Preliminary results in heavy charged particle irradiation of bone sarcoma

Osteosarcoma

Osteosarcoma is a rare tumor that requires complex multidisciplinary management. This paper reviews the general management and standard radiotherapy guidelines for osteosarcoma in both North America and Europe in a joined effort between the Children's Oncology Group and International Society of Pediatric Oncology. Standard treatment involves multiagent induction chemotherapy followed by surgical resection for local tumor control and consolidation local control to metastatic sites. Radiotherapy is reserved for cases with a marginal or incomplete resection or for definitive treatment in the case of unresectable disease. We present supporting data for the role of chemotherapy, surgery, and radiation therapy.

Radiotherapy in the Treatment of Primary Osteosarcoma – a Single Center Experience

Purpose

To analyze our experiences concerning radiation treatment in patients with osteosarcoma.

Materials and methods

Since 1981, 40 patients with osteosarcoma have undergone radiotherapy in Heidelberg; 3 of them were immediately lost to follow-up. Twenty patients with metastases were treated palliatively and 17 patients were treated with a curative intent.

Results

Interestingly, 14 of the 17 patients treated with a curative intent were referred to our clinic during the last 8 years, whereas the number of patients referred for palliation decreased. The mean dose applied for palliation was 47 Gy (range, 26 Gy to >70 GyE), for cure was 59 Gy (range, 45 Gy to >70 GyE). Local control until death could be achieved in 15 of the 20 palliatively treated patients, with a mean survival of 7 months after radiation. Five patients experienced local failure with symptom recurrence, and 3 of them had received doses >60 Gy. At last follow-up, 3 of the 17 curatively treated patients had experienced local recurrence. Median follow-up was 32 months (range, 3-144). Estimated 5-year overall survival and local control rates were 38% and 68%, respectively. Local disease-free survival was shorter in patients treated for recurrent, inoperable or incompletely resected tumors and doses below 60 Gy.

Conclusions

With adequate doses, long-term local control is possible even in inoperable or incompletely resected tumors. Improvements of systemic therapy and modern radiation techniques have begun to bring the possibly curative role of radiation treatment back to the fore. However, in disseminated tumors, even doses beyond 60 Gy do not guarantee local control, suggesting an extremely low radiosensitivity of certain kinds of osteosarcoma.

The role of radiotherapy in oseosarcoma

A survey of the literature shows that the experience with radiotherapy (RT) in the local treatment of osteosarcoma (OS) is limited. This is due to various reasons: OS is a rare tumor and surgery is the treatment of choice with high local control rate, and uncertainty exists in regard to the efficacy and tolerance of radiotherapy. Publications on this topic were analyzed and will be reviewed. Furthermore, experience from the Cooperative Osteosarkomstudiengruppe (COSS)-Registry, including 100 patients (pts) treated using radiotherapy for OS, was analyzed. The COSS-registry includes a total of 175 pts (5% of all pts) with histologically proven OS irradiated over the period of 1980-2007. 100 pts were eligible for analysis. The median age was 18 (3-66) years. Indication for RT was a primary tumor in 66, a local recurrence in 11, and metastases in 23 pts. 94 pts got external photontherapy; 2 pts, proton therapy; 2 pts, neutron therapy; and 2 pts, intraoperative RT. In addition, a group of 17 pts received bone-targeted radionuclide therapy by samarium-153-EDTMP-therapy alone or in combination with external RT. The median dose for external RT was 55.8 Gy (30-120). All the pts received chemotherapy in accordance with different COSS-protocols. The median follow-up was 1.5 (0.2-23) years. Survival and local control rates at 5 years were calculated, and univariate and multivariate analyses performed. 41 pts are alive, 59 pts died. The overall survival rate after biopsy was 41% at 5 years, while the overall survival rates after RT for the whole group, for treatment of primary tumors, local recurrence, and metastases were 36%, 55%, 15%, and 0% respectively.In 41 cases, local control was achieved, whereas local progression or local recurrence occurred in 59 cases, with a median time to local recurrence of 0.5 (0.1-4) years after RT. 15 pts were nonresponders to radiotherapy. Local control for the whole group was 30%. Local control rates for combined surgery and RT were significantly better than those for RT alone (48% vs. 22%, p=0.002). Local control for treatment of primary tumors, local recurrence, and metastases were 40%, 17%, and 0% respectively. Local control for pts given an addition of samarium-153-EDTMP was poor, though not statistically significant. A dose of over 60 Gy had no significant effect on local control. Prognostic factors for survival were indication for RT, RT plus surgery vs. RT alone and tumor location. Prognostic factors for local control were indication for RT, and RT plus surgery vs. RT alone. For the majority of pts, surgery remains the local treatment of choice. Radiotherapy is an important option as local treatment of unresectable tumors, following intralesional resection, or as palliation of symptomatic metastases. Survival prognosis of such pts, however, is poor. Despite the fact that many of these pts will eventually die, they may benefit in terms of prolonged survival and prolonged local control. The combination of surgery, radiotherapy, and chemotherapy can be curative. The consistent use of full-dose chemotherapy is of importance for the response to radiotherapy. Prognostic factors for survival are indication for RT, RT plus surgery vs. RT alone and tumor location. Prognostic factors for local control are indication for RT, and RT plus surgery vs. RT alone.

[The French project ETOILE: review of clinical data for light ion hadrontherapy]

The Lawrence Berkeley Laboratory was the pioneer in light ions hadrontherapy with almost 2500 patients treated between 1957 and 1993 with Helium and Neon. The NIRS (National Institute For Radiological Science, Chiba, Japan) was the first dedicated medical centre for cancer with more than 1200 patients exclusively treated with carbon ion from 1994. A three-year 70 to 100% local control was reported for radio-resistant cancers, supporting the use of high LET particles. Hypo-fractionation was particularly explored for lung cancers and hepatocarcinoma (4 sessions only). Dose escalation studies demonstrated a tumour dose-effect and permitted to precise dose constraints for healthy tissues especially for the rectum. More than 140 patients were treated with carbon ion exclusively or associated with photons since 1997 in the GSI laboratory Gesellschaft Für Schwerionenforschung, Darmstadt, Germany). A very high local control was also obtained for radioresistant cancer of the base of the skull. Preliminary clinical data seem to confirm the expected therapeutic gain with light ions, due to their ballistic and radio-biological properties, and justify the European projects for the construction of dedicated medical facilities for cancers. The French "Etoile" project will be integrated in the European hadrontherapy network "Enlight", with the objectives to coordinate technologic, medical and economic features.

A long-term review of the treatment of patients with Ewing's sarcoma in one institution

AIMS

The treatment of patients suffering from Ewing's sarcoma has changed over the last three decades. We report the analyses, significant prognostic factors, interdisciplinary approach and development of therapy in one institution in Austria.

METHODS

One hundred and forty-two patients treated for Ewing's sarcoma between 1949 and 1994 were reviewed. Median follow-up was 8.5 years. Fifty-six patients were treated between 1949 and 1980 (group 1), and 86 patients between 1981 and 1994 (group 2). Patients in group 1 were treated with polychemotherapy. Patients in group 2 were treated with a neoadjuvant CESS (Cooperative Ewing's Sarcoma Study) regimen. In group 1, 24 patients underwent biopsy only, 32 patients had a definitive operation, 48 patients received either radiation therapy only or additional radiation therapy compared with in group 2: 6, 80 and 44 cases, respectively.

RESULTS

Five-year overall survival (OS) increased from 27% to 57%. Significant prognostic factors for OS were pre-operative metastases (P=0.0001), tumour location (P=0.0048), type of chemotherapy (P=0.002) and response to chemotherapy (P=0.0004). Chemotherapy (P=0.037), tumour location (P=0.0017) and metastases at diagnosis (P=0.0025) were significant.

CONCLUSION

The most effective treatment of Ewing's sarcoma is chemotherapy.

Is there a role for heavy ion beam therapy?

The aim of this contribution is to review the radio-oncological rationale of heavy ion beam radiotherapy in the management of cancer. Protons and helium ions are being investigated because of the improved dose distributions, perhaps superior in many clinical situations to those obtainable with photons or electrons. Heavy ions also bear the advantage of superior dose distribution and may additionally provide higher biological effectivity. A substantial database of historical results supports the hypothesis that conformal radiotherapy is superior to conventional radiotherapy. For the selection of patients for ion beam therapy, the following questions have to be evaluated: Can any significant radiation morbidity by conventional treatment expected? Is the radiation morbidity caused by unintended irradiation of non-target tissue outside the planning target volume? Can the tumor control be improved due to dose escalation with less radiation morbidity? A substantial number of patients have been treated by light ion radiotherapy. There are only a few clinical trials attempting to compare conventional photon radiotherapy with light ion radiotherapy. Clinical results with heavy ions such as carbon ions seem very promising in certain tumors. However results of randomized trials are still to be seen. Clearly the control arm has to be designed to be as close as possible to the optimal photon/electron treatment methods in use. The feasibility of heavy ion treatment has been demonstrated worldwide, with more than 10,000 patients. In the near future more centers worldwide will start patient treatments. The wider availability of light ion beams for clinical use will enable the establishment of a database of clinical results and the elucidation of the role of heavy ion beams in the treatment of cancer.

Particle beam therapy (hadrontherapy): basis for interest and clinical experience

The particle or hadron beams deployed in radiotherapy (protons, neutrons and helium, carbon, oxygen and neon ions) have physical and radiobiological characteristics which differ from those of conventional radiotherapy beams (photons) and which offer a number of theoretical advantages over conventional radiotherapy. After briefly describing the properties of hadron beams in comparison to photons, this review discusses the indications for hadrontherapy and analyses accumulated experience on the use of this modality to treat mainly neoplastic lesions, as published by the relatively few hadrontherapy centres operating around the world. The analysis indicates that for selected patients and tumours (particularly uveal melanomas and base of skull/spinal chordomas and chondrosarcomas), hadrontherapy produces greater disease-free survival. The advantages of hadrontherapy are most promisingly realised when used in conjunction with modern patient positioning, radiation delivery and focusing techniques (e.g. on-line imaging, three-dimensional conformal radiotherapy) developed to improve the efficacy of photon therapy. Although the construction and running costs of hadrontherapy units are considerably greater than those of conventional facilities, a comprehensive analysis that considers all the costs, particularly those resulting from the failure of less effective conventional radiotherapy, might indicate that hadrontherapy could be cost effective. In conclusion, the growing interest in this form of treatment seems to be fully justified by the results obtained to date, although more efficacy and dosing studies are required.

Results of heavy ion radiotherapy

The potential of heavy ion therapy for clinical use in cancer therapy stems from the biological parameters of heavy charged particles and their precise dose localization. Biologically, carbon, neon, and other heavy ion beams (up to about silicon) are clinically useful in overcoming the radioresistance of hypoxic tumors, thus increasing the biological effectiveness relative to low linear energy transfer x-ray or electron beams. Cells irradiated by heavy ions show less variation in cell-cycle-related radiosensitivity and decreased repair of radiation injury. The physical parameters of these heavy charged particles allow precise delivery of high doses to tumors while minimizing irradiation of normal tissues. Clinical use requires a close interaction between radiation oncologists, medical physicists, accelerator physicists, engineers, computer scientists, and radiation biologists.