Lung stereotactic body radiation therapy: personalized PTV margins according to tumor location and number of four-dimensional CT scans.

OBJECTIVES: To characterise the motion of pulmonary tumours during stereotactic body radiation therapy (SBRT) and to evaluate different margins when creating the planning target volume (PTV) on a single 4D CT scan (4DCT). METHODS: We conducted a retrospective single-site analysis on 30 patients undergoing lung SBRT. Two 4DCTs (4DCT1 and 4DCT2) were performed on all patients. First, motion was recorded for each 4DCT in anterior-posterior (AP), superior-inferior (SI) and rightleft (RL) directions. Then, we used 3 different margins (3,4 and 5 mm) to create the PTV, from the internal target volume (ITV) of 4DCT1 only (PTV D1 + 3, PTV D1 + 4, PTV D1 + 5). We compared, using the Dice coefficient, the volumes of these 3 PTVs, to the PTV actually used for the treatment (PTVttt). Finally, new treatment plans were calculated using only these 3 PTVs. We studied the ratio of the D2%, D50% and D98% between each new plan and the plan actually used for the treatment (D2% PTVttt, D50% PTVttt, D50% ITVttt D98% PTVttt). RESULTS: 30 lesions were studied. The greatest motion was observed in the SI axis (8.8 ± 6.6 [0.4-25.8] mm). The Dice index was higher when comparing PTVttt to PTV D1 + 4 mm (0.89 ± 0.04 [0.82-0.98]). Large differences were observed when comparing plans relative to PTVttt and PTV D1 + 3 for D98% PTVttt (0.85 ± 0.24 [0.19-1.00]). and also for D98% ITVttt (0.93 ± 0.12 [0.4-1.0]).D98% PTVttt (0.85 ± 0.24 [0.19-1.00], p value = 0.003) was statistically different when comparing plans relative to PTVttt and PTV D1 + 3. No stastistically differences were observed when comparing plans relative to PTVttt and PTV D1 + 4. A difference greater than 10% relative to D98% PTVttt was found for only in one UL lesion, located under the carina. CONCLUSION: A single 4DCT appears feasible for upper lobe lesions located above the carina, using a 4-mm margin to generate the PTV. ADVANCE IN KNOWLEDGE: Propostion of a personalized SBRT treatment (number of 4DCT, margins) according to tumor location (above or under the carina).

Treatment of cutaneous and/or soft tissue manifestations of corticosteroids refractory chronic graft versus host disease (cGVHD) by a total nodal irradiation (TNI).

The management of corticosteroids refractory chronic graft versus host disease (cGVHD) remains controversial. Retrospective analysis of patients treated at the Integrated Center of Oncology by total nodal irradiation (TNI) was performed to evaluate its therapy potency. TNI delivers a dose of 1 Gy in a single session. The delimitation of the fields is clinical (upper limit: external auditory meatus; lower limit: mid-femur). No pre-therapeutic dosimetry scanner was necessary. Evaluation of the efficacy was by clinical measures at 6 months after the treatment. Twelve patients were treated by TNI between January 2010 and December 2013. TNI was used in second-line treatment or beyond. The median time between allograft and TNI was 31.2 months, and the median time between the first manifestations of cGVHD and TNI was about 24.2 months. Of the 12 patients, nine had a clinical response at 6 months (75%), including five complete clinical responses (41.6%). Five patients could benefit from a reduction of corticosteroid doses. Three patients had hematologic toxicity. TNI could be considered as an option for the treatment of a cutaneous and/or soft tissues corticosteroids refractory cGVHD. However, prospective randomized and double-blind trials remain essential to answer the questions about TNI safety and effectiveness.

Online quality control, hyperfractionated radiotherapy alone and reduced boost volume for standard risk medulloblastoma: long-term results of MSFOP 98.

PURPOSE: To determine event free and overall survival, and long-term cognitive sequelae of children with standard-risk medulloblastoma (SRM) treated with hyperfractionated radiotherapy, conformal reduced boost volume without chemotherapy, and online quality assurance. PATIENTS AND METHODS: Forty-eight patients (age 5 to 18 years) were included in the Medulloblastoma-Société Française d'Oncologie Pédiatrique (MSFOP 98) protocol (December 1998 to October 2001). Patients received hyperfractionated radiotherapy (HFRT; 36 Gy, 1 Gy/fraction twice per day) to the craniospinal axis followed by a boost to the tumor bed (1.5-cm margin) to a dose of 68 Gy. Records of craniospinal irradiation were reviewed before treatment started. Neuropsychologic evaluations were done according to the protocol (1, 3, 5, and 7 years after irradiation). Cognitive outcomes were followed longitudinally with full-scale intelligence quotient (FSIQ) obtained with age-adapted Wechsler scales. RESULTS: After a median follow-up of 77.7 months, 6-year overall survival (OS) and event-free survival (EFS) rates for the cohort were 78% (95% CI, 66% to 90%) and 75%, respectively (95% CI, 62% to 87%). Thanks to quality control, 14 major deviations were detected. Annual full scale IQ decline was 2 points over a 6-year period. Predicted change in FSIQ points per year was 2.15 (95% CI, -1.24 to 3.51) with an intercept (ie, predicted FSIQ) of 93.57 at baseline. CONCLUSION: HFRT protocol with conformal reduced boost and online quality control allows excellent long-term OS and EFS in the absence of chemotherapy. In addition, FSIQ drops seem to be less pronounced than previously reported with standard irradiation regimens.

Conformal radiotherapy, reduced boost volume, hyperfractionated radiotherapy, and online quality control in standard-risk medulloblastoma without chemotherapy: results of the French M-SFOP 98 protocol.

PURPOSE: Between December 1998 and October 2001, patients <19 years old were treated for standard-risk medulloblastoma according to the Medulloblastome-Société Française d'Oncologie Pédiatrique 1998 (M-SFOP 98) protocol. Patients received hyperfractionated radiotherapy (36 Gy in 36 fractions) to the craniospinal axis, a boost with conformal therapy restricted to the tumor bed (to a total dose of 68 Gy in 68 fractions), and no chemotherapy. Records of craniospinal irradiation were reviewed before treatment start. RESULTS: A total of 48 patients were considered assessable. With a median follow-up of 45.7 months, the overall survival and progression-free survival rate at 3 years was 89% and 81%, respectively. Fourteen major deviations were detected and eight were corrected. No relapses occurred in the frontal region and none occurred in the posterior fossa outside the boost volume. Nine patients were available for volume calculation without reduction of the volume irradiated. We observed a reduction in the subtentorial volume irradiated to >60 Gy, but a slight increase in the volume irradiated to 40 Gy. No decrease in intelligence was observed in the 22 children tested during the first 2 years. CONCLUSION: This hyperfractionated radiotherapy protocol with a reduced boost volume and without chemotherapy was not associated with early relapses in children. Moreover, intellectual function seemed to be preserved. These results are promising.

Influence of 5-fluorouracil-loaded microsphere formulation on efficient rat glioma radiosensitization.

PURPOSE: To determine (i) the efficiency of radiosensitizing 5-FU-loaded microspheres and (ii) the impact of microparticle formulation on response to treatment. METHODS: C6 tumor-bearing rats were stereotactically implanted with microspheres and/or allocated to: control groups (untreated) or treatment (only radiotherapy; fast-release 5-FU microspheres + radiotherapy; slow-release 5-FU microspheres + radiotherapy). The next day, fractionated radiotherapy, limited to the hemibrain, was initiated in all treated animals. The irradiation cycle included 36 Gy, given in 9 sessions for 3 consecutive weeks. Tumor development was assessed by T2-weighted MRI. RESULTS: 5-FU microspheres associated with radiotherapy caused a 47% complete remission rate (9/19) as opposed to the 8% rate (1/12) when radiotherapy alone or 0% in control animals. Drug delivery for 3 weeks produced better survival results (57%) compared to one-week sustained release (41%). MR images showed exponentially increasing tumor volumes during the first half of the radiotherapy cycle, followed by a decrease, and the disappearance of the tumor if survival exceeded 120 days. CONCLUSIONS: 5-FU controlled delivery is a promising strategy for radiosensitizing gliomas. Drug delivery system formulation is unambiguously implicated in both the response to treatment and the limitation of toxic side effects.