Avascular osteonecrosis after hyperthermia in children and adolescents with pelvic malignancies: a retrospective analysis of potential risk factors

PURPOSE

In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas.

METHODS

Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output.

RESULTS AND CONCLUSIONS

In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads.

An Approach for Cure: PEI-Chemotherapy and Regional Deep Hyperthermia in Children and Adolescents with Unresectable Malignant Tumors

BACKGROUND

Elevated temperatures of 40 - 44 degrees C increase the actions of various anticancer drugs including N-lost derivatives, cytotoxic antibiotics and platinum analoga. In clinical usage thermochemotherapy (TCH) should facilitate surgical resection and ameliorate local tumor control.

PATIENTS AND METHODS

From 07/1993 to 12/2002 a total of 39 patients have been enrolled onto a phase-II study (female = 24, male = 15, age 1 - 37.5 years, median 5.2). Among these, 24 patients had extracranial non-testicular germ cell tumors and 15 patients soft tissue or chondrosarcomas.

INDICATION

locoregional relapse (n = 29) or unresectable tumor after neoadjuvant chemotherapy (n = 10). Among these two groups, there were ten patients with poor response or progressive disease under primary or relapse chemotherapy. Ten out of the 29 relapse patients had more than one relapse. Tumor site: pelvis (30), abdomen (4), head and neck (2), proximal leg (2) and lumbar spine (1). Thermochemotherapy (TCH): 1800 - 2000 mg ifosfamide/m (2) and 100 mg etoposide/m (2) on days 1 - 4 and 40 mg cisplatin/m (2) on days 1 + 4 combined with regional deep hyperthermia (42 - 44 degrees C, 1 h) on days 1 + 4.

RESULTS

In 39 protocol patients a total of 166 TCH courses (332 heat sessions) were applied. 20 patients achieved complete response, and 10 patients achieved partial response. TCH was followed by surgical tumor resection in 28/39 patients and/or radiotherapy in 13/39 patients. At a median follow-up of 27 months, outcome in this high-risk patient population was 22 NED, 3 AWD, 12 DOD, 2 DOC. Five year event free (EFS) and overall survival (OS) for the whole study cohort was 0.39 +/- 0.11 (20/39 patients) and 0.52 +/- 0.11 (25/39 patients), respectively.

CONCLUSION

TCH shows substantial therapeutic efficacy and facilitates complete tumor resection in 14 out of 28 operated patients. Multimodal treatment including TCH, surgical resection and/or radiotherapy leads to sustained remission in the majority of patients with locoregional tumor recurrence. The therapeutic effect is most pronounced, if TCH is administered at first relapse. Due to the clinical and histologic heterogeneity the number of patients eligible for TCH is limited. Therefore, a more valid assessment of treatment efficacy can only be made by a matched-pair comparison in cooperation with the clinical registers.