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.

Impact of targeting deviations on outcome in medulloblastoma: study of the French Society of Pediatric Oncology (SFOP)

PURPOSE

To correlate targeting deviation in external beam radiation therapy with site of relapse in a prospective study of 174 patients treated for medulloblastoma.

METHODS AND MATERIALS

Between February 1992 and February 1998 the radiotherapy treatment records were reviewed by a panel of radiation oncologists for 174 children treated with radiation therapy for medulloblastoma. The review was done without knowledge of patient outcome. Patterns of relapse were correlated with the results of the quality control review.

RESULTS

Among the 174 patients five relapsed before the start of radiotherapy. One hundred sixty-nine patients were evaluable for correlation between targeting deviation and site of relapse. Number of major deviations in radiation therapy treatment is strongly correlated with the risk of tumor relapse (67% [95% CI: 28-91] of 3-year relapse rate in patient group with 2 major deviations and 78% [95% CI: 35-96] with 3 major deviations). This is particularly correlated with relapse in the frontal region of the brain: 5 relapses occurred in the frontal region in patients with major deviation in this area. An erroneous choice of electron beam energy is also linked with craniospinal fluid (CSF) relapse (3-year relapse rate of 68% [95% CI: 42-86]). Minor deviations in therapy technique are slightly associated with an increased risk of relapse in the same range as the group with only one major deviation.

CONCLUSION

The quality of medulloblastoma radiation therapy technique is strongly correlated with outcome. Pretreatment central quality assurance review or standardized computer-designed blocks would improve survival to an extent equivalent to that attributed to adjuvant chemotherapy.

Quality control of radiotherapeutic treatment of medulloblastoma in a multicentric study: the contribution of radiotherapy technique to tumour relapse. The French Medulloblastoma Group

Between 06.86 and 11.89, 88 medulloblastoma or primitive neuroectodermic tumour (PNET) localised in the posterior fossa have been included in the M7 multicentric protocol, 82 received the totality of the radiotherapy treatment and were evaluable for this study. Twenty-two of these 82 patients relapsed: their radiotherapy treatment is analysed in the present study. In 10 cases out of the 22 relapses treatment failure was probably due to a radiotherapeutic imperfection. This study confirms the necessity of a strict radiotherapy control, particularly in multicentric study.

[Conservative treatment of breast carcinoma with or without prophylactic chemotherapy. Preliminary results in 45 cases (author's transl)]

Between February 1969 and December 1979, 45 breast carcinomas T1 NO or T2 NO (greater than 3cm) were treated by tumorectomy and radiotherapy. Axillary dissection was performed in 22 cases. Twenty-one pre-menopausal patients were castrated either by oophrectomy (13 cas) or by pelvic irradiation (8 cases). From 1977 on, (10 cases) prophylactic chemotherapy using cyclophosphamide, 5 FU, methotrexate, vincristine, was administered for 4 to 6 months according to the number of poor prognostic factors. The five-year actuarial remission rate was 93% (84-100), the metastatic remission rate was 88% (72-100). Indications of prophylactic chemotherapy in forms with good prognostic factors are discussed.

[Non-gonadic complications of chemoradiotherapy in Hodgkin's disease. A study of eighty-three patients (author's transl)]

Eighty-three patients with Hodgkin's disease were treated with a combination of chemotherapy and radiotherapy. 43 were included in protocol 1 (from january 1970 to january 1974) and 40 in protocol 2 (february 1974 to december 1977). In protocol 1, staging laparotomy was not systematically performed (20 cases). Treatment consisted of 2 intravenous injections in Vinblastine and total nodal irradiation. In protocol 2, laparotomy was systematic in patients over 50 (35 cases). Patients with stages 1 and II treated as mentioned above. Patients with stage III received two Mopp courses followed by total nodal irradiation. Patients older than 50 with stages I and II and poor prognosis factors received chemotherapy only. Laparotomy was associated with a 0% mortality rate and a 3,6% morbidity rate. No myelitis or pericarditis were observed. Herpes zoster occurred in 24% of the patients, pulmonary apex fibrosis in 6%, hypothyroiditis in 2,4%, and leucopenia in 3,6%. Two late infectious complications were fatal. No solid tumor was apparent. Acute leukemia and non-Hodgkin malignant lymphoma developed in two patients. Good tolerance, shortness of treatment, and remission rate, warrant the pursuit of protocol 2 in which systematic laparotomy for patients under 50 allows total nodal irradiation and therefore reduction of chemotherapy.

[Analysis of loco-regional control rate, metastatic remission and survival in 178 breast cancer patients treated by radical modified mastectomy and post-operative irradiation (author's transl)]

178 cases of post-operative irradiation for breast cancer (145 T1, T2, T3 and 33 T4) are analyzed. According to the surgical procedure there are 146 cases of radical modified mastectomy (Patey) and 32 cases of radical mastectomy (Halsted). The axillary status reveals 50% of involved nodes, but radiotherapy has been systematic on chest wall and supra-clavicular, parasternal, axillary lymph nodes areas. Loco-regional failures are only situated on chest wall (3,9%) and in the supraclavicular area (1,7%). The five year actuarial rate of locoregional control is 93% and 98% if we exclude 7 locoregional failures contemporaneous or consecutive to a metastatic evolution. The five year actuarial rate of metastatic remission for patients with negative axillary nodes (N-) is 83% against 55% for N+ (p < 0,001). The five year actuarial survival rate is 92% (N-) and 64% (N+) (p < 0,001). We discuss about indications of selective irradiation of chest wall and parasternal area for patients with negative axillary nodes and also about post-operative immuno-suppression, and chronology of chemotherapy.