Non melanoma skin cancer (NMSC) is the most common malignancy. For many decades, radiation therapy (RT) has played a significant role in treating NMSC. High Dose Rate (HDR) brachytherapy (BT) approaches have a paramount relevance due to their adaptability, patient protection and variable dose fractionation schedules. Several innovative applicators have been introduced to the BT community and the use of skin BT has increased significantly. The Valencia applicator is a new superficial device that improves the dose distribution compared with the Leipzig applicator design. The purpose of this work is to assess the tumor control, cosmesis and toxicity events in patients with NMSC treated with the Valencia Applicator and a new regimen of hypofractionation. From January 2008 to March 2010, 32 patients with 45 NMSC were treated with the Valencia applicator. The GTV was visually assessed, but the tumor depth was evaluated using ultrasound imaging. All lesions for the selected cases were limited to 4 mm depth. The prescription dose was 42 Gy in 6 or 7 fractions (Biological effective dose (BED) ≈ 70 Gy), delivered twice a week. The 98% of the lesions were locally controlled at 47 months from treatment. The 93% of patients were out at least 36 months from treatment. Treatment was well tolerated in all cases. The highest skin toxicity was Grade 1 RTOG/EORTC, having resolved with topical treatment at 4 weeks in all but one case which required 2 months. There was not Grade 2 or higher late adverse events. When patients were consulted about their cosmetic impression, all except one (a young woman with hypopigmentation at abdominal location) were very satisfied. In patients with superficial BCC lesions less than 25 mm in maximum diameter, HDR BT treatment with Valencia Applicator using a hypofractionated regimen provides excellent results, for both cosmetic and local control at a minimum of 3 years follow-up. Moreover, the shorter, hypofractionated regimen facilitates compliance, which is very relevant for the elderly patients in our series. Valencia Applicators offer a simple, safe, quick and attractive nonsurgical treatment option.

PURPOSE:The goal of this study is to evaluate the predictability of a novel method using a self background-corrected maximum Standard Uptake Value (cSUVmax) from 18F-FDG Positron Emission Tomography (PET) of the patients following lung cancer stereotactic body radiosurgery (SBRT). METHODS:20 qualified patients treated out of 38 patients treated with SBRT for a single lung malignant lesion between May 2009 and December 2009 were enrolled in the cohort study. All had pre- and at least one post-treatment PET images available at the time of study. The mean normal tissue SUV from the descending aorta was sampled as baseline to divide SUVmax of tumor site. The resultant cSUVmax was used for assess the local control or possible recurrence. The Result was then compared with that using SUVmax alone method. RESULTS:The average follow-up length was 48.9 weeks ranging from 18.6 to 115.0 weeks. The mean SUV of aorta was measured as 1.821±0.364, ranging from 1.173 to 2.576. From the pre-treatment PET, 70% and 65% was indicated positive correspondingly when using SUVmax with 2.50 and cSUVmax with 1.52 thresholds. When PET was taken < 29 weeks post-SBRT, 75% and 67% respectively showed higher values in the locally controlled group. For PET = 29 weeks after SBRT, with cSUVmax both locally controlled and recurrent groups are accurately identified, while SUVmax shows 5% false positive and one possible false negative. CONCLUSIONS:The SUVmax in lung tumor site corrected by the mean SUV of descending aorta or cSUVmax provided a more reliable parameter than using SUVmax alone in predicting the local control and recurrence for follow-up PET of patients after lung SBRT. The method used in this study objectively displayed a strong correlation between low cSUVmax and local control following lung SBRT in this investigation, otherwise a local recurrence is suggested.

To investigate the reliability of a novel method using a regional background-corrected maximum standardized uptake value (cSUVmax) of 18F-FDG Positron Emission Tomography (PET) to assess the local control following stereotactic body radiosurgery (SBRT) for lung cancer. Thirty-one qualified cases from 73 patients treated with lung SBRT for a single malignant lesion between May, 2009 and March, 2010 were enrolled in this cohort study. Qualifications included a pre- and one or more post-treatment PET images available at the time of study. Each course of lung SBRT delivered 50 Gy in 5 fractions over 5-7 days using 6 MV intensity modulated photon beams. The median PET follow-up (FU) time after the first treatment was 38.4 weeks ranging from 14.6 to 115.0 weeks. cSUVmax was defined as the ratio of SUVmax of the treatment volume to the mean SUV of sampled descending aorta (SUVmean-nom)*. The absolute SUVmax and cSUVmax were then compared for predicting the local control of lung SBRT. The measured SUVmean-nom was 1.828 ± 0.378, ranging from 1.173 to 2.592. Using a threshold of 2.5 for SUVmax and 1.6 for cSUVmax, their findings are tabulated into three chronological groups as seen in Table-1. Correspondingly 74% and 71% pre-SBRT PET were identified as positive by SUVmax and cSUVmax; while only 35% and 48% of early (≤30 weeks) post-SBRT PET were found below the thresholds. In the group with PET FU > 30 weeks, 4 out of 31 cases exceeded the threshold of SUVmax, although 3 of which showed reduced cSUVmax from the previous FU PET. The 2 cases exceeded cSUVmax threshold in the last group also displayed further elevated values from their earlier FU PET. Only one case which exhibited high values and strong trend of increase in both cSUVmax and SUVmax was clinically identified as local recurrence. We formulized an objective method to evaluate local control following lung SBRT using cSUVmax of PET, a more reliable index with effective correction for SUV inherent uncertainties. The results of this study have suggested a stronger correlation between low (<1.6) cSUVmax and the local control using PET after 30 weeks post lung SBRT than that with conventional SUVmax (p<0.01). Assessments for PET taken ≤ 30 week post lung SBRT yielded poor specificities with both methods, reflecting early treatment reactions.

Purpose: Non-melanoma skin cancers have been treated with different modalities: surgery alone or in combination with external beam radiotherapy or interstitial low-dose-rate brachytherapy. Recently, treatments have been delivered using HDR brachytherapy and specific applicators like the Valencia applicator. The goal was to obtain similar results in terms of cure rate and desirable cosmetic results. The purpose of this work is to evaluate the oncologic and cosmetic outcomes and the initial acute complications of cutaneous basal cell tumour treatments using the Valencia applicators in a new fractionation regime. Materials and Methods: We have retrospectively reviewed the results of 48 basal cell carcinomas in 33 patients, treated in our hospital between January 2008 and March 2010, with a followup between 6 and 26 months (30% of patients had a followup of more than 2 years). Most patients were male (55%) and 70% were older than 70. In order to provide high-rate brachytherapy dose to skin lesions, a skin applicator (Valencia applicator, Nucletron) have been added to the micro Selectron HDR (Nucletron) unit allowing the treatment of lesions up to 4 mm deep and 3 cm in diameter. The established treatment protocol includes the determination of the GTV-CTV area, performed by a dermatologist under dermatoscopic vision, and the depth of the lesion by a soft tissue ultrasound exploration. The PTV is obtained by the addition of a radial margin between 5 and 10 mm. The treatment schedule is: 6 Gy per fraction, 2 fractions per week in order to deliver 7 fractions (42 Gy). The dose is prescribed at 3 mm in lesions which depth is smaller than 3 mm and 4 mm in lesions between 3 and 4 mm. Results: Among the 38 applications, 35 were located on the face and 13 were extrafacial. In 47/48 applications the depth of the lesion was smaller than 3 mm. At 3 months, the local control was 47/48 (97.9%) at all locations. The maximum acute skin toxicity was grade one in all cases (RTOG). In 47/48 patients this toxicity resolved in 4 weeks with topical moisturizing treatment and in one patient 8 weeks were necessary with the same treatment. Cosmetic results (RTOG) have been excellent in 100% of patients. Conclusions: In our experience, this protocol of high-dose-rate brachytherapy with the Valencia Applicator has turned out to be an excellent treatment of cutaneous basal cell tumours in multiple locations regarding the short-term local control without any severe acute complications and the cosmetic results. Moreover, the "two fractions per week" schedule has shown to be a comfortable regime for patients who are mostly elderly.

Purpose: To evaluate the clinical efficacy of 6D Robotic couch‐top in CBCT image‐guided stereotactic body radiotherapy (SBRT) for lung cancer. Methods: A total 94 analyzable setup cases for Lung SBRT using 6D robotic couch‐top were evaluated. The 6D robotic couch‐top, furnished by Protura (via Civco Medical Solutions™), can be mounted to the table pedestal of the Varianˈs TX accelerator. In addition to the original 4D corrections (3 linear motions and Yaw) offered by the Varian table pedestal, the 6D robotic apparatus allows two additional freedoms ‐ Pitch and Roll, which were investigated in this study. During setup, the patient anatomy from planning CT was first aligned to the kV‐CBCT in Varianˈs 4DTC 3D matching program. The 6D movements were then executed from the treatment console. Results: Concerning the values of Pitch and Roll corrections in the 94 setups using the 6D robotics, the mean absolute values of both adjustments were 0.86 ± 0.33 degree and 0.61 ± 0.31 degree respectively (p = 0.007). Greater than 0.5 degree angular corrections were observed in 69.1% cases for Pitch and in 51.1% cases for Roll, collectively accounting for 90.4% cases. Corrections for one degree or more in either Pitch or Roll consisted 51.1% of cases. However, the average raw adjustments in those were 0.07 ±1.03 degree and −0.11 ± 0.82 degree respectively. Conclusions: Comprehensive correction of high precision alignment for kV‐CBCT imaging guided lung cancer SBRT requires adjustments in all six dimensions, including unconventional Pitch and Roll rotations. About 51% of patients require at least one degree corrections in either Pitch or Roll. Less than 10% of cases Pitch or Roll correction were insignificant or smaller than 0.5 degree. Relative to the manual corrections, the automated 6D robotic process increased the efficiency of alignment when Pitch and Roll corrections were warranted.

The uncertainty of using removable SRS frames was under emphasized. Although when using Brainlab SRS mask system, the 3D displacement of 3.17 mm was reported in a random trial, the discrepancies in most publications were within 2 mm. This study was designed to prospectively analyze clinical uncertainties of the current Brainlab removable SRS head frame; and evaluate the addition of a longitudinal strap in ensuring its geometrical accuracy. From June of 2009 to March of 2010, a total of 26 intracranial lesions were treated with Brainlab SRS head mask system in our institute. The system consists of a back and front thermoplastic (Aquaplast) mashes; reinforcing pieces cross the forehead and upper lip attached by a nose bridge and bite pieces. The mask was routinely molded and dried for 15 minutes before re-attached to the patient before CT simulation. In the test group, a longitudinal strap was added to the mask, tightly extended cross the top of head. During treatment setup, the head was positioned against this longitudinal strap. The isocenter was first aligned with Brainlab SRS localization templates, and then confirmed with Varian's CBCT. The absolute mean 3D displacement in the 16 cases using the commercial masks was 2.7 ± 1.5 mm. Their absolute means of vertical, longitudinal, and lateral shifts were 0.8 ± 0.8 mm, 2.3 ± 1.8 mm (p < 0.01), and 0.4 ± 0.5 mm respectively. The maximal 3D shift was 6.1 mm, basically caused by the longitudinal offset. The mean 3D shift of the 10 cases in the test group was 0.3 ± 0.5 mm (p < 0.01). Discussion: All results were discounted the CBCT ±1 mm uncertainty. Unlike a rigid test phantom, the uncertainty of the setup for real patients can be introduced by distortions of the Aquaplast mask, and the non-rigid surfaces of the patient head and face. The discomfort on the forehead for the tight mask instigates the head to shift inferiorly while raising the chin forward to fit into the mask. Since a small motion of lower jaw is permitted with this frame, longitudinal variation during often occurred without notice, unless advanced imaging modalities are used. The addition of a longitudinal strap provided superior limit for the head and significantly eliminated the uncertainty during setups. The accuracy of current Brainlab SRS head mask system can be compromised often with an inferior shift. Well calibrated CBCT or other kV based imaging modalities shall be a standard confirmation tool in conjunction to a removable SRS frame. The addition of a longitudinal strap has demonstrated its effectiveness in ensuring the accuracy of Brainlab removable SRS head frame during clinical practice.