[Radiotherapy for retroperitoneal sarcomas]

The management of retroperitoneal sarcoma can be very challenging, and the quality of initial treatment strategy appears to be a crucial prognostic factor. En bloc surgery is currently the standard of care for these rare tumours and perioperative treatments such as chemotherapy or radiotherapy have not been validated yet. However, local-regional relapse constitutes the most common disease course. While adjuvant radiotherapy is less and less common due to gastrointestinal toxicities, preoperative radiation therapy offers numerous advantages and is being evaluated as part of a national multicentre phase II study (TOMOREP trial) and is the subject of a European randomized phase III study (STRASS trial). The objective of this article is to present data on preoperative irradiation in terms of dose, volumes and optimal radiotherapy techniques for the treatment of this rare disease.

French multicentre clinical evaluation of helical TomoTherapy for anal cancer in a cohort of 64 consecutive patients

Purpose/Objectives

To assess feasibility and toxicity of Helical TomoTherapy® for treating anal cancer patients.

Methods

From 2007 to 2011, 64 patients were consecutively treated with TomoTherapy® in three centres for locally advanced squamous-cell anal carcinoma (T2 > 4 cm or N positive). Prescribed doses were 45 Gy to the pelvis including inguinal nodes and 59.4 Gy to the primary site and involved nodes with fractions of 1.8 Gy, five days a week. A positional Megavoltage Computed Tomography was performed before each treatment session. All acute and late toxicities were graded according to Common Terminology Criteria for Adverse Events version 3.0. Survival analysis was performed using the Kaplan-Meier method.

Results

Median follow-up was 22.9 months. Fifty-four women and 10 men were treated (median age: 62 years). Nineteen patients (29.7 %) had T2, 16 patients (25.0 %) T3, and 27 patients (42.2 %) T4 tumours. Thirty-nine patients (60.9 %) had nodal involvement. Median tumour size was 45 mm (range, 10–110 mm). Seven patients had a colostomy before treatment initiation. Fifty-seven patients received concomitant chemotherapy (5-FU/cisplatin or 5-FU/mitomycin-based therapy). Forty-seven patients (73.4 %) experienced a complete response, 13 a partial response or local recurrence, and 11 had salvage surgery; among these, six became complete responders, three experienced metastatic failure, and two local failure. At least four patients experienced metastatic recurrence (concomitant to a local failure for one patient). The two-year overall survival was 85.6 % (95 %CI [71.1 %–93.0 %]), and the one-year disease-free survival, and colostomy-free survival were 68.7 % (95 %CI [54.4 %–79.4]), and 75.5 % (95 %CI [60.7 %–85.3 %]) respectively. Overall survival, disease-free survival and colostomy free-survival were significantly better for women than men (p = 0.002, p = 0.004, and p = 0.002 respectively). Acute grade ≥3 toxicity included dermatologic (46.9 % of patients), gastrointestinal (20.3 %), and hematologic (17.2 %) toxicity. Acute grade 4 hematologic toxicity occurred in one patient. No grade 5 event was observed.

Conclusions

TomoTherapy® for locally advanced anal cancer is feasible. In our three centres of expertise, this technique appeared to produce few acute gastrointestinal toxicities. However, high rates of dermatologic toxicity were observed. The therapeutic efficacy was within the range of expectations and similar to previous studies in accordance with the high rates of locally advanced tumours and nodal involvement.

Hypoxia imaging with [18F]-FMISO-PET for guided dose escalation with intensity-modulated radiotherapy in head-and-neck cancers

BACKGROUND AND PURPOSE

Positron emission tomography (PET) with [(18)F]-fluoromisonidazole ([(18)F]-FMISO) provides a non-invasive assessment of hypoxia. The aim of this study is to assess the feasibility of a dose escalation with volumetric modulated arc therapy (VMAT) guided by [(18)F]-FMISO-PET for head-and-neck cancers (HNC).

PATIENTS AND METHODS

Ten patients with inoperable stages III-IV HNC underwent [(18)F]-FMISO-PET before radiotherapy. Hypoxic target volumes (HTV) were segmented automatically by using the fuzzy locally adaptive Bayesian method. Retrospectively, two VMAT plans were generated delivering 70 Gy to the gross tumour volume (GTV) defined on computed tomography simulation or 79.8 Gy to the HTV. A dosimetric comparison was performed, based on calculations of tumour control probability (TCP), normal tissue complication probability (NTCP) for the parotid glands and uncomplicated tumour control probability (UTCP).

RESULTS

The mean hypoxic fraction, defined as the ratio between the HTV and the GTV, was 0.18. The mean average dose for both parotids was 22.7 Gy and 25.5 Gy without and with dose escalation respectively. FMISO-guided dose escalation led to a mean increase of TCP, NTCP for both parotids and UTCP by 18.1, 4.6 and 8% respectively.

CONCLUSION

A dose escalation up to 79.8 Gy guided by [(18)F]-FMISO-PET with VMAT seems feasible with improvement of TCP and without excessive increase of NTCP for parotids.

[Postoperative radiation therapy for a patient with osteogenesis imperfecta: case report]

Osteogenesis imperfecta is an unusual disease also called Lobstein disease. Characterized by abnormalities of collagen biosynthesis, a possible mutation on 17th chromosome is described. On the other hand, 29% of breast cancers present a mutation on the same chromosome. Nevertheless, the association of osteogenesis imperfecta and breast cancer is at the moment unknown. Therapeutic management is very difficult because of a loss in dihydropyrimidine dehydrogenase for patients having osteogenesis imperfecta, generating some toxicity by default in catabolism of 5-fluorouracil. We report the case of a 49-year-old woman with a breast cancer in the context of osteogenesis imperfecta. Dosimetric considerations permitting to reduce chess dose level have been performed for this patient. With a follow-up of 6 months, no imaging fracture has been revealed after radiotherapy. No evident conclusion about radiation injury from a case report could be described in case of osteogenesis imperfecta. To our knowledge, this is the first case which take into account potential radiation induced toxicities.

Potential of [18F]-fluoromisonidazole positron-emission tomography for radiotherapy planning in head and neck squamous cell carcinomas

BACKGROUND AND PURPOSE

Positron-emission tomography (PET) with [(18)F]-fluoromisonidazole (FMISO) permits consideration of radiotherapy dose escalation to hypoxic volumes in head and neck cancers (HNC). However, the definition of FMISO volumes remains problematic. The aims of this study are to confirm that delayed acquisition at 4 h is most appropriate for FMISO-PET imaging and to assess different methods of volume segmentation.

PATIENTS AND METHODS

A total of 15 HNC patients underwent several FMISO-PET/computed tomography (CT) acquisitions 2, 3 and 4 h after FMISO injection. Three automatic methods of PET image segmentation were tested: fixed threshold, adaptive threshold based on the ratio between tumour-derived and background activities (R(T/B)) and the fuzzy locally adaptive Bayesian (FLAB) method. The hypoxic fraction (HF), which is defined as the ratio between the FMISO and CT volumes, was also calculated.

RESULTS

The R(T/B) for images acquired at 2, 3 and 4 h differed significantly, with mean values of 2.5 (1.7-2.9), 3 (2-4.5) and 3.4 (2.3-6.1), respectively. The mean tumour volume, as defined manually using CT images, was 39.1 ml (1.2-116 ml). After 4 h, the mean FMISO volumes were 18.9 (0.1-81), 9.5 (0.9-33.1) and 12.5 ml (0.9-38.4 ml) with fixed threshold, adaptive threshold and the FLAB method, respectively; median HF values were 0.47 (0.1-1.93), 0.25 (0.11-0.75) and 0.35 (0.14-1.05), respectively. FMISO volumes were significantly different.

CONCLUSION

The best contrast is obtained at the 4-hour acquisition time. Large discrepancies were found between the three tested methods of volume segmentation.

[Postoperative radiotherapy of prostate cancer]

After radical prostatectomy, the risk of biological recurrence at 5 years varies from 10 to 40 % and this natural evolution of the disease has led radiation therapy being proposed as a supplement to surgery. When the recurrence risk is essentially local, supplementary radiotherapy is justified in the aim of improving biological recurrence-free survival, local control, metastasis-free survival and specific and global survival, while respecting patient quality of life. Three recent studies, EORTC 22911, ARO 9602 and SWOG 8794 found a similar advantage for biological recurrence-free survival without higher major additional toxicity. However, only the SWOG 8794 study found a significant improvement for metastasis-free survival and global survival. In an adjuvant setting, the optimal moment to propose this postoperative radiotherapy remains uncertain: should it be proposed systematically to all pT3 R1 patients, running the risk of pointlessly treating patients who will never recur, or should it only be proposed at recurrence? The GETUG AFU 17 trial will provide answers to the question of the optimal moment for postoperative radiotherapy for pT3-4 R1 pN0 Nx patients with the objective of comparing an immediate treatment to a differed early treatment initiated at biological recurrence.

[Multifocal Langerhans cell histiocytosis of bone: indications for radiotherapy]

Langerhans cell histiocytosis is a non-malignant proliferative disease of unknown etiology that can affect one or more organs. This is a rare disease, 1 to 2/100,000, affecting mainly children with a male predominance. The osseous lesions are the most frequent (60 to 90%). There is however no consensus treatment for the management of these sites. We report the cases of two patients successfully treated with radiotherapy after primary chemotherapy, at doses of 15 Gy in ten sessions of 1.5 Gy for one patient and 18 Gy in ten fractions of 1.8 Gy for the other. Single or multifocal bone Langerhans cell histiocytosis without visceral involvement is a benign, self-limiting affection in most cases. Some bone lesions could be treated by radiotherapy alone. But the high variability of doses currently given in the literature does not allow determining the lowest effective dose limiting the risk of secondary neoplasia or impaired growth in children, in whom lower doses of 6 to 8 Gy are recommended. The decision of radiotherapy must be weighed against the risk of the disease. Caution should be the rule in this non-malignant tumour pathology.

[Epithelioid sarcoma: a retrospective study of conservative treatment with initial surgery and radiotherapy]

INTRODUCTION

Epithelioid sarcoma is a rare type of soft tissue sarcomas with a high risk of recurrence both local and distant. The place of surgical conservative treatment and the role of radiation therapy remain controversial.

PATIENTS AND METHODS

A serie of 9 consecutive patients treated with initial conservative surgery and postoperative radiotherapy (median dose of 52.8 Gy) from 1987 to 2006 in the same institution was analyzed.

RESULTS

With a median follow-up of 40 months (range 15-153 months), the rate of local, nodal and distant relapse is respectively 56%, 11% and 33%. The rate of death is 44.5%. No imputation has been performed.

CONCLUSION

Even with a high rate of local relapse observed, a conservative treatment doesn't seem to influence badly the overall survival (55.5% alive at 40 months). Indeed the rate of distant relapse and death are comparable with those found in the literature. Moreover relapse occurred almost within the irradiated volumes. An improvement of dose could be also discussed.