Dosimetric comparison between VMAT with different dose calculation algorithms and protons for soft-tissue sarcoma radiotherapy.

BACKGROUND: To appraise the potential of volumetric modulated arc therapy (VMAT, RapidArc) and proton beams to simultaneously achieve target coverage and enhanced sparing of bone tissue in the treatment of soft-tissue sarcoma with adequate target coverage. MATERIAL AND METHODS: Ten patients presenting with soft-tissue sarcoma of the leg were collected for the study. Dose was prescribed to 66.5 Gy in 25 fractions to the planning target volume (PTV) while significant maximum dose to the bone was constrained to 50 Gy. Plans were optimised according to the RapidArc technique with 6 MV photon beams or for intensity modulated protons. RapidArc photon plans were computed with: 1) AAA; 2) Acuros XB as dose to medium; and 3) Acuros XB as dose to water. RESULTS: All plans acceptably met the criteria of target coverage (V95% >90-95%) and bone sparing (D(1 cm3) <50 Gy). Significantly higher PTV dose homogeneity was found for proton plans. Near-to-maximum dose to bone was similar for RapidArc and protons, while volume receiving medium/low dose levels was minimised with protons. Similar results were obtained for the remaining normal tissue. Dose distributions calculated with the dose to water option resulted ~5% higher than corresponding ones computed as dose to medium. CONCLUSION: High plan quality was demonstrated for both VMAT and proton techniques when applied to soft-tissue sarcoma.

Phase I-II study of hypofractionated simultaneous integrated boost using volumetric modulated arc therapy for adjuvant radiation therapy in breast cancer patients: a report of feasibility and early toxicity results in the first 50 treatments.

BACKGROUND: To report results in terms of feasibility and early toxicity of hypofractionated simultaneous integrated boost (SIB) approach with Volumetric Modulated Arc Therapy (VMAT) as adjuvant treatment after breast-conserving surgery. METHODS: Between September 2010 and May 2011, 50 consecutive patients presenting early-stage breast cancer were submitted to adjuvant radiotherapy with SIB-VMAT approach using RapidArc in our Institution (Istituto Clinico Humanitas ICH). Three out of 50 patients were irradiated bilaterally (53 tumours in 50 patients). All patients were enrolled in a phase I-II trial approved by the ICH ethical committee. All 50 patients enrolled in the study underwent VMAT-SIB technique to irradiate the whole breast with concomitant boost irradiation of the tumor bed. Doses to whole breast and surgical bed were 40.5 Gy and 48 Gy respectively, delivered in 15 fractions over 3 weeks. Skin toxicities were recorded during and after treatment according to RTOG acute radiation morbidity scoring criteria with a median follow-up of 12 months (range 8-16). Cosmetic outcomes were assessed as excellent/good or fair/poor. RESULTS: The median age of the population was 68 years (range 36-88). According to AJCC staging system, 38 breast lesions were classified as pT1, and 15 as pT2; 49 cases were assessed as N0 and 4 as N1. The maximum acute skin toxicity by the end of treatment was Grade 0 in 20/50 patients, Grade 1 in 32/50, Grade 2 in 0 and Grade 3 in 1/50 (one of the 3 cases of bilateral breast irradiation). No Grade 4 toxicities were observed. All Grade 1 toxicities had resolved within 3 weeks. No significant differences in cosmetic scores on baseline assessment vs. 3 months and 6 months after the treatment were observed: all patients were scored as excellent/good (50/50) compared with baseline; no fair/poor judgment was recorded. No other toxicities or local failures were recorded during follow-up. CONCLUSIONS: The 3-week course of postoperative radiation using VMAT with SIB showed to be feasible and was associated with acceptable acute skin toxicity profile. Long-term follow-up data are needed to assess late toxicity and clinical outcomes.

Long-term local control achieved after hypofractionated stereotactic body radiotherapy for adrenal gland metastases: a retrospective analysis of 34 patients.

AIMS AND BACKGROUND: To describe feasibility, tolerability and clinical outcomes of stereotactic body radiation therapy (SBRT) in the treatment of adrenal metastases in 34 consecutive cancer patients. MATERIAL AND METHODS: Between March 2004 and July 2010, a total of 34 consecutive patients, accounting for 36 adrenal metastatic lesions, were treated with SBRT. SBRT treatments were delivered by a Linac Varian 600 with microMLC (3DLine, Elekta, Stockholm, Sweden) and a Linac ELEKTA Precise (Elekta). All 34 patients were clinically and radiologically evaluated during and after completion of SBRT. Following outcomes were taken into account: best clinical response at any time, local control, time to systemic progression, time to local progression, overall survival and toxicity. Survival was estimated by the Kaplan-Meier method and factor potentially affecting outcomes were analyzed with Cox regression analysis. RESULTS: Total RT doses ranged from 20 Gy in 4 fractions to 45 Gy in 18 fractions (median dose: 32 Gy; median number of fractions: 4). All doses were prescribed to the 95% isodose line. No cases of Grade ≥ 3 toxicity were recorded. At a median follow-up time of 41 months (range, 12-75) 22 patients were alive. Three of 28 lesions (11%) showed complete response, 13/28 (46%) partial response, 10/28 (36%) stable disease and 2/28 (7%) progressed in the treated area. Local failure was observed in 13 cases. Actuarial local control rates at one and two years were 66% and 32%, respectively. Median time to local progression was 19 months. Median survival was 22 months. CONCLUSION: SBRT in adrenal gland metastasis is feasible without significant acute and late toxicities, with a good rate of local control. New SBRT fractionation schemes and the possibility to combine new systemic approaches should be investigated in order to further increase local control and reduce systemic disease progression.

Initial experience of hypofractionated radiation retreatment with true beam and flattening filter free beam in selected case reports of recurrent nasopharyngeal carcinoma.

AIM: To show our preliminary experience in using TrueBeam with RapidArc technology and FFF beam for stereotactic re-irradiation of nasopharyngeal carcinoma. BACKGROUND: Thanks to new advanced techniques, as well as intensity modulated radiation therapy, it is possible to approach head and neck recurrences in selected patients. Volumetric Modulated Arc Therapy (VMAT) in its RapidArc(®) format, permits to reduce significantly the time to deliver complex intensity modulated plans, allowing to treat hypofractionated regimes within a few minutes. With TrueBeam it is possible to perform photon beams without usage of the flattening filter. It seems possible to expect a reduction of out-of-field dose when flattening filter free (FFF) beams are used. While research into the physics domain for FFF beams is increasing, there are very few clinical data where FFF beams are applied in clinical practice. MATERIALS AND METHODS: We present here the cases of 4 patients with local or regional recurrence of nasopharyngeal carcinoma. All patients were treated using TrueBeam with RapidArc technology and FFF beam for stereotactic hypofractionated re-irradiation. RESULTS: All patients concluded SBRT and showed good tolerability. During follow-up, complete response at imaging evaluation (PET and/or MRI) for all treated patients was documented. CONCLUSIONS: Our preliminary experience using TrueBeam with RapidArc technology and FFF beam for stereotactic hypofractionated re-irradiation of nasopharyngeal carcinoma was safe and effective in all 4 treated patients. Longer follow-up and a larger population of study is needed to confirm these promising results.

Vertebral metastases reirradiation with volumetric-modulated arc radiotherapy.

PURPOSE: To assess the feasibility, acute toxicity, clinical improvement, local control and survival for spinal metastatic patients re-irradiated using volumetric-modulated-arc-radiotherapy (VMAT). METHODS AND MATERIALS: Between February 2009 and November 2010, 31 patients were treated. Surgery was performed in six before re-irradiation. The clinical target volume (CTV) was defined as the whole vertebrae with recurrence excluding the central section of spinal canal. Planning target volume was defined as CTV+0-5mm in the three directions. Dose was prescribed in order to have biological equivalent dose to the spinal cord from the two courses lower than 120 Gy(2) to 1 cc of the volume. Clinical improvement, toxicity and recurrence were evaluated. All patients had back pain before treatment and 15 (48%) neurological deficit. RESULTS: Clinical remission of pain was obtained in 29 patients (93%). Neurological improvement was observed in 73% of patients. No acute or late toxicities were recorded. No recurrence occurred. Median survival was 10 months (range 6-24). At the last follow-up 19 patients (61%) were alive and 12 (39%) dead from systemic disease progression. The 1 and 2 year survival were 55% and 35%, respectively. CONCLUSION: In patients with spinal metastases recurrence re-irradiation with VMAT is feasible and provides clinical benefit in most patients.

Feasibility and early clinical assessment of flattening filter free (FFF) based stereotactic body radiotherapy (SBRT) treatments.

PURPOSE: To test feasibility and safety of clinical usage of Flattening Filter Free (FFF) beams for delivering ablative stereotactic body radiation therapy (SBRT) doses to various tumor sites, by means of Varian TrueBeam™ (Varian Medical Systems). METHODS AND MATERIALS: Seventy patients were treated with SBRT and FFF: 51 lesions were in the thorax (48 patients),10 in the liver, 9 in isolated abdominal lymph node, adrenal gland or pancreas. Doses ranged from 32 to 75 Gy, depending on the anatomical site and the volume of the lesion to irradiate. Lung lesions were treated with cumulative doses of 32 or 48 Gy, delivered in 4 consecutive fractions. The liver patients were treated in 3 fractions with total dose of 75 Gy. The isolated lymph nodes were irradiated in 6 fractions with doses of 45 Gy. The inclusion criteria were the presence of isolated node, or few lymph nodes in the same lymph node region, in absence of other active sites of cancer disease before the SBRT treatment. RESULTS: All 70 patients completed the treatment. The minimum follow-up was 3 months. Six cases of acute toxicities were recorded (2 Grade2 and 2 Grade3 in lung and 2 Grade2 in abdomen). No patient experienced acute toxicity greater than Grade3. No other types or grades of toxicities were observed at clinical evaluation visits. CONCLUSIONS: This study showed that, with respect to acute toxicity, SBRT with FFF beams showed to be a feasible technique in 70 consecutive patients with various primary and metastatic lesions in the body.

Stereotactic body radiation therapy for abdominal targets using volumetric intensity modulated arc therapy with RapidArc: feasibility and clinical preliminary results.

PURPOSE: To report early clinical experience in stereotactic body radiation therapy (SBRT) delivered using volumetric intensity modulated arc therapy with RapidArc (RA) in patients with primary or metastatic tumours at abdominal sites. MATERIAL AND METHODS: Thirty-seven consecutive patients were treated using RA. Of these, 16 had primary or metastatic liver tumours, nine had pancreatic cancer and 12 a nodal metastasis in the retro-peritoneum. Dose prescription varied from 45 to 75 Gy to the Clinical Target Volume in 3 to 6 fractions. The median follow-up was 12 months (6-22). Early local control and toxicity were investigated and reported. RESULTS: Planning objectives on target volumes and organs at risk were met in most cases. Delivery time ranged from 2.8 ± 0.3 to 9.2 ± 2.4 minutes and pre-treatment plan verification resulted in a Gamma Agreement Index from 95.3 ± 3.8 to 98.3 ± 1.7%. At the time of analysis, local control (freedom from progression) at six months, was assessable in 24 of 37 patients and was achieved in 19 patients with a crude rate of 79.2%. Seven patients experienced treatment-related toxicity. Three patients experienced a mild and transient G1 enteritis and two showed a transient G1 liver damage. Two had late toxicity: one developed chronic enteritis causing G1 diarrhoea and G1 abdominal pain and one suffered at three months a G3 gastric bleeding. No patients experienced G4 acute toxicity. CONCLUSIONS: SBRT for abdominal targets delivered by means of RA resulted to be feasible with good early clinical results in terms of local control rate and acute toxicity profile. RA allowed to achieve required target coverage as well as to keep within normal tissue dose/volume constraints.

Early clinical experience with volumetric modulated arc therapy in head and neck cancer patients.

BACKGROUND: To report about early clinical experience in radiation treatment of head and neck cancer of different sites and histology by volumetric modulated arcs with the RapidArc technology. METHODS: During 2009, 45 patients were treated at Istituto Clinico Humanitas with RapidArc (28 males and 17 females, median age 65 years). Of these, 78% received concomitant chemotherapy. Thirty-six patients were treated as exclusive curative intent (group A), three as postoperative curative intent (group B) and six with sinonasal tumours (group C). Dose prescription was at Planning Target Volumes (PTV) with simultaneous integrated boost: 54.45 Gy and 69.96 Gy in 33 fractions (group A); 54.45 Gy and 66 Gy in 33 fractions (group B) and 55 Gy in 25 fractions (group C). RESULTS: Concerning planning optimization strategies and constraints, as per PTV coverage, for all groups, D98% > 95% and V95% > 99%. As regards organs at risk, all planning objectives were respected, and this was correlated with observed acute toxicity rates. Only 28% of patients experienced G3 mucositis, 14% G3 dermitis 44% had G2 dysphagia. Nobody required feeding tubes to be placed during treatment. Acute toxicity is also related to chemotherapy. Two patients interrupted the course of radiotherapy because of a quick worsening of general clinical condition. CONCLUSIONS: These preliminary results stated that volumetric modulated arc therapy in locally advanced head and neck cancers is feasible and effective, with acceptable toxicities.

Large volume unresectable locally advanced non-small cell lung cancer: acute toxicity and initial outcome results with rapid arc.

BACKGROUND: To report acute toxicity, initial outcome results and planning therapeutic parameters in radiation treatment of advanced lung cancer (stage III) with volumetric modulated arcs using RapidArc (RA). METHODS: Twenty-four consecutive patients were treated with RA. All showed locally advanced non-small cell lung cancer with stage IIIA-IIIB and with large volumes (GTV:299 ± 175 cm3, PTV:818 ± 206 cm3). Dose prescription was 66Gy in 33 fractions to mean PTV. Delivery was performed with two partial arcs with a 6 MV photon beam. RESULTS: From a dosimetric point of view, RA allowed us to respect most planning objectives on target volumes and organs at risk. In particular: for GTV D1% = 105.6 ± 1.7%, D99% = 96.7 ± 1.8%, D5%-D95% = 6.3 ± 1.4%; contra-lateral lung mean dose resulted in 13.7 ± 3.9Gy, for spinal cord D1% = 39.5 ± 4.0Gy, for heart V45Gy = 9.0 ± 7.0Gy, for esophagus D1% = 67.4 ± 2.2Gy. Delivery time was 133 ± 7s. At three months partial remission > 50% was observed in 56% of patients. Acute toxicities at 3 months showed 91% with grade 1 and 9% with grade 2 esophageal toxicity; 18% presented grade 1 and 9% with grade 2 pneumonia; no grade 3 acute toxicity was observed. The short follow-up does not allow assessment of local control and progression free survival. CONCLUSIONS: RA proved to be a safe and advantageous treatment modality for NSCLC with large volumes. Long term observation of patients is needed to assess outcome and late toxicity.

Measures of late effects in conservative treatment of breast cancer with standard or hypofractionated radiotherapy.

AIMS AND BACKGROUND: To confirm the equivalence in terms of late effects between two fractionation schedules of radiotherapy in conservative treatment of breast cancer. METHODS: Fifty-eight patients treated at our institution from 1999 to 2002, with a median follow-up of 15 months (range, 7-46 months), were evaluated retrospectively. Twenty-nine patients (group A) were treated with standard fractionation: 5000 cGy/25fx/5 weeks, and 29 patients (group B) were treated with a hypofractionated schedule: 4500 cGy/15fx/5 weeks, three fractions per week. Late effects were evaluated using the LENT-SOMA scoring scale. The cosmetic results were assessed on a five-point scale. Skin elasticity was measured using a dedicated device (Cutometer SEM 575). RESULTS: There were no differences in breast volume, age at diagnosis and follow-up between groups. The LENT-SOMA toxicity observed in groups A and B, respectively, was as follows: grade 2-3 pain in five patients in each group; grade 2 breast edema in two and three patients; grade 2-3 and grade 2 fibrosis in six and eight patients; grade 2 and grade 2-3 telangiectasia in two and three patients; grade > or = 2 and 2 arm edema in two and one patients; no ulceration or atrophy were observed. Two patients in group A and one patient in group B needed treatment for breast and arm edema and arm edema, respectively. Very good, good-acceptable, and poor cosmetic results were observed in seven and two, fifteen and nineteen, and six and eight patients, respectively. Median skin elasticity loss due to treatment was -4.19% in group A and -6.29% in group B. These results are not statistically different. CONCLUSIONS: LENT-SOMA toxicities were minimal and no differences were observed between groups. Few patients in the hypofractionated group had very good cosmetic results, but it is debatable if radiotherapy was the only cause. Skin elasticity was not different between groups. Our results seem to suggest that it is possible to treat patients with both schedules, with similar late toxicity.