions for all plans. Brain coverage and the means of the right, left and bilateral parotids were compared in each of the plans.

Results: In all three techniques of WBRT, brain coverage was adequate with 95% of the dose covering more than 95% of the brain volume. The average of the mean right parotid dose using C2, C1, and the NT were 17.7 Gy ± 4.4, 12.3 Gy ± 3.3, and 5.6 Gy ± 2.1. The average of the mean left parotid dose using C2, C1, and the NT were 18.3 Gy ± 4.2, 13.0 Gy ± 3.1, and 6.2 Gy ± 1.5. The average of the mean bilateral parotids dose using C2, C1, and the NT were 18.0 Gy ±4.0, 12.6 Gy ±2.8, and 5.8 Gy ±1.8.

Conclusion: Our simple new 3DCRT technique for WBRT significantly reduces mean parotid gland dose compared to the standard techniques.

Aim: The aim of this study was to evaluate the efficacy and outcome of early stage non-small cell lung carcinoma in elderly patients treated with SABR in a tertiary care cancer centre in rural India.

Materials and methods: This was a retrospective study. All cases of histopathologically proven, stage 1 lung cancer patients in whom surgical management was not feasible due to various reasons were included. It included patients treated from 2013 to 2018 at our centre. Case records and radiation treatment plans were reviewed and data was collected. All were T1/T2N0 cases. Dose schedules employed were 48 Gy in 4 fractions, 60 Gy in 5 fractions and 60 Gy in 3 fractions. The primary end point was the tolerance and toxicity profile.

Results: A total of 5 patients were treated at our center from 2013 to 2017. All were males. Mean age was 72 years. One had squamous cell and four had adenocarcinoma histology. The dose fractionation schedules employed where 48 Gy in 4 fractions, 60 Gy in 5 fractions and 60 Gy in 3 fractions. All tolerated treatment well. No grade 3 or 4 toxicities were observed.

Conclusion: SABR is a feasible alternative curative treatment modality in stage 1 NSCLC. It is feasible and was tolerated well even in the elderly age group. This can be offered to medically inoperable patients as a curative treatment and is possible in a resource constrained setting also. This modality is a promise to future for operable stage 1 NSCLC also. But more randomized studies need to be carried out before applying it to operable lung cancer patients.