14 Abdominal irradiation in unilateral nephroblastoma and its impact on local control and survival

Proceedings of the 38th Annual ASTRO Meeting

165

13 ASSESSMENT TECHNIQUES

OF CONTRALATERAL NECK FAILURE DESIGNED TO SPARE CONTRALATERAL

B. O’Snlli~an,

P. Warde.

The Department

B. &ice,

IN 229 CASES OF CARCINOMA PAROTlD FUNCTION

C. Goh, T. Keanc, D. Payne, F-F. Lin, M,McLean,

of Radiation Oncology,

The Princess Margaret

Hospital

and University

OF THE TONSILLAR

J.Waldron.

of Toronto,

REGION

TREATED

WITH

B, Cummings

Canada.

Radiation-induced xerostomia is a frequent cause of morbidity in head and neck cancer patients. To minimize this Purpose/Objective: complication unilateral techniques (UT) designed to treat the primary tumor and ipsilateral neck have heen used for many years in selected cases at our institution. Although such techniques exclude the contralateral parotid from the high dose target volume, they also leave the contralateral neck nodes untreated. The purpose of the study was to evaluate the risk of failure in the opposite neck. MaterhIs aud Methods: We identified 229 patients heated with UT from a series of 641 cases with carcinoma of the tonsillar region treated with curative intent between 1970 and 1991. Detailed documentation of the tumor, the radiation dosimetry, the sites of failure, and outcome including local, regional, and distant failure, and late complications, were performed. Actuarial 5-year plots were used to calculate local control, regional control, and survival rates. Results: Median age was 61 years (74 females / 155 males); median follow-up 8 years (range 6 months to 21 years). AICC (1992) T categories were Tl: 73, T2:120, T3:30, T4:6. The N category distribution was: NO:136, Nl: 53, N2a: 29, N2b:8, and N3: 8 cases. Base of tongue and palate were involved in 49 and 82 cases respectively. Irradiation techniques consisted of ipsilateral wedge pairs with Cobalt or 6MV photons in 210 cases (92%). while the remainder were electrons with or without photons. Customized compensators were used in the majority of cases in addition to the use of wedge filters. 75% received 50 Gy in 4 weeks, 10% received 60 Gy in 6 weeks, while the remainder received other doses intended to be curative. A radioactive implant was also used in 20 patients. The 5-year actuarial rates were as follows: overall local control: 76%. regional node control: 80%; cause specific survival: 80%. A total of 7 patients manifested regional disease in the opposite neck (crude rate of 3% or 7 of 229). Of these, 3 had T3 lesions and 4 had T2 lesions. In 4 of the 7, the primary failed prior to or concurrent with the neck failure. The remaining 3 patients had isolated contralateral failure and all three had extensive initial soft palate involvement (to within 1 cm of mid-line in two cases). One of the three also had extensive tongue base involvement Severe late toxitiy was uncommon. Osteoradionecrosis requiring surgery was seen in 3% of patients (7 of 229) but was only seen once in the series after 1983. This is likely due to the introduction of a preventative maintenance dental program Conclusion: advise caution multiple field literature and

This analysis indicates that in appropriately selected cases the risk of failure in for higher radiotherapy doses where toxicity may be arise from technical dose plans to the ipsilateral side may then be preferable. These results are comparable suggest that permanent xerostomia may he avoided in selected cases of carcinoma

the opposite neck is uncommon with UT. We would inhomogeneity with wedged pair photon fields and to the results of bilateral radiation techniques in the of the tonsillar region.

14 ABDOMINAL

IRRADIATION

IN UNILATERAL

Flentje, Michael

MD; *Weirich,

Angela, *Graf,

Dept. of Radiotherapy,

University

of Wiirzburg

NEPHROBLASTOMA Norbert

AND

ITS IMPACT

MD; * Piitter, Richard MD; *Ludwig,

and SIOP9MjPOH

Study Group*;

ON LOCAL

CONTROL

AND

SURVIVAL

Rolf MD

FRG

Pwmose : The intIuence of abdominal radiotherapy in 123 patients with unilateral Wilms tumor eligible for local irradiation according to nostouerative SIOP- stage was analvxed. ktekd&Methods: 1%/452 children with Wihns tumor diagnosed between l/89 and 6/93 in Germany were eligible for abdominal irradiation after oreooerative chemotherauv ._ and tumor resection according to SIOP9/GPOH protocol. There were 90 children with standard histology (SH; local . . stage IIN+ and III) and 33 children with unfavorable histology (III-I; anapladic, clear cell and rhabdoid, local stages II and III ). L&al irradiation was given postoperatively parallel to polychemotherapy accordmg to protocol with appropriate dose reductions of Actinomycin D during the course of radiotherapy. 15 Gy to the tumor bed were prescribed in standard histology, with 30 Gy to regional lymphnodes, if histologically positive 30 Gy were given in unfavorable histology. Boost doses up to 15 Gy were possible for macroscopic residuals. Age ranged between 6 months and 21 years (median 4,2 years.) Results : Only 98 / 123 eligible children were irradiated. Reasons for ommission of radiotherapy were : stage III only due to intraoperative biopsy (n=4), due to resected cava thrombus (n=S); young age(n=4); unknown (s14). There were 21 abdominal recurrences (7/ 90 with SH; 14/33 UH). In 8 patients local recurrence was the only site of failure. There were 8 local failures in 25 nonirradiated but eligible children (33 %) versus 13 / 98 in irradiated children (13 %); P