G. Pesce

Cranio-spinal irradiation with volumetric modulated arc therapy: A multi-institutional treatment experience

PURPOSE To report the treatment of cranio-spinal irradiation (CSI) with volumetric modulated arc therapy (RapidArc) in adults and a child. MATERIALS AND METHODS Five patients from 5 institutions were treated with CSI using RapidArc technology. Patient age varied between 7 and 45 years. The lengths of the planning target volumes (PTV) and dose prescriptions ranged from 54.6 to 78.4 cm, and from 12 to 36 Gy, respectively. Different arc arrangements were used, with two or three isocentres, from two to six modulated arcs, for patient positioned either in prone (n=3) or supine position (n=2). Doses to PTV, organs at risk and non-target tissue are reported for each of the five patients. Data concerning imaging strategy and pre-treatment quality assurance are also reported. RESULTS The mean conformity index CI(95%) was 1.05 ± 0.05 (range: 1.00, 1.13). Mean doses to the lenses, lungs, heart, and kidneys were, respectively, 7.6 ± 1.6, 6.6 ± 3.0, 5.7 ± 2.3, and 6.1 ± 2.1 Gy, keeping those value acceptably low. Mean non-target tissue dose was 21.0 ± 3.8% (5.6 ± 1.8 Gy, range: 3.0-8.1 Gy). All patients were successfully planned and treated with RapidArc. CONCLUSIONS RapidArc techniques achieved highly conformal treatment plans for 5 adults or paediatric patients. Beam-on time was short, and RapidArc plans were satisfactorily delivered to all presented patients.

Neo-adjuvant chemo-radiation of rectal cancer with Volumetric Modulated Arc Therapy: summary of technical and dosimetric features and early clinical experience

BackgroundTo report about initial technical and clinical experience in preoperative radiation treatment of rectal cancer with volumetric modulated arcs with the RapidArc® (RA) technology.MethodsTwenty-five consecutive patients (pts) were treated with RA. All showed locally advanced rectal adenocarcinoma with stage T2-T4, N0-1. Dose prescription was 44 Gy in 22 fractions (or 45 Gy in 25 fractions). Delivery was performed with single arc with a 6 MV photon beam. Twenty patients were treated preoperatively, five did not receive surgery. Twenty-three patients received concomitant chemotherapy with oral capecitabine. A comparison with a cohort of twenty patients with similar characteristics treated with conformal therapy (3DC) is presented as well.ResultsFrom a dosimetric point of view, RA improved conformality of doses (CI95% = 1.1 vs. 1.4 for RA and 3DC), presented similar target coverage with lower maximum doses, significant sparing of femurs and significant reduction of integral and mean dose to healthy tissue. From the clinical point of view, surgical reports resulted in a down-staging in 41% of cases. Acute toxicity was limited to Grade 1-2 diarrhoea in 40% and Grade 3 in 8% of RA pts, 45% and 5% of 3DC pts, compatible with known effects of concomitant chemotherapy. RA treatments were performed with an average of 2.0 vs. 3.4 min of 3DC.ConclusionRA proved to be a safe, qualitatively advantageous treatment modality for rectal cancer, showing some improved results in dosimetric aspects.

Early clinical experience of radiotherapy of prostate cancer with volumetric modulated arc therapy

BackgroundTo report about initial clinical experience in radiation treatment of carcinoma of prostate with volumetric modulated arcs with the RapidArc (RA) technology.MethodsForty-five patients with a median age of 72 ± 3, affected by prostate carcinoma (T1c: 22 patients, T2a-b: 17 patients, T3a-b: 6 patients. N0: 43 patients, N1-Nx: 2 patients, all M0), with initial PSA of 10.0 ± 3.0 ng/mL, were treated with RapidArc in a feasibility study. All patients were treated with single arc using 6MV photons. Dose prescription ranged between 76 (7 patients) and 78 Gy (38 patients) in 2Gy/fraction. Plan quality was assessed by means of Dose Volume Histogram (DVH) analysis. Technical parameters of arcs and pre-treatment quality assurance results (Gamma Agreement Index, GAI) are reported to describe delivery features. Early toxicity was scored (according to the Common Terminology Criteria of Adverse Effects scale, CTCAE, scale) at the end of treatment together with biochemical outcome (PSA).ResultsFrom DVH data, target coverage was fulfilling planning objectives: V95% was in average higher than 98% and V107%~0.0% (D2%~104.0% in average). Homogeneity D5%-D95% ranged between 6.2 ± 1.0% to 6.7 ± 1.3%. For rectum, all planning objectives were largely met (e.g. V70Gy = 10.7 ± 5.5% against an objective of < 25%) similarly for bladder (e.g. D2% = 79.4 ± 1.2Gy against an objective of 80.0Gy). Maximum dose to femurs was D2% = 36.7 ± 5.4Gy against an objective of 47Gy. Monitor Units resulted: MU/Gy = 239 ± 37. Average beam on time was 1.24 ± 0.0 minutes. Pre-treatment GAI resulted in 98.1 ± 1.1%. Clinical data were recorded as PSA at 6 weeks after RT, with median values of 0.4 ± 0.4 ng/mL. Concerning acute toxicity, no patient showed grade 2-3 rectal toxicity; 5/42 (12%) patients experienced grade 2 dysuria; 18/41 (44%) patients preserved complete or partial erectile function.ConclusionRapidArc proved to be a safe, qualitative and advantageous treatment modality for prostate cancer.

Concurrent chemoradiation with volumetric modulated Arc therapy of patients treated for anal cancer—acute toxicity and treatment outcome

BACKGROUND to report the acute toxicity and clinical results in patients with anal cancer treated with volumetric modulated arc therapy (VMAT) concomitant with chemotherapy. METHODS A cohort of 21 patients with histologically confirmed squamous cell carcinoma of the anal canal was treated with VMAT and chemotherapy. Dose prescription was 39.6 Gy, 1.8 Gy/ fraction for the elective nodal PTV, the macroscopic (tumor and involved lymph nodes) PTV doses were 14.4 Gy up to a total dose of 54 Gy in 4 patients and 19.8 up to 59.4 Gy in 15 patients. One patient received a boost dose of 18 Gy up to a total dose of 57.6 Gy and another one was treated with 36 Gy and boost of 19.8 Gy up to a total dose of 55.8 Gy. Chemotherapy with MMC and 5-FU/Capecitabine was administered concomitantly. End points were local control (LC), disease-free survival (DFS) and overall survival (OS). RESULTS Median follow-up time was 35.5 months. Two year OS was 91%, DFS was 73% and LRC was 81%. Acute dermatological toxicity G3 was recorded in one patient, ten patients (47.6%) experienced a G2 skin toxicity, while G1 toxicity was registered in eight patients (38%). One patient developed Grade 3 acute gastrointestinal (GI) toxicity, two patients (9.5%) experienced grade 2 acute GI toxicity and ten patients (47.6%) G1 toxicity. Acute genitourinary toxicity G1 was recorded in ten patients (47.6%). CONCLUSIONS Our results support VMAT as standard radiotherapy technique in the treatment of patients with anal cancer.

The role of radiotherapy in elderly women with early-stage breast cancer treated with breast conserving surgery

Objective: To analyze the impact of adjuvant radiotherapy (RT) on ipsilateral breast recurrence (IBR) and overall survival (OS) in patients older than 69 years with early-stage breast cancer. Methods: From January 2007 to June 2015, we analyzed retrospectively 137 women with estrogen receptor–positive T1–2 invasive breast cancer, with negative axillary lymph nodes, dividing them into 2 subgroups: 70 to 79 years and older than 79 years. Results: After a median follow-up of 43.2 months, the 3-year IBR-free survival in patients treated with surgery plus RT was 98.8% and 92.1% in patients treated with surgery alone, with a significant difference (p = .01). Radiotherapy did not impact overall survival (p = .10). A higher percentage of patients aged between 70 and 79 years received RT after conservative surgery if compared with the older subgroup (p < .01). Conclusions: In elderly women, adjuvant RT reduced the IBR, but did not improve OS.